SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Tue May 13 2025 Valid 132000Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH CAROLINA INTO THE SOUTHERN MID-ATLANTIC...CENTRAL GULF COAST STATES...AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Marginally severe thunderstorms will be possible from this afternoon into tonight across parts of North Carolina, the Mid-Atlantic, central Gulf Coast states, and northern High Plains. ...DISCUSSION... No change is made to the outlook for this issuance. ..Broyles.. 05/13/2025 .PREV DISCUSSION... /ISSUED 1122 AM CDT Tue May 13 2025/ ...North Carolina into the Southern Mid-Atlantic... A closed mid/upper-level low will continue to slowly meander from the TN Valley towards the central Appalachians through the period. An embedded mid-level shortwave trough will rotate northward across the Carolinas into the southern Mid-Atlantic by this evening. Stronger low/mid-level flow will tend to remain across the eastern Carolinas into southern VA today, with generally weaker winds aloft in closer proximity to the mid/upper low. A moist low-level airmass will remain in place over much of the Carolinas, central Appalachians, and southern Mid-Atlantic. But, poor mid-level lapse rates will tend to limit any more than weak instability from developing through this afternoon. Deep-layer shear away from the coast will also tend to remain muted, which should keep overall thunderstorm organization modest. Even with these forecast thermodynamic and kinematic limitations, some organization may occur with thunderstorms that develop and spread northward this afternoon. Isolated damaging winds appear to be the main threat with any loosely organized clusters that can form, but marginally severe hail could also occur with the strongest cores. A tornado or two also appears possible along a pseudo-warm front across northeast NC into southeast VA and vicinity, where low-level flow and shear are forecast to be modestly enhanced compared to locations farther west. ...Mississippi/Alabama... Morning showers and related cloudiness will temper diurnal destabilization to some extent across northern MS/AL this afternoon. But, renewed thunderstorm development still appears possible later today across this region, on the southern fringe of the slowly moving mid/upper low. Weak low-level westerly winds are expected to veer to northwesterly and gradually strengthen with height though mid levels. Related 30-40 kt of deep-layer shear will conditionally support organized updrafts, including the potential for a supercell with an associated hail/wind threat. The overall severe risk should remain quite isolated, which warrants maintaining the Marginal Risk with this update. ...Northern Plains... An amplified mid/upper-level trough will move eastward over the western states through tonight. A surface cold front is forecast to decelerate and eventually stall over parts of the Dakotas by this evening. Stronger mid/upper-level flow is expected to remain displaced to the west of this surface boundary. Even so, there are some indications in guidance that elevated thunderstorms posing a threat for isolated hail may impact parts of the northern Plains this evening into tonight. Weak instability should tend to limit the overall severe threat. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0236 PM CDT Tue May 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST... Minor adjustments were made to bring the Elevated area further north into northwestern New Mexico and far eastern Arizona to account for latest trends in ensemble guidance. Otherwise, the outlook remains on track. See previous discussion below for more information. ..Thornton.. 05/13/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Tue May 13 2025/ ...Synopsis... The upper trough over the western US will continue to intensify as it emerges over the Rockies and onto the Plains Wednesday. Strong mid-level flow will strengthen a lee cyclone with a trailing cold front and dryline across the Great Plains. Dry westerly flow is likely over the Southwest where critical fire-weather conditions are expected. A more conditional threat for locally elevated fire-weather conditions exist over the Plains and Midwest ahead of the cold front. ...Southwest... As the main upper trough begins to move eastward over the Plains, the fire weather threat will persist for portions of Southwest. Moderate mid-level flow at the base of the upper-trough will support westerly downslope winds to 20-25 mph across southern New Mexico and eastern AZ Wednesday afternoon and evening. Amidst a very dry surface pattern with little recent rainfall and abnormally warm temperatures, RH values below 15% are likely. With sufficient fuels in place, and expanding in coverage from recent drying, widespread critical fire-weather conditions are likely Wednesday. ...Central plains and upper Midwest... As the upper trough moves eastward, a lee trough/dryline will gradually sharpen across the central CONUS. To the west, dry downslope flow is possible over parts of the central/northern Plains into the Upper Midwest. With RH minimums below 30% and wind gusting to 20 mph, some elevated fire-weather threat may be possible across parts of CO/KS and NE into the Dakotas. However, the strongest meteorological conditions are not expected to overlap with areas of supportive fuels given rainfall over the past week. Increasing surface moisture and some precipitation potential with the advancing cold front may further limit any appreciable overlap. This will favor a more localized threat with only isolated elevated fire-weather conditions expected. ...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 0236 PM CDT Tue May 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST... Minor adjustments were made to bring the Elevated area further north into northwestern New Mexico and far eastern Arizona to account for latest trends in ensemble guidance. Otherwise, the outlook remains on track. See previous discussion below for more information. ..Thornton.. 05/13/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Tue May 13 2025/ ...Synopsis... The upper trough over the western US will continue to intensify as it emerges over the Rockies and onto the Plains Wednesday. Strong mid-level flow will strengthen a lee cyclone with a trailing cold front and dryline across the Great Plains. Dry westerly flow is likely over the Southwest where critical fire-weather conditions are expected. A more conditional threat for locally elevated fire-weather conditions exist over the Plains and Midwest ahead of the cold front. ...Southwest... As the main upper trough begins to move eastward over the Plains, the fire weather threat will persist for portions of Southwest. Moderate mid-level flow at the base of the upper-trough will support westerly downslope winds to 20-25 mph across southern New Mexico and eastern AZ Wednesday afternoon and evening. Amidst a very dry surface pattern with little recent rainfall and abnormally warm temperatures, RH values below 15% are likely. With sufficient fuels in place, and expanding in coverage from recent drying, widespread critical fire-weather conditions are likely Wednesday. ...Central plains and upper Midwest... As the upper trough moves eastward, a lee trough/dryline will gradually sharpen across the central CONUS. To the west, dry downslope flow is possible over parts of the central/northern Plains into the Upper Midwest. With RH minimums below 30% and wind gusting to 20 mph, some elevated fire-weather threat may be possible across parts of CO/KS and NE into the Dakotas. However, the strongest meteorological conditions are not expected to overlap with areas of supportive fuels given rainfall over the past week. Increasing surface moisture and some precipitation potential with the advancing cold front may further limit any appreciable overlap. This will favor a more localized threat with only isolated elevated fire-weather conditions expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF WISCONSIN... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the western Great Lakes states and into parts of the Midwest Thursday afternoon and evening. Very large hail and a few tornadoes may occur. A more isolated/conditional severe threat will extend southwestward from western Kentucky into Arkansas late. ...Synopsis... An upper low will deepen over the northern Plains as a midlevel wave ejects northeastward toward the upper MS Valley. A surface low will also deepen over ND/MN, with occlusion. Extending southeast from the low will be a warm front, which will rapidly jump into northern MN and WI by late afternoon, and through much of Lower MI during the evening. Southeast winds near this boundary will bring mid to perhaps upper 60s F dewpoints northwestward, resulting in areas of strong instability. Given the fast motion of the shortwave trough and strongly veering winds in the low-levels, the primary severe risk area may be relatively narrow. The main front/dryline will stall near the OH River or Mid MS Valley and southwestward toward the Ozarks. This corridor, primarily later in the evening, will likely foster isolated severe storms as well. Elsewhere, a lingering upper trough will exit the Northeast, and warm advection on the backside of this feature may support isolated strong to severe storms from parts of PA into the Mid Atlantic during the day. ...Upper MS Valley/Great Lakes/Midwest... Models are in good agreement depicting a strong convective signal near the MN/WI border by 20Z or so, with increasing coverage points east through evening. Forecast soundings across WI and vicinity depict steep lapse rates aloft and hodographs favoring supercells. A strong tornado cannot be ruled out given the very favorable thermodynamics, including a slight capping inversion atop the moist boundary layer in combination with 200-300 m2/s2 ESRH. Southeast of the Enhanced Risk area into IL and IN, storm coverage looks to be more isolated. However, any supercells in this area will have the same significant hail and tornado potential as points north. This activity would likely wait until late in the day/after 21Z and closer to 00Z when heating is maximized to break the cap. Nocturnal severe storms will also be likely across much of Lower MI, northern IN and OH as activity moves in from the west. Supercells producing large hail again appear likely. ...OH Valley into AR Late... The aforementioned stalled boundary will be situated beneath persistent southwest flow at 850 mb Thursday evening and overnight. Robust moisture/high theta-e will be in place from eastern OK into the OH Valley, and scattered storms are likely to develop overnight. This area is a bit more conditional in terms of coverage of severe, but clearly large hail will be possible. A brief tornado may occur as well although hodographs will be primarily straight by this time. ..Jewell.. 05/13/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF WISCONSIN... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the western Great Lakes states and into parts of the Midwest Thursday afternoon and evening. Very large hail and a few tornadoes may occur. A more isolated/conditional severe threat will extend southwestward from western Kentucky into Arkansas late. ...Synopsis... An upper low will deepen over the northern Plains as a midlevel wave ejects northeastward toward the upper MS Valley. A surface low will also deepen over ND/MN, with occlusion. Extending southeast from the low will be a warm front, which will rapidly jump into northern MN and WI by late afternoon, and through much of Lower MI during the evening. Southeast winds near this boundary will bring mid to perhaps upper 60s F dewpoints northwestward, resulting in areas of strong instability. Given the fast motion of the shortwave trough and strongly veering winds in the low-levels, the primary severe risk area may be relatively narrow. The main front/dryline will stall near the OH River or Mid MS Valley and southwestward toward the Ozarks. This corridor, primarily later in the evening, will likely foster isolated severe storms as well. Elsewhere, a lingering upper trough will exit the Northeast, and warm advection on the backside of this feature may support isolated strong to severe storms from parts of PA into the Mid Atlantic during the day. ...Upper MS Valley/Great Lakes/Midwest... Models are in good agreement depicting a strong convective signal near the MN/WI border by 20Z or so, with increasing coverage points east through evening. Forecast soundings across WI and vicinity depict steep lapse rates aloft and hodographs favoring supercells. A strong tornado cannot be ruled out given the very favorable thermodynamics, including a slight capping inversion atop the moist boundary layer in combination with 200-300 m2/s2 ESRH. Southeast of the Enhanced Risk area into IL and IN, storm coverage looks to be more isolated. However, any supercells in this area will have the same significant hail and tornado potential as points north. This activity would likely wait until late in the day/after 21Z and closer to 00Z when heating is maximized to break the cap. Nocturnal severe storms will also be likely across much of Lower MI, northern IN and OH as activity moves in from the west. Supercells producing large hail again appear likely. ...OH Valley into AR Late... The aforementioned stalled boundary will be situated beneath persistent southwest flow at 850 mb Thursday evening and overnight. Robust moisture/high theta-e will be in place from eastern OK into the OH Valley, and scattered storms are likely to develop overnight. This area is a bit more conditional in terms of coverage of severe, but clearly large hail will be possible. A brief tornado may occur as well although hodographs will be primarily straight by this time. ..Jewell.. 05/13/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1216 PM CDT Tue May 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS...NEBRASKA...AND WESTERN IOWA AND SOUTHWEST MINNESOTA... ...SUMMARY... Scattered strong to severe thunderstorms are possible mainly over parts of the Dakotas and Nebraska Wednesday afternoon and evening, and perhaps into far western Iowa and southwest Minnesota overnight. A few strong gusts may occur over parts of the Southeast and Mid-Atlantic Wednesday afternoon. ...Synopsis... A potent upper speed max will move from the Four Corners area into the central Plains late Wednesday, with the overall trough taking on a negative tilt from MT into NE late. During the daytime, southerly flow and cooling aloft will proceed eastward across the northern Plains, where a surface trough will also deepen. This will provide a focus for afternoon storms, with additional activity late in the day over the central High Plains in association with the ejecting upper wave. To the east, a weakening upper trough will continue lifting north across the OH Valley, Great Lakes and Mid Atlantic, with cool temperatures aloft aiding daytime destabilization for scattered thunderstorms. ...Northern Plains... A north-south line of convection is forecast to form within the surface trough across the central Dakotas by 00Z, with additional activity developing over western NE. Shear will be marginal early on, but cool temperatures aloft and 1500-2000 J/kg MUCAPE will favor hail and locally strong gusts. During the evening and overnight, the environment will change rapidly as the upper trough approaches. Additional cooling aloft as well as developing 850 mb warm front should support an MCS or two, with damaging wind and hail both spreading across central and northern NE, eastern SD, and finally into western IA and southwest MN. Capping should limit southward development, perhaps to I-80 or so. ...Mid Atlantic Region... Cool midlevel temperatures will remain from the OH Valley into the Mid Atlantic beneath the ejecting upper trough. Dewpoints in the 60s F along with daytime heating will lead to pockets of 1500 J/kg MLCAPE, with generally weak but veering winds with height. Scattered storms appear most likely over central NC and VA, and a few strong wind gusts cannot be ruled out. ..Jewell.. 05/13/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue May 13 2025 Valid 131700Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE DESERT SOUTHWEST... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN NORTH DAKOTA AND NORTHWESTERN MINNESOTA... The Elevated and Critical areas across the southwestern US were expanded to include portions of northern Arizona and northwestern New Mexico. Morning observations indicate critical meteorological conditions are ongoing across these regions. Though some guidance keeps relative humidity just above critical values, it appears windy/drier solutions are verifying more closely to observations. Fuels along the Mogollon Rim and favored downslope regions are around the 75th percentile, which supports inclusion into the Critical. Fuels near the Four Corners and in northwestern New Mexico remain around the 50th percentile as such were included in the Elevated. The Elevated and Critical in the northern Plains was maintained with this outlook. See previous discussion for more information. ..Thornton.. 05/13/2025 .PREV DISCUSSION... /ISSUED 0155 AM CDT Tue May 13 2025/ ...Synopsis... Western US trouhging will deepen and begin to spread eastward as upper-level blocking breaks down over the central US today. A lee low will aid strong southwesterly winds and dry downslope conditions across the Southwest and High Plains. With little recent rainfall and above normal temperatures overlapping the increased surface winds, critical fire-weather conditions are expected. ...Northern Plains... Hot, dry and breezy conditions are again expected across parts of the Red River Valley of the North and upper Midwest, as a strong lee low supporting dry southerly winds over the northern Plains. Ahead of a surface trough and cold front gusty southerly winds of 20-25 mph are likely across the eastern Dakotas and western MN through the afternoon. Abnormally warm temperatures and modest moisture advection should keep afternoon RH values below 30%. With very dry fuels (ERC >90th percentile), several hours of widespread elevated to critical conditions appear likely. ...Southwest... The deepening upper trough over the western US will begin to move eastward today, spreading strong westerly flow over the Southwest and southern Rockies. The accelerating mid-level flow over a deep, dry boundary layer with above normal temperatures will bring gusty west-southwest winds of 15-25 mph to much of the Southwest. Fuels continue to dry/cure farther north into eastern AZ and western NM,supporting widespread elevated and critical fire-weather conditions. ...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 1145 AM CDT Tue May 13 2025 Valid 131700Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE DESERT SOUTHWEST... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN NORTH DAKOTA AND NORTHWESTERN MINNESOTA... The Elevated and Critical areas across the southwestern US were expanded to include portions of northern Arizona and northwestern New Mexico. Morning observations indicate critical meteorological conditions are ongoing across these regions. Though some guidance keeps relative humidity just above critical values, it appears windy/drier solutions are verifying more closely to observations. Fuels along the Mogollon Rim and favored downslope regions are around the 75th percentile, which supports inclusion into the Critical. Fuels near the Four Corners and in northwestern New Mexico remain around the 50th percentile as such were included in the Elevated. The Elevated and Critical in the northern Plains was maintained with this outlook. See previous discussion for more information. ..Thornton.. 05/13/2025 .PREV DISCUSSION... /ISSUED 0155 AM CDT Tue May 13 2025/ ...Synopsis... Western US trouhging will deepen and begin to spread eastward as upper-level blocking breaks down over the central US today. A lee low will aid strong southwesterly winds and dry downslope conditions across the Southwest and High Plains. With little recent rainfall and above normal temperatures overlapping the increased surface winds, critical fire-weather conditions are expected. ...Northern Plains... Hot, dry and breezy conditions are again expected across parts of the Red River Valley of the North and upper Midwest, as a strong lee low supporting dry southerly winds over the northern Plains. Ahead of a surface trough and cold front gusty southerly winds of 20-25 mph are likely across the eastern Dakotas and western MN through the afternoon. Abnormally warm temperatures and modest moisture advection should keep afternoon RH values below 30%. With very dry fuels (ERC >90th percentile), several hours of widespread elevated to critical conditions appear likely. ...Southwest... The deepening upper trough over the western US will begin to move eastward today, spreading strong westerly flow over the Southwest and southern Rockies. The accelerating mid-level flow over a deep, dry boundary layer with above normal temperatures will bring gusty west-southwest winds of 15-25 mph to much of the Southwest. Fuels continue to dry/cure farther north into eastern AZ and western NM,supporting widespread elevated and critical fire-weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Tue May 13 2025 Valid 131630Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH CAROLINA INTO THE SOUTHERN MID-ATLANTIC...CENTRAL GULF COAST STATES...AND NORTHERN PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms appear possible today and tonight across parts of North Carolina into the southern Mid-Atlantic, central Gulf Coast states, and northern Plains. ...North Carolina into the Southern Mid-Atlantic... A closed mid/upper-level low will continue to slowly meander from the TN Valley towards the central Appalachians through the period. An embedded mid-level shortwave trough will rotate northward across the Carolinas into the southern Mid-Atlantic by this evening. Stronger low/mid-level flow will tend to remain across the eastern Carolinas into southern VA today, with generally weaker winds aloft in closer proximity to the mid/upper low. A moist low-level airmass will remain in place over much of the Carolinas, central Appalachians, and southern Mid-Atlantic. But, poor mid-level lapse rates will tend to limit any more than weak instability from developing through this afternoon. Deep-layer shear away from the coast will also tend to remain muted, which should keep overall thunderstorm organization modest. Even with these forecast thermodynamic and kinematic limitations, some organization may occur with thunderstorms that develop and spread northward this afternoon. Isolated damaging winds appear to be the main threat with any loosely organized clusters that can form, but marginally severe hail could also occur with the strongest cores. A tornado or two also appears possible along a pseudo-warm front across northeast NC into southeast VA and vicinity, where low-level flow and shear are forecast to be modestly enhanced compared to locations farther west. ...Mississippi/Alabama... Morning showers and related cloudiness will temper diurnal destabilization to some extent across northern MS/AL this afternoon. But, renewed thunderstorm development still appears possible later today across this region, on the southern fringe of the slowly moving mid/upper low. Weak low-level westerly winds are expected to veer to northwesterly and gradually strengthen with height though mid levels. Related 30-40 kt of deep-layer shear will conditionally support organized updrafts, including the potential for a supercell with an associated hail/wind threat. The overall severe risk should remain quite isolated, which warrants maintaining the Marginal Risk with this update. ...Northern Plains... An amplified mid/upper-level trough will move eastward over the western states through tonight. A surface cold front is forecast to decelerate and eventually stall over parts of the Dakotas by this evening. Stronger mid/upper-level flow is expected to remain displaced to the west of this surface boundary. Even so, there are some indications in guidance that elevated thunderstorms posing a threat for isolated hail may impact parts of the northern Plains this evening into tonight. Weak instability should tend to limit the overall severe threat. ..Gleason/Wendt.. 05/13/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Tue May 13 2025 Valid 131630Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH CAROLINA INTO THE SOUTHERN MID-ATLANTIC...CENTRAL GULF COAST STATES...AND NORTHERN PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms appear possible today and tonight across parts of North Carolina into the southern Mid-Atlantic, central Gulf Coast states, and northern Plains. ...North Carolina into the Southern Mid-Atlantic... A closed mid/upper-level low will continue to slowly meander from the TN Valley towards the central Appalachians through the period. An embedded mid-level shortwave trough will rotate northward across the Carolinas into the southern Mid-Atlantic by this evening. Stronger low/mid-level flow will tend to remain across the eastern Carolinas into southern VA today, with generally weaker winds aloft in closer proximity to the mid/upper low. A moist low-level airmass will remain in place over much of the Carolinas, central Appalachians, and southern Mid-Atlantic. But, poor mid-level lapse rates will tend to limit any more than weak instability from developing through this afternoon. Deep-layer shear away from the coast will also tend to remain muted, which should keep overall thunderstorm organization modest. Even with these forecast thermodynamic and kinematic limitations, some organization may occur with thunderstorms that develop and spread northward this afternoon. Isolated damaging winds appear to be the main threat with any loosely organized clusters that can form, but marginally severe hail could also occur with the strongest cores. A tornado or two also appears possible along a pseudo-warm front across northeast NC into southeast VA and vicinity, where low-level flow and shear are forecast to be modestly enhanced compared to locations farther west. ...Mississippi/Alabama... Morning showers and related cloudiness will temper diurnal destabilization to some extent across northern MS/AL this afternoon. But, renewed thunderstorm development still appears possible later today across this region, on the southern fringe of the slowly moving mid/upper low. Weak low-level westerly winds are expected to veer to northwesterly and gradually strengthen with height though mid levels. Related 30-40 kt of deep-layer shear will conditionally support organized updrafts, including the potential for a supercell with an associated hail/wind threat. The overall severe risk should remain quite isolated, which warrants maintaining the Marginal Risk with this update. ...Northern Plains... An amplified mid/upper-level trough will move eastward over the western states through tonight. A surface cold front is forecast to decelerate and eventually stall over parts of the Dakotas by this evening. Stronger mid/upper-level flow is expected to remain displaced to the west of this surface boundary. Even so, there are some indications in guidance that elevated thunderstorms posing a threat for isolated hail may impact parts of the northern Plains this evening into tonight. Weak instability should tend to limit the overall severe threat. ..Gleason/Wendt.. 05/13/2025 Read more

MD 0774 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN NC INTO SOUTHEAST VA
Mesoscale Discussion 0774 NWS Storm Prediction Center Norman OK 0746 AM CDT Tue May 13 2025 Areas affected...Parts of eastern NC into southeast VA Concerning...Severe potential...Watch unlikely Valid 131246Z - 131445Z Probability of Watch Issuance...20 percent SUMMARY...A localized brief-tornado and wind-damage threat may persist through the morning. DISCUSSION...Extensive convection is ongoing this morning across eastern NC into southeast VA. Weak instability (MLCAPE generally 500 J/kg or less) is limiting updraft intensity, with lightning primarily confined to somewhat deeper convection near the NC coast. However, to the east of the slow-moving midlevel cyclone centered over western TN/KY, rather strong low-level flow continues to be noted on the KMHX and KAKQ VWPs, supporting effective SRH of 150-200 m2/s2. Small cells with occasional rotation have persisted from northeast NC into far southeast VA, and some localized threat for a brief tornado and wind damage could persist through the morning with these smaller cells. Farther south, an extensive convective cluster is ongoing off the NC coast, with some evidence of an MCV south of Morehead City. This cluster could spread northward toward the immediate coast and Outer Banks with time, with embedded cells potentially posing a threat of strong gusts and a brief tornado, especially where surface dewpoints remain near 70 F this morning. ..Dean/Bunting.. 05/13/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH... LAT...LON 34337728 35347780 37077776 37727730 37707663 37337571 36567549 35807518 35197530 34817576 34597642 34337728 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Tue May 13 2025 Valid 131300Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID-ATLANTIC...NORTHERN GREAT PLAINS...AND DEEP SOUTH... ...SUMMARY... Isolated severe thunderstorms are possible: 1) today in vicinity of Virginia-North Carolina-West Virginia, 2) during the late afternoon to mid-evening over a portion of the Deep South, and 3) this evening into early morning Wednesday in parts of the northern Great Plains. ...NC/VA/WV vicinity... The upper-level low centered near the mid-Mississippi Valley will continue to lift east/northeast through tonight, as a notable shortwave trough rotates northeast across the Mid-Atlantic region. Generally weak surface-based instability (MLCAPE at or below 1000 J/kg) will exist across the coastal plain as a belt of stronger 850 mb flow lifts northeast across eastern sections of NC/VA. This will contribute to enlarged low-level hodograph structures and support the continued potential for transient areas of rotation and a few short-lived tornadoes associated with stronger convective elements. See recently issued Mesoscale Discussion 774 for details on short-term convective trends. Farther west into WV/western VA and NC, subtle large-scale forcing for ascent with the approaching upper low will contribute to thunderstorm development. Although deep-layer shear will tend to relax with westward extent, slightly more favorable mid-level lapse rates and 1000-locally 1500 J/kg MLCAPE will result in the potential for isolated strong/severe gusts and hail. ...AL/MS/TN vicinity... Some hi-res guidance continues to suggest a supercell or two may develop to the west of the departing mid-level trough, where a corridor of differential boundary-layer heating may support a favored zone for late afternoon through mid-evening storm development. Some veering of the wind profile should yield modest hodograph curvature. This, coupled with moderate mid-level west-northwesterly flow, will favor a conditional supercell threat. ...Northern Great Plains... An upstream upper-level trough over the western U.S. will move steadily east, resulting in strengthening southerly mid-level flow across the northern Plains. A Pacific cold front will make modest eastward progress today before becoming quasi-stationary across the western/central Dakotas, however the stronger mid-level flow will remain generally displaced to the west. Weak elevated buoyancy and sufficient deep-layer shear may still result in scattered storms, including supercells, with potential for severe hail. Some risk for strong/severe gusts may also exist with storms closer to the surface front. ..Bunting/Dean.. 05/13/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Tue May 13 2025 Valid 131300Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID-ATLANTIC...NORTHERN GREAT PLAINS...AND DEEP SOUTH... ...SUMMARY... Isolated severe thunderstorms are possible: 1) today in vicinity of Virginia-North Carolina-West Virginia, 2) during the late afternoon to mid-evening over a portion of the Deep South, and 3) this evening into early morning Wednesday in parts of the northern Great Plains. ...NC/VA/WV vicinity... The upper-level low centered near the mid-Mississippi Valley will continue to lift east/northeast through tonight, as a notable shortwave trough rotates northeast across the Mid-Atlantic region. Generally weak surface-based instability (MLCAPE at or below 1000 J/kg) will exist across the coastal plain as a belt of stronger 850 mb flow lifts northeast across eastern sections of NC/VA. This will contribute to enlarged low-level hodograph structures and support the continued potential for transient areas of rotation and a few short-lived tornadoes associated with stronger convective elements. See recently issued Mesoscale Discussion 774 for details on short-term convective trends. Farther west into WV/western VA and NC, subtle large-scale forcing for ascent with the approaching upper low will contribute to thunderstorm development. Although deep-layer shear will tend to relax with westward extent, slightly more favorable mid-level lapse rates and 1000-locally 1500 J/kg MLCAPE will result in the potential for isolated strong/severe gusts and hail. ...AL/MS/TN vicinity... Some hi-res guidance continues to suggest a supercell or two may develop to the west of the departing mid-level trough, where a corridor of differential boundary-layer heating may support a favored zone for late afternoon through mid-evening storm development. Some veering of the wind profile should yield modest hodograph curvature. This, coupled with moderate mid-level west-northwesterly flow, will favor a conditional supercell threat. ...Northern Great Plains... An upstream upper-level trough over the western U.S. will move steadily east, resulting in strengthening southerly mid-level flow across the northern Plains. A Pacific cold front will make modest eastward progress today before becoming quasi-stationary across the western/central Dakotas, however the stronger mid-level flow will remain generally displaced to the west. Weak elevated buoyancy and sufficient deep-layer shear may still result in scattered storms, including supercells, with potential for severe hail. Some risk for strong/severe gusts may also exist with storms closer to the surface front. ..Bunting/Dean.. 05/13/2025 Read more

MD 0773 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN NC INTO SOUTHEAST VA
Mesoscale Discussion 0773 NWS Storm Prediction Center Norman OK 0419 AM CDT Tue May 13 2025 Areas affected...Parts of eastern NC into southeast VA Concerning...Severe potential...Watch unlikely Valid 130919Z - 131145Z Probability of Watch Issuance...20 percent SUMMARY...A localized brief-tornado and wind-damage threat will spread northward through dawn. DISCUSSION...Occasional rotation continues to be noted with embedded northward-moving cells across eastern NC. An apparent tornado occurred earlier in Edgecombe County, NC, and the environment remains modestly favorable for transient supercells, with MLCAPE approaching 500 J/kg and effective SRH generally in the 150-200 m2/s2 range. This environment is expected to gradually spread northward with time, in conjunction with a strengthening low-level jet. As this occurs, a localized brief-tornado and wind-damage threat will potentially expand across northeast NC into far southeast VA by dawn. Farther south, some veering and weakening of low-level flow has been noted on the KLTX VWP. However, convection remains somewhat vigorous (as evidenced by recent lightning activity) across southeast NC, and this trailing convective cluster could pose a localized severe threat as it continues to move northeastward. ..Dean/Bunting.. 05/13/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM...RNK... LAT...LON 35467541 35357549 34547652 34187716 33857815 34147836 34527842 34917859 36417934 36747884 36897799 37017710 36897627 36647601 35937560 35647549 35467541 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

MD 0772 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN NC
Mesoscale Discussion 0772 NWS Storm Prediction Center Norman OK 0140 AM CDT Tue May 13 2025 Areas affected...Parts of eastern NC Concerning...Severe potential...Watch unlikely Valid 130640Z - 130915Z Probability of Watch Issuance...20 percent SUMMARY...Some localized brief-tornado and wind-damage threat may persist overnight. DISCUSSION...Multiple clusters of convection are ongoing from northeast SC into eastern NC early this morning. This activity will continue to be aided by a shortwave trough that is moving northeastward around the periphery of a persistent mid/upper-level cyclone centered over parts of the Mid-South/TN Valley. Rather strong low-level flow (with 35-45 kt at 1-2 km AGL per recent objective analyses and VWPs from KLTX, KRAX, and KMHX) will continue to enlarge hodographs, with effective SRH of 150-200 m2/s2. Weak lapse rates/buoyancy and modest deep-layer shear will continue to be a general limiting factor for severe potential. However, given the relatively favorable low-level wind profiles, MLCAPE approaching 500 J/kg within a moist environment could support occasional transient supercell structures, with some localized brief-tornado and wind-damage potential through the overnight. ..Dean/Bunting.. 05/13/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM... LAT...LON 34747913 35397896 35627843 36097715 35907608 35237551 34907589 34397669 34067719 33887752 33547815 33747851 33997880 34747913 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CDT Tue May 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST.... ...Synopsis... The upper trough over the western US will continue to intensify as it emerges over the Rockies and onto the Plains Wednesday. Strong mid-level flow will strengthen a lee cyclone with a trailing cold front and dryline across the Great Plains. Dry westerly flow is likely over the Southwest where critical fire-weather conditions are expected. A more conditional threat for locally elevated fire-weather conditions exist over the Plains and Midwest ahead of the cold front. ...Southwest... As the main upper trough begins to move eastward over the Plains, the fire weather threat will persist for portions of Southwest. Moderate mid-level flow at the base of the upper-trough will support westerly downslope winds to 20-25 mph across southern New Mexico and eastern AZ Wednesday afternoon and evening. Amidst a very dry surface pattern with little recent rainfall and abnormally warm temperatures, RH values below 15% are likely. With sufficient fuels in place, and expanding in coverage from recent drying, widespread critical fire-weather conditions are likely Wednesday. ...Central plains and upper Midwest... As the upper trough moves eastward, a lee trough/dryline will gradually sharpen across the central CONUS. To the west, dry downslope flow is possible over parts of the central/northern Plains into the Upper Midwest. With RH minimums below 30% and wind gusting to 20 mph, some elevated fire-weather threat may be possible across parts of CO/KS and NE into the Dakotas. However, the strongest meteorological conditions are not expected to overlap with areas of supportive fuels given rainfall over the past week. Increasing surface moisture and some precipitation potential with the advancing cold front may further limit any appreciable overlap. This will favor a more localized threat with only isolated elevated fire-weather conditions expected. ..Lyons.. 05/13/2025 ...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 0159 AM CDT Tue May 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST.... ...Synopsis... The upper trough over the western US will continue to intensify as it emerges over the Rockies and onto the Plains Wednesday. Strong mid-level flow will strengthen a lee cyclone with a trailing cold front and dryline across the Great Plains. Dry westerly flow is likely over the Southwest where critical fire-weather conditions are expected. A more conditional threat for locally elevated fire-weather conditions exist over the Plains and Midwest ahead of the cold front. ...Southwest... As the main upper trough begins to move eastward over the Plains, the fire weather threat will persist for portions of Southwest. Moderate mid-level flow at the base of the upper-trough will support westerly downslope winds to 20-25 mph across southern New Mexico and eastern AZ Wednesday afternoon and evening. Amidst a very dry surface pattern with little recent rainfall and abnormally warm temperatures, RH values below 15% are likely. With sufficient fuels in place, and expanding in coverage from recent drying, widespread critical fire-weather conditions are likely Wednesday. ...Central plains and upper Midwest... As the upper trough moves eastward, a lee trough/dryline will gradually sharpen across the central CONUS. To the west, dry downslope flow is possible over parts of the central/northern Plains into the Upper Midwest. With RH minimums below 30% and wind gusting to 20 mph, some elevated fire-weather threat may be possible across parts of CO/KS and NE into the Dakotas. However, the strongest meteorological conditions are not expected to overlap with areas of supportive fuels given rainfall over the past week. Increasing surface moisture and some precipitation potential with the advancing cold front may further limit any appreciable overlap. This will favor a more localized threat with only isolated elevated fire-weather conditions expected. ..Lyons.. 05/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more