Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun Sep 15 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE EASTERN GREAT BASIN TO FOUR CORNERS...THE RED RIVER VALLEY OF THE NORTH...AND EASTERN NC... ...SUMMARY... On Monday, sporadic severe gusts and marginally severe hail will be possible during the afternoon to early evening across parts of the eastern Great Basin to Four Corners. Isolated, marginally severe storms are possible over eastern North Dakota into northwest Minnesota during the late afternoon and evening. A low-probability tornado threat may develop over eastern North Carolina. ...Eastern Great Basin to the Four Corners... An amplified mid-level low near the Bay Area at 12Z Monday should initially move east before curling northeast Monday night towards the NV/UT/ID border area. This will occur in response to a strong mid-level jet translating through the basal portion of the large-scale trough across the Desert Southwest into the eastern Great Basin. Convection should be ongoing Monday morning immediately ahead of the mid-level low and separately in the low-level warm/moist conveyor over the Four Corners region. Greater boundary-layer heating should occur between these two regimes across eastern NV into UT, west of the Wasatch Range. Despite meager MLCAPE, the deepening boundary layer amid a strengthening meridional wind profile should yield efficient downward mixing. This will be further augmented by evaporatively cooled downdraft accelerations and promote a threat for sporadic severe gusts. Farther southeast, a more southwesterly mid to upper-flow regime should yield hodograph elongation, supporting a few splitting supercells. Warmer mid-level temperatures and correspondingly weaker lapse rates will temper parcel acceleration to an extent, but this may be offset by somewhat higher PW values. Marginal severe hail/gusts will be possible. ...Eastern ND to northwest MN... With the primary upper-level trough displaced well to the west, deep-layer shear will remain weak across much of the Great Plains. However, most guidance suggests an MCV will emanate out of D1 central High Plains convection and gradually progress northeast towards the Red River Valley. In conjunction with the northern nose of a strengthening central to northern Great Plains low-level jet, a focused corridor for regenerative thunderstorm development may occur during the late afternoon and evening. Some low-level hodograph enlargement should support a predominantly clustered convective mode, with transient supercell structures possible. An isolated, lower-end severe hail/wind threat may develop, and a brief tornado is also possible. ...Coastal NC... While guidance consensus increasingly favors offshore cyclogenesis, the amplitude of this development along with timing of inland progression remain quite varied for a D2 forecast. The 00Z NAM and some of the 18Z ECMWF ENS members suggest particularly robust deepening will occur. The more aggressive scenarios would yield substantial enlargement of low-level hodographs, likely becoming coupled with a narrow swath of high theta-e air spreading west-northwestward from the Gulf Stream. Given the potential range of scenarios from nil threat to multiple tornadic supercells, a low-probability tornado highlight appears warranted. ..Grams.. 09/15/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun Sep 15 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE EASTERN GREAT BASIN TO FOUR CORNERS...THE RED RIVER VALLEY OF THE NORTH...AND EASTERN NC... ...SUMMARY... On Monday, sporadic severe gusts and marginally severe hail will be possible during the afternoon to early evening across parts of the eastern Great Basin to Four Corners. Isolated, marginally severe storms are possible over eastern North Dakota into northwest Minnesota during the late afternoon and evening. A low-probability tornado threat may develop over eastern North Carolina. ...Eastern Great Basin to the Four Corners... An amplified mid-level low near the Bay Area at 12Z Monday should initially move east before curling northeast Monday night towards the NV/UT/ID border area. This will occur in response to a strong mid-level jet translating through the basal portion of the large-scale trough across the Desert Southwest into the eastern Great Basin. Convection should be ongoing Monday morning immediately ahead of the mid-level low and separately in the low-level warm/moist conveyor over the Four Corners region. Greater boundary-layer heating should occur between these two regimes across eastern NV into UT, west of the Wasatch Range. Despite meager MLCAPE, the deepening boundary layer amid a strengthening meridional wind profile should yield efficient downward mixing. This will be further augmented by evaporatively cooled downdraft accelerations and promote a threat for sporadic severe gusts. Farther southeast, a more southwesterly mid to upper-flow regime should yield hodograph elongation, supporting a few splitting supercells. Warmer mid-level temperatures and correspondingly weaker lapse rates will temper parcel acceleration to an extent, but this may be offset by somewhat higher PW values. Marginal severe hail/gusts will be possible. ...Eastern ND to northwest MN... With the primary upper-level trough displaced well to the west, deep-layer shear will remain weak across much of the Great Plains. However, most guidance suggests an MCV will emanate out of D1 central High Plains convection and gradually progress northeast towards the Red River Valley. In conjunction with the northern nose of a strengthening central to northern Great Plains low-level jet, a focused corridor for regenerative thunderstorm development may occur during the late afternoon and evening. Some low-level hodograph enlargement should support a predominantly clustered convective mode, with transient supercell structures possible. An isolated, lower-end severe hail/wind threat may develop, and a brief tornado is also possible. ...Coastal NC... While guidance consensus increasingly favors offshore cyclogenesis, the amplitude of this development along with timing of inland progression remain quite varied for a D2 forecast. The 00Z NAM and some of the 18Z ECMWF ENS members suggest particularly robust deepening will occur. The more aggressive scenarios would yield substantial enlargement of low-level hodographs, likely becoming coupled with a narrow swath of high theta-e air spreading west-northwestward from the Gulf Stream. Given the potential range of scenarios from nil threat to multiple tornadic supercells, a low-probability tornado highlight appears warranted. ..Grams.. 09/15/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun Sep 15 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE EASTERN GREAT BASIN TO FOUR CORNERS...THE RED RIVER VALLEY OF THE NORTH...AND EASTERN NC... ...SUMMARY... On Monday, sporadic severe gusts and marginally severe hail will be possible during the afternoon to early evening across parts of the eastern Great Basin to Four Corners. Isolated, marginally severe storms are possible over eastern North Dakota into northwest Minnesota during the late afternoon and evening. A low-probability tornado threat may develop over eastern North Carolina. ...Eastern Great Basin to the Four Corners... An amplified mid-level low near the Bay Area at 12Z Monday should initially move east before curling northeast Monday night towards the NV/UT/ID border area. This will occur in response to a strong mid-level jet translating through the basal portion of the large-scale trough across the Desert Southwest into the eastern Great Basin. Convection should be ongoing Monday morning immediately ahead of the mid-level low and separately in the low-level warm/moist conveyor over the Four Corners region. Greater boundary-layer heating should occur between these two regimes across eastern NV into UT, west of the Wasatch Range. Despite meager MLCAPE, the deepening boundary layer amid a strengthening meridional wind profile should yield efficient downward mixing. This will be further augmented by evaporatively cooled downdraft accelerations and promote a threat for sporadic severe gusts. Farther southeast, a more southwesterly mid to upper-flow regime should yield hodograph elongation, supporting a few splitting supercells. Warmer mid-level temperatures and correspondingly weaker lapse rates will temper parcel acceleration to an extent, but this may be offset by somewhat higher PW values. Marginal severe hail/gusts will be possible. ...Eastern ND to northwest MN... With the primary upper-level trough displaced well to the west, deep-layer shear will remain weak across much of the Great Plains. However, most guidance suggests an MCV will emanate out of D1 central High Plains convection and gradually progress northeast towards the Red River Valley. In conjunction with the northern nose of a strengthening central to northern Great Plains low-level jet, a focused corridor for regenerative thunderstorm development may occur during the late afternoon and evening. Some low-level hodograph enlargement should support a predominantly clustered convective mode, with transient supercell structures possible. An isolated, lower-end severe hail/wind threat may develop, and a brief tornado is also possible. ...Coastal NC... While guidance consensus increasingly favors offshore cyclogenesis, the amplitude of this development along with timing of inland progression remain quite varied for a D2 forecast. The 00Z NAM and some of the 18Z ECMWF ENS members suggest particularly robust deepening will occur. The more aggressive scenarios would yield substantial enlargement of low-level hodographs, likely becoming coupled with a narrow swath of high theta-e air spreading west-northwestward from the Gulf Stream. Given the potential range of scenarios from nil threat to multiple tornadic supercells, a low-probability tornado highlight appears warranted. ..Grams.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0819 PM CDT Sat Sep 14 2024 Valid 150100Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... CORRECTED FOR FLIPPED THUNDER LINE ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible this evening over parts of the central and northern Plains. ...Central and Northern Plains... The latest water vapor imagery shows a shortwave trough over the Dakotas extending southward into northern Nebraska. Along this corridor, the RAP has a two distinct vorticity maxima analyzed. At the surface, a trough is located in the northern High Plains, and a moist airmass is present over much of the central and northern Plains. Surface dewpoints within this moist airmass vary from the mid 50s to mid 60s F. The RAP suggests that moderate instability is present from west-central Nebraska into parts of the Dakotas, where isolated to scattered thunderstorms are ongoing. The North Platte 00Z sounding has the best severe environment regionally, with MLCAPE near 1500 J/kg, and 0-3 km shear around 35 knots. On this sounding, the average low to mid-level lapse rate is near 7.5 C/km. This, along with instability and shear suggest that a marginal severe threat will likely continue for a few more hours. Isolated severe gusts and hail will be possible with rotating cells. The threat is expected to diminish during the mid to late evening as instability decreases across the region. ..Broyles.. 09/15/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0819 PM CDT Sat Sep 14 2024 Valid 150100Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... CORRECTED FOR FLIPPED THUNDER LINE ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible this evening over parts of the central and northern Plains. ...Central and Northern Plains... The latest water vapor imagery shows a shortwave trough over the Dakotas extending southward into northern Nebraska. Along this corridor, the RAP has a two distinct vorticity maxima analyzed. At the surface, a trough is located in the northern High Plains, and a moist airmass is present over much of the central and northern Plains. Surface dewpoints within this moist airmass vary from the mid 50s to mid 60s F. The RAP suggests that moderate instability is present from west-central Nebraska into parts of the Dakotas, where isolated to scattered thunderstorms are ongoing. The North Platte 00Z sounding has the best severe environment regionally, with MLCAPE near 1500 J/kg, and 0-3 km shear around 35 knots. On this sounding, the average low to mid-level lapse rate is near 7.5 C/km. This, along with instability and shear suggest that a marginal severe threat will likely continue for a few more hours. Isolated severe gusts and hail will be possible with rotating cells. The threat is expected to diminish during the mid to late evening as instability decreases across the region. ..Broyles.. 09/15/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 PM CDT Sat Sep 14 2024 Valid 150100Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible this evening over parts of the central and northern Plains. ...Central and Northern Plains... The latest water vapor imagery shows a shortwave trough over the Dakotas extending southward into northern Nebraska. Along this corridor, the RAP has a two distinct vorticity maxima analyzed. At the surface, a trough is located in the northern High Plains, and a moist airmass is present over much of the central and northern Plains. Surface dewpoints within this moist airmass vary from the mid 50s to mid 60s F. The RAP suggests that moderate instability is present from west-central Nebraska into parts of the Dakotas, where isolated to scattered thunderstorms are ongoing. The North Platte 00Z sounding has the best severe environment regionally, with MLCAPE near 1500 J/kg, and 0-3 km shear around 35 knots. On this sounding, the average low to mid-level lapse rate is near 7.5 C/km. This, along with instability and shear suggest that a marginal severe threat will likely continue for a few more hours. Isolated severe gusts and hail will be possible with rotating cells. The threat is expected to diminish during the mid to late evening as instability decreases across the region. ..Broyles.. 09/15/2024 Read more

No Mesoscale Discussions are in effect as of Sat Sep 14 23:59:01 UTC 2024.

No watches are valid as of Sat Sep 14 23:59:01 UTC 2024.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...20z Update... Minimal changes have been made to trim the northern Plains Marginal behind ongoing convection, otherwise the Day 1 Convective Outlook remains on track. See previous discussion below for more information. ..Thornton/Gleason.. 09/14/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Sep 14 2024/ ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...20z Update... Minimal changes have been made to trim the northern Plains Marginal behind ongoing convection, otherwise the Day 1 Convective Outlook remains on track. See previous discussion below for more information. ..Thornton/Gleason.. 09/14/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Sep 14 2024/ ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...20z Update... Minimal changes have been made to trim the northern Plains Marginal behind ongoing convection, otherwise the Day 1 Convective Outlook remains on track. See previous discussion below for more information. ..Thornton/Gleason.. 09/14/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Sep 14 2024/ ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...20z Update... Minimal changes have been made to trim the northern Plains Marginal behind ongoing convection, otherwise the Day 1 Convective Outlook remains on track. See previous discussion below for more information. ..Thornton/Gleason.. 09/14/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Sep 14 2024/ ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...20z Update... Minimal changes have been made to trim the northern Plains Marginal behind ongoing convection, otherwise the Day 1 Convective Outlook remains on track. See previous discussion below for more information. ..Thornton/Gleason.. 09/14/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Sep 14 2024/ ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...20z Update... Minimal changes have been made to trim the northern Plains Marginal behind ongoing convection, otherwise the Day 1 Convective Outlook remains on track. See previous discussion below for more information. ..Thornton/Gleason.. 09/14/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Sep 14 2024/ ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 161200Z - 221200Z A broad mid-level trough, with multiple embedded impulses, will amplify while gradually translating eastward from the West Coast to the Plains states through the upcoming week. Rainfall should accompany the passing mid-level trough across the Interior West through early parts of the week. Ahead of the mid-level trough, patches of overlapping dry and breezy conditions may develop along parts of the High Plains through Day 5/Wednesday. These conditions are too localized to address with Critical probabilities this outlook, though Elevated highlights may be introduced by Days 1-2. A dry low-level air mass should linger over parts of the Ohio Valley through the middle of the upcoming week. Surface high pressure across the Northeast will encourage dry easterly flow atop receptive fuels over portions of Indiana into Ohio and surrounding areas. Medium-range guidance consensus suggests that surface winds should not be overly strong, so any fire weather highlights that are added would probably take place in the Days 1-2 time frame if areas of locally higher gusts becomes apparent in short-range guidance. ..Squitieri.. 09/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more