SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0343 PM CST Thu Feb 27 2025 Valid 011200Z - 071200Z Critical fire weather conditions are expected this weekend and into early next week across portions of the southern High Plains. Long-range guidance continues to show very good agreement in the evolution of the upper-level regime through the extended period as a series of shortwave troughs migrate across the Southwest into the southern Plains and OH Valley beginning this weekend and into the middle of the upcoming work week. Persistent dry conditions across AZ, NM, and much of OK/TX has resulted in an expanding swath of receptive fuels with most locations now reporting ERCs near or above the 80th percentile and 10-hour fuel moisture below 10%. This fuel environment will support fire spread as surface winds increase with the passage of these upper disturbances. ...D3/Sat to D4/Sun - Southwest/Southern High Plains... The first of two waves is currently off the CA coast and is expected to move into the lower CO River Valley over the next 72 hours. As this occurs, surface pressure falls across the Four Corners region will promote a widespread swath of 15-25 mph winds from southeast AZ into NM. Elevated fire weather conditions are likely as RH values fall into the teens/low 20s, and critical conditions are possible along the AZ/NM border based on windier/drier ensemble solutions. A stronger wind signal is noted across the southern High Plains on D4/Sunday as a lee cyclone deepens across the region. Post-dryline winds will likely exceed 20 mph, though the coverage of the wind swath remains uncertain due to spread in the exact location of the surface low in deterministic/ensemble guidance. Additionally, some solutions hint at scattered showers across the TX Panhandle into western OK. A 70% risk area has been introduced to southeast NM/west TX where confidence in critical conditions is highest, but critical conditions are possible across the TX Panhandle if the low develops on the northern end of the ensemble envelope across southeast CO/southwest KS and precipitation amounts are minimal. ...D5/Mon to D6/Tue - Southwest and Southern High Plains... A repeat of the Sat/Sun sequence is expected on Mon/Tue as a second, more amplified, upper trough translates across the Southwest and southern High Plains. The stronger kinematic fields associated with the second wave will likely result in a more robust low-level mass response as a surface low develops late Monday into Tuesday over the High Plains. While critical wind speeds are possible both days, both GEFS and ECENS guidance depicts the strongest signal on D6/Tuesday across southeast NM into southwest TX. Some solutions, including the 12z ECMWF, which typically has a weak wind bias, show the potential for a swath of 30 mph winds under the mid-level jet. While exact details remain uncertain at this range, the overall signal has been consistent enough through multiple model runs to support 70% risk probabilities. ..Moore.. 02/27/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Feb 27 2025 Valid 272000Z - 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. ...20Z Update... The forecast remains on track, and very minimal changes were made with this update. Isolated to widely scattered low-topped thunderstorms are developing within a weak low-level convergence zone across southwestern Ohio and southeastern Indiana this afternoon, with additional development northward along the surface trough in northern Indiana. This activity will continue tracking/developing east-southeastward into this evening, and any small clusters that evolve will be capable of producing strong to locally damaging wind gusts and small hail. For additional information, see the previous discussion below. ..Weinman.. 02/27/2025 .PREV DISCUSSION... /ISSUED 1028 AM CST Thu Feb 27 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Feb 27 2025 Valid 272000Z - 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. ...20Z Update... The forecast remains on track, and very minimal changes were made with this update. Isolated to widely scattered low-topped thunderstorms are developing within a weak low-level convergence zone across southwestern Ohio and southeastern Indiana this afternoon, with additional development northward along the surface trough in northern Indiana. This activity will continue tracking/developing east-southeastward into this evening, and any small clusters that evolve will be capable of producing strong to locally damaging wind gusts and small hail. For additional information, see the previous discussion below. ..Weinman.. 02/27/2025 .PREV DISCUSSION... /ISSUED 1028 AM CST Thu Feb 27 2025/ ...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. Read more

No Mesoscale Discussions are in effect as of Thu Feb 27 19:58:02 UTC 2025.

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 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