SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Sat Mar 22 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF MISSOURI...EASTERN KANSAS...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered thunderstorms capable of producing isolated large hail and strong gusts are possible this evening and overnight from northeast Oklahoma into portions of eastern Kansas and much of Missouri. ...Synopsis... As a leading shortwave trough moves eastward across the Mid Atlantic, high pressure behind a cold front will shift into the Great Lakes and OH/TN Valleys, also extending into the Gulf of America. Meanwhile, another wave will be moving into the northern Rockies by 00Z, and will amplify as it moves across the northern Plains and mid MO Valley overnight. As this system emerges into the Plains, low pressure will deepen over SD, and southerly winds will increase from the western Gulf into the southern Plains. Dewpoints into the 50s F will spread as far north as Kansas City by 12Z Sunday. As the upper trough interacts with this moist plume, strong storms will become increasingly likely from late evening into the overnight hours from far northeast OK into the lower MO Valley, with primarily hail potential. ...Northeast OK into the lower MO Valley and vicinity... Daytime heating combined with the developing moist plume will lead to destabilization over eastern OK and western AR through 00Z, with stronger elevated instability rapidly spreading across eastern KS and MO during the evening. Indications are that initial activity may develop between 00-03Z over northeast OK near the low-level jet axis as moisture spreads into the heated-air mass and beneath cool temperatures aloft. Strong and veering winds with height as well as deepening moisture through 700 mb will favor cells producing large hail as cells proceed into southern MO. There is also a risk of a tornado, though highly conditional at this time, with any potential far-southern cell closer to the stronger SBCAPE from far northeast OK into extreme northwest AR. Overnight, as a cold front moves east across KS, lift will be enhanced further. A few cells or perhaps a cluster of storms could develop along the front, conditional on capping, with both hail and wind gust potential. In addition, the unstable air mass extending north toward the IA/MO border will support isolated hail as well in the warm advection regime. ...Northern High Plains... Steep lapse rates through a deep layer will develop this afternoon north of the midlevel jet axis and behind the cold front and developing low to the east. Forecast soundings indicate minimal instability in this drier air mass, however, moderate northwest flow and favorable time of day could yield a few strong gusts. ..Jewell/Lyons.. 03/22/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 PM CDT Fri Mar 21 2025 Valid 220100Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight. ...Synopsis... A shortwave trough now over IA will continue southeastward across the OH Valley tonight, with decreasing availability of instability. Steep lapse rates owing to daytime heating beneath the upper trough have resulted in scattered weak thunderstorms over IA and northern MO this evening, and some of this activity may persist into IL this evening. Very weak instability will preclude any severe threat. Elsewhere, similarly weak instability exists over parts of the Pacific Northwest this evening, in association with an upper jet diving into WA/OR. Isolated convection may yield a few lightning flashes as far east as western MT. ..Jewell.. 03/22/2025 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0441 PM CDT Fri Mar 21 2025 Valid 231200Z - 291200Z ...Synopsis... A mid to upper-level shortwave trough will traverse the Central Plains and Midwest D3/Sunday. Thereafter, the synoptic pattern will become fairly persistent with a long-wave trough encompassing the eastern half of CONUS, and ridging present over the Rockies and Southwest. ...Central and Southern Plains... A deepening surface cyclone over the Upper Midwest is expected to accompany the aforementioned shortwave trough D3/Sunday. An associated tightening pressure gradient across the Central and Northern Great Plains will support breezy west-northwest surface winds there, while a cold front dives south in the lee of the Rockies into the Southern Plains. Although RH will likely remain just above critical thresholds within a cooler air mass, these areas continue to remain unseasonably dry with receptive fuels for fire ignition and spread present. Therefore, two low probability areas for critical fire weather conditions have been introduced from western NE/northern KS, and western OK/northwestern TX. By D4/Monday a surface high over the Missouri River Valley will migrate slowly southward, shunting low-level moisture to the Gulf coast. Meanwhile, lee troughing will commence across the High Plains with accompanying southerly surface winds developing within dry antecedent conditions over western OK. A 40% area has been introduced here for D4/Monday, as projected ERC percentile estimates continue to indicate receptive fuel states across this region. Another cold front will result in breezy northwest winds developing across the Central Plains (NE) D5/Tuesday, and although a cooler air mass should keep relative humidity from falling into critical limits, deteriorating fuel conditions are anticipated given a lack of rainfall. After early next week, rainfall probabilities will begin to increase across most of the CONUS along frontal boundaries and in association with a southern stream Pacific shortwave trough entering the Southern Plains. This should limit the overall potential for significant fire weather concerns. ..Barnes/Williams.. 03/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Fri Mar 21 20:58:02 UTC 2025.

No Mesoscale Discussions are in effect as of Fri Mar 21 20:58:02 UTC 2025.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0234 PM CDT Fri Mar 21 2025 Valid 212000Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight. ...20Z Update... Prior forecast remains largely intact. Only change is to trim the thunder area over southeast SD/far southwest MN in the wake/north of the passing mid-level shortwave impulse in eastern NE. ..Grams.. 03/21/2025 .PREV DISCUSSION... /ISSUED 1124 AM CDT Fri Mar 21 2025/ ...Iowa Vicinity... An upper shortwave trough will move across the Midwest today and tonight, with increasing deep-layer west/northwest flow associated with this feature overspreading the region. Boundary layer moisture will remain scant ahead of an east/southeast moving cold front sweeping across the Lower MO/Mid-MS Valley this afternoon and evening. Nevertheless, very cold temperatures aloft (near -25 C at 500 mb, as sampled by 12z regional balloon observations), will support steep midlevel lapse rates. Additionally, surface heating into the mid 50s to low 60s will support steepening low-level lapse rates. These steep lapse rates amid cold temperatures aloft should be sufficient for SBCAPE values up to 300 J/kg. As such, isolated high-based, low-topped thunderstorms are expected this afternoon and evening from the Mid-MO Valley into the Mid-MS Valley. Given the dry boundary layer and near 30-40 kt flow between 850-700 mb, convection may locally enhance already gusty surface winds, and a few stronger gusts near 40-45 kt may occur, especially across southeast Iowa into northwest IL. A couple instances of small hail/graupel also could accompany this activity. ...Pacific Northwest/Northern Rockies... An upper shortwave trough will move across the region tonight. Cooling aloft will support steepening lapse rates and sufficient destabilization to support isolated lightning flashes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0234 PM CDT Fri Mar 21 2025 Valid 212000Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight. ...20Z Update... Prior forecast remains largely intact. Only change is to trim the thunder area over southeast SD/far southwest MN in the wake/north of the passing mid-level shortwave impulse in eastern NE. ..Grams.. 03/21/2025 .PREV DISCUSSION... /ISSUED 1124 AM CDT Fri Mar 21 2025/ ...Iowa Vicinity... An upper shortwave trough will move across the Midwest today and tonight, with increasing deep-layer west/northwest flow associated with this feature overspreading the region. Boundary layer moisture will remain scant ahead of an east/southeast moving cold front sweeping across the Lower MO/Mid-MS Valley this afternoon and evening. Nevertheless, very cold temperatures aloft (near -25 C at 500 mb, as sampled by 12z regional balloon observations), will support steep midlevel lapse rates. Additionally, surface heating into the mid 50s to low 60s will support steepening low-level lapse rates. These steep lapse rates amid cold temperatures aloft should be sufficient for SBCAPE values up to 300 J/kg. As such, isolated high-based, low-topped thunderstorms are expected this afternoon and evening from the Mid-MO Valley into the Mid-MS Valley. Given the dry boundary layer and near 30-40 kt flow between 850-700 mb, convection may locally enhance already gusty surface winds, and a few stronger gusts near 40-45 kt may occur, especially across southeast Iowa into northwest IL. A couple instances of small hail/graupel also could accompany this activity. ...Pacific Northwest/Northern Rockies... An upper shortwave trough will move across the region tonight. Cooling aloft will support steepening lapse rates and sufficient destabilization to support isolated lightning flashes. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Fri Mar 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR UPPER TRANS-PECOS OF TEXAS...PORTIONS OF WEST TEXAS...AND SOUTHEASTERN AND EASTERN NEW MEXICO... ...Update... Two additional Elevated areas of fire-weather conditions have been added for Saturday. The first is across the Piedmont of the Appalachians from northern GA into central VA. Sustained westerly, down-slope wind speeds are expected to reach 15 to 20 mph here by early afternoon with stronger gusts. Relative humidity will also fall into the low 20s, with isolated locations dropping well into the teens, juxtaposed with critically dry fuel conditions. Most of the recent rainfall over the past several days fell further east and north, so fire ignition and spread potential remains present here. The second Elevated area was included for a small portion of north central OK and southeast/east-central KS where a drier localized air mass is expected to combine with southerly winds around 15 to 20 mph. Further south of here, RH will likely remain too high as low-level moisture advection begins to return to the region. In addition to the Elevated areas, the Critical area across West TX and southeastern NM has been expanded northward to cover much of east-central NM and the far western TX panhandle. A majority of the NWP models, including hi-resolution guidance, are indicating higher wind speeds will develop here via the pressure gradient associated with a deepening lee surface trough near the Panhandles of OK and TX Saturday afternoon. Fuels across this region remain highly receptive due to a lack of recent precipitation. Only minor adjustments were made to the remaining Elevated areas across the Central and Southern Plains. Please see the discussion below for additional details pertaining to these areas. ..Barnes/Williams.. 03/21/2025 .PREV DISCUSSION... /ISSUED 0211 AM CDT Fri Mar 21 2025/ ...Synopsis... Strong northwesterly flow aloft will continue Saturday as a shortwave trough and mid-level jet move over the central Rockies and Plains. A lee low will deepen over the northern Plains with a surface trough trailing south into the southern Plains. Strong downslope winds are likely, along with dry conditions, supporting elevated to critical fire-weather concerns. ...Northern/Central Plains... Near the strong lee low, northwesterly downslope winds of 15-25 mph are likely across parts of eastern SD, WY, CO and NE as the upper trough and strong jet shift southeast. Downslope warming/drying should also support RH values below 30% across much of the central High Plains. While area fuels remain of mixed receptiveness, some antecedent drying Friday should allow for more widespread elevated to locally critical fire-weather concerns to develop, given the dry and breezy conditions. ...West Texas and southern High Plains... As the lee trough intensifies, westerly downslope winds are likely across much of eastern New Mexico and west Texas. Stronger mid-level flow, and the surface trough, will aid in bolstering surface winds to 15-25 mph, with the strong winds likely across the Rio Grande Valley to the Davis Mountains. With warm diurnal temperatures in the 70s and 80s, the dry downslope flow and strong diurnal mixing will favor low afternoon RH of 10-20%. Widespread elevated fire-weather conditions are likely across the southern High Plains. Additionally, several hours of critical conditions appear likely across southeastern New Mexico and southwest Texas, given stronger surface winds and little recent rainfall. ...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 0228 PM CDT Fri Mar 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR UPPER TRANS-PECOS OF TEXAS...PORTIONS OF WEST TEXAS...AND SOUTHEASTERN AND EASTERN NEW MEXICO... ...Update... Two additional Elevated areas of fire-weather conditions have been added for Saturday. The first is across the Piedmont of the Appalachians from northern GA into central VA. Sustained westerly, down-slope wind speeds are expected to reach 15 to 20 mph here by early afternoon with stronger gusts. Relative humidity will also fall into the low 20s, with isolated locations dropping well into the teens, juxtaposed with critically dry fuel conditions. Most of the recent rainfall over the past several days fell further east and north, so fire ignition and spread potential remains present here. The second Elevated area was included for a small portion of north central OK and southeast/east-central KS where a drier localized air mass is expected to combine with southerly winds around 15 to 20 mph. Further south of here, RH will likely remain too high as low-level moisture advection begins to return to the region. In addition to the Elevated areas, the Critical area across West TX and southeastern NM has been expanded northward to cover much of east-central NM and the far western TX panhandle. A majority of the NWP models, including hi-resolution guidance, are indicating higher wind speeds will develop here via the pressure gradient associated with a deepening lee surface trough near the Panhandles of OK and TX Saturday afternoon. Fuels across this region remain highly receptive due to a lack of recent precipitation. Only minor adjustments were made to the remaining Elevated areas across the Central and Southern Plains. Please see the discussion below for additional details pertaining to these areas. ..Barnes/Williams.. 03/21/2025 .PREV DISCUSSION... /ISSUED 0211 AM CDT Fri Mar 21 2025/ ...Synopsis... Strong northwesterly flow aloft will continue Saturday as a shortwave trough and mid-level jet move over the central Rockies and Plains. A lee low will deepen over the northern Plains with a surface trough trailing south into the southern Plains. Strong downslope winds are likely, along with dry conditions, supporting elevated to critical fire-weather concerns. ...Northern/Central Plains... Near the strong lee low, northwesterly downslope winds of 15-25 mph are likely across parts of eastern SD, WY, CO and NE as the upper trough and strong jet shift southeast. Downslope warming/drying should also support RH values below 30% across much of the central High Plains. While area fuels remain of mixed receptiveness, some antecedent drying Friday should allow for more widespread elevated to locally critical fire-weather concerns to develop, given the dry and breezy conditions. ...West Texas and southern High Plains... As the lee trough intensifies, westerly downslope winds are likely across much of eastern New Mexico and west Texas. Stronger mid-level flow, and the surface trough, will aid in bolstering surface winds to 15-25 mph, with the strong winds likely across the Rio Grande Valley to the Davis Mountains. With warm diurnal temperatures in the 70s and 80s, the dry downslope flow and strong diurnal mixing will favor low afternoon RH of 10-20%. Widespread elevated fire-weather conditions are likely across the southern High Plains. Additionally, several hours of critical conditions appear likely across southeastern New Mexico and southwest Texas, given stronger surface winds and little recent rainfall. ...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 0204 PM CDT Fri Mar 21 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF FAR NORTHEASTERN TEXAS INTO THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Afternoon storms from western Tennessee southwestward to northeastern Texas may pose a risk for severe wind and hail, though a tornado cannot be completely ruled out, especially over northern Mississippi. ...Synopsis... A mid-level trough will progress across the central CONUS as a surface cyclone drifts over the Great Lakes and an associated cold front sweeps across the OH Valley to Lower MS Valley regions on Sunday. Relatively rich low-level moisture will advect northeastward across the Lower MS Valley with the aid of a departing low-level jet, promoting enough buoyancy amid a sheared airmass to support scattered strong to severe thunderstorms. ...Lower MS Valley... As the surface cold front approaches the Lower MS/TN Valley regions Sunday afternoon, surface heating across the warm sector will support temperatures rising into the 70s F amid low to mid 60s F dewpoints. An EML is poised to overspread this warm/moist low-level airmass, boosting MLCAPE to 2000 J/kg in spots, but also introducing some convective inhibition within the 850-700 mb layer. Since stronger upper-level support will drift to the northeast with time, the primary forcing mechanism for convection will be low-level convergence associated with the surface cold front. Given 50 kts of effective bulk shear, multicells, supercells, and short line segments are the expected modes for any thunderstorms that can mature and become established. At least severe wind/hail will accompany these storms, assuming they do not become immediately undercut by the cold front. Tornado potential is somewhat less certain given aforementioned concerns with inhibition and an undercutting cold front. However, the trailing/residual portion of a southwesterly low-level jet will persist across northern MS by late Sunday afternoon/early evening, contributing to sizeable, curved low-level hodographs. If surface heating can overcome inhibition to support any sustained, robust convective updrafts appreciably ahead of the cold front, supercells could develop with a tornado threat. However, confidence in this scenario is low at this time. ..Squitieri.. 03/21/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1211 PM CDT Fri Mar 21 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF EASTERN KANSAS INTO MISSOURI... ...SUMMARY... A few thunderstorms capable of producing isolated severe gusts/hail are possible Saturday night into early Sunday morning across portions of eastern Kansas into Missouri. ...Synopsis... A mid-level trough will rapidly traverse the central Rockies and eject into the Plains states as another mid-level trough moves into the Atlantic tomorrow (Saturday). Surface cyclone development should take place over the northern Plains by Saturday afternoon, promoting modest moisture return up into the mid-MO Valley as cold temperatures aloft advect over the central Rockies/Plains from the west. High-based, low-topped convection will become prevalent across the Plains, along with gusty conditions during the afternoon, before deeper convection becomes established in the low-level warm-air advection regime across the MO Valley Saturday night. Isolated strong to severe thunderstorms could develop late Saturday night/early Sunday morning across eastern KS into MO. ...Central/Northern Rockies into the central Plains... As the upper trough ejects into the Plains and supports surface low development, cold temperatures aloft (i.e. -20C around 500 mb) will support 8+ C/km mid-level lapse rates overspreading a relatively deep, dry boundary layer Saturday afternoon. High-based, low-topped storms should develop by afternoon peak heating amid vertical profiles characterized by wind speeds quickly increasing with height. Overall buoyancy should be shallow, with no more than a couple hundred J/kg MUCAPE expected. However, some of the more robust convective updrafts that develop may be deep enough to support both charge separation for lightning flashes, and effective downward momentum transport of the stronger flow aloft for strong wind gusts given steep lapse rates through the column. However, questions remain how prevalent 50+ kt gusts would become with these storms, precluding severe probabilities this outlook. ...Eastern KS into MO Saturday... By late Saturday night, a 50-60 kt southwesterly low-level jet will develop around 850 mb, encouraging appreciable low-level warm-air and moisture advection ahead of an approaching surface cold front. Steep lapse rates will also precede the cold front, supporting at least 500-750 J/kg MUCAPE amid largely curved and elongated hodographs/well over 50 kts of effective bulk shear. Nearly all of this buoyancy is contained above 850 mb, so elevated multicells/supercells with an isolated severe gust/hail threat is expected late Saturday night into Sunday morning. ..Squitieri.. 03/21/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1211 PM CDT Fri Mar 21 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF EASTERN KANSAS INTO MISSOURI... ...SUMMARY... A few thunderstorms capable of producing isolated severe gusts/hail are possible Saturday night into early Sunday morning across portions of eastern Kansas into Missouri. ...Synopsis... A mid-level trough will rapidly traverse the central Rockies and eject into the Plains states as another mid-level trough moves into the Atlantic tomorrow (Saturday). Surface cyclone development should take place over the northern Plains by Saturday afternoon, promoting modest moisture return up into the mid-MO Valley as cold temperatures aloft advect over the central Rockies/Plains from the west. High-based, low-topped convection will become prevalent across the Plains, along with gusty conditions during the afternoon, before deeper convection becomes established in the low-level warm-air advection regime across the MO Valley Saturday night. Isolated strong to severe thunderstorms could develop late Saturday night/early Sunday morning across eastern KS into MO. ...Central/Northern Rockies into the central Plains... As the upper trough ejects into the Plains and supports surface low development, cold temperatures aloft (i.e. -20C around 500 mb) will support 8+ C/km mid-level lapse rates overspreading a relatively deep, dry boundary layer Saturday afternoon. High-based, low-topped storms should develop by afternoon peak heating amid vertical profiles characterized by wind speeds quickly increasing with height. Overall buoyancy should be shallow, with no more than a couple hundred J/kg MUCAPE expected. However, some of the more robust convective updrafts that develop may be deep enough to support both charge separation for lightning flashes, and effective downward momentum transport of the stronger flow aloft for strong wind gusts given steep lapse rates through the column. However, questions remain how prevalent 50+ kt gusts would become with these storms, precluding severe probabilities this outlook. ...Eastern KS into MO Saturday... By late Saturday night, a 50-60 kt southwesterly low-level jet will develop around 850 mb, encouraging appreciable low-level warm-air and moisture advection ahead of an approaching surface cold front. Steep lapse rates will also precede the cold front, supporting at least 500-750 J/kg MUCAPE amid largely curved and elongated hodographs/well over 50 kts of effective bulk shear. Nearly all of this buoyancy is contained above 850 mb, so elevated multicells/supercells with an isolated severe gust/hail threat is expected late Saturday night into Sunday morning. ..Squitieri.. 03/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Fri Mar 21 2025 Valid 211630Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast today. ...Iowa Vicinity... An upper shortwave trough will move across the Midwest today and tonight, with increasing deep-layer west/northwest flow associated with this feature overspreading the region. Boundary layer moisture will remain scant ahead of an east/southeast moving cold front sweeping across the Lower MO/Mid-MS Valley this afternoon and evening. Nevertheless, very cold temperatures aloft (near -25 C at 500 mb, as sampled by 12z regional balloon observations), will support steep midlevel lapse rates. Additionally, surface heating into the mid 50s to low 60s will support steepening low-level lapse rates. These steep lapse rates amid cold temperatures aloft should be sufficient for SBCAPE values up to 300 J/kg. As such, isolated high-based, low-topped thunderstorms are expected this afternoon and evening from the Mid-MO Valley into the Mid-MS Valley. Given the dry boundary layer and near 30-40 kt flow between 850-700 mb, convection may locally enhance already gusty surface winds, and a few stronger gusts near 40-45 kt may occur, especially across southeast Iowa into northwest IL. A couple instances of small hail/graupel also could accompany this activity. ...Pacific Northwest/Northern Rockies... An upper shortwave trough will move across the region tonight. Cooling aloft will support steepening lapse rates and sufficient destabilization to support isolated lightning flashes. ..Leitman/Halbert.. 03/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Fri Mar 21 2025 Valid 211630Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast today. ...Iowa Vicinity... An upper shortwave trough will move across the Midwest today and tonight, with increasing deep-layer west/northwest flow associated with this feature overspreading the region. Boundary layer moisture will remain scant ahead of an east/southeast moving cold front sweeping across the Lower MO/Mid-MS Valley this afternoon and evening. Nevertheless, very cold temperatures aloft (near -25 C at 500 mb, as sampled by 12z regional balloon observations), will support steep midlevel lapse rates. Additionally, surface heating into the mid 50s to low 60s will support steepening low-level lapse rates. These steep lapse rates amid cold temperatures aloft should be sufficient for SBCAPE values up to 300 J/kg. As such, isolated high-based, low-topped thunderstorms are expected this afternoon and evening from the Mid-MO Valley into the Mid-MS Valley. Given the dry boundary layer and near 30-40 kt flow between 850-700 mb, convection may locally enhance already gusty surface winds, and a few stronger gusts near 40-45 kt may occur, especially across southeast Iowa into northwest IL. A couple instances of small hail/graupel also could accompany this activity. ...Pacific Northwest/Northern Rockies... An upper shortwave trough will move across the region tonight. Cooling aloft will support steepening lapse rates and sufficient destabilization to support isolated lightning flashes. ..Leitman/Halbert.. 03/21/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1055 AM CDT Fri Mar 21 2025 Valid 211700Z - 221200Z ...Update... Elevated fire-weather conditions are expected across east-central NM later this afternoon, where sustained localized westerly downslope winds up to 20 to 25 mph will combine with RH in the low teens. ERC estimates and monthly percentiles across this region suggest fuels are receptive to ignition and spread. Only subtle adjustments to the forecast were made elsewhere, including a slight extension to the southeast for the Elevated area within NE and far northwest KS. Although widespread fuel conditions appear less receptive here, persistent breezy northwest downslope flow will aid in drier conditions/lower RH spreading into more of southwest NE this afternoon. In addition, the Elevated area for central TX was nudged slightly westward to account for some ongoing stronger southwesterly flow (expected to continue through early this afternoon), and was reduced across the TX panhandle where wind speeds should slowly decrease throughout the day. For additional details, please see the previous discussion below. ..Barnes/Williams.. 03/21/2025 .PREV DISCUSSION... /ISSUED 0210 AM CDT Fri Mar 21 2025/ ...Synopsis... Elevated to critical fire-weather conditions are likely this afternoon and evening over parts of the central US. A shortwave trough within northwesterly flow will move from the central Rockies to the southern Plains. A weak surface low will shift eastward over the Midwest as a cold front moves south into the Plains. Gusty winds and low humidity are expected near the front, supporting widespread fire-weather concerns amidst dry fuels. ...Southern Plains... South of the surface low and ahead of the cold front, southerly flow is forecast to intensify over much of the southern Plains and parts of the central MS valley. Southerly gusts of 15-20 mph are likely through peak heating. The recent frontal intrusion into the Gulf has shunted the majority of appreciable moisture well offshore with low 30 dewpoints noted along the northwest Gulf coast. This will support continued dry return flow, with afternoon RH values of 20-25%, colocated with the strong gusts. Widespread elevated to locally critical fire-weather conditions appear likely over much of the southern Plains and central MS Valley, given the dry fuels and fire activity in recent days. A more focused corridor of critical conditions is expected across north-central Texas early this afternoon. Stronger surface winds are expected along and behind the front with gusts of 20-25 mph likely. Along with the stronger gusts, strong diurnal heating and the dry return flow will favor lower RH below 20% atop dry fuels. ...Central High Plains... Northwesterly downslope flow is likely over portions of the central high Plains today and tonight as the upper trough and cold front move south. Elevated fire weather conditions are expected to be fairly widespread behind the front from the NE Panhandle southward into the High Plains. Downslope warming/drying should support RH values in the 15-25% range and widespread wind gusts of 15-25 mph. While area fuels are only partially supportive given recent rainfall/snow, enough dryness exists to support sufficient fire-weather risk to maintain the Elevated area. ...Florida... Offshore flow is likely over much of the Southeast today as surface high pressure builds over the central Gulf Coast. Northerly flow is likely over the Peninsula with a relatively dry air mass. While winds most of the day will be modest, occasional gusts of 10-15 mph may overlap with RH values below 30% and areas of dry fuels. This could support several hours of locally elevated fire-weather concerns given recent fire activity and little rainfall. ...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 0738 AM CDT Fri Mar 21 2025 Valid 211300Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast today. ...Synopsis... Within a largely zonal flow regime, embedded shortwave troughs will move from the Great Plains to the OH Valley, and inland over the Pacific Northwest and northern Rockies. The Great Plains trough will move over NE/IA by this afternoon/evening with an associated surface trough/weak cold front. Despite very limited low-level moisture, surface heating beneath cold midlevel temperatures (approaching -30 C at 500 mb) will allow for steep low-midlevel lapse rates and weak surface-based buoyancy this afternoon/evening. A few high-based, low-topped thunderstorms will be possible this afternoon through late evening. The steep lapse rates and moderately strong midlevel flow suggest some potential for gusty outflow winds and small hail/graupel with the convection, but the threat appears too limited to warrant severe probabilities. Otherwise, isolated lightning flashes will be possible later today into tonight from the WA Cascades into the northern Rockies. ..Thompson/Bentley.. 03/21/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0351 AM CDT Fri Mar 21 2025 Valid 241200Z - 291200Z ...DISCUSSION... Models suggest that a west-to-east cold front will move slowly southward across the Gulf Coast states/Southeast on Monday/Day 4, as an upper trough shifts slowly eastward across the eastern CONUS. Ample instability should evolve along the front to support afternoon storm development, but quasi-unidirectional flow with height, weak at low levels, may hinder prospects for severe storms despite ample mid-level flow. At this time, while some severe risk is apparent, potential appears too low to warrant inclusion of a risk area at this time. The front should continue shifting southward while weakening Days 5-6 (Tuesday and Wednesday), as weak surface high pressure settles into the eastern states. While thunder will be possible near the Gulf Coast Tuesday, and lingering over Florida Thursday, severe risk appears to be low. Model differences begin to increase substantially beyond Wednesday/through the end of the period. The ECMWF depicts a substantial mid-level short-wave trough and accompanying surface system moving into the Plains Day 8, while quasi-zonal flow aloft is depicted by the GFS. As such, predictability concerns preclude assessment of severe potential beyond Day 6. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0351 AM CDT Fri Mar 21 2025 Valid 241200Z - 291200Z ...DISCUSSION... Models suggest that a west-to-east cold front will move slowly southward across the Gulf Coast states/Southeast on Monday/Day 4, as an upper trough shifts slowly eastward across the eastern CONUS. Ample instability should evolve along the front to support afternoon storm development, but quasi-unidirectional flow with height, weak at low levels, may hinder prospects for severe storms despite ample mid-level flow. At this time, while some severe risk is apparent, potential appears too low to warrant inclusion of a risk area at this time. The front should continue shifting southward while weakening Days 5-6 (Tuesday and Wednesday), as weak surface high pressure settles into the eastern states. While thunder will be possible near the Gulf Coast Tuesday, and lingering over Florida Thursday, severe risk appears to be low. Model differences begin to increase substantially beyond Wednesday/through the end of the period. The ECMWF depicts a substantial mid-level short-wave trough and accompanying surface system moving into the Plains Day 8, while quasi-zonal flow aloft is depicted by the GFS. As such, predictability concerns preclude assessment of severe potential beyond Day 6. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Mar 21 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEASTERN TEXAS TO WESTERN TENNESSEE/CENTRAL AND NORTHERN MISSISSIPPI... ...SUMMARY... Afternoon storms from western Tennessee southwestward to northeastern Texas may pose a risk for locally damaging winds and hail. ...Synopsis... A short-wave trough crossing the central/northern Plains is forecast to evolve into a closed low, that is then progged to drift eastward into the Upper Great Lakes region through the period. As this occurs, a surface low -- initially over the Minnesota vicinity -- will become increasingly occluded, and likewise will drift eastward into the Upper Great Lakes. At the surface, a weak triple-point low is forecast to shift northeastward across the Mid Mississippi/Ohio Valleys through the day, while a cold front sags southward into western Kentucky/western Tennessee/Arkansas/Texas. By the end of the period, this front should extend from western Pennsylvania to the southern Appalachians, and then westward into Texas. ...East Texas to the Tennessee Valley... Daytime heating ahead of the cold front will combine with ample warm-sector dewpoints to support airmass destabilization. Mixed-layer CAPE ranging from around 500 J/kg in western Tennessee to 1500 J/kg or so into eastern Texas seems likely evolve, and should be sufficient to support development of scattered strong/locally severe storms. Updraft intensity will be aided by weakly veering/increasing flow with height through the mid troposphere, with shear sufficient for organized/rotating updrafts. While a tornado or two may be possible, greater risk appears to be hail and locally damaging wind gusts. This risk should peak through late afternoon, after which diurnal cooling/stabilization should result in a gradual decrease in storm intensity/severe potential. ..Goss.. 03/21/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Mar 21 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEASTERN TEXAS TO WESTERN TENNESSEE/CENTRAL AND NORTHERN MISSISSIPPI... ...SUMMARY... Afternoon storms from western Tennessee southwestward to northeastern Texas may pose a risk for locally damaging winds and hail. ...Synopsis... A short-wave trough crossing the central/northern Plains is forecast to evolve into a closed low, that is then progged to drift eastward into the Upper Great Lakes region through the period. As this occurs, a surface low -- initially over the Minnesota vicinity -- will become increasingly occluded, and likewise will drift eastward into the Upper Great Lakes. At the surface, a weak triple-point low is forecast to shift northeastward across the Mid Mississippi/Ohio Valleys through the day, while a cold front sags southward into western Kentucky/western Tennessee/Arkansas/Texas. By the end of the period, this front should extend from western Pennsylvania to the southern Appalachians, and then westward into Texas. ...East Texas to the Tennessee Valley... Daytime heating ahead of the cold front will combine with ample warm-sector dewpoints to support airmass destabilization. Mixed-layer CAPE ranging from around 500 J/kg in western Tennessee to 1500 J/kg or so into eastern Texas seems likely evolve, and should be sufficient to support development of scattered strong/locally severe storms. Updraft intensity will be aided by weakly veering/increasing flow with height through the mid troposphere, with shear sufficient for organized/rotating updrafts. While a tornado or two may be possible, greater risk appears to be hail and locally damaging wind gusts. This risk should peak through late afternoon, after which diurnal cooling/stabilization should result in a gradual decrease in storm intensity/severe potential. ..Goss.. 03/21/2025 Read more