Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Tue May 07 2024 Valid 072000Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL TEXAS... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley through evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...20z Update... Most of the ongoing outlook remains on track and reasoning has not changed from the previous forecast. See Tornado Watch 195 and any forthcoming MCDs regarding short term severe potential across parts of the Midwest. A small Slight risk (level 2 of 5) has been added over portions of central TX. A few storms capable of large hail (2.5+ inches diameter) appear possible through evening. Agitated cumulus in a very moist/unstable environment amid modest low-level convergence continue to deepen this afternoon. Forecast soundings depict a favorable environment for isolated but possible significant hail. While this risk is somewhat conditional/isolated, given the possibility for 2.5+ inch hail an upgrade to 15% SIG hail probabilities appears warranted. For more details, see MCD 678. ..Leitman.. 05/07/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Tue May 07 2024/ ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Tue May 07 2024 Valid 072000Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL TEXAS... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley through evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...20z Update... Most of the ongoing outlook remains on track and reasoning has not changed from the previous forecast. See Tornado Watch 195 and any forthcoming MCDs regarding short term severe potential across parts of the Midwest. A small Slight risk (level 2 of 5) has been added over portions of central TX. A few storms capable of large hail (2.5+ inches diameter) appear possible through evening. Agitated cumulus in a very moist/unstable environment amid modest low-level convergence continue to deepen this afternoon. Forecast soundings depict a favorable environment for isolated but possible significant hail. While this risk is somewhat conditional/isolated, given the possibility for 2.5+ inch hail an upgrade to 15% SIG hail probabilities appears warranted. For more details, see MCD 678. ..Leitman.. 05/07/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Tue May 07 2024/ ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Tue May 07 2024 Valid 072000Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL TEXAS... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley through evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...20z Update... Most of the ongoing outlook remains on track and reasoning has not changed from the previous forecast. See Tornado Watch 195 and any forthcoming MCDs regarding short term severe potential across parts of the Midwest. A small Slight risk (level 2 of 5) has been added over portions of central TX. A few storms capable of large hail (2.5+ inches diameter) appear possible through evening. Agitated cumulus in a very moist/unstable environment amid modest low-level convergence continue to deepen this afternoon. Forecast soundings depict a favorable environment for isolated but possible significant hail. While this risk is somewhat conditional/isolated, given the possibility for 2.5+ inch hail an upgrade to 15% SIG hail probabilities appears warranted. For more details, see MCD 678. ..Leitman.. 05/07/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Tue May 07 2024/ ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Tue May 07 2024 Valid 072000Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL TEXAS... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley through evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...20z Update... Most of the ongoing outlook remains on track and reasoning has not changed from the previous forecast. See Tornado Watch 195 and any forthcoming MCDs regarding short term severe potential across parts of the Midwest. A small Slight risk (level 2 of 5) has been added over portions of central TX. A few storms capable of large hail (2.5+ inches diameter) appear possible through evening. Agitated cumulus in a very moist/unstable environment amid modest low-level convergence continue to deepen this afternoon. Forecast soundings depict a favorable environment for isolated but possible significant hail. While this risk is somewhat conditional/isolated, given the possibility for 2.5+ inch hail an upgrade to 15% SIG hail probabilities appears warranted. For more details, see MCD 678. ..Leitman.. 05/07/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Tue May 07 2024/ ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. Read more

WW 0195 Status Updates
STATUS REPORT ON WW 195 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SW DEC TO 20 N BMI TO 25 SSW RFD. ..GRAMS..05/07/24 ATTN...WFO...LOT...ILX...IND...IWX...GRR...MKX... STATUS REPORT FOR WT 195 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-019-021-023-025-029-031-033-035-037-039-041-043-045-049- 053-063-075-079-089-091-093-097-099-101-103-105-111-113-115-139- 141-147-159-173-183-197-201-072040- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE CHAMPAIGN CHRISTIAN CLARK CLAY COLES COOK CRAWFORD CUMBERLAND DE KALB DE WITT DOUGLAS DUPAGE EDGAR EFFINGHAM FORD GRUNDY IROQUOIS JASPER KANE KANKAKEE KENDALL LAKE LA SALLE LAWRENCE LEE LIVINGSTON MCHENRY MCLEAN MACON MOULTRIE OGLE PIATT RICHLAND SHELBY VERMILION WILL WINNEBAGO INC005-007-011-013-015-017-021-023-027-039-045-049-053-055-057- 059-063-067-069-071-073-081-083-085-087-089-091-093-095-097-099- 101-103-105-107-109-111-113-119-121-127-131-133-141-145-149-153- Read more

MD 0677 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHERN OH...EASTERN KY...AND WESTERN WV
Mesoscale Discussion 0677 NWS Storm Prediction Center Norman OK 1248 PM CDT Tue May 07 2024 Areas affected...southern OH...eastern KY...and western WV Concerning...Severe potential...Watch possible Valid 071748Z - 071915Z Probability of Watch Issuance...40 percent SUMMARY...A brief tornado and locally damaging wind threat should persist into late afternoon with the remnants of an earlier MCS that may contain transient, weak supercell structures. Greater severe threat is expected later into the evening. DISCUSSION...Remnants of a largely decaying MCS/QLCS have persisted across southwest OH into eastern KY, supported by downstream boundary-layer heating with 17Z surface temperatures commonly in the mid to upper 70s. Amid a modest combination of mid-level lapse rates and deep-layer shear, convection has struggled to intensify as MLCAPE has increased to 500-1500 J/kg. Nevertheless, moderate low-level SRH (0-1 km of 100-150 m2/s2) should be adequate to support transient, lower-end updraft rotation within embedded updrafts that spread east amid the larger-scale decaying cluster. A more favorable environment for supercells is anticipated this evening in the wake of this afternoon convection. ..Grams/Smith.. 05/07/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RLX...MRX...JKL...ILN...LMK... LAT...LON 39298401 39698344 39758287 39658210 39258175 38708171 37828191 37418216 36968249 36578341 36588401 37228394 39298401 Read more

MD 0676 CONCERNING SEVERE POTENTIAL...TORNADO WATCH LIKELY FOR CENTRAL/EASTERN IL...WESTERN/NORTHERN IN...AND SOUTHWEST LOWER MI
Mesoscale Discussion 0676 NWS Storm Prediction Center Norman OK 1214 PM CDT Tue May 07 2024 Areas affected...central/eastern IL...western/northern IN...and southwest Lower MI Concerning...Severe potential...Tornado Watch likely Valid 071714Z - 071915Z Probability of Watch Issuance...80 percent SUMMARY...A few supercells are expected to develop from central to eastern Illinois into western Indiana by mid-afternoon. Large hail and isolated damaging winds will be the primary threat west, with tornado potential becoming greater east. DISCUSSION...Pronounced boundary-layer recovery is ongoing in the wake of an earlier morning QLCS with robust insolation beneath the eastern periphery of a central Great Plains elevated mixed-layer. Low-level convergence along the surface cold front is expected to strengthen as the nose of an intense mid/upper-level jet overspreads the boundary through the afternoon. While convective development is largely expected to remain on the northern gradient of the richer low-level moisture/larger buoyancy spreading into the Lower OH Valley, the highly favorable mid to upper-level wind profiles will support splitting supercell structures as convection matures. Low-level flow will become increasingly veered near the front from west to east, suggesting that large hail and isolated damaging winds should be the primary threat with western extent. The risk for a few tornadoes will be greater with eastern extent, including potential for a strong tornado in IN. ..Grams/Smith.. 05/07/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...GRR...IND...LOT...ILX...DVN... LAT...LON 39298869 39798926 40288944 41008964 41788939 41978901 42318856 42438755 42578585 42068512 40968572 39858640 39308767 39298869 Read more

WW 0195 Status Updates
STATUS FOR WATCH 0195 HAS NOT BEEN ISSUED YET Read more

No watches are valid as of Tue May 7 17:54:01 UTC 2024.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue May 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ...SUMMARY... Scattered to numerous severe thunderstorms appear likely Wednesday across parts of the southern Plains into the mid Mississippi, Ohio, and Tennessee Valleys. All severe hazards, including tornadoes, very large hail, and severe/damaging winds should occur. Some of the tornadoes may be strong. ...Synopsis... An upper low/trough, initially over the northern Plains Wednesday morning, will develop east to the Upper Midwest/Great Lakes vicinity by Thursday morning. Meanwhile, a more compact upper shortwave trough over the Lower Great Lakes will shift east/northeast over the Northeastern U.S. This regime will maintain a broad swath of 50-70 kt southwesterly midlevel/upper flow from the central/southern Plains to the Midwest/Mid-South and Northeast. This broad area of enhanced flow aloft will contribute to a strongly sheared environment atop a very moist boundary-layer. While the upper low/trough will progress east through the period, overall height falls across the Midwest/OH-TN Valleys are expected to remain modest until overnight. Large-scale ascent will be somewhat modest/nebulous through the day, with mesoscale features/ascent perhaps more of a driver of storm development/evolution. At the surface, the general expectation is that a surface low over MO early in the period will develop east across the Ohio Valley vicinity. A warm front will extend east from the low across IL/IN/OH, but there is quite a bit of variability in forecast guidance regarding how far north this boundary will retreat during the day. A cold front/dryline also is forecast to extend southwest from the low across western MO/eastern OK/central TX during the afternoon. The cold front will surge east/southeast overnight across the Ozarks/Mid-South. These boundaries will collectively focus thunderstorm development through the period. ...ArkLaTex into the Mid-MS/OH/TN Valleys... A very moist and broad warm sector is anticipated, with surface dewpoints in the upper 60s to mid 70s F already in place across much of the region. Heating into the 80s F and a plume of steep midlevel lapse rates overspreading the region will aid in strong destabilization (MLCAPE 2500-4000 J/kg). With 40-50 kt effective shear magnitudes, organized convection is expected. Convective mode may be somewhat messy, with clusters/semi-discrete supercells and bowing line segments possible. Little inhibition is expected across the warm sector, so thunderstorm coverage could be quite widespread. Initial thunderstorms development is likely during the morning near the triple point in MO. Most guidance suggests this activity will quickly grow upscale into an eastward advancing line/bow across MO. More semi-discrete convection is then anticipated by midday/early afternoon in the vicinity of the warm front across southern IL/western KY, spreading eastward with time across IN/KY/southern OH and TN. Additional storms are expected by mid to late afternoon along the cold front across AR/southeast OK/northeast TX. Large to very large hail (2-3 inch diameter) will be possible with more cellular convection given very large instability, steep midlevel lapse rates and favorable vertical shear. Tornado potential is also apparent, given favorable low-level shear as is evident in enlarged, curved 0-3 km forecast hodographs. Mesovortex tornado potential also will accompany any bows/QLCS structures as well. Furthermore, potentially widespread damaging/severe winds appears possible, especially if strong enough cold pools can be generated within linear segments. Given little inhibition across the region and somewhat nebulous large-scale forcing, convective evolution is somewhat uncertain (widespread convection all at once vs. semi-discrete convection growing upscale with time, etc). A corridor of higher probability severe may develop from southeast MO/southern IL into western KY. However, confidence is too low at this time for a categorical upgrade. ...Iowa and Vicinity... Isolated strong to severe thunderstorms appear possible in associated with a cold-core upper low across parts of IA and vicinity, mainly Wednesday afternoon. Although forecast instability and deep-layer shear appear fairly weak/marginal, a few instances of hail and strong/gusty winds appear possible. A brief tornado or two may also occur along/near the occluded front. ...Southern New England into NY and the Mid-Atlantic/Carolinas... Occasional hail and strong to locally damaging winds appear possible with isolated thunderstorms across parts of NY into southern New England as a surface low and attendant cold front move eastward through the day. Farther south into the Mid-Atlantic/Carolinas, more substantial instability is forecast (up to 2500 J/kg MLCAPE). Large-scale ascent is expected to remain weak over the region. However, strong heating of a moist boundary-layer and the presence of a surface trough extending southward into the Carolinas may be sufficient for greater thunderstorm coverage than previously expected. As a result, a Slight risk has been extended eastward across parts of VA/NC. Large hail and damaging gusts will be possible with thunderstorm activity through the evening. ..Leitman.. 05/07/2024 Read more