Severe Storms

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 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS AS WELL AS PORTIONS OF THE SOUTHEAST... ...SUMMARY... Scattered severe thunderstorms are possible over parts of the central and northern Great Plains, mainly during the late afternoon and evening on Thursday. Additional severe thunderstorms will be possible during the afternoon across portions of the Southeast. ... Synopsis ... A complex evolution of the mid-to-upper level pattern is expected to unfold on Thursday across the central United States. A de-amplifying short-wave trough will move from northern Utah into the central Great Plains. At the same time, a larger-scale, positive-tilt trough will amplify during the period across southern Canada as it pushes east. This will result in an effective split-flow pattern across the north-central US. ... Central and Northern Great Plains ... Thunderstorms are expected at the start of the period across eastern portions of the central and northern Great Plains, driven primarily by warm, moist low-level advection. In the wake of this convection, the airmass is expected to quickly recover yielding moderate to extreme instability. By late afternoon, thunderstorms are expected to develop across the terrain of northeast Colorado and eastern Wyoming. As the aforementioned low-amplitude short-wave trough begins to eject into the central Great Plains, these thunderstorms should quickly move off the terrain and into the Plains. Damaging winds will be possible with these storms as the quickly grow upscale in response to the increasing large-scale ascent. The overall degree of instability will also support the potential for sporadic large hail. To the north across North Dakota, convective evolution is more uncertain. The atmosphere will be extremely unstable in the presence of a surface boundary and approaching large-scale ascent. Despite the absence of a more robust signal in the convective allowing guidance for afternoon convection, coarser-scale guidance suggests at least scattered thunderstorm development will occur during the evening and overnight hours. These thunderstorms will be capable of damaging thunderstorm winds with at least some potential for large hail. ... Portions of the Southeast ... Thunderstorms will once again develop within a warm, moist, and weakly capped environment. High precipitable water value (locally in excess of 2 inches) will support water loaded downdrafts giving way to wet downbursts capable of wind damage. A Level 2/Slight Risk was added to highlight the area of highest coverage of potential wet downbursts. ... Portions of the Northeast ... Diurnal heating of a moist boundary layer will result in scattered thunderstorm development across the region. Most-unstable CAPE values greater than 1000 J/kg and modest effective-layer shear should support the potential for scattered wind damage. Should coverage of thunderstorms be greater than currently anticipated an upgrade to Level 2/Slight Risk may be warranted in subsequent forecasts. ..Marsh.. 07/09/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS AS WELL AS PORTIONS OF THE SOUTHEAST... ...SUMMARY... Scattered severe thunderstorms are possible over parts of the central and northern Great Plains, mainly during the late afternoon and evening on Thursday. Additional severe thunderstorms will be possible during the afternoon across portions of the Southeast. ... Synopsis ... A complex evolution of the mid-to-upper level pattern is expected to unfold on Thursday across the central United States. A de-amplifying short-wave trough will move from northern Utah into the central Great Plains. At the same time, a larger-scale, positive-tilt trough will amplify during the period across southern Canada as it pushes east. This will result in an effective split-flow pattern across the north-central US. ... Central and Northern Great Plains ... Thunderstorms are expected at the start of the period across eastern portions of the central and northern Great Plains, driven primarily by warm, moist low-level advection. In the wake of this convection, the airmass is expected to quickly recover yielding moderate to extreme instability. By late afternoon, thunderstorms are expected to develop across the terrain of northeast Colorado and eastern Wyoming. As the aforementioned low-amplitude short-wave trough begins to eject into the central Great Plains, these thunderstorms should quickly move off the terrain and into the Plains. Damaging winds will be possible with these storms as the quickly grow upscale in response to the increasing large-scale ascent. The overall degree of instability will also support the potential for sporadic large hail. To the north across North Dakota, convective evolution is more uncertain. The atmosphere will be extremely unstable in the presence of a surface boundary and approaching large-scale ascent. Despite the absence of a more robust signal in the convective allowing guidance for afternoon convection, coarser-scale guidance suggests at least scattered thunderstorm development will occur during the evening and overnight hours. These thunderstorms will be capable of damaging thunderstorm winds with at least some potential for large hail. ... Portions of the Southeast ... Thunderstorms will once again develop within a warm, moist, and weakly capped environment. High precipitable water value (locally in excess of 2 inches) will support water loaded downdrafts giving way to wet downbursts capable of wind damage. A Level 2/Slight Risk was added to highlight the area of highest coverage of potential wet downbursts. ... Portions of the Northeast ... Diurnal heating of a moist boundary layer will result in scattered thunderstorm development across the region. Most-unstable CAPE values greater than 1000 J/kg and modest effective-layer shear should support the potential for scattered wind damage. Should coverage of thunderstorms be greater than currently anticipated an upgrade to Level 2/Slight Risk may be warranted in subsequent forecasts. ..Marsh.. 07/09/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS AS WELL AS PORTIONS OF THE SOUTHEAST... ...SUMMARY... Scattered severe thunderstorms are possible over parts of the central and northern Great Plains, mainly during the late afternoon and evening on Thursday. Additional severe thunderstorms will be possible during the afternoon across portions of the Southeast. ... Synopsis ... A complex evolution of the mid-to-upper level pattern is expected to unfold on Thursday across the central United States. A de-amplifying short-wave trough will move from northern Utah into the central Great Plains. At the same time, a larger-scale, positive-tilt trough will amplify during the period across southern Canada as it pushes east. This will result in an effective split-flow pattern across the north-central US. ... Central and Northern Great Plains ... Thunderstorms are expected at the start of the period across eastern portions of the central and northern Great Plains, driven primarily by warm, moist low-level advection. In the wake of this convection, the airmass is expected to quickly recover yielding moderate to extreme instability. By late afternoon, thunderstorms are expected to develop across the terrain of northeast Colorado and eastern Wyoming. As the aforementioned low-amplitude short-wave trough begins to eject into the central Great Plains, these thunderstorms should quickly move off the terrain and into the Plains. Damaging winds will be possible with these storms as the quickly grow upscale in response to the increasing large-scale ascent. The overall degree of instability will also support the potential for sporadic large hail. To the north across North Dakota, convective evolution is more uncertain. The atmosphere will be extremely unstable in the presence of a surface boundary and approaching large-scale ascent. Despite the absence of a more robust signal in the convective allowing guidance for afternoon convection, coarser-scale guidance suggests at least scattered thunderstorm development will occur during the evening and overnight hours. These thunderstorms will be capable of damaging thunderstorm winds with at least some potential for large hail. ... Portions of the Southeast ... Thunderstorms will once again develop within a warm, moist, and weakly capped environment. High precipitable water value (locally in excess of 2 inches) will support water loaded downdrafts giving way to wet downbursts capable of wind damage. A Level 2/Slight Risk was added to highlight the area of highest coverage of potential wet downbursts. ... Portions of the Northeast ... Diurnal heating of a moist boundary layer will result in scattered thunderstorm development across the region. Most-unstable CAPE values greater than 1000 J/kg and modest effective-layer shear should support the potential for scattered wind damage. Should coverage of thunderstorms be greater than currently anticipated an upgrade to Level 2/Slight Risk may be warranted in subsequent forecasts. ..Marsh.. 07/09/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Wed Jul 09 2025 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS AS WELL AS PORTIONS OF THE SOUTHEAST... ...SUMMARY... Scattered severe thunderstorms are possible over parts of the central and northern Great Plains, mainly during the late afternoon and evening on Thursday. Additional severe thunderstorms will be possible during the afternoon across portions of the Southeast. ... Synopsis ... A complex evolution of the mid-to-upper level pattern is expected to unfold on Thursday across the central United States. A de-amplifying short-wave trough will move from northern Utah into the central Great Plains. At the same time, a larger-scale, positive-tilt trough will amplify during the period across southern Canada as it pushes east. This will result in an effective split-flow pattern across the north-central US. ... Central and Northern Great Plains ... Thunderstorms are expected at the start of the period across eastern portions of the central and northern Great Plains, driven primarily by warm, moist low-level advection. In the wake of this convection, the airmass is expected to quickly recover yielding moderate to extreme instability. By late afternoon, thunderstorms are expected to develop across the terrain of northeast Colorado and eastern Wyoming. As the aforementioned low-amplitude short-wave trough begins to eject into the central Great Plains, these thunderstorms should quickly move off the terrain and into the Plains. Damaging winds will be possible with these storms as the quickly grow upscale in response to the increasing large-scale ascent. The overall degree of instability will also support the potential for sporadic large hail. To the north across North Dakota, convective evolution is more uncertain. The atmosphere will be extremely unstable in the presence of a surface boundary and approaching large-scale ascent. Despite the absence of a more robust signal in the convective allowing guidance for afternoon convection, coarser-scale guidance suggests at least scattered thunderstorm development will occur during the evening and overnight hours. These thunderstorms will be capable of damaging thunderstorm winds with at least some potential for large hail. ... Portions of the Southeast ... Thunderstorms will once again develop within a warm, moist, and weakly capped environment. High precipitable water value (locally in excess of 2 inches) will support water loaded downdrafts giving way to wet downbursts capable of wind damage. A Level 2/Slight Risk was added to highlight the area of highest coverage of potential wet downbursts. ... Portions of the Northeast ... Diurnal heating of a moist boundary layer will result in scattered thunderstorm development across the region. Most-unstable CAPE values greater than 1000 J/kg and modest effective-layer shear should support the potential for scattered wind damage. Should coverage of thunderstorms be greater than currently anticipated an upgrade to Level 2/Slight Risk may be warranted in subsequent forecasts. ..Marsh.. 07/09/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Jul 09 2025 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS INTO THE MID-ATLANTIC...AND PORTIONS OF THE 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 gusts are also possible across parts of the northern/central Plains beginning late this afternoon and continuing into the evening. ...Southeast into the Mid-Atlantic... A weak mid-level trough will move slowly eastward today across the Great Lakes/OH 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. The presence of rich low-level moisture will compensate for poor lapse rates aloft to support MLCAPE generally around 1500-3000 J/kg across lower elevations. A few loosely organized clusters may eventually develop from parts of VA 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. Generally minor adjustments have been made to the ongoing Marginal/Slight Risk areas to account for latest guidance trends. ...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. Ample low-level moisture ahead of this trough will gradually build beneath a stout EML. A corridor of strong to very strong instability will likely exist by late afternoon/early evening from parts of western/central ND into NE, aided by daytime heating and steep lapse rates aloft. 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 perhaps parts of NE, with a risk for scattered severe gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. While confidence is somewhat lower regarding convective coverage with southward extent across the central Plains (into KS and vicinity), a conditionally favorable environment for at least isolated severe convection will be in place. Have therefore expanded the Marginal Risk southward to account for this potential. ...Interior Northwest/Northern Rockies... Downstream of a shortwave trough moving eastward across northern CA into the northwest 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 gusts from parts of eastern OR into MT. ...Lower Michigan into Northwest Ohio... Isolated/marginally severe hail and locally damaging winds appear possible this afternoon across parts of Lower Michigan and northwest OH as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Gleason/Weinman.. 07/09/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Jul 09 2025 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS INTO THE MID-ATLANTIC...AND PORTIONS OF THE 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 gusts are also possible across parts of the northern/central Plains beginning late this afternoon and continuing into the evening. ...Southeast into the Mid-Atlantic... A weak mid-level trough will move slowly eastward today across the Great Lakes/OH 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. The presence of rich low-level moisture will compensate for poor lapse rates aloft to support MLCAPE generally around 1500-3000 J/kg across lower elevations. A few loosely organized clusters may eventually develop from parts of VA 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. Generally minor adjustments have been made to the ongoing Marginal/Slight Risk areas to account for latest guidance trends. ...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. Ample low-level moisture ahead of this trough will gradually build beneath a stout EML. A corridor of strong to very strong instability will likely exist by late afternoon/early evening from parts of western/central ND into NE, aided by daytime heating and steep lapse rates aloft. 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 perhaps parts of NE, with a risk for scattered severe gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. While confidence is somewhat lower regarding convective coverage with southward extent across the central Plains (into KS and vicinity), a conditionally favorable environment for at least isolated severe convection will be in place. Have therefore expanded the Marginal Risk southward to account for this potential. ...Interior Northwest/Northern Rockies... Downstream of a shortwave trough moving eastward across northern CA into the northwest 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 gusts from parts of eastern OR into MT. ...Lower Michigan into Northwest Ohio... Isolated/marginally severe hail and locally damaging winds appear possible this afternoon across parts of Lower Michigan and northwest OH as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Gleason/Weinman.. 07/09/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Jul 09 2025 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS INTO THE MID-ATLANTIC...AND PORTIONS OF THE 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 gusts are also possible across parts of the northern/central Plains beginning late this afternoon and continuing into the evening. ...Southeast into the Mid-Atlantic... A weak mid-level trough will move slowly eastward today across the Great Lakes/OH 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. The presence of rich low-level moisture will compensate for poor lapse rates aloft to support MLCAPE generally around 1500-3000 J/kg across lower elevations. A few loosely organized clusters may eventually develop from parts of VA 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. Generally minor adjustments have been made to the ongoing Marginal/Slight Risk areas to account for latest guidance trends. ...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. Ample low-level moisture ahead of this trough will gradually build beneath a stout EML. A corridor of strong to very strong instability will likely exist by late afternoon/early evening from parts of western/central ND into NE, aided by daytime heating and steep lapse rates aloft. 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 perhaps parts of NE, with a risk for scattered severe gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. While confidence is somewhat lower regarding convective coverage with southward extent across the central Plains (into KS and vicinity), a conditionally favorable environment for at least isolated severe convection will be in place. Have therefore expanded the Marginal Risk southward to account for this potential. ...Interior Northwest/Northern Rockies... Downstream of a shortwave trough moving eastward across northern CA into the northwest 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 gusts from parts of eastern OR into MT. ...Lower Michigan into Northwest Ohio... Isolated/marginally severe hail and locally damaging winds appear possible this afternoon across parts of Lower Michigan and northwest OH as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Gleason/Weinman.. 07/09/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Jul 09 2025 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS INTO THE MID-ATLANTIC...AND PORTIONS OF THE 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 gusts are also possible across parts of the northern/central Plains beginning late this afternoon and continuing into the evening. ...Southeast into the Mid-Atlantic... A weak mid-level trough will move slowly eastward today across the Great Lakes/OH 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. The presence of rich low-level moisture will compensate for poor lapse rates aloft to support MLCAPE generally around 1500-3000 J/kg across lower elevations. A few loosely organized clusters may eventually develop from parts of VA 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. Generally minor adjustments have been made to the ongoing Marginal/Slight Risk areas to account for latest guidance trends. ...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. Ample low-level moisture ahead of this trough will gradually build beneath a stout EML. A corridor of strong to very strong instability will likely exist by late afternoon/early evening from parts of western/central ND into NE, aided by daytime heating and steep lapse rates aloft. 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 perhaps parts of NE, with a risk for scattered severe gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. While confidence is somewhat lower regarding convective coverage with southward extent across the central Plains (into KS and vicinity), a conditionally favorable environment for at least isolated severe convection will be in place. Have therefore expanded the Marginal Risk southward to account for this potential. ...Interior Northwest/Northern Rockies... Downstream of a shortwave trough moving eastward across northern CA into the northwest 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 gusts from parts of eastern OR into MT. ...Lower Michigan into Northwest Ohio... Isolated/marginally severe hail and locally damaging winds appear possible this afternoon across parts of Lower Michigan and northwest OH as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Gleason/Weinman.. 07/09/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Jul 09 2025 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS INTO THE MID-ATLANTIC...AND PORTIONS OF THE 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 gusts are also possible across parts of the northern/central Plains beginning late this afternoon and continuing into the evening. ...Southeast into the Mid-Atlantic... A weak mid-level trough will move slowly eastward today across the Great Lakes/OH 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. The presence of rich low-level moisture will compensate for poor lapse rates aloft to support MLCAPE generally around 1500-3000 J/kg across lower elevations. A few loosely organized clusters may eventually develop from parts of VA 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. Generally minor adjustments have been made to the ongoing Marginal/Slight Risk areas to account for latest guidance trends. ...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. Ample low-level moisture ahead of this trough will gradually build beneath a stout EML. A corridor of strong to very strong instability will likely exist by late afternoon/early evening from parts of western/central ND into NE, aided by daytime heating and steep lapse rates aloft. 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 perhaps parts of NE, with a risk for scattered severe gusts, some of which could be 75+ mph on an isolated basis given the rather favorable thermodynamic environment forecast. While confidence is somewhat lower regarding convective coverage with southward extent across the central Plains (into KS and vicinity), a conditionally favorable environment for at least isolated severe convection will be in place. Have therefore expanded the Marginal Risk southward to account for this potential. ...Interior Northwest/Northern Rockies... Downstream of a shortwave trough moving eastward across northern CA into the northwest 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 gusts from parts of eastern OR into MT. ...Lower Michigan into Northwest Ohio... Isolated/marginally severe hail and locally damaging winds appear possible this afternoon across parts of Lower Michigan and northwest OH as scattered thunderstorms develop beneath a weak upper trough, supported by a modest combination of instability and deep-layer shear. ..Gleason/Weinman.. 07/09/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 PM CDT Tue Jul 08 2025 Valid 090100Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID-ATLANTIC/SOUTHERN NEW ENGLAND AND THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms should continue this evening across parts of the central/southern Plains and Mid-Atlantic into southern New England. ...Mid-Atlantic/Southern New England... Bands of loosely organized convection will continue to spread eastward across the DelMarVa Peninsula and southeast VA/northeast NC vicinity over the next couple of hours this evening. A sufficiently moist and unstable airmass should support occasional severe/damaging winds with this activity until it moves offshore or eventually weakens with the loss of daytime heating. ...Central/Southern Plains... Widely spaced strong to severe thunderstorms are present this evening across the central/southern Plains, generally along/south of a convectively reinforced boundary extending across KS into the Ozarks. Large-scale forcing across these regions will tend to remain weak on the northeast periphery of the upper ridge centered over the Southwest. But, multiple low-amplitude mid-level perturbations should aid in thunderstorm maintenance for several more hours this evening given the presence of moderate to strong instability and marginally sufficient deep-layer shear for updraft organization. Isolated severe winds and hail may occur with loosely organized multicells and occasional supercells. But, the overall severe threat still appears too unfocused/widely spaced to include greater severe probabilities. ..Gleason.. 07/09/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 PM CDT Tue Jul 08 2025 Valid 090100Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID-ATLANTIC/SOUTHERN NEW ENGLAND AND THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms should continue this evening across parts of the central/southern Plains and Mid-Atlantic into southern New England. ...Mid-Atlantic/Southern New England... Bands of loosely organized convection will continue to spread eastward across the DelMarVa Peninsula and southeast VA/northeast NC vicinity over the next couple of hours this evening. A sufficiently moist and unstable airmass should support occasional severe/damaging winds with this activity until it moves offshore or eventually weakens with the loss of daytime heating. ...Central/Southern Plains... Widely spaced strong to severe thunderstorms are present this evening across the central/southern Plains, generally along/south of a convectively reinforced boundary extending across KS into the Ozarks. Large-scale forcing across these regions will tend to remain weak on the northeast periphery of the upper ridge centered over the Southwest. But, multiple low-amplitude mid-level perturbations should aid in thunderstorm maintenance for several more hours this evening given the presence of moderate to strong instability and marginally sufficient deep-layer shear for updraft organization. Isolated severe winds and hail may occur with loosely organized multicells and occasional supercells. But, the overall severe threat still appears too unfocused/widely spaced to include greater severe probabilities. ..Gleason.. 07/09/2025 Read more

MD 1610 CONCERNING SEVERE THUNDERSTORM WATCH 496... FOR MIDDLE ATLANTIC
Mesoscale Discussion 1610 NWS Storm Prediction Center Norman OK 0546 PM CDT Tue Jul 08 2025 Areas affected...Middle Atlantic Concerning...Severe Thunderstorm Watch 496... Valid 082246Z - 090045Z The severe weather threat for Severe Thunderstorm Watch 496 continues. SUMMARY...Scattered strong-severe thunderstorms will spread across eastern and southern portions of ww496 over the next several hours. Damaging winds are the primary concern. DISCUSSION...Loosely organized band of strong-severe thunderstorms is spreading across the Middle Atlantic early this evening. This activity is propagating across an instability axis characterized by MLCAPE on the order of 2000 J/kg. Surface temperatures are holding near 90F along the coast and modest westerly flow should encourage a robust squall line to spread offshore over the next several hours. Damaging winds can be expected with this convection. ..Darrow.. 07/08/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...BGM...AKQ...CTP...LWX...RNK... LAT...LON 37007963 41137559 41137271 36997691 37007963 MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

MD 1609 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF THE CENTRAL HIGH PLAINS
Mesoscale Discussion 1609 NWS Storm Prediction Center Norman OK 0529 PM CDT Tue Jul 08 2025 Areas affected...Parts of the central High Plains Concerning...Severe potential...Watch unlikely Valid 082229Z - 090030Z Probability of Watch Issuance...20 percent SUMMARY...Isolated large hail and severe gusts will be possible with the stronger storms that evolve into this evening. DISCUSSION...Isolated high-based thunderstorms are developing along the central High Plains this afternoon, where diurnal heating has eroded antecedent low-level inhibition. As storms track slowly east-southeastward into increasing boundary-layer moisture and buoyancy, steep lapse rates and elongated/straight hodographs (around 40 kt of effective shear) will support transient supercell structures and small organized clusters. Isolated large hail and severe gusts will be possible with any longer-lived storms that evolve into this evening, though weak large-scale forcing for ascent may limit overall storm longevity and coverage. ..Weinman/Hart.. 07/08/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 39540332 39940351 40460383 40930387 41810376 42300370 42590346 42690322 42630256 42430215 41750189 41190176 40330134 39730091 39000084 38680116 38580194 38720257 39030300 39540332 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

MD 1611 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN KANSAS...NORTHERN OKLAHOMA AND FAR SOUTHWEST MISSOURI
Mesoscale Discussion 1611 NWS Storm Prediction Center Norman OK 0558 PM CDT Tue Jul 08 2025 Areas affected...Southern Kansas...northern Oklahoma and far southwest Missouri Concerning...Severe potential...Watch unlikely Valid 082258Z - 090030Z Probability of Watch Issuance...20 percent SUMMARY...Isolated instances of large hail and severe wind gusts will remain possible for the next couple hours. DISCUSSION...Widely scattered thunderstorms have been intensifying along an east-west corridor in southern KS this afternoon, where a warm/moist boundary layer and steep deep-layer lapse rates are in place. While low-level flow is weak, around 25-30 kt of midlevel northerly winds (per ICT VWP) are supporting transient updraft organization. The environment will continue to support severe downbursts and isolated large hail with the stronger storms for the next couple hours, though the risk is expected to remain too sporadic for a watch. ..Weinman/Hart.. 07/08/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...TOP...ICT...OUN...DDC...AMA... LAT...LON 37929419 37679368 37179365 36799388 36579518 36849997 37090054 37380082 37970099 38240075 38410022 38429913 38109675 37929419 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

WW 0496 Status Updates
340- STATUS REPORT ON WW 496 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 N CHO TO 5 SSE DCA TO 20 NNW ILG TO 35 NNW EWR. ..SPC..07/08/25 ATTN...WFO...OKX...LWX...PHI...AKQ...CTP...RNK... STATUS REPORT FOR WS 496 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC001-082340- CT . CONNECTICUT COUNTIES INCLUDED ARE FAIRFIELD DEC001-003-005-082340- DE . DELAWARE COUNTIES INCLUDED ARE KENT NEW CASTLE SUSSEX MDC003-009-011-015-017-019-029-033-035-037-039-041-045-047-510- 082340- MD . MARYLAND COUNTIES INCLUDED ARE ANNE ARUNDEL CALVERT CAROLINE CECIL CHARLES DORCHESTER Read more

WW 496 SEVERE TSTM CT DC DE MD NJ NY PA VA CW 081740Z - 090100Z
CWZ000-090100- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 496 NWS Storm Prediction Center Norman OK 140 PM EDT Tue Jul 8 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Connecticut District Of Columbia Delaware Maryland New Jersey Far southeast New York Eastern Pennsylvania Central and eastern Virginia Coastal Waters * Effective this Tuesday afternoon and evening from 140 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely SUMMARY...Scattered thunderstorms are expected to develop and spread eastward through the afternoon and evening. The storm environment will favor a mix of small clusters and line segments capable of producing damaging winds of 60-70 mph. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 55 miles east southeast of Lynchburg VA to 30 miles north of Newark NJ. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26020. ...Thompson Read more

MD 1611 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN KANSAS...NORTHERN OKLAHOMA AND FAR SOUTHWEST MISSOURI
Mesoscale Discussion 1611 NWS Storm Prediction Center Norman OK 0558 PM CDT Tue Jul 08 2025 Areas affected...Southern Kansas...northern Oklahoma and far southwest Missouri Concerning...Severe potential...Watch unlikely Valid 082258Z - 090030Z Probability of Watch Issuance...20 percent SUMMARY...Isolated instances of large hail and severe wind gusts will remain possible for the next couple hours. DISCUSSION...Widely scattered thunderstorms have been intensifying along an east-west corridor in southern KS this afternoon, where a warm/moist boundary layer and steep deep-layer lapse rates are in place. While low-level flow is weak, around 25-30 kt of midlevel northerly winds (per ICT VWP) are supporting transient updraft organization. The environment will continue to support severe downbursts and isolated large hail with the stronger storms for the next couple hours, though the risk is expected to remain too sporadic for a watch. ..Weinman/Hart.. 07/08/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...TOP...ICT...OUN...DDC...AMA... LAT...LON 37929419 37679368 37179365 36799388 36579518 36849997 37090054 37380082 37970099 38240075 38410022 38429913 38109675 37929419 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

MD 1610 CONCERNING SEVERE THUNDERSTORM WATCH 496... FOR MIDDLE ATLANTIC
Mesoscale Discussion 1610 NWS Storm Prediction Center Norman OK 0546 PM CDT Tue Jul 08 2025 Areas affected...Middle Atlantic Concerning...Severe Thunderstorm Watch 496... Valid 082246Z - 090045Z The severe weather threat for Severe Thunderstorm Watch 496 continues. SUMMARY...Scattered strong-severe thunderstorms will spread across eastern and southern portions of ww496 over the next several hours. Damaging winds are the primary concern. DISCUSSION...Loosely organized band of strong-severe thunderstorms is spreading across the Middle Atlantic early this evening. This activity is propagating across an instability axis characterized by MLCAPE on the order of 2000 J/kg. Surface temperatures are holding near 90F along the coast and modest westerly flow should encourage a robust squall line to spread offshore over the next several hours. Damaging winds can be expected with this convection. ..Darrow.. 07/08/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...BGM...AKQ...CTP...LWX...RNK... LAT...LON 37007963 41137559 41137271 36997691 37007963 MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

MD 1609 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF THE CENTRAL HIGH PLAINS
Mesoscale Discussion 1609 NWS Storm Prediction Center Norman OK 0529 PM CDT Tue Jul 08 2025 Areas affected...Parts of the central High Plains Concerning...Severe potential...Watch unlikely Valid 082229Z - 090030Z Probability of Watch Issuance...20 percent SUMMARY...Isolated large hail and severe gusts will be possible with the stronger storms that evolve into this evening. DISCUSSION...Isolated high-based thunderstorms are developing along the central High Plains this afternoon, where diurnal heating has eroded antecedent low-level inhibition. As storms track slowly east-southeastward into increasing boundary-layer moisture and buoyancy, steep lapse rates and elongated/straight hodographs (around 40 kt of effective shear) will support transient supercell structures and small organized clusters. Isolated large hail and severe gusts will be possible with any longer-lived storms that evolve into this evening, though weak large-scale forcing for ascent may limit overall storm longevity and coverage. ..Weinman/Hart.. 07/08/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 39540332 39940351 40460383 40930387 41810376 42300370 42590346 42690322 42630256 42430215 41750189 41190176 40330134 39730091 39000084 38680116 38580194 38720257 39030300 39540332 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more