Severe Storms

MD 1743 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF SOUTHEAST NE...NORTHEAST KS AND FAR NORTHWEST MO
Mesoscale Discussion 1743 NWS Storm Prediction Center Norman OK 1111 AM CDT Thu Aug 15 2019 Areas affected...portions of southeast NE...northeast KS and far northwest MO Concerning...Severe potential...Watch unlikely Valid 151611Z - 151815Z Probability of Watch Issuance...20 percent SUMMARY...Sporadic strong gusts are possible with east/southeastward progressing band of storms through early afternoon. DISCUSSION...An MCS over southeast NE will continue to track east/southeast at around 35-40 kt over the next few hours. After initial weakening earlier in the morning, this system appears to be maintaining current intensity with some periodic increases in strength. The most recent measured wind gust with the system was 47 mph at KHSI at 1451Z. The expectation is that the line segment will continue east/southeast along/just north of instability gradient oriented across central/eastern KS. The overnight southwesterly low level jet should continue to weaken through midday, and downstream anvil debris will inhibit stronger destabilization. The exception may be along the southern fringes of the MCS where cloud cover is thinner, and where any renewed convection will be closer to the moist axis and increasing instability. As low level lapse rates steepen to the south across KS, some intermittent strong gusts are possible. However, overall severe threat is expected to remain limited as the bulk of this system remains north and east of a more favorable severe environment. A watch is not expected at this time, but trends will continue to be monitored. ..Leitman/Grams.. 08/15/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...OAX...TOP...GID... LAT...LON 40479790 40819753 40709630 40429500 40139454 39719432 39159429 38939435 38849471 39019568 39279674 39569797 39829854 40029851 40359804 40479790 Read more

No Mesoscale Discussions are in effect as of Thu Aug 15 13:54:03 UTC 2019.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Thu Aug 15 2019 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF KS TO SD AND WY... ...SUMMARY... Scattered severe storms are expected across parts of the central Plains through tonight. Large to very large hail and severe gusts are forecast with the stronger storms. ...KS to SD and WY through tonight... A thunderstorm cluster in central NE has been maintained this morning by warm advection on the nose of a 30-40 kt low-level jet and frontogenesis in the 850-700 mb layer. This convection will likely persist into early afternoon while moving southeastward into southeast NE/northeast KS. Convective evolution thereafter is somewhat in question, with the possibility of the storms weakening, or for additional development by mid afternoon along the southwest flank of the outflow across central KS. The latter scenario would continuously reinforce the cold pool and shunt the severe hail/wind threat to the south. If the convection weakens across northeast KS by mid afternoon, there will be potential for redevelopment on the edge of the modifying cold pool by this evening. The potential for supercells with very large hail and a tornado or two will depend heavily on the MCS weakening by early afternoon, and then the cold pool having several hours to modify by this evening such that surface-based storms can form along the edge of the remnant cold pool, where low-level shear will be strongest. The MCS should stabilize central NE enough to lower the severe threat through the afternoon/evening. Outflow will reinforce a baroclinic zone and upslope flow into WY this afternoon, though the boundary layer will likely remain relatively cool/capped. Late this evening, isolated storms may form in upslope flow regime, in an environment conditionally favorable for supercells with large hail. Farther north in SD, some moistening and surface heating west-northwest of the morning convection could result in sufficient destabilization for a few severe storms this afternoon. The focus for thunderstorm development will be a weak surface trough in advance of a midlevel shortwave trough moving east-southeastward from MT. Assuming MLCAPE can increase to 1500+ J/kg this afternoon, deep-layer shear will be sufficient for organized/supercell storms capable of producing large hail and damaging winds from about 20-00z. ...OH/PA area this afternoon/evening... A series of low-amplitude speed maxima aloft will progress eastward this afternoon from roughly northern IN to western PA. Similar to the previous two days farther west, surface heating within a residual moist boundary layer and a weak surface low/trough, plus lake-enhanced boundaries, will help focus thunderstorm development this afternoon from eastern OH/WV into central PA and far western NY. Though low-level flow/shear will be weak, there will be sufficient deep-layer vertical shear for a low-end supercell threat, based on moderate buoyancy (MLCAPE near 1500 J/kg). A few damaging winds and isolated large hail will be the main threats. ..Thompson/Kerr.. 08/15/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Thu Aug 15 2019 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF KS TO SD AND WY... ...SUMMARY... Scattered severe storms are expected across parts of the central Plains through tonight. Large to very large hail and severe gusts are forecast with the stronger storms. ...KS to SD and WY through tonight... A thunderstorm cluster in central NE has been maintained this morning by warm advection on the nose of a 30-40 kt low-level jet and frontogenesis in the 850-700 mb layer. This convection will likely persist into early afternoon while moving southeastward into southeast NE/northeast KS. Convective evolution thereafter is somewhat in question, with the possibility of the storms weakening, or for additional development by mid afternoon along the southwest flank of the outflow across central KS. The latter scenario would continuously reinforce the cold pool and shunt the severe hail/wind threat to the south. If the convection weakens across northeast KS by mid afternoon, there will be potential for redevelopment on the edge of the modifying cold pool by this evening. The potential for supercells with very large hail and a tornado or two will depend heavily on the MCS weakening by early afternoon, and then the cold pool having several hours to modify by this evening such that surface-based storms can form along the edge of the remnant cold pool, where low-level shear will be strongest. The MCS should stabilize central NE enough to lower the severe threat through the afternoon/evening. Outflow will reinforce a baroclinic zone and upslope flow into WY this afternoon, though the boundary layer will likely remain relatively cool/capped. Late this evening, isolated storms may form in upslope flow regime, in an environment conditionally favorable for supercells with large hail. Farther north in SD, some moistening and surface heating west-northwest of the morning convection could result in sufficient destabilization for a few severe storms this afternoon. The focus for thunderstorm development will be a weak surface trough in advance of a midlevel shortwave trough moving east-southeastward from MT. Assuming MLCAPE can increase to 1500+ J/kg this afternoon, deep-layer shear will be sufficient for organized/supercell storms capable of producing large hail and damaging winds from about 20-00z. ...OH/PA area this afternoon/evening... A series of low-amplitude speed maxima aloft will progress eastward this afternoon from roughly northern IN to western PA. Similar to the previous two days farther west, surface heating within a residual moist boundary layer and a weak surface low/trough, plus lake-enhanced boundaries, will help focus thunderstorm development this afternoon from eastern OH/WV into central PA and far western NY. Though low-level flow/shear will be weak, there will be sufficient deep-layer vertical shear for a low-end supercell threat, based on moderate buoyancy (MLCAPE near 1500 J/kg). A few damaging winds and isolated large hail will be the main threats. ..Thompson/Kerr.. 08/15/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Thu Aug 15 2019 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF KS TO SD AND WY... ...SUMMARY... Scattered severe storms are expected across parts of the central Plains through tonight. Large to very large hail and severe gusts are forecast with the stronger storms. ...KS to SD and WY through tonight... A thunderstorm cluster in central NE has been maintained this morning by warm advection on the nose of a 30-40 kt low-level jet and frontogenesis in the 850-700 mb layer. This convection will likely persist into early afternoon while moving southeastward into southeast NE/northeast KS. Convective evolution thereafter is somewhat in question, with the possibility of the storms weakening, or for additional development by mid afternoon along the southwest flank of the outflow across central KS. The latter scenario would continuously reinforce the cold pool and shunt the severe hail/wind threat to the south. If the convection weakens across northeast KS by mid afternoon, there will be potential for redevelopment on the edge of the modifying cold pool by this evening. The potential for supercells with very large hail and a tornado or two will depend heavily on the MCS weakening by early afternoon, and then the cold pool having several hours to modify by this evening such that surface-based storms can form along the edge of the remnant cold pool, where low-level shear will be strongest. The MCS should stabilize central NE enough to lower the severe threat through the afternoon/evening. Outflow will reinforce a baroclinic zone and upslope flow into WY this afternoon, though the boundary layer will likely remain relatively cool/capped. Late this evening, isolated storms may form in upslope flow regime, in an environment conditionally favorable for supercells with large hail. Farther north in SD, some moistening and surface heating west-northwest of the morning convection could result in sufficient destabilization for a few severe storms this afternoon. The focus for thunderstorm development will be a weak surface trough in advance of a midlevel shortwave trough moving east-southeastward from MT. Assuming MLCAPE can increase to 1500+ J/kg this afternoon, deep-layer shear will be sufficient for organized/supercell storms capable of producing large hail and damaging winds from about 20-00z. ...OH/PA area this afternoon/evening... A series of low-amplitude speed maxima aloft will progress eastward this afternoon from roughly northern IN to western PA. Similar to the previous two days farther west, surface heating within a residual moist boundary layer and a weak surface low/trough, plus lake-enhanced boundaries, will help focus thunderstorm development this afternoon from eastern OH/WV into central PA and far western NY. Though low-level flow/shear will be weak, there will be sufficient deep-layer vertical shear for a low-end supercell threat, based on moderate buoyancy (MLCAPE near 1500 J/kg). A few damaging winds and isolated large hail will be the main threats. ..Thompson/Kerr.. 08/15/2019 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Thu Aug 15 2019 Valid 181200Z - 231200Z ...DISCUSSION... On Sun/D4, an upper trough will lift north out of the Upper MS Valley and into Ontario, with rising heights across the central states. As such, little large-scale support will be available to focus severe storms, although isolated storms are possible across parts of the central Plains where instability will be large. By Mon/D5, an upper high will build over the southern High Plains, with zonal flow along the northern tier of states. Nocturnal storms are possible across the upper MS Valley late Monday in a warm advection regime. While areas of damaging wind cannot be ruled out with an MCS, predictability is low. The upper high will remain in place or retrograde slightly through the remainder of the period, and southerly winds across the Plains will maintain a somewhat moist, unstable air mass. However, predictability for any minor disturbance within the northwest flow that may focus storms across the northern Plains is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Thu Aug 15 2019 Valid 181200Z - 231200Z ...DISCUSSION... On Sun/D4, an upper trough will lift north out of the Upper MS Valley and into Ontario, with rising heights across the central states. As such, little large-scale support will be available to focus severe storms, although isolated storms are possible across parts of the central Plains where instability will be large. By Mon/D5, an upper high will build over the southern High Plains, with zonal flow along the northern tier of states. Nocturnal storms are possible across the upper MS Valley late Monday in a warm advection regime. While areas of damaging wind cannot be ruled out with an MCS, predictability is low. The upper high will remain in place or retrograde slightly through the remainder of the period, and southerly winds across the Plains will maintain a somewhat moist, unstable air mass. However, predictability for any minor disturbance within the northwest flow that may focus storms across the northern Plains is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Thu Aug 15 2019 Valid 181200Z - 231200Z ...DISCUSSION... On Sun/D4, an upper trough will lift north out of the Upper MS Valley and into Ontario, with rising heights across the central states. As such, little large-scale support will be available to focus severe storms, although isolated storms are possible across parts of the central Plains where instability will be large. By Mon/D5, an upper high will build over the southern High Plains, with zonal flow along the northern tier of states. Nocturnal storms are possible across the upper MS Valley late Monday in a warm advection regime. While areas of damaging wind cannot be ruled out with an MCS, predictability is low. The upper high will remain in place or retrograde slightly through the remainder of the period, and southerly winds across the Plains will maintain a somewhat moist, unstable air mass. However, predictability for any minor disturbance within the northwest flow that may focus storms across the northern Plains is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Thu Aug 15 2019 Valid 181200Z - 231200Z ...DISCUSSION... On Sun/D4, an upper trough will lift north out of the Upper MS Valley and into Ontario, with rising heights across the central states. As such, little large-scale support will be available to focus severe storms, although isolated storms are possible across parts of the central Plains where instability will be large. By Mon/D5, an upper high will build over the southern High Plains, with zonal flow along the northern tier of states. Nocturnal storms are possible across the upper MS Valley late Monday in a warm advection regime. While areas of damaging wind cannot be ruled out with an MCS, predictability is low. The upper high will remain in place or retrograde slightly through the remainder of the period, and southerly winds across the Plains will maintain a somewhat moist, unstable air mass. However, predictability for any minor disturbance within the northwest flow that may focus storms across the northern Plains is low. Read more

MD 1742 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN WYOMING...SOUTHWESTERN SOUTH DAKOTA AND NORTHWESTERN NEBRASKA
Mesoscale Discussion 1742 NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Aug 15 2019 Areas affected...Parts of eastern Wyoming...southwestern South Dakota and northwestern Nebraska Concerning...Severe potential...Watch unlikely Valid 150729Z - 150930Z Probability of Watch Issuance...20 percent SUMMARY...A relatively isolated, but intense storm probably will continue to pose at least a localized severe hail and wind threat across northern portions of the Nebraska panhandle through daybreak. Barring further upscale growth, it is not certain that a watch is needed, but trends will continue to be monitored. DISCUSSION...A number of generally low amplitude mid/upper waves appear to be progressing through broader-scale anticyclonic mid/upper flow across the northern Rockies and Plains. In association with one of these perturbations, forcing for ascent appears to be aiding ongoing thunderstorm development now south of the Black Hills, near the western Nebraska/South Dakota border area. The strongest convection, mainly limited to an isolated but sustained supercell, has been confined to areas west/southwest of the Black Hills during the past few hours, aided by inflow of moderate CAPE of 1500-3000 J/kg, in the presence of steep lower/mid-tropospheric lapse rates. Large-scale forcing for ascent associated with warm advection along a tightening mid-level thermal gradient (roughly around 700 mb) also appears to be providing support for this storm. This front extends east-southeastward across northern portions of the Nebraska panhandle, and may provide a continuing focus and support for the maintenance of intense convective development into areas northeast of Alliance NE through 9-11Z. Reflectivity associated with the isolated supercell has recently transitioned to more of a bowing structure, in the presence of strong deep-layer shear, likely accompanied by at least localized strong to severe surface gusts. This threat may continue, along with a risk for severe hail through daybreak. ..Kerr/Thompson.. 08/15/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...UNR...CYS... LAT...LON 43660482 43610386 43290276 42800174 42210127 41830188 42040296 42330354 42730405 43250463 43660482 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Thu Aug 15 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central Great Plains today. Large to very large hail and severe gusts are forecast with the stronger storms. ...Central and northern Great Plains... A mid-level shortwave trough is forecast to move from eastern MT this morning to the mid-upper MS Valley by daybreak Friday. A weak area of low pressure will develop over western KS while a cold front moves southeastward across the western Dakotas during the day. An elevated cluster of thunderstorms is possible over the central Great Plains associated with a warm advection regime before this activity weakens by the late morning. Considerable uncertainty is apparent and partially attributed to the evolution of storms during the morning. An outflow boundary associated with this early day convection may serve as a focus for additional storms by late afternoon from NE into northern KS. Elongated hodographs would favor supercells with large to very large hail. Isolated storms are forecast farther southwest into southern KS into the TX Panhandle with a wind/hail risk with the sustained/strong storms. Farther north over the Dakotas and Wyoming into western NE, diurnal storms are forecast to develop along the front over the Dakotas and in a post-frontal area over WY. Hail/wind are possible with this activity. ...Upper Ohio Valley... At the surface, a front will advance eastward across upper Ohio Valley with moderate destabilization expected by afternoon. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. A few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Coastal Carolinas... Weak mid-level troughing will slowly move east across the southern Appalachians. A cold front and a sea breeze front will serve as foci for thunderstorm development during the midday through the early evening. A reservoir of rich low-level moisture (low-middle 70s dewpoints) will remain over the coastal plain and combine with strong heating to yield moderate destabilization. Strong gusts (45-55mph, locally higher) occurring in pockets associated with wet microbursts will be capable of isolated wind damage. Storms will weaken by the early evening and dissipate soon after sunset. ..Smith/Cook.. 08/15/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Thu Aug 15 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central Great Plains today. Large to very large hail and severe gusts are forecast with the stronger storms. ...Central and northern Great Plains... A mid-level shortwave trough is forecast to move from eastern MT this morning to the mid-upper MS Valley by daybreak Friday. A weak area of low pressure will develop over western KS while a cold front moves southeastward across the western Dakotas during the day. An elevated cluster of thunderstorms is possible over the central Great Plains associated with a warm advection regime before this activity weakens by the late morning. Considerable uncertainty is apparent and partially attributed to the evolution of storms during the morning. An outflow boundary associated with this early day convection may serve as a focus for additional storms by late afternoon from NE into northern KS. Elongated hodographs would favor supercells with large to very large hail. Isolated storms are forecast farther southwest into southern KS into the TX Panhandle with a wind/hail risk with the sustained/strong storms. Farther north over the Dakotas and Wyoming into western NE, diurnal storms are forecast to develop along the front over the Dakotas and in a post-frontal area over WY. Hail/wind are possible with this activity. ...Upper Ohio Valley... At the surface, a front will advance eastward across upper Ohio Valley with moderate destabilization expected by afternoon. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. A few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Coastal Carolinas... Weak mid-level troughing will slowly move east across the southern Appalachians. A cold front and a sea breeze front will serve as foci for thunderstorm development during the midday through the early evening. A reservoir of rich low-level moisture (low-middle 70s dewpoints) will remain over the coastal plain and combine with strong heating to yield moderate destabilization. Strong gusts (45-55mph, locally higher) occurring in pockets associated with wet microbursts will be capable of isolated wind damage. Storms will weaken by the early evening and dissipate soon after sunset. ..Smith/Cook.. 08/15/2019 Read more