Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Wed Jul 09 2025 Valid 091300Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES/CAROLINAS AND NORTHERN/CENTRAL PLAINS... ...SUMMARY... Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic. Large hail and severe wind gusts are also possible across parts of the northern/central Plains late this afternoon into evening. ...Mid-Atlantic/Southeast States... A weak mid-level trough will move slowly eastward today across the Great Lakes and Ohio Valley. A belt of modestly enhanced southwesterly mid-level flow will remain over the Mid-Atlantic through this evening, diminishing with southward extent in the Southeast. Scattered to numerous thunderstorms are once again expected to develop this afternoon over the southern Appalachians and Blue Ridge Mountains, and then spread eastward towards the coast. Steepening low-level lapse rates and rich low-level moisture will support MLCAPE generally around 1500-3000 J/kg across lower elevations. Loosely organized clusters may eventually develop from parts of Virginia towards the DelMarVa Peninsula and vicinity owing to somewhat more favorable deep-layer shear across these regions. Isolated hail may occur initially with the more cellular/discrete convection, before scattered severe/damaging winds becomes the primary risk with eastward extent as multiple clusters potentially develop. ...Northern/central Plains... Downstream of a low-amplitude mid-level ridge emanating from an upper-level anticyclone over the Southwest, most guidance continues to suggest that isolated to scattered thunderstorms should form by late this afternoon along a weak surface trough. However, it should be noted that guidance continues to vary considerably in the short-term spatial details, likely owing to owing to degree of elevated mixed layer/warmth aloft. Recent HRRR (and RRFS) runs are somewhat uncharacteristically more aggressive (given the capping and modest forcing regime etc.) in terms of overall degree of deep convective development and the southward extent thereof, as compared to various global guidance. A corridor of strong to very strong instability will exist by late afternoon/early evening from parts of western/central Dakotas to northern Nebraska, aided by daytime heating and very steep lapse rates. Despite modest mid-level west-northwesterlies owing to the proximity of the upper ridge, stronger upper-level westerlies will support adequate deep-layer shear for a few supercells initially, with associated threat for large to isolated very large hail. Outflow-dominated downdrafts should foster clustering east-southeastward across the Dakotas and parts of Nebraska, with a risk for severe-caliber wind gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. Risk-magnitude uncertainty increases southward across Kansas, but at least isolated severe storms may occur across western/central/northern parts of Kansas, and possibly into northern Oklahoma. ...Northern Intermountain West/Rockies and northern Great Basin... Downstream of a shortwave trough moving eastward toward the northern Great Basin, an elongated belt of enhanced southwesterly mid-level flow will exist across the northern Great Basin/Rockies. Within this favorable flow regime amid steepened low-level lapse rates through daytime heating, scattered thunderstorms should foster strong to isolated severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. ...Lower Michigan to northwest Ohio... Isolated/marginally severe hail and locally damaging winds may occur this afternoon across parts of Lower Michigan and northwest Ohio. This will be as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Guyer/Dean.. 07/09/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Wed Jul 09 2025 Valid 091300Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES/CAROLINAS AND NORTHERN/CENTRAL PLAINS... ...SUMMARY... Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic. Large hail and severe wind gusts are also possible across parts of the northern/central Plains late this afternoon into evening. ...Mid-Atlantic/Southeast States... A weak mid-level trough will move slowly eastward today across the Great Lakes and Ohio Valley. A belt of modestly enhanced southwesterly mid-level flow will remain over the Mid-Atlantic through this evening, diminishing with southward extent in the Southeast. Scattered to numerous thunderstorms are once again expected to develop this afternoon over the southern Appalachians and Blue Ridge Mountains, and then spread eastward towards the coast. Steepening low-level lapse rates and rich low-level moisture will support MLCAPE generally around 1500-3000 J/kg across lower elevations. Loosely organized clusters may eventually develop from parts of Virginia towards the DelMarVa Peninsula and vicinity owing to somewhat more favorable deep-layer shear across these regions. Isolated hail may occur initially with the more cellular/discrete convection, before scattered severe/damaging winds becomes the primary risk with eastward extent as multiple clusters potentially develop. ...Northern/central Plains... Downstream of a low-amplitude mid-level ridge emanating from an upper-level anticyclone over the Southwest, most guidance continues to suggest that isolated to scattered thunderstorms should form by late this afternoon along a weak surface trough. However, it should be noted that guidance continues to vary considerably in the short-term spatial details, likely owing to owing to degree of elevated mixed layer/warmth aloft. Recent HRRR (and RRFS) runs are somewhat uncharacteristically more aggressive (given the capping and modest forcing regime etc.) in terms of overall degree of deep convective development and the southward extent thereof, as compared to various global guidance. A corridor of strong to very strong instability will exist by late afternoon/early evening from parts of western/central Dakotas to northern Nebraska, aided by daytime heating and very steep lapse rates. Despite modest mid-level west-northwesterlies owing to the proximity of the upper ridge, stronger upper-level westerlies will support adequate deep-layer shear for a few supercells initially, with associated threat for large to isolated very large hail. Outflow-dominated downdrafts should foster clustering east-southeastward across the Dakotas and parts of Nebraska, with a risk for severe-caliber wind gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. Risk-magnitude uncertainty increases southward across Kansas, but at least isolated severe storms may occur across western/central/northern parts of Kansas, and possibly into northern Oklahoma. ...Northern Intermountain West/Rockies and northern Great Basin... Downstream of a shortwave trough moving eastward toward the northern Great Basin, an elongated belt of enhanced southwesterly mid-level flow will exist across the northern Great Basin/Rockies. Within this favorable flow regime amid steepened low-level lapse rates through daytime heating, scattered thunderstorms should foster strong to isolated severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. ...Lower Michigan to northwest Ohio... Isolated/marginally severe hail and locally damaging winds may occur this afternoon across parts of Lower Michigan and northwest Ohio. This will be as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Guyer/Dean.. 07/09/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Wed Jul 09 2025 Valid 091300Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES/CAROLINAS AND NORTHERN/CENTRAL PLAINS... ...SUMMARY... Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic. Large hail and severe wind gusts are also possible across parts of the northern/central Plains late this afternoon into evening. ...Mid-Atlantic/Southeast States... A weak mid-level trough will move slowly eastward today across the Great Lakes and Ohio Valley. A belt of modestly enhanced southwesterly mid-level flow will remain over the Mid-Atlantic through this evening, diminishing with southward extent in the Southeast. Scattered to numerous thunderstorms are once again expected to develop this afternoon over the southern Appalachians and Blue Ridge Mountains, and then spread eastward towards the coast. Steepening low-level lapse rates and rich low-level moisture will support MLCAPE generally around 1500-3000 J/kg across lower elevations. Loosely organized clusters may eventually develop from parts of Virginia towards the DelMarVa Peninsula and vicinity owing to somewhat more favorable deep-layer shear across these regions. Isolated hail may occur initially with the more cellular/discrete convection, before scattered severe/damaging winds becomes the primary risk with eastward extent as multiple clusters potentially develop. ...Northern/central Plains... Downstream of a low-amplitude mid-level ridge emanating from an upper-level anticyclone over the Southwest, most guidance continues to suggest that isolated to scattered thunderstorms should form by late this afternoon along a weak surface trough. However, it should be noted that guidance continues to vary considerably in the short-term spatial details, likely owing to owing to degree of elevated mixed layer/warmth aloft. Recent HRRR (and RRFS) runs are somewhat uncharacteristically more aggressive (given the capping and modest forcing regime etc.) in terms of overall degree of deep convective development and the southward extent thereof, as compared to various global guidance. A corridor of strong to very strong instability will exist by late afternoon/early evening from parts of western/central Dakotas to northern Nebraska, aided by daytime heating and very steep lapse rates. Despite modest mid-level west-northwesterlies owing to the proximity of the upper ridge, stronger upper-level westerlies will support adequate deep-layer shear for a few supercells initially, with associated threat for large to isolated very large hail. Outflow-dominated downdrafts should foster clustering east-southeastward across the Dakotas and parts of Nebraska, with a risk for severe-caliber wind gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. Risk-magnitude uncertainty increases southward across Kansas, but at least isolated severe storms may occur across western/central/northern parts of Kansas, and possibly into northern Oklahoma. ...Northern Intermountain West/Rockies and northern Great Basin... Downstream of a shortwave trough moving eastward toward the northern Great Basin, an elongated belt of enhanced southwesterly mid-level flow will exist across the northern Great Basin/Rockies. Within this favorable flow regime amid steepened low-level lapse rates through daytime heating, scattered thunderstorms should foster strong to isolated severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. ...Lower Michigan to northwest Ohio... Isolated/marginally severe hail and locally damaging winds may occur this afternoon across parts of Lower Michigan and northwest Ohio. This will be as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Guyer/Dean.. 07/09/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Wed Jul 09 2025 Valid 091300Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES/CAROLINAS AND NORTHERN/CENTRAL PLAINS... ...SUMMARY... Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic. Large hail and severe wind gusts are also possible across parts of the northern/central Plains late this afternoon into evening. ...Mid-Atlantic/Southeast States... A weak mid-level trough will move slowly eastward today across the Great Lakes and Ohio Valley. A belt of modestly enhanced southwesterly mid-level flow will remain over the Mid-Atlantic through this evening, diminishing with southward extent in the Southeast. Scattered to numerous thunderstorms are once again expected to develop this afternoon over the southern Appalachians and Blue Ridge Mountains, and then spread eastward towards the coast. Steepening low-level lapse rates and rich low-level moisture will support MLCAPE generally around 1500-3000 J/kg across lower elevations. Loosely organized clusters may eventually develop from parts of Virginia towards the DelMarVa Peninsula and vicinity owing to somewhat more favorable deep-layer shear across these regions. Isolated hail may occur initially with the more cellular/discrete convection, before scattered severe/damaging winds becomes the primary risk with eastward extent as multiple clusters potentially develop. ...Northern/central Plains... Downstream of a low-amplitude mid-level ridge emanating from an upper-level anticyclone over the Southwest, most guidance continues to suggest that isolated to scattered thunderstorms should form by late this afternoon along a weak surface trough. However, it should be noted that guidance continues to vary considerably in the short-term spatial details, likely owing to owing to degree of elevated mixed layer/warmth aloft. Recent HRRR (and RRFS) runs are somewhat uncharacteristically more aggressive (given the capping and modest forcing regime etc.) in terms of overall degree of deep convective development and the southward extent thereof, as compared to various global guidance. A corridor of strong to very strong instability will exist by late afternoon/early evening from parts of western/central Dakotas to northern Nebraska, aided by daytime heating and very steep lapse rates. Despite modest mid-level west-northwesterlies owing to the proximity of the upper ridge, stronger upper-level westerlies will support adequate deep-layer shear for a few supercells initially, with associated threat for large to isolated very large hail. Outflow-dominated downdrafts should foster clustering east-southeastward across the Dakotas and parts of Nebraska, with a risk for severe-caliber wind gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. Risk-magnitude uncertainty increases southward across Kansas, but at least isolated severe storms may occur across western/central/northern parts of Kansas, and possibly into northern Oklahoma. ...Northern Intermountain West/Rockies and northern Great Basin... Downstream of a shortwave trough moving eastward toward the northern Great Basin, an elongated belt of enhanced southwesterly mid-level flow will exist across the northern Great Basin/Rockies. Within this favorable flow regime amid steepened low-level lapse rates through daytime heating, scattered thunderstorms should foster strong to isolated severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. ...Lower Michigan to northwest Ohio... Isolated/marginally severe hail and locally damaging winds may occur this afternoon across parts of Lower Michigan and northwest Ohio. This will be as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Guyer/Dean.. 07/09/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Wed Jul 09 2025 Valid 091300Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES/CAROLINAS AND NORTHERN/CENTRAL PLAINS... ...SUMMARY... Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic. Large hail and severe wind gusts are also possible across parts of the northern/central Plains late this afternoon into evening. ...Mid-Atlantic/Southeast States... A weak mid-level trough will move slowly eastward today across the Great Lakes and Ohio Valley. A belt of modestly enhanced southwesterly mid-level flow will remain over the Mid-Atlantic through this evening, diminishing with southward extent in the Southeast. Scattered to numerous thunderstorms are once again expected to develop this afternoon over the southern Appalachians and Blue Ridge Mountains, and then spread eastward towards the coast. Steepening low-level lapse rates and rich low-level moisture will support MLCAPE generally around 1500-3000 J/kg across lower elevations. Loosely organized clusters may eventually develop from parts of Virginia towards the DelMarVa Peninsula and vicinity owing to somewhat more favorable deep-layer shear across these regions. Isolated hail may occur initially with the more cellular/discrete convection, before scattered severe/damaging winds becomes the primary risk with eastward extent as multiple clusters potentially develop. ...Northern/central Plains... Downstream of a low-amplitude mid-level ridge emanating from an upper-level anticyclone over the Southwest, most guidance continues to suggest that isolated to scattered thunderstorms should form by late this afternoon along a weak surface trough. However, it should be noted that guidance continues to vary considerably in the short-term spatial details, likely owing to owing to degree of elevated mixed layer/warmth aloft. Recent HRRR (and RRFS) runs are somewhat uncharacteristically more aggressive (given the capping and modest forcing regime etc.) in terms of overall degree of deep convective development and the southward extent thereof, as compared to various global guidance. A corridor of strong to very strong instability will exist by late afternoon/early evening from parts of western/central Dakotas to northern Nebraska, aided by daytime heating and very steep lapse rates. Despite modest mid-level west-northwesterlies owing to the proximity of the upper ridge, stronger upper-level westerlies will support adequate deep-layer shear for a few supercells initially, with associated threat for large to isolated very large hail. Outflow-dominated downdrafts should foster clustering east-southeastward across the Dakotas and parts of Nebraska, with a risk for severe-caliber wind gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. Risk-magnitude uncertainty increases southward across Kansas, but at least isolated severe storms may occur across western/central/northern parts of Kansas, and possibly into northern Oklahoma. ...Northern Intermountain West/Rockies and northern Great Basin... Downstream of a shortwave trough moving eastward toward the northern Great Basin, an elongated belt of enhanced southwesterly mid-level flow will exist across the northern Great Basin/Rockies. Within this favorable flow regime amid steepened low-level lapse rates through daytime heating, scattered thunderstorms should foster strong to isolated severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. ...Lower Michigan to northwest Ohio... Isolated/marginally severe hail and locally damaging winds may occur this afternoon across parts of Lower Michigan and northwest Ohio. This will be as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Guyer/Dean.. 07/09/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0318 AM CDT Wed Jul 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... The overall large-scale pattern looks to remain characterized by mid-to-upper-level ridging across the western United States with a zonal to broadly cyclonic flow across the northern tier of the US through the forecast period. At the same time, rich/moist low-level moisture looks to remain entrenched across much of the eastern US, sustained in part by broad, southerly flow, albeit with some fluctuations in raw values. Global models continue to be bullish on a seasonably strong cold front pushing south through much of the central US late in the forecast period, ushering in a cooler/drier airmass. Strong-to-locally severe thunderstorms will be possible somewhere across the eastern CONUS every day of the forecast period. However, with synoptic-scale forcing/dynamics primarily constrained to Canada, most thunderstorms will be determined by sub-synoptic/mesoscale details dictated by/reinforced with each prior day's convection. Thus, confidence is too low in any one location on any given day to introduce unconditional severe probabilities at this time. However, some areas/scenarios of interest to monitor include the southern Great Plains on Days 4-5/Saturday-Sunday as a moist, weakly capped environment will exist in proximity to an increasing diffuse surface boundary. Other areas include the East Coast most afternoons and the along and ahead of seasonably strong cold front pushing south through the Great Plains from Days 6-8. For each of the areas of interest/scenarios of interest above, weak effective-layer shear stemming from generally weak tropospheric flow will be a limiting factor for a more organized severe potential and confidence to introduce unconditional probabilities. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0318 AM CDT Wed Jul 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... The overall large-scale pattern looks to remain characterized by mid-to-upper-level ridging across the western United States with a zonal to broadly cyclonic flow across the northern tier of the US through the forecast period. At the same time, rich/moist low-level moisture looks to remain entrenched across much of the eastern US, sustained in part by broad, southerly flow, albeit with some fluctuations in raw values. Global models continue to be bullish on a seasonably strong cold front pushing south through much of the central US late in the forecast period, ushering in a cooler/drier airmass. Strong-to-locally severe thunderstorms will be possible somewhere across the eastern CONUS every day of the forecast period. However, with synoptic-scale forcing/dynamics primarily constrained to Canada, most thunderstorms will be determined by sub-synoptic/mesoscale details dictated by/reinforced with each prior day's convection. Thus, confidence is too low in any one location on any given day to introduce unconditional severe probabilities at this time. However, some areas/scenarios of interest to monitor include the southern Great Plains on Days 4-5/Saturday-Sunday as a moist, weakly capped environment will exist in proximity to an increasing diffuse surface boundary. Other areas include the East Coast most afternoons and the along and ahead of seasonably strong cold front pushing south through the Great Plains from Days 6-8. For each of the areas of interest/scenarios of interest above, weak effective-layer shear stemming from generally weak tropospheric flow will be a limiting factor for a more organized severe potential and confidence to introduce unconditional probabilities. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0318 AM CDT Wed Jul 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... The overall large-scale pattern looks to remain characterized by mid-to-upper-level ridging across the western United States with a zonal to broadly cyclonic flow across the northern tier of the US through the forecast period. At the same time, rich/moist low-level moisture looks to remain entrenched across much of the eastern US, sustained in part by broad, southerly flow, albeit with some fluctuations in raw values. Global models continue to be bullish on a seasonably strong cold front pushing south through much of the central US late in the forecast period, ushering in a cooler/drier airmass. Strong-to-locally severe thunderstorms will be possible somewhere across the eastern CONUS every day of the forecast period. However, with synoptic-scale forcing/dynamics primarily constrained to Canada, most thunderstorms will be determined by sub-synoptic/mesoscale details dictated by/reinforced with each prior day's convection. Thus, confidence is too low in any one location on any given day to introduce unconditional severe probabilities at this time. However, some areas/scenarios of interest to monitor include the southern Great Plains on Days 4-5/Saturday-Sunday as a moist, weakly capped environment will exist in proximity to an increasing diffuse surface boundary. Other areas include the East Coast most afternoons and the along and ahead of seasonably strong cold front pushing south through the Great Plains from Days 6-8. For each of the areas of interest/scenarios of interest above, weak effective-layer shear stemming from generally weak tropospheric flow will be a limiting factor for a more organized severe potential and confidence to introduce unconditional probabilities. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0318 AM CDT Wed Jul 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... The overall large-scale pattern looks to remain characterized by mid-to-upper-level ridging across the western United States with a zonal to broadly cyclonic flow across the northern tier of the US through the forecast period. At the same time, rich/moist low-level moisture looks to remain entrenched across much of the eastern US, sustained in part by broad, southerly flow, albeit with some fluctuations in raw values. Global models continue to be bullish on a seasonably strong cold front pushing south through much of the central US late in the forecast period, ushering in a cooler/drier airmass. Strong-to-locally severe thunderstorms will be possible somewhere across the eastern CONUS every day of the forecast period. However, with synoptic-scale forcing/dynamics primarily constrained to Canada, most thunderstorms will be determined by sub-synoptic/mesoscale details dictated by/reinforced with each prior day's convection. Thus, confidence is too low in any one location on any given day to introduce unconditional severe probabilities at this time. However, some areas/scenarios of interest to monitor include the southern Great Plains on Days 4-5/Saturday-Sunday as a moist, weakly capped environment will exist in proximity to an increasing diffuse surface boundary. Other areas include the East Coast most afternoons and the along and ahead of seasonably strong cold front pushing south through the Great Plains from Days 6-8. For each of the areas of interest/scenarios of interest above, weak effective-layer shear stemming from generally weak tropospheric flow will be a limiting factor for a more organized severe potential and confidence to introduce unconditional probabilities. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0318 AM CDT Wed Jul 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... The overall large-scale pattern looks to remain characterized by mid-to-upper-level ridging across the western United States with a zonal to broadly cyclonic flow across the northern tier of the US through the forecast period. At the same time, rich/moist low-level moisture looks to remain entrenched across much of the eastern US, sustained in part by broad, southerly flow, albeit with some fluctuations in raw values. Global models continue to be bullish on a seasonably strong cold front pushing south through much of the central US late in the forecast period, ushering in a cooler/drier airmass. Strong-to-locally severe thunderstorms will be possible somewhere across the eastern CONUS every day of the forecast period. However, with synoptic-scale forcing/dynamics primarily constrained to Canada, most thunderstorms will be determined by sub-synoptic/mesoscale details dictated by/reinforced with each prior day's convection. Thus, confidence is too low in any one location on any given day to introduce unconditional severe probabilities at this time. However, some areas/scenarios of interest to monitor include the southern Great Plains on Days 4-5/Saturday-Sunday as a moist, weakly capped environment will exist in proximity to an increasing diffuse surface boundary. Other areas include the East Coast most afternoons and the along and ahead of seasonably strong cold front pushing south through the Great Plains from Days 6-8. For each of the areas of interest/scenarios of interest above, weak effective-layer shear stemming from generally weak tropospheric flow will be a limiting factor for a more organized severe potential and confidence to introduce unconditional probabilities. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Wed Jul 09 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE HIGH PLAINS OF THE SOUTHERN AND CENTRAL ROCKIES NORTHEAST TO THE UPPER GREAT LAKES AND FROM THE CAROLINAS TO CENTRAL PENNSYLVANIA... ...SUMMARY... A few strong to severe thunderstorms capable of producing large hail and damaging winds will be possible across portions of the central Great Plains. Additional strong storms capable of producing sporadic wind damage will be possible from the Carolinas to central Pennsylvania. ... Central Plains ... A low-amplitude short-wave trough across the central Great Plains will begin to phase with / be absorbed by a larger scale trough moving across the northern Great Plains. At the surface, a cold front will slowly push southeast through much of Iowa during the day. At the start of the forecast period, convection from the previous day should still be ongoing across portions of the area. The overall pattern would suggest that one or more mesoscale convective vortices (MCVs) may accompany this ongoing convection. Guidance consensus and the overall pattern would support this convection persisting through much of the day. To the south of this convection, diurnal heating of a moist airmass below steep mid-level lapse rates will result in a strongly unstable atmosphere by mid afternoon. Additional thunderstorms should develop within this strongly unstable atmosphere and be capable of producing large hail and damaging winds. At present, the combination of a weakening mid-level wind field and uncertainty associated with the location of any ongoing/persistent convection prevents the inclusion of higher probabilities with this forecast. However, locally enhanced effective-layer shear associated with any remnant MCVs should support some organization of a severe threat such that an upgrade to Level 2/Slight Risk may be warranted as the details of such features become clear. ... Carolinas to central Pennsylvania ... Diurnal heating of a moist and weakly capped boundary layer will result in afternoon thunderstorms. Precipitable water values look to be less on Friday than previous days, but still should be sufficient for widely scattered to scattered wet downbursts. Wind damage will be possible with the stronger downbursts. ... Eastern Colorado into the southern Great Plains ... Thunderstorms are expected to develop across northeast Colorado during the afternoon. Large-scale flow should result in these storms moving southeast through the evening and overnight hours as they grow upscale into a large MCS. The overall pattern would suggest the potential for at least a couple of severe wind reports associated with this southeastward moving MCS. ..Marsh.. 07/09/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Wed Jul 09 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE HIGH PLAINS OF THE SOUTHERN AND CENTRAL ROCKIES NORTHEAST TO THE UPPER GREAT LAKES AND FROM THE CAROLINAS TO CENTRAL PENNSYLVANIA... ...SUMMARY... A few strong to severe thunderstorms capable of producing large hail and damaging winds will be possible across portions of the central Great Plains. Additional strong storms capable of producing sporadic wind damage will be possible from the Carolinas to central Pennsylvania. ... Central Plains ... A low-amplitude short-wave trough across the central Great Plains will begin to phase with / be absorbed by a larger scale trough moving across the northern Great Plains. At the surface, a cold front will slowly push southeast through much of Iowa during the day. At the start of the forecast period, convection from the previous day should still be ongoing across portions of the area. The overall pattern would suggest that one or more mesoscale convective vortices (MCVs) may accompany this ongoing convection. Guidance consensus and the overall pattern would support this convection persisting through much of the day. To the south of this convection, diurnal heating of a moist airmass below steep mid-level lapse rates will result in a strongly unstable atmosphere by mid afternoon. Additional thunderstorms should develop within this strongly unstable atmosphere and be capable of producing large hail and damaging winds. At present, the combination of a weakening mid-level wind field and uncertainty associated with the location of any ongoing/persistent convection prevents the inclusion of higher probabilities with this forecast. However, locally enhanced effective-layer shear associated with any remnant MCVs should support some organization of a severe threat such that an upgrade to Level 2/Slight Risk may be warranted as the details of such features become clear. ... Carolinas to central Pennsylvania ... Diurnal heating of a moist and weakly capped boundary layer will result in afternoon thunderstorms. Precipitable water values look to be less on Friday than previous days, but still should be sufficient for widely scattered to scattered wet downbursts. Wind damage will be possible with the stronger downbursts. ... Eastern Colorado into the southern Great Plains ... Thunderstorms are expected to develop across northeast Colorado during the afternoon. Large-scale flow should result in these storms moving southeast through the evening and overnight hours as they grow upscale into a large MCS. The overall pattern would suggest the potential for at least a couple of severe wind reports associated with this southeastward moving MCS. ..Marsh.. 07/09/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Wed Jul 09 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE HIGH PLAINS OF THE SOUTHERN AND CENTRAL ROCKIES NORTHEAST TO THE UPPER GREAT LAKES AND FROM THE CAROLINAS TO CENTRAL PENNSYLVANIA... ...SUMMARY... A few strong to severe thunderstorms capable of producing large hail and damaging winds will be possible across portions of the central Great Plains. Additional strong storms capable of producing sporadic wind damage will be possible from the Carolinas to central Pennsylvania. ... Central Plains ... A low-amplitude short-wave trough across the central Great Plains will begin to phase with / be absorbed by a larger scale trough moving across the northern Great Plains. At the surface, a cold front will slowly push southeast through much of Iowa during the day. At the start of the forecast period, convection from the previous day should still be ongoing across portions of the area. The overall pattern would suggest that one or more mesoscale convective vortices (MCVs) may accompany this ongoing convection. Guidance consensus and the overall pattern would support this convection persisting through much of the day. To the south of this convection, diurnal heating of a moist airmass below steep mid-level lapse rates will result in a strongly unstable atmosphere by mid afternoon. Additional thunderstorms should develop within this strongly unstable atmosphere and be capable of producing large hail and damaging winds. At present, the combination of a weakening mid-level wind field and uncertainty associated with the location of any ongoing/persistent convection prevents the inclusion of higher probabilities with this forecast. However, locally enhanced effective-layer shear associated with any remnant MCVs should support some organization of a severe threat such that an upgrade to Level 2/Slight Risk may be warranted as the details of such features become clear. ... Carolinas to central Pennsylvania ... Diurnal heating of a moist and weakly capped boundary layer will result in afternoon thunderstorms. Precipitable water values look to be less on Friday than previous days, but still should be sufficient for widely scattered to scattered wet downbursts. Wind damage will be possible with the stronger downbursts. ... Eastern Colorado into the southern Great Plains ... Thunderstorms are expected to develop across northeast Colorado during the afternoon. Large-scale flow should result in these storms moving southeast through the evening and overnight hours as they grow upscale into a large MCS. The overall pattern would suggest the potential for at least a couple of severe wind reports associated with this southeastward moving MCS. ..Marsh.. 07/09/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Wed Jul 09 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE HIGH PLAINS OF THE SOUTHERN AND CENTRAL ROCKIES NORTHEAST TO THE UPPER GREAT LAKES AND FROM THE CAROLINAS TO CENTRAL PENNSYLVANIA... ...SUMMARY... A few strong to severe thunderstorms capable of producing large hail and damaging winds will be possible across portions of the central Great Plains. Additional strong storms capable of producing sporadic wind damage will be possible from the Carolinas to central Pennsylvania. ... Central Plains ... A low-amplitude short-wave trough across the central Great Plains will begin to phase with / be absorbed by a larger scale trough moving across the northern Great Plains. At the surface, a cold front will slowly push southeast through much of Iowa during the day. At the start of the forecast period, convection from the previous day should still be ongoing across portions of the area. The overall pattern would suggest that one or more mesoscale convective vortices (MCVs) may accompany this ongoing convection. Guidance consensus and the overall pattern would support this convection persisting through much of the day. To the south of this convection, diurnal heating of a moist airmass below steep mid-level lapse rates will result in a strongly unstable atmosphere by mid afternoon. Additional thunderstorms should develop within this strongly unstable atmosphere and be capable of producing large hail and damaging winds. At present, the combination of a weakening mid-level wind field and uncertainty associated with the location of any ongoing/persistent convection prevents the inclusion of higher probabilities with this forecast. However, locally enhanced effective-layer shear associated with any remnant MCVs should support some organization of a severe threat such that an upgrade to Level 2/Slight Risk may be warranted as the details of such features become clear. ... Carolinas to central Pennsylvania ... Diurnal heating of a moist and weakly capped boundary layer will result in afternoon thunderstorms. Precipitable water values look to be less on Friday than previous days, but still should be sufficient for widely scattered to scattered wet downbursts. Wind damage will be possible with the stronger downbursts. ... Eastern Colorado into the southern Great Plains ... Thunderstorms are expected to develop across northeast Colorado during the afternoon. Large-scale flow should result in these storms moving southeast through the evening and overnight hours as they grow upscale into a large MCS. The overall pattern would suggest the potential for at least a couple of severe wind reports associated with this southeastward moving MCS. ..Marsh.. 07/09/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...Synopsis... Along the northern periphery of a large-scale ridge over the Southwest, a midlevel shortwave trough will move eastward from the Great Basin into the central Rockies. Enhanced westerly flow aloft accompanying this feature will overspread a deeply mixed boundary layer during the afternoon. As a result, an expansive area of 15 percent RH and 15-20 mph sustained westerly surface winds will favor elevated to locally critical fire-weather conditions across the Four Corners region. ..Weinman.. 07/09/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...Synopsis... Along the northern periphery of a large-scale ridge over the Southwest, a midlevel shortwave trough will move eastward from the Great Basin into the central Rockies. Enhanced westerly flow aloft accompanying this feature will overspread a deeply mixed boundary layer during the afternoon. As a result, an expansive area of 15 percent RH and 15-20 mph sustained westerly surface winds will favor elevated to locally critical fire-weather conditions across the Four Corners region. ..Weinman.. 07/09/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...Synopsis... Along the northern periphery of a large-scale ridge over the Southwest, a midlevel shortwave trough will move eastward from the Great Basin into the central Rockies. Enhanced westerly flow aloft accompanying this feature will overspread a deeply mixed boundary layer during the afternoon. As a result, an expansive area of 15 percent RH and 15-20 mph sustained westerly surface winds will favor elevated to locally critical fire-weather conditions across the Four Corners region. ..Weinman.. 07/09/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...Synopsis... Along the northern periphery of a large-scale ridge over the Southwest, a midlevel shortwave trough will move eastward from the Great Basin into the central Rockies. Enhanced westerly flow aloft accompanying this feature will overspread a deeply mixed boundary layer during the afternoon. As a result, an expansive area of 15 percent RH and 15-20 mph sustained westerly surface winds will favor elevated to locally critical fire-weather conditions across the Four Corners region. ..Weinman.. 07/09/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Wed Jul 09 2025 Valid 091200Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL NEVADA INTO WESTERN UTAH... ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ..Weinman.. 07/09/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Wed Jul 09 2025 Valid 091200Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL NEVADA INTO WESTERN UTAH... ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ..Weinman.. 07/09/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more