SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 PM CDT Sat Apr 12 2025 Valid 130100Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHEAST MONTANA...NORTHERN WYOMING AND FAR WESTERN SOUTH DAKOTA... ...SUMMARY... Thunderstorms with isolated severe gusts are possible this evening from parts of southeastern Montana and northern Wyoming into the Black Hills. ...Southeast Montana/Northern Wyoming/Far Western South Dakota... The latest water vapor imagery shows a shortwave trough over the northern Rockies, with two narrow streams of mid-level moisture associated with a mid-level jet extending northeastward from the Intermountain West into the northern High Plains. At the surface, a 1000 mb low is located in eastern Wyoming, with a cold front extending from eastern Montana southwestward into eastern Idaho. Ahead of the front, surface dewpoints are in the lower to mid 40s F from near the Wyoming-Montana state line extending northward across parts of southeast Montana. In this vicinity, the RAP has a maximum of weak instability with MLCAPE near 300 J/kg. In addition, RAP forecast soundings this evening in far southeast Montana have 60 to 70 knots of 0-6 km shear, and steep low-level lapse rates exceeding 8 C/km. This environment may support marginally severe gusts associated with cells that develop near the front as it moves eastward. The threat may affect parts of far western South Dakota later this evening. ..Broyles.. 04/13/2025 Read more

No Mesoscale Discussions are in effect as of Sat Apr 12 22:32:02 UTC 2025.

No watches are valid as of Sat Apr 12 22:32:02 UTC 2025.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0333 PM CDT Sat Apr 12 2025 Valid 141200Z - 201200Z A dry and breezy post-frontal airmass across the Central Plains, associated with an eastward moving mid-level shortwave trough, will result in some elevated fire-weather concerns on D3/Monday from southwest South Dakota/northwest Nebraska into northeastern Kansas. By D4/Tuesday, generally west-southwesterly flow will overspread the Southwestern U.S., where deep mixing will transport momentum downward into a warm, dry boundary layer. The ECMWF also indicates some potential for an embedded shortwave trough to move from Baja into the Four Corners, which could provide some enhancement to the surface winds and associated fire-weather concerns. On D5/Wednesday, a surface cyclone is forecast to develop in the lee of the Rockies beneath generally zonal mid-level flow. Deep boundary layer mixing on the west side of a dryline will result in some heightened fire-weather concerns across portions of the western Texas Panhandle into eastern New Mexico. Heading into D6/Thursday, a mid-level trough is forecast to move from the Pacific Northwest into the Great Basin, with fairly good agreement from both the ECMWF and GFS deterministic and ensemble forecasts. This will result in an intensifying 500mb height gradient across the southern Rockies, along with a deepening of the forecast surface low over the Central/Northern plains. The response in surface winds will result in widespread 20-25 MPH winds across portions of West Texas, eastern New Mexico, and southern Colorado with relative humidity values at or below 10%. Future outlooks for D6/Thursday may need an upgrade to 70% Critical pending continued forecast consistency and agreement between ensembles. While some fire-weather threat may persist into D7/Friday and D8/Saturday across the Southern Plains, predictability is too low for any highlight areas at this time. ..Halbert.. 04/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0333 PM CDT Sat Apr 12 2025 Valid 141200Z - 201200Z A dry and breezy post-frontal airmass across the Central Plains, associated with an eastward moving mid-level shortwave trough, will result in some elevated fire-weather concerns on D3/Monday from southwest South Dakota/northwest Nebraska into northeastern Kansas. By D4/Tuesday, generally west-southwesterly flow will overspread the Southwestern U.S., where deep mixing will transport momentum downward into a warm, dry boundary layer. The ECMWF also indicates some potential for an embedded shortwave trough to move from Baja into the Four Corners, which could provide some enhancement to the surface winds and associated fire-weather concerns. On D5/Wednesday, a surface cyclone is forecast to develop in the lee of the Rockies beneath generally zonal mid-level flow. Deep boundary layer mixing on the west side of a dryline will result in some heightened fire-weather concerns across portions of the western Texas Panhandle into eastern New Mexico. Heading into D6/Thursday, a mid-level trough is forecast to move from the Pacific Northwest into the Great Basin, with fairly good agreement from both the ECMWF and GFS deterministic and ensemble forecasts. This will result in an intensifying 500mb height gradient across the southern Rockies, along with a deepening of the forecast surface low over the Central/Northern plains. The response in surface winds will result in widespread 20-25 MPH winds across portions of West Texas, eastern New Mexico, and southern Colorado with relative humidity values at or below 10%. Future outlooks for D6/Thursday may need an upgrade to 70% Critical pending continued forecast consistency and agreement between ensembles. While some fire-weather threat may persist into D7/Friday and D8/Saturday across the Southern Plains, predictability is too low for any highlight areas at this time. ..Halbert.. 04/12/2025 ...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 0237 PM CDT Sat Apr 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN MONTANA INTO NORTHERN WYOMING AND FAR WESTERN SOUTH DAKOTA... ...SUMMARY... Thunderstorms with isolated severe gusts are possible across parts of southern Montana/northern Wyoming to the Black Hills this afternoon and evening. ...20Z Update... The forecast remains on track, and no changes were made with this update. For details, see the previous discussion below. ..Weinman.. 04/12/2025 .PREV DISCUSSION... /ISSUED 1112 AM CDT Sat Apr 12 2025/ ...Southern Montana into Northern Wyoming and Far Western South Dakota... A mid-level shortwave trough over WA/OR will move eastward over ID/MT/WY by tonight, with downstream lee cyclogenesis occurring across the central High Plains. Low-level moisture will remain very limited across the northern Rockies and adjacent High Plains, with surface dewpoints generally in the 30s. But, forcing for ascent and mid-level moisture should be sufficient for high-based thunderstorms to develop this afternoon/evening across parts of northern WY and southern MT. Forecast soundings show inverted-v profiles with weak instability and some increase in mid-level winds, which could support isolated strong to severe wind gusts with this convection as it spreads eastward. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0237 PM CDT Sat Apr 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN MONTANA INTO NORTHERN WYOMING AND FAR WESTERN SOUTH DAKOTA... ...SUMMARY... Thunderstorms with isolated severe gusts are possible across parts of southern Montana/northern Wyoming to the Black Hills this afternoon and evening. ...20Z Update... The forecast remains on track, and no changes were made with this update. For details, see the previous discussion below. ..Weinman.. 04/12/2025 .PREV DISCUSSION... /ISSUED 1112 AM CDT Sat Apr 12 2025/ ...Southern Montana into Northern Wyoming and Far Western South Dakota... A mid-level shortwave trough over WA/OR will move eastward over ID/MT/WY by tonight, with downstream lee cyclogenesis occurring across the central High Plains. Low-level moisture will remain very limited across the northern Rockies and adjacent High Plains, with surface dewpoints generally in the 30s. But, forcing for ascent and mid-level moisture should be sufficient for high-based thunderstorms to develop this afternoon/evening across parts of northern WY and southern MT. Forecast soundings show inverted-v profiles with weak instability and some increase in mid-level winds, which could support isolated strong to severe wind gusts with this convection as it spreads eastward. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Sat Apr 12 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHERN KENTUCKY INTO SOUTHERN OHIO...SOUTHWEST PENNSYLVANIA...AND WEST VIRGINIA... ...SUMMARY... Scattered storms, a few severe, are possible on Monday afternoon and evening across parts of the Upper Ohio Valley and central Appalachians. ...Synopsis... An upper low will deepen as it moves eastward across the Great Lakes on Monday, with a leading speed max moving across the OH Valley during the day and a secondary stronger wave arriving overnight. At the surface, low pressure will deepen from Lake Superior into southwest Quebec, with a cold front extending southwestward across OH and into the OH Valley during the day. Just off the surface, 850 mb winds will be veered to westerly, with speeds increasing to around 40 kt with the cold front passage. High pressure will maintain dry conditions over much of the Southeast, but a narrow plume of mid 50s F dewpoints will develop ahead of the cold front. Midlevel moistening with the lead wave will shift east from MO across IL, IN, OH and northern KY during the day. ...Northern KY into OH, WV, PA, MD... Increasing midlevel moisture, as well as low-level moisture advection will lead to gradual destabilization, but also perhaps reduced daytime heating ahead of the cold front. Forecast soundings from several models indicate relatively poor lapse rates below 700 mb with a relative warm nose at that level. Midlevel cooling will still result in 500-1000 J/kg MUCAPE, likely elevated instability over northern areas. That said, increasing mean boundary-layer wind speeds near the front and potential for pockets of stronger instability/heating could still yield strong to severe gusts, and, marginal hail as hodographs will be long. ..Jewell.. 04/12/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Sat Apr 12 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHERN KENTUCKY INTO SOUTHERN OHIO...SOUTHWEST PENNSYLVANIA...AND WEST VIRGINIA... ...SUMMARY... Scattered storms, a few severe, are possible on Monday afternoon and evening across parts of the Upper Ohio Valley and central Appalachians. ...Synopsis... An upper low will deepen as it moves eastward across the Great Lakes on Monday, with a leading speed max moving across the OH Valley during the day and a secondary stronger wave arriving overnight. At the surface, low pressure will deepen from Lake Superior into southwest Quebec, with a cold front extending southwestward across OH and into the OH Valley during the day. Just off the surface, 850 mb winds will be veered to westerly, with speeds increasing to around 40 kt with the cold front passage. High pressure will maintain dry conditions over much of the Southeast, but a narrow plume of mid 50s F dewpoints will develop ahead of the cold front. Midlevel moistening with the lead wave will shift east from MO across IL, IN, OH and northern KY during the day. ...Northern KY into OH, WV, PA, MD... Increasing midlevel moisture, as well as low-level moisture advection will lead to gradual destabilization, but also perhaps reduced daytime heating ahead of the cold front. Forecast soundings from several models indicate relatively poor lapse rates below 700 mb with a relative warm nose at that level. Midlevel cooling will still result in 500-1000 J/kg MUCAPE, likely elevated instability over northern areas. That said, increasing mean boundary-layer wind speeds near the front and potential for pockets of stronger instability/heating could still yield strong to severe gusts, and, marginal hail as hodographs will be long. ..Jewell.. 04/12/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sat Apr 12 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHWEST INTO THE HIGH PLAINS... Only minor updates have been made to the Critical across Arizona, New Mexico, and West Texas, as well as the Elevated in the Central Plains. A slight expansion of the Critical into east-central Arizona was made to reflect morning ensemble guidance, and a westward expansion of the Elevated across Nebraska into eastern Wyoming was made to reflect higher confidence in lower RH values coupled with the previously forecast 20 MPH winds. Otherwise, the forecast remains on track. See previous discussion for further detail. ..Halbert.. 04/12/2025 .PREV DISCUSSION... /ISSUED 0133 AM CDT Sat Apr 12 2025/ ...Synopsis... As an upper-level trough moves into the northern Plains on Sunday, some moderate mid-level flow will extend into the southern Rockies. A broad surface trough will evolve into a deepening low in the Upper Midwest and in the southern High Plains. A cold front will move through the northern/central Plains. ...Southwest into southern High Plains and Central Texas... With the deepening surface low and stronger mid-level winds than on Saturday, a broader area of 20 mph winds is expected. RH could again reach single digits locally. Otherwise, 10-15% will be more common. Critical fire weather is expected from southeast Arizona, southern/central New Mexico, into parts of the Texas Panhandle/South Plains. ...Nebraska... Though the front will be through the area, cooler temperatures will tend to lag behind as strong northwesterly flow--with some downslope component--and surface heating occur into part of the afternoon. Winds of 20-25 mph, with higher gusts, appear possible. RH during the afternoon is somewhat uncertain, but temperatures in this pattern should end up warmer than guidance suggests. With that in mind, the warmer/drier guidance was weighted more for this forecast. RH in this scenario of 15-25% is probable. Elevated fire weather is possible given the ongoing drought and dry grasses. ...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 1229 PM CDT Sat Apr 12 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHWEST INTO THE HIGH PLAINS... Only minor updates have been made to the Critical across Arizona, New Mexico, and West Texas, as well as the Elevated in the Central Plains. A slight expansion of the Critical into east-central Arizona was made to reflect morning ensemble guidance, and a westward expansion of the Elevated across Nebraska into eastern Wyoming was made to reflect higher confidence in lower RH values coupled with the previously forecast 20 MPH winds. Otherwise, the forecast remains on track. See previous discussion for further detail. ..Halbert.. 04/12/2025 .PREV DISCUSSION... /ISSUED 0133 AM CDT Sat Apr 12 2025/ ...Synopsis... As an upper-level trough moves into the northern Plains on Sunday, some moderate mid-level flow will extend into the southern Rockies. A broad surface trough will evolve into a deepening low in the Upper Midwest and in the southern High Plains. A cold front will move through the northern/central Plains. ...Southwest into southern High Plains and Central Texas... With the deepening surface low and stronger mid-level winds than on Saturday, a broader area of 20 mph winds is expected. RH could again reach single digits locally. Otherwise, 10-15% will be more common. Critical fire weather is expected from southeast Arizona, southern/central New Mexico, into parts of the Texas Panhandle/South Plains. ...Nebraska... Though the front will be through the area, cooler temperatures will tend to lag behind as strong northwesterly flow--with some downslope component--and surface heating occur into part of the afternoon. Winds of 20-25 mph, with higher gusts, appear possible. RH during the afternoon is somewhat uncertain, but temperatures in this pattern should end up warmer than guidance suggests. With that in mind, the warmer/drier guidance was weighted more for this forecast. RH in this scenario of 15-25% is probable. Elevated fire weather is possible given the ongoing drought and dry grasses. ...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 1200 PM CDT Sat Apr 12 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis... A deep upper trough will depart the East Coast Saturday night, with a surface high settling over the Southeast on Sunday. To the west, a shortwave trough will move east out of MT and toward the upper MS Valley by Monday morning. A cold front in association with this trough will quickly push across the northern and central Plains, with a pre-frontal trough roughly from MN into MO and southwestward into OK. Given the southeastern surface high, moisture return will be limited ahead of the Plains feature. However, cooling aloft and steepening of lapse rates, as well as lift will allow for elevated instability to develop into the upper MS Valley and Great Lakes, supporting isolated to scattered thunderstorms overnight. Weak instability should preclude any severe threat. ..Jewell.. 04/12/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 PM CDT Sat Apr 12 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis... A deep upper trough will depart the East Coast Saturday night, with a surface high settling over the Southeast on Sunday. To the west, a shortwave trough will move east out of MT and toward the upper MS Valley by Monday morning. A cold front in association with this trough will quickly push across the northern and central Plains, with a pre-frontal trough roughly from MN into MO and southwestward into OK. Given the southeastern surface high, moisture return will be limited ahead of the Plains feature. However, cooling aloft and steepening of lapse rates, as well as lift will allow for elevated instability to develop into the upper MS Valley and Great Lakes, supporting isolated to scattered thunderstorms overnight. Weak instability should preclude any severe threat. ..Jewell.. 04/12/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Sat Apr 12 2025 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN HIGH PLAINS... The current forecast remains on track, with minor changes to the Critical area in southwest Kansas in order to reflect current forecast guidance. See the previous discussion below for further detail. ..Halbert.. 04/12/2025 .PREV DISCUSSION... /ISSUED 0105 AM CDT Sat Apr 12 2025/ ...Synopsis... With an upper-level trough approaching the northern/central Rockies today, a surface low will deepen in the central Plains. Dry and windy conditions will extend from the Southwest into the southern/central Plains. Dry, down-peninsula winds behind a cold front will increase fire danger in parts of central/southern Florida. ...Southwest into southern/central High Plains... A broad area of 15-25 mph winds will be possible in these regions. The higher wind speeds will primarily occur within the higher terrain of the Southwest into the central/southern Rockies. The upper-level trough will be displaced farther northward and shortwave ridging aloft will keep wind speeds modest to moderate. Winds will be driven be the deepening central Plains surface cyclone. RH in some locations could reach into the single digits. More broadly, 10-20% is expected. Critical fire weather is most likely in the Raton Mesa vicinity where surface winds west of the surface trough will be around 20 mph for a longer duration. Elsewhere, elevated conditions are expected. ...Florida... RH during the afternoon will likely fall to 20-30% in parts of central/southern Florida. Winds will not be overly strong, but a broad area of near 10 mph appears probable. Dry fuels will support elevated fire weather. ...Central Plains... With the low-level jet expected to maintain some intensity into the afternoon, gusty southerly winds will persist through the afternoon. Moisture return will occur, but Friday night observed dewpoints in the southern Plains would at least suggest some drier conditions are probable on the western/northern flanks of the initial return flow. Stronger winds will extend eastward, but confidence in more than a locally elevated threat farther east is low. Areas of sustained winds of 15-20 mph and RH of 15-25% will be possible from western Kansas into central/eastern Nebraska. Dry grasses will support an increase risk of fire spread. ...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 1115 AM CDT Sat Apr 12 2025 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN HIGH PLAINS... The current forecast remains on track, with minor changes to the Critical area in southwest Kansas in order to reflect current forecast guidance. See the previous discussion below for further detail. ..Halbert.. 04/12/2025 .PREV DISCUSSION... /ISSUED 0105 AM CDT Sat Apr 12 2025/ ...Synopsis... With an upper-level trough approaching the northern/central Rockies today, a surface low will deepen in the central Plains. Dry and windy conditions will extend from the Southwest into the southern/central Plains. Dry, down-peninsula winds behind a cold front will increase fire danger in parts of central/southern Florida. ...Southwest into southern/central High Plains... A broad area of 15-25 mph winds will be possible in these regions. The higher wind speeds will primarily occur within the higher terrain of the Southwest into the central/southern Rockies. The upper-level trough will be displaced farther northward and shortwave ridging aloft will keep wind speeds modest to moderate. Winds will be driven be the deepening central Plains surface cyclone. RH in some locations could reach into the single digits. More broadly, 10-20% is expected. Critical fire weather is most likely in the Raton Mesa vicinity where surface winds west of the surface trough will be around 20 mph for a longer duration. Elsewhere, elevated conditions are expected. ...Florida... RH during the afternoon will likely fall to 20-30% in parts of central/southern Florida. Winds will not be overly strong, but a broad area of near 10 mph appears probable. Dry fuels will support elevated fire weather. ...Central Plains... With the low-level jet expected to maintain some intensity into the afternoon, gusty southerly winds will persist through the afternoon. Moisture return will occur, but Friday night observed dewpoints in the southern Plains would at least suggest some drier conditions are probable on the western/northern flanks of the initial return flow. Stronger winds will extend eastward, but confidence in more than a locally elevated threat farther east is low. Areas of sustained winds of 15-20 mph and RH of 15-25% will be possible from western Kansas into central/eastern Nebraska. Dry grasses will support an increase risk of fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Sat Apr 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN MONTANA INTO NORTHERN WYOMING AND FAR WESTERN SOUTH DAKOTA... ...SUMMARY... Thunderstorms with isolated severe gusts are possible across parts of southern Montana/northern Wyoming to the Black Hills this afternoon and evening. ...Southern Montana into Northern Wyoming and Far Western South Dakota... A mid-level shortwave trough over WA/OR will move eastward over ID/MT/WY by tonight, with downstream lee cyclogenesis occurring across the central High Plains. Low-level moisture will remain very limited across the northern Rockies and adjacent High Plains, with surface dewpoints generally in the 30s. But, forcing for ascent and mid-level moisture should be sufficient for high-based thunderstorms to develop this afternoon/evening across parts of northern WY and southern MT. Forecast soundings show inverted-v profiles with weak instability and some increase in mid-level winds, which could support isolated strong to severe wind gusts with this convection as it spreads eastward. ..Gleason/Goss.. 04/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Sat Apr 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN MONTANA INTO NORTHERN WYOMING AND FAR WESTERN SOUTH DAKOTA... ...SUMMARY... Thunderstorms with isolated severe gusts are possible across parts of southern Montana/northern Wyoming to the Black Hills this afternoon and evening. ...Southern Montana into Northern Wyoming and Far Western South Dakota... A mid-level shortwave trough over WA/OR will move eastward over ID/MT/WY by tonight, with downstream lee cyclogenesis occurring across the central High Plains. Low-level moisture will remain very limited across the northern Rockies and adjacent High Plains, with surface dewpoints generally in the 30s. But, forcing for ascent and mid-level moisture should be sufficient for high-based thunderstorms to develop this afternoon/evening across parts of northern WY and southern MT. Forecast soundings show inverted-v profiles with weak instability and some increase in mid-level winds, which could support isolated strong to severe wind gusts with this convection as it spreads eastward. ..Gleason/Goss.. 04/12/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0732 AM CDT Sat Apr 12 2025 Valid 121300Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING ACROSS NORTHERN WY...SOUTHEASTERN MT AND EXTREME WESTERN SD... ...SUMMARY... Thunderstorms with isolated severe gusts are possible from the Big Horns and southeast Montana to the Black Hills this afternoon into the evening. ...Northern WY/southeastern MT/western SD this afternoon/evening... A midlevel shortwave trough over WA/OR this morning will progress eastward over ID/MT/WY by tonight, with downstream lee cyclogenesis into the central Plains. Low-level moisture will remain limited across the northern Rockies and adjacent High Plains, but forcing for ascent and midlevel moisture should be sufficient for some high-based convection this afternoon/evening across northern WY and southern MT. Inverted-V profiles with weak buoyancy and some increase in midlevel flow could result in isolated outflow gusts of 50-65 mph. ..Thompson/Dean.. 04/12/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Sat Apr 12 2025 Valid 151200Z - 201200Z ...DISCUSSION... After a relative lull in severe potential mid-week, latest guidance indicates increasing severe possibilities late week. Compared to 24 hours ago, deterministic models have vastly changed to an evolution of a shortwave trough digging south from the Canadian Rockies into the Lower CO Valley during D5-7/Wednesday-Friday. This would support a greater breadth and quality of western Gulf moisture advection across the central states beneath an initially pronounced EML. SPC and NSSL GEFS-based ML guidance indicate broadening 5 to mesoscale pockets of 15 percent probabilities during D6-8/Thursday-Saturday. But given the lack of day-to-day continuity and rather large spread across ensemble guidance, consideration of any severe area appears premature this cycle. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Sat Apr 12 2025 Valid 151200Z - 201200Z ...DISCUSSION... After a relative lull in severe potential mid-week, latest guidance indicates increasing severe possibilities late week. Compared to 24 hours ago, deterministic models have vastly changed to an evolution of a shortwave trough digging south from the Canadian Rockies into the Lower CO Valley during D5-7/Wednesday-Friday. This would support a greater breadth and quality of western Gulf moisture advection across the central states beneath an initially pronounced EML. SPC and NSSL GEFS-based ML guidance indicate broadening 5 to mesoscale pockets of 15 percent probabilities during D6-8/Thursday-Saturday. But given the lack of day-to-day continuity and rather large spread across ensemble guidance, consideration of any severe area appears premature this cycle. Read more