Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 14 2019 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Widely scattered severe thunderstorms with very large hail and damaging winds are expected across the central High Plains this afternoon and evening. A few strong storms may be noted across the Gulf Coast to the southern Middle Atlantic. ...Central High Plains this afternoon through tonight... The larger-scale pattern is rather quiescent with a flat ridge over the Rockies and moderate west-northwest flow aloft over the central and northern High Plains. Subtle speed maxima embedded in the flow will crest the ridge and move over the High Plains, the first and most apparent of which will progress from central WY to the central Plains this afternoon. In the wake of a frontal passage and widespread convection last night across the central/southern High Plains, surface ridging extends from western SD to the TX Panhandle/NM border. West of the ridge, boundary-layer dewpoints in the mid 50s have spread west to the Front Range in CO on upslope flow, and slightly lesser moisture extends northward across eastern WY. Steep midlevel lapse rates above a seasonally moist boundary layer with daytime heating will result in a corridor of MLCAPE of 2000-3000 J/kg this afternoon from northeast CO across eastern WY. Forcing for ascent will be rather weak near the higher terrain, so storm coverage within the corridor most favorable for supercells is somewhat in question. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will favor supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete storm interacting with the somewhat greater low-level shear/hodograph curvature expected from western NE into extreme northeast CO along the east edge of the greater buoyancy. There will be some potential for storms to grow upscale into a small MCS tonight, with the more probable corridor for upscale growth centering near western NE and southwest SD where warm advection will be strongest on the nose of a 25-35 kt nocturnal low-level jet, as weak midlevel height falls occur tonight. ...Gulf Coast to the Mid-Atlantic this afternoon... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Gulf Coast and southeastward toward the southeast Atlantic and Mid-Atlantic coasts. The richer moisture/buoyancy (PW greater than 2 inches and MLCAPE greater than 3000 J/kg) are expected along the southern fringe of the lingering clouds this morning, though vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor midlevel lapse rates. ...Northern IN and vicinity this afternoon... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a midlevel trough approaches from WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms could be strong with hail/wind near severe criteria, and a brief/weak tornado cannot be ruled out. ..Thompson/Kerr.. 08/14/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 14 2019 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Widely scattered severe thunderstorms with very large hail and damaging winds are expected across the central High Plains this afternoon and evening. A few strong storms may be noted across the Gulf Coast to the southern Middle Atlantic. ...Central High Plains this afternoon through tonight... The larger-scale pattern is rather quiescent with a flat ridge over the Rockies and moderate west-northwest flow aloft over the central and northern High Plains. Subtle speed maxima embedded in the flow will crest the ridge and move over the High Plains, the first and most apparent of which will progress from central WY to the central Plains this afternoon. In the wake of a frontal passage and widespread convection last night across the central/southern High Plains, surface ridging extends from western SD to the TX Panhandle/NM border. West of the ridge, boundary-layer dewpoints in the mid 50s have spread west to the Front Range in CO on upslope flow, and slightly lesser moisture extends northward across eastern WY. Steep midlevel lapse rates above a seasonally moist boundary layer with daytime heating will result in a corridor of MLCAPE of 2000-3000 J/kg this afternoon from northeast CO across eastern WY. Forcing for ascent will be rather weak near the higher terrain, so storm coverage within the corridor most favorable for supercells is somewhat in question. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will favor supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete storm interacting with the somewhat greater low-level shear/hodograph curvature expected from western NE into extreme northeast CO along the east edge of the greater buoyancy. There will be some potential for storms to grow upscale into a small MCS tonight, with the more probable corridor for upscale growth centering near western NE and southwest SD where warm advection will be strongest on the nose of a 25-35 kt nocturnal low-level jet, as weak midlevel height falls occur tonight. ...Gulf Coast to the Mid-Atlantic this afternoon... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Gulf Coast and southeastward toward the southeast Atlantic and Mid-Atlantic coasts. The richer moisture/buoyancy (PW greater than 2 inches and MLCAPE greater than 3000 J/kg) are expected along the southern fringe of the lingering clouds this morning, though vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor midlevel lapse rates. ...Northern IN and vicinity this afternoon... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a midlevel trough approaches from WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms could be strong with hail/wind near severe criteria, and a brief/weak tornado cannot be ruled out. ..Thompson/Kerr.. 08/14/2019 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0308 AM CDT Wed Aug 14 2019 Valid 171200Z - 221200Z ...DISCUSSION... An amplified upper trough is forecast to move from the northern Rockies toward the upper Great Lakes on Sat/D4, with attendant cold front. Southerly winds ahead of the upper trough will allow for warm advection and destabilization from the central Plains into the upper MS Valley with a few severe storms expected north of NE/IA. However, models are already in disagreement with timing, thus predictability is too low to depict an area. By Sun/D5, the aforementioned upper trough will lift north, allowing rising heights over the Rockies and Plains, resulting in decreasing thunderstorm coverage. Models do hint at a breakdown of the upper ridge across the northern Plains into the Tue/D7 or Wed/D8 period, and this will likely result in severe storms as strong instability will be present over the northern Plains. However, predictability is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0308 AM CDT Wed Aug 14 2019 Valid 171200Z - 221200Z ...DISCUSSION... An amplified upper trough is forecast to move from the northern Rockies toward the upper Great Lakes on Sat/D4, with attendant cold front. Southerly winds ahead of the upper trough will allow for warm advection and destabilization from the central Plains into the upper MS Valley with a few severe storms expected north of NE/IA. However, models are already in disagreement with timing, thus predictability is too low to depict an area. By Sun/D5, the aforementioned upper trough will lift north, allowing rising heights over the Rockies and Plains, resulting in decreasing thunderstorm coverage. Models do hint at a breakdown of the upper ridge across the northern Plains into the Tue/D7 or Wed/D8 period, and this will likely result in severe storms as strong instability will be present over the northern Plains. However, predictability is low. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Wed Aug 14 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CENTRAL PLAINS INTO THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS... ...SUMMARY... Severe storms are possible from parts of the central Plains into the lower Missouri and mid Mississippi Valleys on Friday. ...Synopsis... A belt of relatively strong westerlies will remain situated over the northern Rockies and Plains, as will a surface low over southwest KS. A warm front is forecast from northern KS into northern MO, and this is where mid 70s F dewpoints and backed surface winds will likely reside. Farther west, moist northeast surface winds will bring a boundary westward into northeast CO. A shortwave trough embedded in the westerlies will move from SD/NE toward the Upper MS Valley, and this will induce increasing southerly 850 mb winds across the central Plains and mid MS Valley, maintaining a feed of unstable air toward the warm front region. ...Central Plains into the Lower MO and mid MS Valleys... Storms, possibly in the form of an MCS, are likely to be ongoing from eastern KS into MO, and may persist into western IL by midday. Strong wind gusts are possible with this activity, but weakening is expected as the low-level jet backs during the day. Any outflow boundaries are expected to modify over KS and MO, with a low-level lapse rate plume extending from the southern Plains into central KS. The greatest theta-e is thus expected to develop over KS during the day, spreading into southeast NE and into northern MO during the evening. Extreme instability is expected over KS, with storms most numerous after 00Z along the east-west boundary from northeast KS into northern MO. Given that this forecast is several days out, the exact corridor is likely to shift, but potentially damaging winds will be possible with a severe MCS Friday evening and overnight. Particularly damaging winds are possible should the more unstable model solutions verify. In addition, the extreme instability along with increasing low-level SRH near the warm front during the evening will likely favor at least isolated supercells with a tornado risk. ..Jewell.. 08/14/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Wed Aug 14 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CENTRAL PLAINS INTO THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS... ...SUMMARY... Severe storms are possible from parts of the central Plains into the lower Missouri and mid Mississippi Valleys on Friday. ...Synopsis... A belt of relatively strong westerlies will remain situated over the northern Rockies and Plains, as will a surface low over southwest KS. A warm front is forecast from northern KS into northern MO, and this is where mid 70s F dewpoints and backed surface winds will likely reside. Farther west, moist northeast surface winds will bring a boundary westward into northeast CO. A shortwave trough embedded in the westerlies will move from SD/NE toward the Upper MS Valley, and this will induce increasing southerly 850 mb winds across the central Plains and mid MS Valley, maintaining a feed of unstable air toward the warm front region. ...Central Plains into the Lower MO and mid MS Valleys... Storms, possibly in the form of an MCS, are likely to be ongoing from eastern KS into MO, and may persist into western IL by midday. Strong wind gusts are possible with this activity, but weakening is expected as the low-level jet backs during the day. Any outflow boundaries are expected to modify over KS and MO, with a low-level lapse rate plume extending from the southern Plains into central KS. The greatest theta-e is thus expected to develop over KS during the day, spreading into southeast NE and into northern MO during the evening. Extreme instability is expected over KS, with storms most numerous after 00Z along the east-west boundary from northeast KS into northern MO. Given that this forecast is several days out, the exact corridor is likely to shift, but potentially damaging winds will be possible with a severe MCS Friday evening and overnight. Particularly damaging winds are possible should the more unstable model solutions verify. In addition, the extreme instability along with increasing low-level SRH near the warm front during the evening will likely favor at least isolated supercells with a tornado risk. ..Jewell.. 08/14/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Wed Aug 14 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CENTRAL PLAINS INTO THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS... ...SUMMARY... Severe storms are possible from parts of the central Plains into the lower Missouri and mid Mississippi Valleys on Friday. ...Synopsis... A belt of relatively strong westerlies will remain situated over the northern Rockies and Plains, as will a surface low over southwest KS. A warm front is forecast from northern KS into northern MO, and this is where mid 70s F dewpoints and backed surface winds will likely reside. Farther west, moist northeast surface winds will bring a boundary westward into northeast CO. A shortwave trough embedded in the westerlies will move from SD/NE toward the Upper MS Valley, and this will induce increasing southerly 850 mb winds across the central Plains and mid MS Valley, maintaining a feed of unstable air toward the warm front region. ...Central Plains into the Lower MO and mid MS Valleys... Storms, possibly in the form of an MCS, are likely to be ongoing from eastern KS into MO, and may persist into western IL by midday. Strong wind gusts are possible with this activity, but weakening is expected as the low-level jet backs during the day. Any outflow boundaries are expected to modify over KS and MO, with a low-level lapse rate plume extending from the southern Plains into central KS. The greatest theta-e is thus expected to develop over KS during the day, spreading into southeast NE and into northern MO during the evening. Extreme instability is expected over KS, with storms most numerous after 00Z along the east-west boundary from northeast KS into northern MO. Given that this forecast is several days out, the exact corridor is likely to shift, but potentially damaging winds will be possible with a severe MCS Friday evening and overnight. Particularly damaging winds are possible should the more unstable model solutions verify. In addition, the extreme instability along with increasing low-level SRH near the warm front during the evening will likely favor at least isolated supercells with a tornado risk. ..Jewell.. 08/14/2019 Read more

MD 1734 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST NEW MEXICO AND ADJACENT PORTIONS OF THE TEXAS PANHANDLE
Mesoscale Discussion 1734 NWS Storm Prediction Center Norman OK 0225 AM CDT Wed Aug 14 2019 Areas affected...Northeast New Mexico and adjacent portions of the Texas Panhandle Concerning...Severe potential...Watch unlikely Valid 140725Z - 140900Z Probability of Watch Issuance...5 percent SUMMARY...An isolated strong storm or two, posing some risk for severe hail and wind, appears possible through about 3-4 AM MDT. DISCUSSION...Synoptic forcing for ascent appears weak to negligible. However, relatively moist southeasterly/easterly low-level upslope flow, aided by lift associated with a southward advancing convectively generated outflow boundary appear to be contributing to recent thunderstorm development near the Raton Mesa vicinity. Some further intensification appears possible during the next hour or so, supported by inflow of boundary layer air still characterized by CAPE up to around 1500 J/kg. In the presence of strong deep-layer shear, due to pronounced veering of winds with height beneath 20-25+ kt northwesterly flow around 500 mb, one or two supercell structures appears possible. As activity tends to propagate south-southeastward, it may pose a risk for at least marginally severe hail and locally strong surface gusts, before waning after 09-10Z. ..Kerr/Thompson.. 08/14/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AMA...PUB...ABQ... LAT...LON 37070416 36840281 35690275 35280360 35990420 36310446 37070416 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central and northern Plains on Thursday. Isolated severe storms are possible from Ohio into western Pennsylvania and New York, and over the eastern Carolinas. ...Synopsis... Moderately strong mid to high-level flow will persist from the northern Rockies across the Plains and into the Northeast, with multiple embedded shortwave troughs. One wave will move from the OH Valley into the Northeast, with 35 kt midlevel winds increasing to over 50 kt at 300 mb. This wave will interact with a weak surface low and mid 60s F dewpoints, supporting a few strong to severe storms during the afternoon. To the west, a low-amplitude progressive shortwave trough will dive southeast out of MT and across the northern Plains, providing ample deep-layer shear and steep lapse rates to support severe storms near a cold front moving southeastward across the Dakotas. Another area of severe weather is possible from NE into KS with a leading wave, in association with possible early-day storms and northeast of a surface low over southwest KS. ...Black Hills into central SD and northern NE... Ample heating will occur ahead of an approaching cold front with dewpoints remaining in the mid to upper 50s F. Deep-layer shear profiles will be strong for this time of year, with elongated straight-line hodographs developing. Storms may develop by 18Z as capping will be eroded with little heating. Scattered severe storms capable of large hail are expected, and a wind threat may develop along the front as storms merge. A few longer-lived storms will persist at least into northern NE where the air mass will have time to recover from possible early day storms. ...NE into KS... Storms may be ongoing early in the day from central NE into northeast KS, on the nose of a 40 kt low-level jet. Despite the time of day, this activity may be severe with damaging winds or isolated hail. South of this activity, heating will lead to strong destabilization, and may sustain any ongoing storms or support new development along outflow boundaries. The deeply mixed boundary layer along with steep lapse rates aloft will support propagating storms producing severe outflow winds, especially on the nose of the steeper low-level lapse rates into central and east-central KS. ...Eastern OH into western PA and NY... An upper level trough will move quickly east from the OH Valley into the Northeast, with modest mid to upper-level westerlies and cooling aloft. Mid 60s F dewpoints will exist from OH into PA with a weak surface low over OH, aiding both lift and instability. Scattered storms are likely to form over OH near the low and will spread into PA and NY. Although low-level winds will be weak, they will veer with height, and this may support an isolated supercell with a brief/weak tornado not out of the question. Otherwise, marginal wind and hail will be possible. ...Eastern Carolinas... A surface trough will develop during the day with westerly winds aloft and strong heating. MLCAPE to 2000 J/kg appears possible with 70s F dewpoints. Although winds below 500 mb will generally be less than 20 kt, they will veer with height, which may aid updraft propagation, while good mid to upper-level winds elongate the hodographs and help sustain the storms. Scattered storms producing locally strong wind gusts or marginal hail are expected by early afternoon, with a broken line of storms approaching the coast by evening. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 08/14/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central and northern Plains on Thursday. Isolated severe storms are possible from Ohio into western Pennsylvania and New York, and over the eastern Carolinas. ...Synopsis... Moderately strong mid to high-level flow will persist from the northern Rockies across the Plains and into the Northeast, with multiple embedded shortwave troughs. One wave will move from the OH Valley into the Northeast, with 35 kt midlevel winds increasing to over 50 kt at 300 mb. This wave will interact with a weak surface low and mid 60s F dewpoints, supporting a few strong to severe storms during the afternoon. To the west, a low-amplitude progressive shortwave trough will dive southeast out of MT and across the northern Plains, providing ample deep-layer shear and steep lapse rates to support severe storms near a cold front moving southeastward across the Dakotas. Another area of severe weather is possible from NE into KS with a leading wave, in association with possible early-day storms and northeast of a surface low over southwest KS. ...Black Hills into central SD and northern NE... Ample heating will occur ahead of an approaching cold front with dewpoints remaining in the mid to upper 50s F. Deep-layer shear profiles will be strong for this time of year, with elongated straight-line hodographs developing. Storms may develop by 18Z as capping will be eroded with little heating. Scattered severe storms capable of large hail are expected, and a wind threat may develop along the front as storms merge. A few longer-lived storms will persist at least into northern NE where the air mass will have time to recover from possible early day storms. ...NE into KS... Storms may be ongoing early in the day from central NE into northeast KS, on the nose of a 40 kt low-level jet. Despite the time of day, this activity may be severe with damaging winds or isolated hail. South of this activity, heating will lead to strong destabilization, and may sustain any ongoing storms or support new development along outflow boundaries. The deeply mixed boundary layer along with steep lapse rates aloft will support propagating storms producing severe outflow winds, especially on the nose of the steeper low-level lapse rates into central and east-central KS. ...Eastern OH into western PA and NY... An upper level trough will move quickly east from the OH Valley into the Northeast, with modest mid to upper-level westerlies and cooling aloft. Mid 60s F dewpoints will exist from OH into PA with a weak surface low over OH, aiding both lift and instability. Scattered storms are likely to form over OH near the low and will spread into PA and NY. Although low-level winds will be weak, they will veer with height, and this may support an isolated supercell with a brief/weak tornado not out of the question. Otherwise, marginal wind and hail will be possible. ...Eastern Carolinas... A surface trough will develop during the day with westerly winds aloft and strong heating. MLCAPE to 2000 J/kg appears possible with 70s F dewpoints. Although winds below 500 mb will generally be less than 20 kt, they will veer with height, which may aid updraft propagation, while good mid to upper-level winds elongate the hodographs and help sustain the storms. Scattered storms producing locally strong wind gusts or marginal hail are expected by early afternoon, with a broken line of storms approaching the coast by evening. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 08/14/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central and northern Plains on Thursday. Isolated severe storms are possible from Ohio into western Pennsylvania and New York, and over the eastern Carolinas. ...Synopsis... Moderately strong mid to high-level flow will persist from the northern Rockies across the Plains and into the Northeast, with multiple embedded shortwave troughs. One wave will move from the OH Valley into the Northeast, with 35 kt midlevel winds increasing to over 50 kt at 300 mb. This wave will interact with a weak surface low and mid 60s F dewpoints, supporting a few strong to severe storms during the afternoon. To the west, a low-amplitude progressive shortwave trough will dive southeast out of MT and across the northern Plains, providing ample deep-layer shear and steep lapse rates to support severe storms near a cold front moving southeastward across the Dakotas. Another area of severe weather is possible from NE into KS with a leading wave, in association with possible early-day storms and northeast of a surface low over southwest KS. ...Black Hills into central SD and northern NE... Ample heating will occur ahead of an approaching cold front with dewpoints remaining in the mid to upper 50s F. Deep-layer shear profiles will be strong for this time of year, with elongated straight-line hodographs developing. Storms may develop by 18Z as capping will be eroded with little heating. Scattered severe storms capable of large hail are expected, and a wind threat may develop along the front as storms merge. A few longer-lived storms will persist at least into northern NE where the air mass will have time to recover from possible early day storms. ...NE into KS... Storms may be ongoing early in the day from central NE into northeast KS, on the nose of a 40 kt low-level jet. Despite the time of day, this activity may be severe with damaging winds or isolated hail. South of this activity, heating will lead to strong destabilization, and may sustain any ongoing storms or support new development along outflow boundaries. The deeply mixed boundary layer along with steep lapse rates aloft will support propagating storms producing severe outflow winds, especially on the nose of the steeper low-level lapse rates into central and east-central KS. ...Eastern OH into western PA and NY... An upper level trough will move quickly east from the OH Valley into the Northeast, with modest mid to upper-level westerlies and cooling aloft. Mid 60s F dewpoints will exist from OH into PA with a weak surface low over OH, aiding both lift and instability. Scattered storms are likely to form over OH near the low and will spread into PA and NY. Although low-level winds will be weak, they will veer with height, and this may support an isolated supercell with a brief/weak tornado not out of the question. Otherwise, marginal wind and hail will be possible. ...Eastern Carolinas... A surface trough will develop during the day with westerly winds aloft and strong heating. MLCAPE to 2000 J/kg appears possible with 70s F dewpoints. Although winds below 500 mb will generally be less than 20 kt, they will veer with height, which may aid updraft propagation, while good mid to upper-level winds elongate the hodographs and help sustain the storms. Scattered storms producing locally strong wind gusts or marginal hail are expected by early afternoon, with a broken line of storms approaching the coast by evening. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 08/14/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...NO CRITICAL AREAS... ...Synopsis... Mid-level flow will strengthen across portions of the Pacific Northwest and northern Rockies as a couple of shortwaves migrate through the area. Farther south, weak ridging will remain in place across the Southwest. In the East, broadly cyclonic flow aloft will remain in place. ...Eastern Idaho into southwestern Wyoming... Surface flow in this region will be slightly stronger compared to prior days owing to 1) stronger mid-level flow (40-50 kts) and 2) vertical mixing processes. This stronger (15-25 mph) surface flow will occur within areas of dry fuels, with RH values flirting with critical thresholds (around 15% or so) for a few hours in the afternoon/early evening. These conditions are consistent with elevated fire weather, though locally critical conditions cannot be ruled out especially in terrain-favored areas that typically experience locally stronger wind speeds. ..Cook.. 08/14/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...NO CRITICAL AREAS... ...Synopsis... Mid-level flow will strengthen across portions of the Pacific Northwest and northern Rockies as a couple of shortwaves migrate through the area. Farther south, weak ridging will remain in place across the Southwest. In the East, broadly cyclonic flow aloft will remain in place. ...Eastern Idaho into southwestern Wyoming... Surface flow in this region will be slightly stronger compared to prior days owing to 1) stronger mid-level flow (40-50 kts) and 2) vertical mixing processes. This stronger (15-25 mph) surface flow will occur within areas of dry fuels, with RH values flirting with critical thresholds (around 15% or so) for a few hours in the afternoon/early evening. These conditions are consistent with elevated fire weather, though locally critical conditions cannot be ruled out especially in terrain-favored areas that typically experience locally stronger wind speeds. ..Cook.. 08/14/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...NO CRITICAL AREAS... ...Synopsis... Mid-level flow will strengthen across portions of the Pacific Northwest and northern Rockies as a couple of shortwaves migrate through the area. Farther south, weak ridging will remain in place across the Southwest. In the East, broadly cyclonic flow aloft will remain in place. ...Eastern Idaho into southwestern Wyoming... Surface flow in this region will be slightly stronger compared to prior days owing to 1) stronger mid-level flow (40-50 kts) and 2) vertical mixing processes. This stronger (15-25 mph) surface flow will occur within areas of dry fuels, with RH values flirting with critical thresholds (around 15% or so) for a few hours in the afternoon/early evening. These conditions are consistent with elevated fire weather, though locally critical conditions cannot be ruled out especially in terrain-favored areas that typically experience locally stronger wind speeds. ..Cook.. 08/14/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more