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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Sun May 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. ..Mosier/Wendt.. 05/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Sun May 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. ..Mosier/Wendt.. 05/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Sun May 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. ..Mosier/Wendt.. 05/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Sun May 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. ..Mosier/Wendt.. 05/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Sun May 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. ..Mosier/Wendt.. 05/11/2025 Read more

MD 0763 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FL PANHANDLE/NORTH FL INTO SOUTHEAST AL...SOUTH GA...AND SOUTHERN SC
Mesoscale Discussion 0763 NWS Storm Prediction Center Norman OK 0759 AM CDT Sun May 11 2025 Areas affected...FL Panhandle/north FL into southeast AL...south GA...and southern SC Concerning...Severe potential...Watch unlikely Valid 111259Z - 111500Z Probability of Watch Issuance...20 percent SUMMARY...The threat for strong to locally severe storms may increase through the morning. DISCUSSION...Scattered storms are ongoing this morning from southeast GA into the FL Panhandle. Other than an MCS now moving off the Carolina coast, convection has largely been disorganized thus far. However, modest diurnal heating/destabilization could lead to increasingly vigorous storms with time this morning. Some increase in deep-layer flow/shear is also possible as a vorticity maximum rotates around a midlevel low centered over LA. Locally damaging winds and perhaps some hail could accompany the stronger storms through the morning. Effective SRH of 100-150 m2/s2 could also support at least transient supercell structures, with localized tornado potential, especially from the FL Panhandle into adjacent parts of southeast AL and south GA. ..Dean/Guyer.. 05/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...JAX...FFC...TAE...BMX...MOB... LAT...LON 31788641 31978448 32518218 32698132 32868047 32128049 31308136 30688165 30358196 30138240 29848374 29468505 29728594 29908620 30148676 30608672 31078661 31788641 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Sun May 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains fom mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... The leading portion of an eastward-transitioning upper-level trough will overspread the northern Rockies and northern Great Basin later today and tonight, with preceding height falls and a regionally strengthening 60-80 kt southwesterly mid-level jet. These trends in conjunction with orographic influences/differential heating will lead to another round of isolated to scattered thunderstorms by mid/late afternoon. Similar to Saturday, severe-caliber wind gusts will be the primary hazard as storms develop in association with deeply mixed boundary layers, especially with eastward extent from southeast Idaho to central/eastern Montana. Corridors of modest buoyancy, coupled with moderate to strong deep-layer southwesterly speed shear, could yield a few high-based supercell structures producing small to marginally severe hail. This should be focused from the Oregon/Washington/Idaho border vicinity into central Montana, and separately over southeast Idaho into Yellowstone. ...Southeast States... A persistent, slow-moving, and essentially vertically stacked low will persist, centered over the ArkLaMiss vicinity, with a preceding belt of moderately strong mid-level winds extending over the northeast Gulf to the coastal Southeast. This will overlie a moderately moist warm sector to the east of the surface cyclone and along/south of the eastward-extending stationary front (or slow-moving warm front). Scattered thunderstorms are ongoing regionally this morning, including semi-extensively over the northeast Gulf. A 30-40 kt southerly low-level jet is expected to sustain adequately enlarged low-level hodographs within this corridor, but especially towards the coast and near the warm front. But convection is expected to be within a messy, outflow-dominated mode at times. Regardless, isolated damaging wind and tornado potential is apparent. While the severe risk does not appear as semi-focused as yesterday, portions of far northern Florida to southern/southeast Georgia in vicinity of the stationary/warm front will be reevaluated for a potential Slight Risk upgrade. Farther west in Alabama and Mississippi, despite somewhat cooler mid-level temperatures closer to the upper cyclone, lapse rates still appear modest. But deep-layer speed shear will be moderately favorable amid a nearly unidirectional southeasterly wind profile. A few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, mainly from late afternoon through early/mid-evening. ..Guyer/Dean.. 05/11/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Sun May 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains fom mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... The leading portion of an eastward-transitioning upper-level trough will overspread the northern Rockies and northern Great Basin later today and tonight, with preceding height falls and a regionally strengthening 60-80 kt southwesterly mid-level jet. These trends in conjunction with orographic influences/differential heating will lead to another round of isolated to scattered thunderstorms by mid/late afternoon. Similar to Saturday, severe-caliber wind gusts will be the primary hazard as storms develop in association with deeply mixed boundary layers, especially with eastward extent from southeast Idaho to central/eastern Montana. Corridors of modest buoyancy, coupled with moderate to strong deep-layer southwesterly speed shear, could yield a few high-based supercell structures producing small to marginally severe hail. This should be focused from the Oregon/Washington/Idaho border vicinity into central Montana, and separately over southeast Idaho into Yellowstone. ...Southeast States... A persistent, slow-moving, and essentially vertically stacked low will persist, centered over the ArkLaMiss vicinity, with a preceding belt of moderately strong mid-level winds extending over the northeast Gulf to the coastal Southeast. This will overlie a moderately moist warm sector to the east of the surface cyclone and along/south of the eastward-extending stationary front (or slow-moving warm front). Scattered thunderstorms are ongoing regionally this morning, including semi-extensively over the northeast Gulf. A 30-40 kt southerly low-level jet is expected to sustain adequately enlarged low-level hodographs within this corridor, but especially towards the coast and near the warm front. But convection is expected to be within a messy, outflow-dominated mode at times. Regardless, isolated damaging wind and tornado potential is apparent. While the severe risk does not appear as semi-focused as yesterday, portions of far northern Florida to southern/southeast Georgia in vicinity of the stationary/warm front will be reevaluated for a potential Slight Risk upgrade. Farther west in Alabama and Mississippi, despite somewhat cooler mid-level temperatures closer to the upper cyclone, lapse rates still appear modest. But deep-layer speed shear will be moderately favorable amid a nearly unidirectional southeasterly wind profile. A few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, mainly from late afternoon through early/mid-evening. ..Guyer/Dean.. 05/11/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Sun May 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains fom mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... The leading portion of an eastward-transitioning upper-level trough will overspread the northern Rockies and northern Great Basin later today and tonight, with preceding height falls and a regionally strengthening 60-80 kt southwesterly mid-level jet. These trends in conjunction with orographic influences/differential heating will lead to another round of isolated to scattered thunderstorms by mid/late afternoon. Similar to Saturday, severe-caliber wind gusts will be the primary hazard as storms develop in association with deeply mixed boundary layers, especially with eastward extent from southeast Idaho to central/eastern Montana. Corridors of modest buoyancy, coupled with moderate to strong deep-layer southwesterly speed shear, could yield a few high-based supercell structures producing small to marginally severe hail. This should be focused from the Oregon/Washington/Idaho border vicinity into central Montana, and separately over southeast Idaho into Yellowstone. ...Southeast States... A persistent, slow-moving, and essentially vertically stacked low will persist, centered over the ArkLaMiss vicinity, with a preceding belt of moderately strong mid-level winds extending over the northeast Gulf to the coastal Southeast. This will overlie a moderately moist warm sector to the east of the surface cyclone and along/south of the eastward-extending stationary front (or slow-moving warm front). Scattered thunderstorms are ongoing regionally this morning, including semi-extensively over the northeast Gulf. A 30-40 kt southerly low-level jet is expected to sustain adequately enlarged low-level hodographs within this corridor, but especially towards the coast and near the warm front. But convection is expected to be within a messy, outflow-dominated mode at times. Regardless, isolated damaging wind and tornado potential is apparent. While the severe risk does not appear as semi-focused as yesterday, portions of far northern Florida to southern/southeast Georgia in vicinity of the stationary/warm front will be reevaluated for a potential Slight Risk upgrade. Farther west in Alabama and Mississippi, despite somewhat cooler mid-level temperatures closer to the upper cyclone, lapse rates still appear modest. But deep-layer speed shear will be moderately favorable amid a nearly unidirectional southeasterly wind profile. A few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, mainly from late afternoon through early/mid-evening. ..Guyer/Dean.. 05/11/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Sun May 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains fom mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... The leading portion of an eastward-transitioning upper-level trough will overspread the northern Rockies and northern Great Basin later today and tonight, with preceding height falls and a regionally strengthening 60-80 kt southwesterly mid-level jet. These trends in conjunction with orographic influences/differential heating will lead to another round of isolated to scattered thunderstorms by mid/late afternoon. Similar to Saturday, severe-caliber wind gusts will be the primary hazard as storms develop in association with deeply mixed boundary layers, especially with eastward extent from southeast Idaho to central/eastern Montana. Corridors of modest buoyancy, coupled with moderate to strong deep-layer southwesterly speed shear, could yield a few high-based supercell structures producing small to marginally severe hail. This should be focused from the Oregon/Washington/Idaho border vicinity into central Montana, and separately over southeast Idaho into Yellowstone. ...Southeast States... A persistent, slow-moving, and essentially vertically stacked low will persist, centered over the ArkLaMiss vicinity, with a preceding belt of moderately strong mid-level winds extending over the northeast Gulf to the coastal Southeast. This will overlie a moderately moist warm sector to the east of the surface cyclone and along/south of the eastward-extending stationary front (or slow-moving warm front). Scattered thunderstorms are ongoing regionally this morning, including semi-extensively over the northeast Gulf. A 30-40 kt southerly low-level jet is expected to sustain adequately enlarged low-level hodographs within this corridor, but especially towards the coast and near the warm front. But convection is expected to be within a messy, outflow-dominated mode at times. Regardless, isolated damaging wind and tornado potential is apparent. While the severe risk does not appear as semi-focused as yesterday, portions of far northern Florida to southern/southeast Georgia in vicinity of the stationary/warm front will be reevaluated for a potential Slight Risk upgrade. Farther west in Alabama and Mississippi, despite somewhat cooler mid-level temperatures closer to the upper cyclone, lapse rates still appear modest. But deep-layer speed shear will be moderately favorable amid a nearly unidirectional southeasterly wind profile. A few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, mainly from late afternoon through early/mid-evening. ..Guyer/Dean.. 05/11/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Sun May 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains fom mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... The leading portion of an eastward-transitioning upper-level trough will overspread the northern Rockies and northern Great Basin later today and tonight, with preceding height falls and a regionally strengthening 60-80 kt southwesterly mid-level jet. These trends in conjunction with orographic influences/differential heating will lead to another round of isolated to scattered thunderstorms by mid/late afternoon. Similar to Saturday, severe-caliber wind gusts will be the primary hazard as storms develop in association with deeply mixed boundary layers, especially with eastward extent from southeast Idaho to central/eastern Montana. Corridors of modest buoyancy, coupled with moderate to strong deep-layer southwesterly speed shear, could yield a few high-based supercell structures producing small to marginally severe hail. This should be focused from the Oregon/Washington/Idaho border vicinity into central Montana, and separately over southeast Idaho into Yellowstone. ...Southeast States... A persistent, slow-moving, and essentially vertically stacked low will persist, centered over the ArkLaMiss vicinity, with a preceding belt of moderately strong mid-level winds extending over the northeast Gulf to the coastal Southeast. This will overlie a moderately moist warm sector to the east of the surface cyclone and along/south of the eastward-extending stationary front (or slow-moving warm front). Scattered thunderstorms are ongoing regionally this morning, including semi-extensively over the northeast Gulf. A 30-40 kt southerly low-level jet is expected to sustain adequately enlarged low-level hodographs within this corridor, but especially towards the coast and near the warm front. But convection is expected to be within a messy, outflow-dominated mode at times. Regardless, isolated damaging wind and tornado potential is apparent. While the severe risk does not appear as semi-focused as yesterday, portions of far northern Florida to southern/southeast Georgia in vicinity of the stationary/warm front will be reevaluated for a potential Slight Risk upgrade. Farther west in Alabama and Mississippi, despite somewhat cooler mid-level temperatures closer to the upper cyclone, lapse rates still appear modest. But deep-layer speed shear will be moderately favorable amid a nearly unidirectional southeasterly wind profile. A few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, mainly from late afternoon through early/mid-evening. ..Guyer/Dean.. 05/11/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Sun May 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies to Montana High Plains fom mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...Northern Rockies/High Plains and northeast Great Basin... The leading portion of an eastward-transitioning upper-level trough will overspread the northern Rockies and northern Great Basin later today and tonight, with preceding height falls and a regionally strengthening 60-80 kt southwesterly mid-level jet. These trends in conjunction with orographic influences/differential heating will lead to another round of isolated to scattered thunderstorms by mid/late afternoon. Similar to Saturday, severe-caliber wind gusts will be the primary hazard as storms develop in association with deeply mixed boundary layers, especially with eastward extent from southeast Idaho to central/eastern Montana. Corridors of modest buoyancy, coupled with moderate to strong deep-layer southwesterly speed shear, could yield a few high-based supercell structures producing small to marginally severe hail. This should be focused from the Oregon/Washington/Idaho border vicinity into central Montana, and separately over southeast Idaho into Yellowstone. ...Southeast States... A persistent, slow-moving, and essentially vertically stacked low will persist, centered over the ArkLaMiss vicinity, with a preceding belt of moderately strong mid-level winds extending over the northeast Gulf to the coastal Southeast. This will overlie a moderately moist warm sector to the east of the surface cyclone and along/south of the eastward-extending stationary front (or slow-moving warm front). Scattered thunderstorms are ongoing regionally this morning, including semi-extensively over the northeast Gulf. A 30-40 kt southerly low-level jet is expected to sustain adequately enlarged low-level hodographs within this corridor, but especially towards the coast and near the warm front. But convection is expected to be within a messy, outflow-dominated mode at times. Regardless, isolated damaging wind and tornado potential is apparent. While the severe risk does not appear as semi-focused as yesterday, portions of far northern Florida to southern/southeast Georgia in vicinity of the stationary/warm front will be reevaluated for a potential Slight Risk upgrade. Farther west in Alabama and Mississippi, despite somewhat cooler mid-level temperatures closer to the upper cyclone, lapse rates still appear modest. But deep-layer speed shear will be moderately favorable amid a nearly unidirectional southeasterly wind profile. A few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, mainly from late afternoon through early/mid-evening. ..Guyer/Dean.. 05/11/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sun May 11 2025 Valid 141200Z - 191200Z ...DISCUSSION... Latest medium-range output remains generally similar to prior runs concerning the pattern evolution Wednesday into Thursday. A significant short wave trough emerging from the Intermountain West is forecast to support modest cyclogenesis across the central and northern Great Plains through the mid/upper Mississippi Valley vicinity. It appears that this probably will be accompanied by increasing potential for strong to severe thunderstorm development, with severe probabilities maximizing across parts of the Midwest late Thursday into Thursday night, as the stronger large-scale forcing for ascent becomes better coupled with substantive boundary-layer moistening and destabilization. Aided by steep lower/mid-tropospheric lapse rates associated with elevated mixed-layer air, and moderate to strong low-level and deep-layer shear, it appears that the environment will become conducive to the evolution of an upscale growing and organizing convective system. But initial convection may include supercells posing a risk for large hail and a couple of tornadoes, before damaging wind gusts become the predominate severe hazard. Based on the subsequent pattern evolution, it appears that this convection could persist into, or re-intensify, Friday across parts of the mid/upper Ohio Valley, with additional upscale growing convection evolving along a stalling trailing cold front near the southern edge of the stronger westerlies. Into next weekend, renewed cyclogenesis appears possible along the trailing flank of the front across the south central Great Plains, where additional strong to severe thunderstorm development may focus along a developing warm front, and a developing dryline southward through the plains, as the warm sector destabilizes with increasing Gulf moisture return. However, by late Thursday into Friday, and beyond, these developments remain much more unclear, as spread among and within the various medium-range models begins to increase. Substantive differences begin to develop concerning the progressiveness of the lead trough, and a trailing short wave trough emerging from the mid-latitude Pacific. The uncertain impacts of potentially multiple evolving large convective clusters on succeeding days adds to low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sun May 11 2025 Valid 141200Z - 191200Z ...DISCUSSION... Latest medium-range output remains generally similar to prior runs concerning the pattern evolution Wednesday into Thursday. A significant short wave trough emerging from the Intermountain West is forecast to support modest cyclogenesis across the central and northern Great Plains through the mid/upper Mississippi Valley vicinity. It appears that this probably will be accompanied by increasing potential for strong to severe thunderstorm development, with severe probabilities maximizing across parts of the Midwest late Thursday into Thursday night, as the stronger large-scale forcing for ascent becomes better coupled with substantive boundary-layer moistening and destabilization. Aided by steep lower/mid-tropospheric lapse rates associated with elevated mixed-layer air, and moderate to strong low-level and deep-layer shear, it appears that the environment will become conducive to the evolution of an upscale growing and organizing convective system. But initial convection may include supercells posing a risk for large hail and a couple of tornadoes, before damaging wind gusts become the predominate severe hazard. Based on the subsequent pattern evolution, it appears that this convection could persist into, or re-intensify, Friday across parts of the mid/upper Ohio Valley, with additional upscale growing convection evolving along a stalling trailing cold front near the southern edge of the stronger westerlies. Into next weekend, renewed cyclogenesis appears possible along the trailing flank of the front across the south central Great Plains, where additional strong to severe thunderstorm development may focus along a developing warm front, and a developing dryline southward through the plains, as the warm sector destabilizes with increasing Gulf moisture return. However, by late Thursday into Friday, and beyond, these developments remain much more unclear, as spread among and within the various medium-range models begins to increase. Substantive differences begin to develop concerning the progressiveness of the lead trough, and a trailing short wave trough emerging from the mid-latitude Pacific. The uncertain impacts of potentially multiple evolving large convective clusters on succeeding days adds to low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sun May 11 2025 Valid 141200Z - 191200Z ...DISCUSSION... Latest medium-range output remains generally similar to prior runs concerning the pattern evolution Wednesday into Thursday. A significant short wave trough emerging from the Intermountain West is forecast to support modest cyclogenesis across the central and northern Great Plains through the mid/upper Mississippi Valley vicinity. It appears that this probably will be accompanied by increasing potential for strong to severe thunderstorm development, with severe probabilities maximizing across parts of the Midwest late Thursday into Thursday night, as the stronger large-scale forcing for ascent becomes better coupled with substantive boundary-layer moistening and destabilization. Aided by steep lower/mid-tropospheric lapse rates associated with elevated mixed-layer air, and moderate to strong low-level and deep-layer shear, it appears that the environment will become conducive to the evolution of an upscale growing and organizing convective system. But initial convection may include supercells posing a risk for large hail and a couple of tornadoes, before damaging wind gusts become the predominate severe hazard. Based on the subsequent pattern evolution, it appears that this convection could persist into, or re-intensify, Friday across parts of the mid/upper Ohio Valley, with additional upscale growing convection evolving along a stalling trailing cold front near the southern edge of the stronger westerlies. Into next weekend, renewed cyclogenesis appears possible along the trailing flank of the front across the south central Great Plains, where additional strong to severe thunderstorm development may focus along a developing warm front, and a developing dryline southward through the plains, as the warm sector destabilizes with increasing Gulf moisture return. However, by late Thursday into Friday, and beyond, these developments remain much more unclear, as spread among and within the various medium-range models begins to increase. Substantive differences begin to develop concerning the progressiveness of the lead trough, and a trailing short wave trough emerging from the mid-latitude Pacific. The uncertain impacts of potentially multiple evolving large convective clusters on succeeding days adds to low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sun May 11 2025 Valid 141200Z - 191200Z ...DISCUSSION... Latest medium-range output remains generally similar to prior runs concerning the pattern evolution Wednesday into Thursday. A significant short wave trough emerging from the Intermountain West is forecast to support modest cyclogenesis across the central and northern Great Plains through the mid/upper Mississippi Valley vicinity. It appears that this probably will be accompanied by increasing potential for strong to severe thunderstorm development, with severe probabilities maximizing across parts of the Midwest late Thursday into Thursday night, as the stronger large-scale forcing for ascent becomes better coupled with substantive boundary-layer moistening and destabilization. Aided by steep lower/mid-tropospheric lapse rates associated with elevated mixed-layer air, and moderate to strong low-level and deep-layer shear, it appears that the environment will become conducive to the evolution of an upscale growing and organizing convective system. But initial convection may include supercells posing a risk for large hail and a couple of tornadoes, before damaging wind gusts become the predominate severe hazard. Based on the subsequent pattern evolution, it appears that this convection could persist into, or re-intensify, Friday across parts of the mid/upper Ohio Valley, with additional upscale growing convection evolving along a stalling trailing cold front near the southern edge of the stronger westerlies. Into next weekend, renewed cyclogenesis appears possible along the trailing flank of the front across the south central Great Plains, where additional strong to severe thunderstorm development may focus along a developing warm front, and a developing dryline southward through the plains, as the warm sector destabilizes with increasing Gulf moisture return. However, by late Thursday into Friday, and beyond, these developments remain much more unclear, as spread among and within the various medium-range models begins to increase. Substantive differences begin to develop concerning the progressiveness of the lead trough, and a trailing short wave trough emerging from the mid-latitude Pacific. The uncertain impacts of potentially multiple evolving large convective clusters on succeeding days adds to low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sun May 11 2025 Valid 141200Z - 191200Z ...DISCUSSION... Latest medium-range output remains generally similar to prior runs concerning the pattern evolution Wednesday into Thursday. A significant short wave trough emerging from the Intermountain West is forecast to support modest cyclogenesis across the central and northern Great Plains through the mid/upper Mississippi Valley vicinity. It appears that this probably will be accompanied by increasing potential for strong to severe thunderstorm development, with severe probabilities maximizing across parts of the Midwest late Thursday into Thursday night, as the stronger large-scale forcing for ascent becomes better coupled with substantive boundary-layer moistening and destabilization. Aided by steep lower/mid-tropospheric lapse rates associated with elevated mixed-layer air, and moderate to strong low-level and deep-layer shear, it appears that the environment will become conducive to the evolution of an upscale growing and organizing convective system. But initial convection may include supercells posing a risk for large hail and a couple of tornadoes, before damaging wind gusts become the predominate severe hazard. Based on the subsequent pattern evolution, it appears that this convection could persist into, or re-intensify, Friday across parts of the mid/upper Ohio Valley, with additional upscale growing convection evolving along a stalling trailing cold front near the southern edge of the stronger westerlies. Into next weekend, renewed cyclogenesis appears possible along the trailing flank of the front across the south central Great Plains, where additional strong to severe thunderstorm development may focus along a developing warm front, and a developing dryline southward through the plains, as the warm sector destabilizes with increasing Gulf moisture return. However, by late Thursday into Friday, and beyond, these developments remain much more unclear, as spread among and within the various medium-range models begins to increase. Substantive differences begin to develop concerning the progressiveness of the lead trough, and a trailing short wave trough emerging from the mid-latitude Pacific. The uncertain impacts of potentially multiple evolving large convective clusters on succeeding days adds to low predictability. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sun May 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms currently appears negligible across the U.S. Tuesday through Tuesday night. ...Discussion... It appears that significant mid/upper-level troughing progressing inland of the U.S. Pacific coast may dig as far south as the lower Colorado Valley, and suppress ridging within a belt of westerlies emanating from the subtropical eastern Pacific, across the southwestern international border area. Thereafter, models indicate that the perturbation will turn eastward across the Intermountain West later Tuesday through Tuesday night, with intensifying difluent west-southwesterly mid/upper flow overspreading the southern Rockies by 12Z Wednesday. In lower levels, modestly deep surface troughing to the lee of the Rockies may continue to slowly shift eastward across the Great Plains. However, in the wake of broad, weak negatively tilted mid/upper troughing shifting east of the Mississippi Valley, toward the Atlantic coast at a slower pace than the upstream trough, strengthening low-level flow (up to 30-40 kt around 850 mb) is forecast to maintain a pronounced westerly component across the southern Great Plains into lower Mississippi Valley. This will continue to impede boundary-layer moisture return off the Gulf into the Great Plains, though evapotranspiration may contribute to moistening beneath the leading edge of a plume of warm elevated mixed-layer air advecting eastward across the central and southern Great Plains. Downstream, models indicate that there will be gradual further deepening of broad, weak surface troughing across much of the Southeast. However, the plume of seasonably high moisture content air emanating from the lower latitudes is forecast to generally shift east of the south Atlantic coast during the day Tuesday, though this may be slower to occur across southeast coastal areas of the Florida Peninsula. ...Intermountain West into Great Plains... Models suggest that destabilization beneath an elongated mid-level cold pool, trailing the surface cold front, may contribute to scattered, generally weak/diurnal thunderstorm activity across the northern Rockies and intermountain region, into the vicinity of the northern Sierra Nevada. Near the surface troughing across the Dakotas, it appears that a strongly heated and deeply mixed boundary may become characterized by 40-50 F surface temperature/dew point spreads, but with thermodynamic profiles still supportive of CAPE on the order of 500-1000 J/kg. High-based thunderstorm development appears possible near/after peak heating, which could pose some risk for locally strong surface gusts. However, the extent of this potential remains unclear, and too uncertain to introduce even low severe probabilities at the present time. ...Ohio Valley/Mid Atlantic/Southeast... Scattered, largely diurnal thunderstorm activity will again be possible beneath the weak/weakening mid-level troughing. Stronger convection may focus along the sea breeze near southeastern Florida coastal areas, and perhaps across parts of the mid and southern Atlantic Piedmont, where at least modest boundary-layer destabilization may occur. However, it is not yet clear that this will be accompanied by an appreciable risk for severe weather. ..Kerr.. 05/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sun May 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms currently appears negligible across the U.S. Tuesday through Tuesday night. ...Discussion... It appears that significant mid/upper-level troughing progressing inland of the U.S. Pacific coast may dig as far south as the lower Colorado Valley, and suppress ridging within a belt of westerlies emanating from the subtropical eastern Pacific, across the southwestern international border area. Thereafter, models indicate that the perturbation will turn eastward across the Intermountain West later Tuesday through Tuesday night, with intensifying difluent west-southwesterly mid/upper flow overspreading the southern Rockies by 12Z Wednesday. In lower levels, modestly deep surface troughing to the lee of the Rockies may continue to slowly shift eastward across the Great Plains. However, in the wake of broad, weak negatively tilted mid/upper troughing shifting east of the Mississippi Valley, toward the Atlantic coast at a slower pace than the upstream trough, strengthening low-level flow (up to 30-40 kt around 850 mb) is forecast to maintain a pronounced westerly component across the southern Great Plains into lower Mississippi Valley. This will continue to impede boundary-layer moisture return off the Gulf into the Great Plains, though evapotranspiration may contribute to moistening beneath the leading edge of a plume of warm elevated mixed-layer air advecting eastward across the central and southern Great Plains. Downstream, models indicate that there will be gradual further deepening of broad, weak surface troughing across much of the Southeast. However, the plume of seasonably high moisture content air emanating from the lower latitudes is forecast to generally shift east of the south Atlantic coast during the day Tuesday, though this may be slower to occur across southeast coastal areas of the Florida Peninsula. ...Intermountain West into Great Plains... Models suggest that destabilization beneath an elongated mid-level cold pool, trailing the surface cold front, may contribute to scattered, generally weak/diurnal thunderstorm activity across the northern Rockies and intermountain region, into the vicinity of the northern Sierra Nevada. Near the surface troughing across the Dakotas, it appears that a strongly heated and deeply mixed boundary may become characterized by 40-50 F surface temperature/dew point spreads, but with thermodynamic profiles still supportive of CAPE on the order of 500-1000 J/kg. High-based thunderstorm development appears possible near/after peak heating, which could pose some risk for locally strong surface gusts. However, the extent of this potential remains unclear, and too uncertain to introduce even low severe probabilities at the present time. ...Ohio Valley/Mid Atlantic/Southeast... Scattered, largely diurnal thunderstorm activity will again be possible beneath the weak/weakening mid-level troughing. Stronger convection may focus along the sea breeze near southeastern Florida coastal areas, and perhaps across parts of the mid and southern Atlantic Piedmont, where at least modest boundary-layer destabilization may occur. However, it is not yet clear that this will be accompanied by an appreciable risk for severe weather. ..Kerr.. 05/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sun May 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms currently appears negligible across the U.S. Tuesday through Tuesday night. ...Discussion... It appears that significant mid/upper-level troughing progressing inland of the U.S. Pacific coast may dig as far south as the lower Colorado Valley, and suppress ridging within a belt of westerlies emanating from the subtropical eastern Pacific, across the southwestern international border area. Thereafter, models indicate that the perturbation will turn eastward across the Intermountain West later Tuesday through Tuesday night, with intensifying difluent west-southwesterly mid/upper flow overspreading the southern Rockies by 12Z Wednesday. In lower levels, modestly deep surface troughing to the lee of the Rockies may continue to slowly shift eastward across the Great Plains. However, in the wake of broad, weak negatively tilted mid/upper troughing shifting east of the Mississippi Valley, toward the Atlantic coast at a slower pace than the upstream trough, strengthening low-level flow (up to 30-40 kt around 850 mb) is forecast to maintain a pronounced westerly component across the southern Great Plains into lower Mississippi Valley. This will continue to impede boundary-layer moisture return off the Gulf into the Great Plains, though evapotranspiration may contribute to moistening beneath the leading edge of a plume of warm elevated mixed-layer air advecting eastward across the central and southern Great Plains. Downstream, models indicate that there will be gradual further deepening of broad, weak surface troughing across much of the Southeast. However, the plume of seasonably high moisture content air emanating from the lower latitudes is forecast to generally shift east of the south Atlantic coast during the day Tuesday, though this may be slower to occur across southeast coastal areas of the Florida Peninsula. ...Intermountain West into Great Plains... Models suggest that destabilization beneath an elongated mid-level cold pool, trailing the surface cold front, may contribute to scattered, generally weak/diurnal thunderstorm activity across the northern Rockies and intermountain region, into the vicinity of the northern Sierra Nevada. Near the surface troughing across the Dakotas, it appears that a strongly heated and deeply mixed boundary may become characterized by 40-50 F surface temperature/dew point spreads, but with thermodynamic profiles still supportive of CAPE on the order of 500-1000 J/kg. High-based thunderstorm development appears possible near/after peak heating, which could pose some risk for locally strong surface gusts. However, the extent of this potential remains unclear, and too uncertain to introduce even low severe probabilities at the present time. ...Ohio Valley/Mid Atlantic/Southeast... Scattered, largely diurnal thunderstorm activity will again be possible beneath the weak/weakening mid-level troughing. Stronger convection may focus along the sea breeze near southeastern Florida coastal areas, and perhaps across parts of the mid and southern Atlantic Piedmont, where at least modest boundary-layer destabilization may occur. However, it is not yet clear that this will be accompanied by an appreciable risk for severe weather. ..Kerr.. 05/11/2025 Read more