SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0125 PM CST Thu Feb 27 2025 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Little thunderstorm activity is anticipated for Saturday. A flash or two cannot be ruled out over northern Arizona and vicinity. ...Synopsis and Discussion... An upper low will move east from southern CA into AZ during the day, beneath a large-scale ridge over the Pacific Northwest and northern Rockies. Strong cooling aloft combined with daytime heating may yield weak instability supporting isolated, weak diurnal convection from southern NV across northern AZ and toward the Four Corners area. Elsewhere, a large-scale upper trough will remain over the East, with cool/stable air due to high pressure and offshore flow from the Gulf to the East Coast. An amplified upper trough will approach the West Coast Saturday night, with little instability forecast. ..Jewell.. 02/27/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Thu Feb 27 2025 Valid 281200Z - 011200Z An Elevated risk area has been introduced to portions of northwest TX/the eastern TX Panhandle and western OK. Recent guidance suggests 15-20 mph winds will likely develop across the TX Panhandle into much of OK by late afternoon as RH values fall into the mid to upper teens. Given an expanding swath of 80+ percentile ERC values across the region, fire weather concerns appears probable. Stronger winds are anticipated from northeast OK into portions of central MO and western IL ahead of a cold front, and some areas may see RH reductions into the 20-25% range. Consideration was given to expanding the new Elevated risk area east/northeast into these regions, but confidence on fuel status is more limited based on recent ERC and 10-hour fuel analyses. Forecast concerns regarding the central Plains remain on track as outlined in the previous discussion below. ..Moore.. 02/27/2025 .PREV DISCUSSION... /ISSUED 0151 AM CST Thu Feb 27 2025/ ...Synopsis... Mid-level ridging over the western US is expected to weaken as a shortwave trough approaches from southern Canada. The upper trough is forecast to intensify as it moves southeastward over the Plains and Midwest. An associated surface low will also quickly deepen over the Great Lakes. A dry cold front will move south through the central Plains with strong gusts to 25-30 mph along and behind the front. Dry conditions are also expected with afternoon RH values between 20 and 30% ahead of the cooler air mass. Ongoing drought and dry fine fuels are supportive of fire spread. However, larger fuels are less receptive currently. As such, some risk for wind-driven fire weather conditions is probable for a few hours D2/Friday afternoon across central/eastern SD/NE into far western portions of MN and IA. ...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 0123 PM CST Thu Feb 27 2025 Valid 281200Z - 011200Z An Elevated risk area has been introduced to portions of northwest TX/the eastern TX Panhandle and western OK. Recent guidance suggests 15-20 mph winds will likely develop across the TX Panhandle into much of OK by late afternoon as RH values fall into the mid to upper teens. Given an expanding swath of 80+ percentile ERC values across the region, fire weather concerns appears probable. Stronger winds are anticipated from northeast OK into portions of central MO and western IL ahead of a cold front, and some areas may see RH reductions into the 20-25% range. Consideration was given to expanding the new Elevated risk area east/northeast into these regions, but confidence on fuel status is more limited based on recent ERC and 10-hour fuel analyses. Forecast concerns regarding the central Plains remain on track as outlined in the previous discussion below. ..Moore.. 02/27/2025 .PREV DISCUSSION... /ISSUED 0151 AM CST Thu Feb 27 2025/ ...Synopsis... Mid-level ridging over the western US is expected to weaken as a shortwave trough approaches from southern Canada. The upper trough is forecast to intensify as it moves southeastward over the Plains and Midwest. An associated surface low will also quickly deepen over the Great Lakes. A dry cold front will move south through the central Plains with strong gusts to 25-30 mph along and behind the front. Dry conditions are also expected with afternoon RH values between 20 and 30% ahead of the cooler air mass. Ongoing drought and dry fine fuels are supportive of fire spread. However, larger fuels are less receptive currently. As such, some risk for wind-driven fire weather conditions is probable for a few hours D2/Friday afternoon across central/eastern SD/NE into far western portions of MN and IA. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CST Thu Feb 27 2025 Valid 281200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Low thunderstorm chances may develop into parts of southern and central California Friday night. ...Synopsis... Substantial offshore flow will exist along the East Coast and trailing into the northern Gulf of America on Friday, as a shortwave trough moves out the Northeast. Behind this feature, another wave will expand southeastward from the upper MS Valley across the Great Lakes and into the Northeast through Saturday morning. Low pressure will track across the Great Lakes in association with the developing upper trough, with a new surge of high pressure spreading south across the northern Plains/Upper MS Valley. West of this regime, a compact upper low will move eastward toward southern CA, providing increasing lift and cooling aloft, with isolated weak thunderstorm activity possible. ...Southern CA... As the upper low approaches, midlevel temperatures will cool, steepening lapse rates. Elevated instability may develop after 00Z north of the low where minimal moisture and lift will coexist. Forecast soundings suggest a few lightning flashes may result as MUCAPE on the order of 100-200 J/kg develops. ..Jewell.. 02/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CST Thu Feb 27 2025 Valid 281200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Low thunderstorm chances may develop into parts of southern and central California Friday night. ...Synopsis... Substantial offshore flow will exist along the East Coast and trailing into the northern Gulf of America on Friday, as a shortwave trough moves out the Northeast. Behind this feature, another wave will expand southeastward from the upper MS Valley across the Great Lakes and into the Northeast through Saturday morning. Low pressure will track across the Great Lakes in association with the developing upper trough, with a new surge of high pressure spreading south across the northern Plains/Upper MS Valley. West of this regime, a compact upper low will move eastward toward southern CA, providing increasing lift and cooling aloft, with isolated weak thunderstorm activity possible. ...Southern CA... As the upper low approaches, midlevel temperatures will cool, steepening lapse rates. Elevated instability may develop after 00Z north of the low where minimal moisture and lift will coexist. Forecast soundings suggest a few lightning flashes may result as MUCAPE on the order of 100-200 J/kg develops. ..Jewell.. 02/27/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Thu Feb 27 2025 Valid 271630Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY... ...SUMMARY... Isolated to scattered thunderstorms are possible today across parts of the Mid/Upper Ohio Valley, and Carolinas into central Georgia. Occasional strong to damaging winds may occur this afternoon and early evening across portions of the Upper Ohio Valley vicinity. ...Upper Ohio Valley... Very cold mid-level temperatures (around -30 C at 500 mb) will overspread OH and vicinity this afternoon, as the primary upper trough pivots eastward over the Great Lakes and OH Valley. The airmass across this region is behind the main cold front, and low-level moisture will admittedly remain quite limited (surface dewpoints generally in the 30s to low 40s). Even so, the combination of modest daytime heating, coupled with cooling temperatures aloft and steepening low/mid-level lapse rates, should allow for weak MLCAPE to develop across parts of the Upper OH Valley through late this afternoon. Low/mid-level winds are not forecast to be overly strong through much of the day, but some increase in westerly boundary-layer flow is anticipated this afternoon. Current expectations are for at least isolated thunderstorms to develop this afternoon and early evening as large-scale ascent associated with the upper trough overspreads this region, and as a weak secondary surface trough/wind shift moves southeastward. Given the steepened lapse rate environment, some of this convection may be capable of producing occasional strong to damaging winds and small hail. Accordingly, a Marginal Risk has been added across parts of OH, northeast KY, and WV, where the greatest concentration of thunderstorms with some wind threat is anticipated. ...Georgia into the Carolinas... Modest instability should develop later today across parts of central GA into the Carolinas ahead of a cold front amid increasing mid-level moisture and diurnal heating. This should support a chance for isolated thunderstorms to develop across these areas as the cold front continues east-southeastward. While small hail and gusty winds may occur with the more robust thunderstorms, the mainly anafrontal and elevated convective structure will likely limit the overall severe potential. ..Gleason/Supinie.. 02/27/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Thu Feb 27 2025 Valid 271630Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY... ...SUMMARY... Isolated to scattered thunderstorms are possible today across parts of the Mid/Upper Ohio Valley, and Carolinas into central Georgia. Occasional strong to damaging winds may occur this afternoon and early evening across portions of the Upper Ohio Valley vicinity. ...Upper Ohio Valley... Very cold mid-level temperatures (around -30 C at 500 mb) will overspread OH and vicinity this afternoon, as the primary upper trough pivots eastward over the Great Lakes and OH Valley. The airmass across this region is behind the main cold front, and low-level moisture will admittedly remain quite limited (surface dewpoints generally in the 30s to low 40s). Even so, the combination of modest daytime heating, coupled with cooling temperatures aloft and steepening low/mid-level lapse rates, should allow for weak MLCAPE to develop across parts of the Upper OH Valley through late this afternoon. Low/mid-level winds are not forecast to be overly strong through much of the day, but some increase in westerly boundary-layer flow is anticipated this afternoon. Current expectations are for at least isolated thunderstorms to develop this afternoon and early evening as large-scale ascent associated with the upper trough overspreads this region, and as a weak secondary surface trough/wind shift moves southeastward. Given the steepened lapse rate environment, some of this convection may be capable of producing occasional strong to damaging winds and small hail. Accordingly, a Marginal Risk has been added across parts of OH, northeast KY, and WV, where the greatest concentration of thunderstorms with some wind threat is anticipated. ...Georgia into the Carolinas... Modest instability should develop later today across parts of central GA into the Carolinas ahead of a cold front amid increasing mid-level moisture and diurnal heating. This should support a chance for isolated thunderstorms to develop across these areas as the cold front continues east-southeastward. While small hail and gusty winds may occur with the more robust thunderstorms, the mainly anafrontal and elevated convective structure will likely limit the overall severe potential. ..Gleason/Supinie.. 02/27/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1014 AM CST Thu Feb 27 2025 Valid 271700Z - 281200Z ...Carolinas... An Elevated risk area has been introduced to portions of the Carolinas for this afternoon. 16 UTC surface observations showed RH values falling into the 35-40% range, which is slightly drier than depicted by most morning guidance with the exception of the typically drier RAP/HRRR. These solutions hint that RH reductions into the low 30s (with localized pockets between 25-30%) are likely by mid afternoon ahead of a cold front. Additionally, regional VWPs show 20-30 mph winds within a residual boundary layer above a shallow nocturnal inversion (sampled by the 12 UTC GSO and CHS soundings). These winds will likely manifest at the surface as frequent 25-30 mph gusts later this afternoon. Recent fire activity in the region indicates that fuels are receptive after 7+ days of minimal rainfall. While showers and thunderstorms are expected later this evening/overnight, a several-hour window should emerge this afternoon of elevated to briefly critical fire weather conditions. ...Arizona... Elevated fire weather conditions are ongoing across central to western AZ this morning. Ongoing 15-25 mph winds are expected to peak within the next 1-2 hours (around 18 UTC) before slowly diminishing through the afternoon. Hence, peak winds are expected to be temporally displaced from diurnal RH minimums, which should limit the duration/coverage of fire weather concerns. ..Moore.. 02/27/2025 .PREV DISCUSSION... /ISSUED 0150 AM CST Thu Feb 27 2025/ ...Synopsis... Split mid-level flow with a strong northern stream shortwave trough is forecast to amplify as it moves over the eastern US. At the same time, ridging will intensify to the west as an upper low weakens over the Southwest. At the surface, a cold front will quickly move eastward with gusty winds and drier air behind it. Dry and breezy conditions are possible in the lee of the Appalachians and across parts of the Southeast, supporting some localized fire-weather concerns. ...Southeast US... As the eastern end of the cold front moves through the eastern US, dry continental flow is likely in the lee of the southern Appalachians and the Southeastern US. Gusty west/northwest winds of 10-15 mph are possible along with afternoon minimum humidity near 35%. After several weeks of unusually dry conditions, area fuels are supportive of some localized fire-weather risk. However, increasing moisture ahead of the cold front will likely keep RH values high enough to limit more widespread fire-weather concerns. ...Desert Southwest... A backdoor cold front will continue to weaken as it moves westward over the Southwest and southern High Plains. A surface low over western AZ will support moderate easterly flow across parts of western NM and AZ. While the air mass will be cooler in the wake of the front, relatively mild temperatures may still support a few hours of RH below 25%. Overlapping with easterly gusts of 15-20 mph and dry fuels, a few hours of locally elevated fire-weather conditions are possible across eastern AZ and western NM. ...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 1014 AM CST Thu Feb 27 2025 Valid 271700Z - 281200Z ...Carolinas... An Elevated risk area has been introduced to portions of the Carolinas for this afternoon. 16 UTC surface observations showed RH values falling into the 35-40% range, which is slightly drier than depicted by most morning guidance with the exception of the typically drier RAP/HRRR. These solutions hint that RH reductions into the low 30s (with localized pockets between 25-30%) are likely by mid afternoon ahead of a cold front. Additionally, regional VWPs show 20-30 mph winds within a residual boundary layer above a shallow nocturnal inversion (sampled by the 12 UTC GSO and CHS soundings). These winds will likely manifest at the surface as frequent 25-30 mph gusts later this afternoon. Recent fire activity in the region indicates that fuels are receptive after 7+ days of minimal rainfall. While showers and thunderstorms are expected later this evening/overnight, a several-hour window should emerge this afternoon of elevated to briefly critical fire weather conditions. ...Arizona... Elevated fire weather conditions are ongoing across central to western AZ this morning. Ongoing 15-25 mph winds are expected to peak within the next 1-2 hours (around 18 UTC) before slowly diminishing through the afternoon. Hence, peak winds are expected to be temporally displaced from diurnal RH minimums, which should limit the duration/coverage of fire weather concerns. ..Moore.. 02/27/2025 .PREV DISCUSSION... /ISSUED 0150 AM CST Thu Feb 27 2025/ ...Synopsis... Split mid-level flow with a strong northern stream shortwave trough is forecast to amplify as it moves over the eastern US. At the same time, ridging will intensify to the west as an upper low weakens over the Southwest. At the surface, a cold front will quickly move eastward with gusty winds and drier air behind it. Dry and breezy conditions are possible in the lee of the Appalachians and across parts of the Southeast, supporting some localized fire-weather concerns. ...Southeast US... As the eastern end of the cold front moves through the eastern US, dry continental flow is likely in the lee of the southern Appalachians and the Southeastern US. Gusty west/northwest winds of 10-15 mph are possible along with afternoon minimum humidity near 35%. After several weeks of unusually dry conditions, area fuels are supportive of some localized fire-weather risk. However, increasing moisture ahead of the cold front will likely keep RH values high enough to limit more widespread fire-weather concerns. ...Desert Southwest... A backdoor cold front will continue to weaken as it moves westward over the Southwest and southern High Plains. A surface low over western AZ will support moderate easterly flow across parts of western NM and AZ. While the air mass will be cooler in the wake of the front, relatively mild temperatures may still support a few hours of RH below 25%. Overlapping with easterly gusts of 15-20 mph and dry fuels, a few hours of locally elevated fire-weather conditions are possible across eastern AZ and western NM. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CST Thu Feb 27 2025 Valid 271300Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms are possible from the Mid and Upper Ohio Valley to the Carolinas/southern Virginia. ...Synopsis... Recent satellite imagery shows a pair of shortwave troughs moving through the broadly cyclonic flow aloft extending from the northern/central Plains and southern Canadian Prairies into the OH Valley and Northeast. The lead wave in the pair is currently over the Upper OH Valley, and should continue northeastward through the Northeast States today. The trailing wave is currently moving southeastward through the Upper Midwest, with the expectation that it will pivot more eastward as it moves through the Upper Great Lakes and OH Valley today before then continuing eastward through the Mid-Atlantic States overnight. Recent surface analysis placed a low over eastern Lake Erie, with an extensive cold front extending southwestward from this low into the TX Hill Country. This low is forecast to progress northeastward up the St. Lawrence Valley just ahead of the lead shortwave, with the attendant front moving eastward/southeastward. A weak, secondary frontal boundary is expected to move through the OH Valley, demarcated primarily by a shift to stronger, more northwesterly winds. Isolated thunderstorms are possible along both of these fronts, mostly during the late afternoon and early evening. ...Mid/Upper OH Valley... Very cold mid-level temperatures are expected to spread across the region as the shortwave trough mentioned in the synopsis progresses through. These cold temperatures and associated steep mid-level lapse rates will occur atop a well-mixed boundary layer, resulting in 7 to 8 deg C/km lapse rates throughout the troposphere. These lapse rates will help support modest buoyancy, despite surface temperatures in the upper 40s/low 50s and dewpoints in the upper 30s. Isolated thunderstorm development is anticipated along the surface boundary that is expected to move through the region, with the greatest coverage in the OH/KY/WV border vicinity this evening. Predominantly low-topped thunderstorms with transient updraft structures are anticipated. Even so, gusty winds and small hail may be noted with the more persistent and organized updrafts. Overall severe coverage is expected to be below thresholds for outlooking any areas. ...Carolinas in central GA... Modest pre-frontal buoyancy is expected to develop amid increasing mid-level moisture and diurnal heating, supporting the potential for isolated thunderstorms as the front moves through. Small hail and a damaging gust or two are possible within the strongest storms, but a largely anafrontal and elevated storm structure should keep the overall severe potential low. ..Mosier/Grams.. 02/27/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CST Thu Feb 27 2025 Valid 271300Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms are possible from the Mid and Upper Ohio Valley to the Carolinas/southern Virginia. ...Synopsis... Recent satellite imagery shows a pair of shortwave troughs moving through the broadly cyclonic flow aloft extending from the northern/central Plains and southern Canadian Prairies into the OH Valley and Northeast. The lead wave in the pair is currently over the Upper OH Valley, and should continue northeastward through the Northeast States today. The trailing wave is currently moving southeastward through the Upper Midwest, with the expectation that it will pivot more eastward as it moves through the Upper Great Lakes and OH Valley today before then continuing eastward through the Mid-Atlantic States overnight. Recent surface analysis placed a low over eastern Lake Erie, with an extensive cold front extending southwestward from this low into the TX Hill Country. This low is forecast to progress northeastward up the St. Lawrence Valley just ahead of the lead shortwave, with the attendant front moving eastward/southeastward. A weak, secondary frontal boundary is expected to move through the OH Valley, demarcated primarily by a shift to stronger, more northwesterly winds. Isolated thunderstorms are possible along both of these fronts, mostly during the late afternoon and early evening. ...Mid/Upper OH Valley... Very cold mid-level temperatures are expected to spread across the region as the shortwave trough mentioned in the synopsis progresses through. These cold temperatures and associated steep mid-level lapse rates will occur atop a well-mixed boundary layer, resulting in 7 to 8 deg C/km lapse rates throughout the troposphere. These lapse rates will help support modest buoyancy, despite surface temperatures in the upper 40s/low 50s and dewpoints in the upper 30s. Isolated thunderstorm development is anticipated along the surface boundary that is expected to move through the region, with the greatest coverage in the OH/KY/WV border vicinity this evening. Predominantly low-topped thunderstorms with transient updraft structures are anticipated. Even so, gusty winds and small hail may be noted with the more persistent and organized updrafts. Overall severe coverage is expected to be below thresholds for outlooking any areas. ...Carolinas in central GA... Modest pre-frontal buoyancy is expected to develop amid increasing mid-level moisture and diurnal heating, supporting the potential for isolated thunderstorms as the front moves through. Small hail and a damaging gust or two are possible within the strongest storms, but a largely anafrontal and elevated storm structure should keep the overall severe potential low. ..Mosier/Grams.. 02/27/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0402 AM CST Thu Feb 27 2025 Valid 021200Z - 071200Z ...DISCUSSION... ...D6/Tue - East Texas into the Mid/Lower Mississippi Valley... A compact mid-level low will translate east across the Southwest on Sunday which will result in lee cyclogenesis in the southern/central High Plains. As surface high pressure across the Midwest translates east, favorable low-level trajectories and strengthening flow across the Gulf and southern Plains will initiate significant moisture return across Texas. The initial mid-level low will weaken as it moves across the Plains and into the Mid-Mississippi Valley on D5/Monday. However, lee cyclogenesis will likely strengthen Monday afternoon as a larger scale trough approaches the southern Plains. Shortwave ridging will likely keep the dryline capped on Monday with continued moistening beneath the capping inversion as low-level moisture advection continues. By 12Z Tuesday, moisture recovery across the western Gulf should be complete with 70F dewpoints forecast near the Gulf Coast by both GFS and ECMWF ensembles. Confidence in the upper-level pattern is increasing as the ECMWF and EC Ensembles have been consistent with an amplified mid-level pattern across the central and southern Plains now for several consecutive runs. In addition, the GFS/GEFS has trended toward the more amplified ECMWF solution. As the confidence in the overall pattern increases, the confidence for a significant severe weather threat has also increased and 30% severe weather probabilities have been added from East Texas to central Mississippi. While specifics will remain uncertain until the event draws closer, the potential for multiple rounds of severe convection including supercells, clusters, and likely an eventual squall line will likely bring a threat for all severe weather hazards including strong tornadoes. ...D7/Wed - Carolinas into the Southeast... The ECMWF/ECS, which has been several days ahead of other extended guidance on with this upcoming pattern, has trended toward greater moisture penetration into the Southeast US and east of the Appalachians. Low to mid 60s dewpoints in the presence of a very strong wind field will support a large area of severe weather threat from the Southeast to the Carolinas and perhaps into parts of the Mid-Atlantic. Storm mode and specific hazards will be impacted by prior day convection and the overall evolution of the deepening surface low and associated cold front, but a great enough threat exists for 15% severe weather probabilities for D7/Wednesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0402 AM CST Thu Feb 27 2025 Valid 021200Z - 071200Z ...DISCUSSION... ...D6/Tue - East Texas into the Mid/Lower Mississippi Valley... A compact mid-level low will translate east across the Southwest on Sunday which will result in lee cyclogenesis in the southern/central High Plains. As surface high pressure across the Midwest translates east, favorable low-level trajectories and strengthening flow across the Gulf and southern Plains will initiate significant moisture return across Texas. The initial mid-level low will weaken as it moves across the Plains and into the Mid-Mississippi Valley on D5/Monday. However, lee cyclogenesis will likely strengthen Monday afternoon as a larger scale trough approaches the southern Plains. Shortwave ridging will likely keep the dryline capped on Monday with continued moistening beneath the capping inversion as low-level moisture advection continues. By 12Z Tuesday, moisture recovery across the western Gulf should be complete with 70F dewpoints forecast near the Gulf Coast by both GFS and ECMWF ensembles. Confidence in the upper-level pattern is increasing as the ECMWF and EC Ensembles have been consistent with an amplified mid-level pattern across the central and southern Plains now for several consecutive runs. In addition, the GFS/GEFS has trended toward the more amplified ECMWF solution. As the confidence in the overall pattern increases, the confidence for a significant severe weather threat has also increased and 30% severe weather probabilities have been added from East Texas to central Mississippi. While specifics will remain uncertain until the event draws closer, the potential for multiple rounds of severe convection including supercells, clusters, and likely an eventual squall line will likely bring a threat for all severe weather hazards including strong tornadoes. ...D7/Wed - Carolinas into the Southeast... The ECMWF/ECS, which has been several days ahead of other extended guidance on with this upcoming pattern, has trended toward greater moisture penetration into the Southeast US and east of the Appalachians. Low to mid 60s dewpoints in the presence of a very strong wind field will support a large area of severe weather threat from the Southeast to the Carolinas and perhaps into parts of the Mid-Atlantic. Storm mode and specific hazards will be impacted by prior day convection and the overall evolution of the deepening surface low and associated cold front, but a great enough threat exists for 15% severe weather probabilities for D7/Wednesday. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0207 AM CST Thu Feb 27 2025 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible along the northern California and southern Oregon Coast on Saturday night. ...Discussion... On Saturday, the large scale pattern will feature a trough across the eastern CONUS with ridging across the western CONUS and another larger scale trough approaching the West Coast. Beneath this ridge, an upper low will translate east across the Southwest. A dry airmass will limit thunderstorm potential across most of the eastern CONUS on Saturday. A few lightning flashes may be possible late along the northern California/southern Oregon coast Saturday night as temperatures cool aloft and mid-level lapse rates steepen, yielding weak instability after 06Z. ..Bentley.. 02/27/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CST Thu Feb 27 2025 Valid 281200Z - 011200Z ...Synopsis... Mid-level ridging over the western US is expected to weaken as a shortwave trough approaches from southern Canada. The upper trough is forecast to intensify as it moves southeastward over the Plains and Midwest. An associated surface low will also quickly deepen over the Great Lakes. A dry cold front will move south through the central Plains with strong gusts to 25-30 mph along and behind the front. Dry conditions are also expected with afternoon RH values between 20 and 30% ahead of the cooler air mass. Ongoing drought and dry fine fuels are supportive of fire spread. However, larger fuels are less receptive currently. As such, some risk for wind-driven fire weather conditions is probable for a few hours D2/Friday afternoon across central/eastern SD/NE into far western portions of MN and IA. ..Lyons.. 02/27/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Thu Feb 27 2025 Valid 271200Z - 281200Z ...NO CRITICAL AREAS... ...Synopsis... Split mid-level flow with a strong northern stream shortwave trough is forecast to amplify as it moves over the eastern US. At the same time, ridging will intensify to the west as an upper low weakens over the Southwest. At the surface, a cold front will quickly move eastward with gusty winds and drier air behind it. Dry and breezy conditions are possible in the lee of the Appalachians and across parts of the Southeast, supporting some localized fire-weather concerns. ...Southeast US... As the eastern end of the cold front moves through the eastern US, dry continental flow is likely in the lee of the southern Appalachians and the Southeastern US. Gusty west/northwest winds of 10-15 mph are possible along with afternoon minimum humidity near 35%. After several weeks of unusually dry conditions, area fuels are supportive of some localized fire-weather risk. However, increasing moisture ahead of the cold front will likely keep RH values high enough to limit more widespread fire-weather concerns. ...Desert Southwest... A backdoor cold front will continue to weaken as it moves westward over the Southwest and southern High Plains. A surface low over western AZ will support moderate easterly flow across parts of western NM and AZ. While the air mass will be cooler in the wake of the front, relatively mild temperatures may still support a few hours of RH below 25%. Overlapping with easterly gusts of 15-20 mph and dry fuels, a few hours of locally elevated fire-weather conditions are possible across eastern AZ and western NM. ..Lyons.. 02/27/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CST Thu Feb 27 2025 Valid 281200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across parts of central and southern California on Friday. ...Synopsis... A mid-level trough will move off the East Coast on Friday with a secondary reinforcing trough digging into the Great Lakes in its wake. An upper low beneath a ridge across the western CONUS will drift slowly east and eventually overspread parts of central and southern California Friday night. ...Portions of central and southern California... Isolated to potentially scattered thunderstorms are forecast, mostly Friday evening and Friday night, as temperatures cool aloft as an upper low moves inland across central and southern California. While instability may be sufficient for a few thunderstorms, it should remain too weak for any appreciable severe weather threat. ..Bentley.. 02/27/2025 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CST Thu Feb 27 2025 Valid 281200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across parts of central and southern California on Friday. ...Synopsis... A mid-level trough will move off the East Coast on Friday with a secondary reinforcing trough digging into the Great Lakes in its wake. An upper low beneath a ridge across the western CONUS will drift slowly east and eventually overspread parts of central and southern California Friday night. ...Portions of central and southern California... Isolated to potentially scattered thunderstorms are forecast, mostly Friday evening and Friday night, as temperatures cool aloft as an upper low moves inland across central and southern California. While instability may be sufficient for a few thunderstorms, it should remain too weak for any appreciable severe weather threat. ..Bentley.. 02/27/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Wed Feb 26 2025 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms are possible from the Mid and Upper Ohio Valley to the Carolinas/southern Virginia. ...Indiana/Ohio/Kentucky/West Virginia... Notable mid-level short-wave trough is currently digging across the upper MS Valley, and will extend across lower MI/IN region by 18z, before advancing into the middle Atlantic by late evening. Very cold temperatures are noted with this feature, and profiles should cool/steepen during the day as a secondary weak surface boundary advances southeast across the OH Valley. Latest model guidance suggests surface heating will aid steepening low-level lapse rates, and 0-3km values will likely approach 8-9 C/km by mid afternoon, despite surface temperatures only warming into the mid 40s-50s. As a result, forecast soundings yield several hundred J/kg SBCAPE within a strongly sheared west-northwesterly flow regime. Current thinking is scattered low-topped thunderstorms will evolve along the boundary by mid afternoon, then propagate southeast toward the higher terrain of the central Appalachians. While this activity will evolve within a weak-instability air mass, gusty winds and small hail may be noted with the more organized updrafts. At this time it appears the prospect for severe winds and hail are too low to warrant probabilities. ..Darrow/Lyons.. 02/27/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Wed Feb 26 2025 Valid 270100Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms remain possible across the Midwest and Ohio Valley this evening. Severe thunderstorm threat is low. ...01z Update... Low-amplitude short-wave trough is ejecting across the Ohio Valley. Large-scale forcing ahead of this feature is primarily responsible for scattered convection that currently extends from western PA, arcing southwest along the Ohio River into southeast MO. While much of this activity is not producing lightning, isolated thunderstorms are noted along a corridor of somewhat stronger instability that extends into central OH. However, 00z sounding from ILN does not exhibit appreciable buoyancy, though lapse rates are fairly steep and moist. Deepest updrafts will continue to produce lightning for the next few hours, but overall thunderstorms should remain mostly isolated. ..Darrow.. 02/27/2025 Read more