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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Jun 27 2024 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF UT AND WESTERN CO... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening, where very large hail, significant damaging winds, and a few tornadoes are possible. ...Western MT into Eastern Great Basin... Morning water vapor loop shows an impressive shortwave trough rotating across the northwest states. This feature will result in strengthening winds aloft across much of the Great Basin and northern Rockies today, along with increasing large scale forcing for ascent. This will lead to scattered thunderstorms over the higher terrain of western MT into parts of WY/CO/UT by early afternoon. Forecast soundings show sufficient westerly flow/shear through the cloud-bearing layer to support organized and occasionally supercell storms capable of hail and damaging wind gusts. ...Eastern MT into the Dakotas... As convection spreads off the higher terrain into eastern MT, storms will encounter greater low level moisture/shear, further promoting supercell structures and the risk of very large hail and perhaps a few tornadoes. These storms will progress eastward through the afternoon/evening into the Dakotas, where upscale growth into bowing structures is anticipated - capable of significant damaging winds. ...Central Plains... Farther south, forcing will be weaker and convective coverage should be less. However, convection will intensify as outflows from the High Plains spread eastward into the moist axis, with a combination of bowing and supercell storms expected. Damaging winds are probably the main risk, but substantial low level and deep layer shear could support large hail and a tornado or two in this region as well. ...Carolinas/GA... A very moist and unstable air mass is present today from central/eastern NC southwestward into eastern GA. Scattered mid and high clouds will somewhat mitigate afternoon heating. But a few strong/severe storms are expected, with water-loaded downdrafts capable of locally damaging wind gusts. ..Hart/Weinman.. 06/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Jun 27 2024 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF UT AND WESTERN CO... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening, where very large hail, significant damaging winds, and a few tornadoes are possible. ...Western MT into Eastern Great Basin... Morning water vapor loop shows an impressive shortwave trough rotating across the northwest states. This feature will result in strengthening winds aloft across much of the Great Basin and northern Rockies today, along with increasing large scale forcing for ascent. This will lead to scattered thunderstorms over the higher terrain of western MT into parts of WY/CO/UT by early afternoon. Forecast soundings show sufficient westerly flow/shear through the cloud-bearing layer to support organized and occasionally supercell storms capable of hail and damaging wind gusts. ...Eastern MT into the Dakotas... As convection spreads off the higher terrain into eastern MT, storms will encounter greater low level moisture/shear, further promoting supercell structures and the risk of very large hail and perhaps a few tornadoes. These storms will progress eastward through the afternoon/evening into the Dakotas, where upscale growth into bowing structures is anticipated - capable of significant damaging winds. ...Central Plains... Farther south, forcing will be weaker and convective coverage should be less. However, convection will intensify as outflows from the High Plains spread eastward into the moist axis, with a combination of bowing and supercell storms expected. Damaging winds are probably the main risk, but substantial low level and deep layer shear could support large hail and a tornado or two in this region as well. ...Carolinas/GA... A very moist and unstable air mass is present today from central/eastern NC southwestward into eastern GA. Scattered mid and high clouds will somewhat mitigate afternoon heating. But a few strong/severe storms are expected, with water-loaded downdrafts capable of locally damaging wind gusts. ..Hart/Weinman.. 06/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Jun 27 2024 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF UT AND WESTERN CO... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening, where very large hail, significant damaging winds, and a few tornadoes are possible. ...Western MT into Eastern Great Basin... Morning water vapor loop shows an impressive shortwave trough rotating across the northwest states. This feature will result in strengthening winds aloft across much of the Great Basin and northern Rockies today, along with increasing large scale forcing for ascent. This will lead to scattered thunderstorms over the higher terrain of western MT into parts of WY/CO/UT by early afternoon. Forecast soundings show sufficient westerly flow/shear through the cloud-bearing layer to support organized and occasionally supercell storms capable of hail and damaging wind gusts. ...Eastern MT into the Dakotas... As convection spreads off the higher terrain into eastern MT, storms will encounter greater low level moisture/shear, further promoting supercell structures and the risk of very large hail and perhaps a few tornadoes. These storms will progress eastward through the afternoon/evening into the Dakotas, where upscale growth into bowing structures is anticipated - capable of significant damaging winds. ...Central Plains... Farther south, forcing will be weaker and convective coverage should be less. However, convection will intensify as outflows from the High Plains spread eastward into the moist axis, with a combination of bowing and supercell storms expected. Damaging winds are probably the main risk, but substantial low level and deep layer shear could support large hail and a tornado or two in this region as well. ...Carolinas/GA... A very moist and unstable air mass is present today from central/eastern NC southwestward into eastern GA. Scattered mid and high clouds will somewhat mitigate afternoon heating. But a few strong/severe storms are expected, with water-loaded downdrafts capable of locally damaging wind gusts. ..Hart/Weinman.. 06/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Jun 27 2024 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF UT AND WESTERN CO... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening, where very large hail, significant damaging winds, and a few tornadoes are possible. ...Western MT into Eastern Great Basin... Morning water vapor loop shows an impressive shortwave trough rotating across the northwest states. This feature will result in strengthening winds aloft across much of the Great Basin and northern Rockies today, along with increasing large scale forcing for ascent. This will lead to scattered thunderstorms over the higher terrain of western MT into parts of WY/CO/UT by early afternoon. Forecast soundings show sufficient westerly flow/shear through the cloud-bearing layer to support organized and occasionally supercell storms capable of hail and damaging wind gusts. ...Eastern MT into the Dakotas... As convection spreads off the higher terrain into eastern MT, storms will encounter greater low level moisture/shear, further promoting supercell structures and the risk of very large hail and perhaps a few tornadoes. These storms will progress eastward through the afternoon/evening into the Dakotas, where upscale growth into bowing structures is anticipated - capable of significant damaging winds. ...Central Plains... Farther south, forcing will be weaker and convective coverage should be less. However, convection will intensify as outflows from the High Plains spread eastward into the moist axis, with a combination of bowing and supercell storms expected. Damaging winds are probably the main risk, but substantial low level and deep layer shear could support large hail and a tornado or two in this region as well. ...Carolinas/GA... A very moist and unstable air mass is present today from central/eastern NC southwestward into eastern GA. Scattered mid and high clouds will somewhat mitigate afternoon heating. But a few strong/severe storms are expected, with water-loaded downdrafts capable of locally damaging wind gusts. ..Hart/Weinman.. 06/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Jun 27 2024 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF UT AND WESTERN CO... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening, where very large hail, significant damaging winds, and a few tornadoes are possible. ...Western MT into Eastern Great Basin... Morning water vapor loop shows an impressive shortwave trough rotating across the northwest states. This feature will result in strengthening winds aloft across much of the Great Basin and northern Rockies today, along with increasing large scale forcing for ascent. This will lead to scattered thunderstorms over the higher terrain of western MT into parts of WY/CO/UT by early afternoon. Forecast soundings show sufficient westerly flow/shear through the cloud-bearing layer to support organized and occasionally supercell storms capable of hail and damaging wind gusts. ...Eastern MT into the Dakotas... As convection spreads off the higher terrain into eastern MT, storms will encounter greater low level moisture/shear, further promoting supercell structures and the risk of very large hail and perhaps a few tornadoes. These storms will progress eastward through the afternoon/evening into the Dakotas, where upscale growth into bowing structures is anticipated - capable of significant damaging winds. ...Central Plains... Farther south, forcing will be weaker and convective coverage should be less. However, convection will intensify as outflows from the High Plains spread eastward into the moist axis, with a combination of bowing and supercell storms expected. Damaging winds are probably the main risk, but substantial low level and deep layer shear could support large hail and a tornado or two in this region as well. ...Carolinas/GA... A very moist and unstable air mass is present today from central/eastern NC southwestward into eastern GA. Scattered mid and high clouds will somewhat mitigate afternoon heating. But a few strong/severe storms are expected, with water-loaded downdrafts capable of locally damaging wind gusts. ..Hart/Weinman.. 06/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Jun 27 2024 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF UT AND WESTERN CO... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening, where very large hail, significant damaging winds, and a few tornadoes are possible. ...Western MT into Eastern Great Basin... Morning water vapor loop shows an impressive shortwave trough rotating across the northwest states. This feature will result in strengthening winds aloft across much of the Great Basin and northern Rockies today, along with increasing large scale forcing for ascent. This will lead to scattered thunderstorms over the higher terrain of western MT into parts of WY/CO/UT by early afternoon. Forecast soundings show sufficient westerly flow/shear through the cloud-bearing layer to support organized and occasionally supercell storms capable of hail and damaging wind gusts. ...Eastern MT into the Dakotas... As convection spreads off the higher terrain into eastern MT, storms will encounter greater low level moisture/shear, further promoting supercell structures and the risk of very large hail and perhaps a few tornadoes. These storms will progress eastward through the afternoon/evening into the Dakotas, where upscale growth into bowing structures is anticipated - capable of significant damaging winds. ...Central Plains... Farther south, forcing will be weaker and convective coverage should be less. However, convection will intensify as outflows from the High Plains spread eastward into the moist axis, with a combination of bowing and supercell storms expected. Damaging winds are probably the main risk, but substantial low level and deep layer shear could support large hail and a tornado or two in this region as well. ...Carolinas/GA... A very moist and unstable air mass is present today from central/eastern NC southwestward into eastern GA. Scattered mid and high clouds will somewhat mitigate afternoon heating. But a few strong/severe storms are expected, with water-loaded downdrafts capable of locally damaging wind gusts. ..Hart/Weinman.. 06/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Thu Jun 27 2024 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF UT AND WESTERN CO... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening, where very large hail, significant damaging winds, and a few tornadoes are possible. ...Western MT into Eastern Great Basin... Morning water vapor loop shows an impressive shortwave trough rotating across the northwest states. This feature will result in strengthening winds aloft across much of the Great Basin and northern Rockies today, along with increasing large scale forcing for ascent. This will lead to scattered thunderstorms over the higher terrain of western MT into parts of WY/CO/UT by early afternoon. Forecast soundings show sufficient westerly flow/shear through the cloud-bearing layer to support organized and occasionally supercell storms capable of hail and damaging wind gusts. ...Eastern MT into the Dakotas... As convection spreads off the higher terrain into eastern MT, storms will encounter greater low level moisture/shear, further promoting supercell structures and the risk of very large hail and perhaps a few tornadoes. These storms will progress eastward through the afternoon/evening into the Dakotas, where upscale growth into bowing structures is anticipated - capable of significant damaging winds. ...Central Plains... Farther south, forcing will be weaker and convective coverage should be less. However, convection will intensify as outflows from the High Plains spread eastward into the moist axis, with a combination of bowing and supercell storms expected. Damaging winds are probably the main risk, but substantial low level and deep layer shear could support large hail and a tornado or two in this region as well. ...Carolinas/GA... A very moist and unstable air mass is present today from central/eastern NC southwestward into eastern GA. Scattered mid and high clouds will somewhat mitigate afternoon heating. But a few strong/severe storms are expected, with water-loaded downdrafts capable of locally damaging wind gusts. ..Hart/Weinman.. 06/27/2024 Read more

No Mesoscale Discussions are in effect as of Thu Jun 27 16:17:02 UTC 2024.

000
ABPZ20 KNHC 271310
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Thu Jun 27 2024

For the eastern North Pacific...east of 140 degrees west longitude:

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Roberts

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more