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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0133 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN IDAHO... ...Synopsis... Widespread elevated to critical fire weather conditions are expected today across a large swath of the Intermountain West. An upper wave currently approaching the Pacific Northwest is expected to progress quickly to the High Plains over the next 24 hours. As this occurs, ascent ahead of the wave will induce surface pressure falls across the northern Great Basin and northern Rockies. The low-level mass response should promote widespread sustained winds in the 15-25 mph range from the lee of the Cascades and Sierra Nevada into portions of WY. Deep mixing should promote frequent gusts between 25-30 mph. Transient swaths of 20+ mph winds will be possible across much of the region, but confidence in sustained critical wind speeds remains highest through the Snake River Plain in southern/eastern ID where flow will be orographically enhanced. 06 UTC surface observations across the Great Basin show very dry conditions already in place, and diurnal heating of this dry air mass will support widespread RH reductions into the 5-15% range. Recent fuel guidance shows widespread ERCs above the 90th percentile across much of the region, which should support the fire weather threat. ...Dry Thunderstorms... A few early-morning thunderstorms are noted in GOES GLM data between 04-05 UTC across portions of NV (likely associated with ascent ahead of a weak leading upper perturbation), though more substantial thunderstorm activity is expected later this afternoon and evening across the Great Basin. 00z soundings, water-vapor imagery, and the recent convection all confirm that a plume of mid-level moisture is in place ahead of the primary upper trough. As ascent and diurnal heating increase through the afternoon, a swath of isolated to scattered thunderstorms will likely develop from far eastern CA to eastern ID/western WY. Very deep and well-mixed boundary layers, coupled with storm motions near 20 knots, will promote mainly dry thunderstorms. With receptive fuels in place, this convection will pose a threat for new fire starts. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0133 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN IDAHO... ...Synopsis... Widespread elevated to critical fire weather conditions are expected today across a large swath of the Intermountain West. An upper wave currently approaching the Pacific Northwest is expected to progress quickly to the High Plains over the next 24 hours. As this occurs, ascent ahead of the wave will induce surface pressure falls across the northern Great Basin and northern Rockies. The low-level mass response should promote widespread sustained winds in the 15-25 mph range from the lee of the Cascades and Sierra Nevada into portions of WY. Deep mixing should promote frequent gusts between 25-30 mph. Transient swaths of 20+ mph winds will be possible across much of the region, but confidence in sustained critical wind speeds remains highest through the Snake River Plain in southern/eastern ID where flow will be orographically enhanced. 06 UTC surface observations across the Great Basin show very dry conditions already in place, and diurnal heating of this dry air mass will support widespread RH reductions into the 5-15% range. Recent fuel guidance shows widespread ERCs above the 90th percentile across much of the region, which should support the fire weather threat. ...Dry Thunderstorms... A few early-morning thunderstorms are noted in GOES GLM data between 04-05 UTC across portions of NV (likely associated with ascent ahead of a weak leading upper perturbation), though more substantial thunderstorm activity is expected later this afternoon and evening across the Great Basin. 00z soundings, water-vapor imagery, and the recent convection all confirm that a plume of mid-level moisture is in place ahead of the primary upper trough. As ascent and diurnal heating increase through the afternoon, a swath of isolated to scattered thunderstorms will likely develop from far eastern CA to eastern ID/western WY. Very deep and well-mixed boundary layers, coupled with storm motions near 20 knots, will promote mainly dry thunderstorms. With receptive fuels in place, this convection will pose a threat for new fire starts. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0133 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN IDAHO... ...Synopsis... Widespread elevated to critical fire weather conditions are expected today across a large swath of the Intermountain West. An upper wave currently approaching the Pacific Northwest is expected to progress quickly to the High Plains over the next 24 hours. As this occurs, ascent ahead of the wave will induce surface pressure falls across the northern Great Basin and northern Rockies. The low-level mass response should promote widespread sustained winds in the 15-25 mph range from the lee of the Cascades and Sierra Nevada into portions of WY. Deep mixing should promote frequent gusts between 25-30 mph. Transient swaths of 20+ mph winds will be possible across much of the region, but confidence in sustained critical wind speeds remains highest through the Snake River Plain in southern/eastern ID where flow will be orographically enhanced. 06 UTC surface observations across the Great Basin show very dry conditions already in place, and diurnal heating of this dry air mass will support widespread RH reductions into the 5-15% range. Recent fuel guidance shows widespread ERCs above the 90th percentile across much of the region, which should support the fire weather threat. ...Dry Thunderstorms... A few early-morning thunderstorms are noted in GOES GLM data between 04-05 UTC across portions of NV (likely associated with ascent ahead of a weak leading upper perturbation), though more substantial thunderstorm activity is expected later this afternoon and evening across the Great Basin. 00z soundings, water-vapor imagery, and the recent convection all confirm that a plume of mid-level moisture is in place ahead of the primary upper trough. As ascent and diurnal heating increase through the afternoon, a swath of isolated to scattered thunderstorms will likely develop from far eastern CA to eastern ID/western WY. Very deep and well-mixed boundary layers, coupled with storm motions near 20 knots, will promote mainly dry thunderstorms. With receptive fuels in place, this convection will pose a threat for new fire starts. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0133 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN IDAHO... ...Synopsis... Widespread elevated to critical fire weather conditions are expected today across a large swath of the Intermountain West. An upper wave currently approaching the Pacific Northwest is expected to progress quickly to the High Plains over the next 24 hours. As this occurs, ascent ahead of the wave will induce surface pressure falls across the northern Great Basin and northern Rockies. The low-level mass response should promote widespread sustained winds in the 15-25 mph range from the lee of the Cascades and Sierra Nevada into portions of WY. Deep mixing should promote frequent gusts between 25-30 mph. Transient swaths of 20+ mph winds will be possible across much of the region, but confidence in sustained critical wind speeds remains highest through the Snake River Plain in southern/eastern ID where flow will be orographically enhanced. 06 UTC surface observations across the Great Basin show very dry conditions already in place, and diurnal heating of this dry air mass will support widespread RH reductions into the 5-15% range. Recent fuel guidance shows widespread ERCs above the 90th percentile across much of the region, which should support the fire weather threat. ...Dry Thunderstorms... A few early-morning thunderstorms are noted in GOES GLM data between 04-05 UTC across portions of NV (likely associated with ascent ahead of a weak leading upper perturbation), though more substantial thunderstorm activity is expected later this afternoon and evening across the Great Basin. 00z soundings, water-vapor imagery, and the recent convection all confirm that a plume of mid-level moisture is in place ahead of the primary upper trough. As ascent and diurnal heating increase through the afternoon, a swath of isolated to scattered thunderstorms will likely develop from far eastern CA to eastern ID/western WY. Very deep and well-mixed boundary layers, coupled with storm motions near 20 knots, will promote mainly dry thunderstorms. With receptive fuels in place, this convection will pose a threat for new fire starts. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0133 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN IDAHO... ...Synopsis... Widespread elevated to critical fire weather conditions are expected today across a large swath of the Intermountain West. An upper wave currently approaching the Pacific Northwest is expected to progress quickly to the High Plains over the next 24 hours. As this occurs, ascent ahead of the wave will induce surface pressure falls across the northern Great Basin and northern Rockies. The low-level mass response should promote widespread sustained winds in the 15-25 mph range from the lee of the Cascades and Sierra Nevada into portions of WY. Deep mixing should promote frequent gusts between 25-30 mph. Transient swaths of 20+ mph winds will be possible across much of the region, but confidence in sustained critical wind speeds remains highest through the Snake River Plain in southern/eastern ID where flow will be orographically enhanced. 06 UTC surface observations across the Great Basin show very dry conditions already in place, and diurnal heating of this dry air mass will support widespread RH reductions into the 5-15% range. Recent fuel guidance shows widespread ERCs above the 90th percentile across much of the region, which should support the fire weather threat. ...Dry Thunderstorms... A few early-morning thunderstorms are noted in GOES GLM data between 04-05 UTC across portions of NV (likely associated with ascent ahead of a weak leading upper perturbation), though more substantial thunderstorm activity is expected later this afternoon and evening across the Great Basin. 00z soundings, water-vapor imagery, and the recent convection all confirm that a plume of mid-level moisture is in place ahead of the primary upper trough. As ascent and diurnal heating increase through the afternoon, a swath of isolated to scattered thunderstorms will likely develop from far eastern CA to eastern ID/western WY. Very deep and well-mixed boundary layers, coupled with storm motions near 20 knots, will promote mainly dry thunderstorms. With receptive fuels in place, this convection will pose a threat for new fire starts. ..Moore.. 08/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA AND FAR NORTHEAST SOUTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A shortwave trough will move eastward across the northern Plains on Thursday, with the primary upper low well north into Canada. The southern periphery of this wave will move across ND and northern MN late day and overnight, with minimal cooling aloft and increasing mid to upper level winds of 40-50 kt. At the surface, a trough will extend from central ND into western SD during the afternoon, where a surface low will exist within the warm plume. Southeast winds will bring moisture northward ahead of the front, with moderate instability forecast. Effective shear of 40-50 kt will develop late as the upper wave approaches and low-level jet increases to 30-40 kt. Storms are likely to form near 00Z along the cold front over central/eastern ND and extending into northern SD, and progress across northwest MN during the evening. Large hail appears likely as storm mode should be cellular, but areas of severe gusts may occur. Steep lapse rates aloft and strong instability may also yield hail over 2.00" diameter. Strong heating into central SD and western NE will likely yield isolated strong to severe storms as well with brief hail and locally strong gusts. ..Jewell.. 08/13/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA AND FAR NORTHEAST SOUTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A shortwave trough will move eastward across the northern Plains on Thursday, with the primary upper low well north into Canada. The southern periphery of this wave will move across ND and northern MN late day and overnight, with minimal cooling aloft and increasing mid to upper level winds of 40-50 kt. At the surface, a trough will extend from central ND into western SD during the afternoon, where a surface low will exist within the warm plume. Southeast winds will bring moisture northward ahead of the front, with moderate instability forecast. Effective shear of 40-50 kt will develop late as the upper wave approaches and low-level jet increases to 30-40 kt. Storms are likely to form near 00Z along the cold front over central/eastern ND and extending into northern SD, and progress across northwest MN during the evening. Large hail appears likely as storm mode should be cellular, but areas of severe gusts may occur. Steep lapse rates aloft and strong instability may also yield hail over 2.00" diameter. Strong heating into central SD and western NE will likely yield isolated strong to severe storms as well with brief hail and locally strong gusts. ..Jewell.. 08/13/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA AND FAR NORTHEAST SOUTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A shortwave trough will move eastward across the northern Plains on Thursday, with the primary upper low well north into Canada. The southern periphery of this wave will move across ND and northern MN late day and overnight, with minimal cooling aloft and increasing mid to upper level winds of 40-50 kt. At the surface, a trough will extend from central ND into western SD during the afternoon, where a surface low will exist within the warm plume. Southeast winds will bring moisture northward ahead of the front, with moderate instability forecast. Effective shear of 40-50 kt will develop late as the upper wave approaches and low-level jet increases to 30-40 kt. Storms are likely to form near 00Z along the cold front over central/eastern ND and extending into northern SD, and progress across northwest MN during the evening. Large hail appears likely as storm mode should be cellular, but areas of severe gusts may occur. Steep lapse rates aloft and strong instability may also yield hail over 2.00" diameter. Strong heating into central SD and western NE will likely yield isolated strong to severe storms as well with brief hail and locally strong gusts. ..Jewell.. 08/13/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA AND FAR NORTHEAST SOUTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A shortwave trough will move eastward across the northern Plains on Thursday, with the primary upper low well north into Canada. The southern periphery of this wave will move across ND and northern MN late day and overnight, with minimal cooling aloft and increasing mid to upper level winds of 40-50 kt. At the surface, a trough will extend from central ND into western SD during the afternoon, where a surface low will exist within the warm plume. Southeast winds will bring moisture northward ahead of the front, with moderate instability forecast. Effective shear of 40-50 kt will develop late as the upper wave approaches and low-level jet increases to 30-40 kt. Storms are likely to form near 00Z along the cold front over central/eastern ND and extending into northern SD, and progress across northwest MN during the evening. Large hail appears likely as storm mode should be cellular, but areas of severe gusts may occur. Steep lapse rates aloft and strong instability may also yield hail over 2.00" diameter. Strong heating into central SD and western NE will likely yield isolated strong to severe storms as well with brief hail and locally strong gusts. ..Jewell.. 08/13/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA AND FAR NORTHEAST SOUTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A shortwave trough will move eastward across the northern Plains on Thursday, with the primary upper low well north into Canada. The southern periphery of this wave will move across ND and northern MN late day and overnight, with minimal cooling aloft and increasing mid to upper level winds of 40-50 kt. At the surface, a trough will extend from central ND into western SD during the afternoon, where a surface low will exist within the warm plume. Southeast winds will bring moisture northward ahead of the front, with moderate instability forecast. Effective shear of 40-50 kt will develop late as the upper wave approaches and low-level jet increases to 30-40 kt. Storms are likely to form near 00Z along the cold front over central/eastern ND and extending into northern SD, and progress across northwest MN during the evening. Large hail appears likely as storm mode should be cellular, but areas of severe gusts may occur. Steep lapse rates aloft and strong instability may also yield hail over 2.00" diameter. Strong heating into central SD and western NE will likely yield isolated strong to severe storms as well with brief hail and locally strong gusts. ..Jewell.. 08/13/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears probable across parts of the central Plains this evening and overnight. Scattered thunderstorms across the Mid-Atlantic/Northeast may produce sporadic damaging winds this afternoon. ...Synopsis... Strong to severe thunderstorm chances today will primarily be focused across the Mid-Atlantic/Northeast and across the central Plains. Early-morning water-vapor imagery depicts a broad upper-level trough across eastern Canada and Great Lakes region with a diffuse surface front draped from the Midwest southwestward into the Plains. This wave and its attendant surface front will spread east through the day, reaching the Mid-Atlantic by around peak heating when conditions should be adequately unstable for thunderstorms. Further west, a deepening upper trough will progress rapidly across the Pacific Northwest and northern Rockies over the next 24 hours. Ascent ahead of this wave overspreading a dry, but buoyant, air mass will promote scattered thunderstorms with robust convection anticipated across the Plains later this evening/overnight as lift impinges on a more moist/buoyant air mass. ...Central Plains... 05 UTC surface observations show modest moisture return ongoing across the Plains in the wake of a recent frontal passage. Through the afternoon, a deepening of the lee trough will promote stronger moisture return just as lift ahead of the approaching wave and high-based convection emanating off the central Rockies spreads east. Deep, well-mixed boundary layers to the west of the surface trough will promote strong to severe downbursts winds as well as outflow dominant storms. Most CAM guidance suggest cold pool consolidation will be adequate for upscale growth of at least one convective cluster across the High Plains by mid/late evening. This activity will likely intensify as it encounters richer moisture within a moderately sheared environment (35-40 knots of effective shear). This scenario appears to be the most probable based on ensemble consensus, and hints that strong to severe winds will likely overspread much of southern SD and northern NE through the overnight hours. While CAMs show reasonably good agreement on the trajectory of this system, the exact corridor of propagation remains uncertain. A few solutions hint at more cellular development across portions of SD after roughly 02 UTC as isentropic ascent over an effective warm frontal zone increases with a strengthening of the nocturnal jet. Cells developing within the warm advection regime may evolve into supercells with an attendant risk for large hail given strong veering between 1-3 km and moderate effective shear. A propagating cluster may emerge out of this regime, but ensemble support for this scenario is comparatively weak. ...Mid-Atlantic/Northeast... 00z soundings across the region sampled rich low-level moisture as well as poor mid-level lapse rates. However, west/southwesterly flow aloft will advect steeper mid-level lapse rates over the next 12-18 hours. The combination of steepening lapse rates and diurnal heating of a moist air mass should result in a modestly buoyant, but weakly capped, environment across the Mid-Atlantic. Focused forcing along the front coupled with limited inhibition should promote scattered to widespread thunderstorms by 19-21 UTC. Damaging downbursts will be possible with this activity - especially where surface temperatures can warm into the upper 80s and low 90s. Based on recent ensemble guidance, this appears most probable from southern PA into the New England region. While deep-layer shear will be fairly weak, very weak surface winds under 20-25 knot mid-level flow may provide adequate deep-layer wind shear for a few persistent, more robust cells and/or clusters. ..Moore/Hart.. 08/13/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears probable across parts of the central Plains this evening and overnight. Scattered thunderstorms across the Mid-Atlantic/Northeast may produce sporadic damaging winds this afternoon. ...Synopsis... Strong to severe thunderstorm chances today will primarily be focused across the Mid-Atlantic/Northeast and across the central Plains. Early-morning water-vapor imagery depicts a broad upper-level trough across eastern Canada and Great Lakes region with a diffuse surface front draped from the Midwest southwestward into the Plains. This wave and its attendant surface front will spread east through the day, reaching the Mid-Atlantic by around peak heating when conditions should be adequately unstable for thunderstorms. Further west, a deepening upper trough will progress rapidly across the Pacific Northwest and northern Rockies over the next 24 hours. Ascent ahead of this wave overspreading a dry, but buoyant, air mass will promote scattered thunderstorms with robust convection anticipated across the Plains later this evening/overnight as lift impinges on a more moist/buoyant air mass. ...Central Plains... 05 UTC surface observations show modest moisture return ongoing across the Plains in the wake of a recent frontal passage. Through the afternoon, a deepening of the lee trough will promote stronger moisture return just as lift ahead of the approaching wave and high-based convection emanating off the central Rockies spreads east. Deep, well-mixed boundary layers to the west of the surface trough will promote strong to severe downbursts winds as well as outflow dominant storms. Most CAM guidance suggest cold pool consolidation will be adequate for upscale growth of at least one convective cluster across the High Plains by mid/late evening. This activity will likely intensify as it encounters richer moisture within a moderately sheared environment (35-40 knots of effective shear). This scenario appears to be the most probable based on ensemble consensus, and hints that strong to severe winds will likely overspread much of southern SD and northern NE through the overnight hours. While CAMs show reasonably good agreement on the trajectory of this system, the exact corridor of propagation remains uncertain. A few solutions hint at more cellular development across portions of SD after roughly 02 UTC as isentropic ascent over an effective warm frontal zone increases with a strengthening of the nocturnal jet. Cells developing within the warm advection regime may evolve into supercells with an attendant risk for large hail given strong veering between 1-3 km and moderate effective shear. A propagating cluster may emerge out of this regime, but ensemble support for this scenario is comparatively weak. ...Mid-Atlantic/Northeast... 00z soundings across the region sampled rich low-level moisture as well as poor mid-level lapse rates. However, west/southwesterly flow aloft will advect steeper mid-level lapse rates over the next 12-18 hours. The combination of steepening lapse rates and diurnal heating of a moist air mass should result in a modestly buoyant, but weakly capped, environment across the Mid-Atlantic. Focused forcing along the front coupled with limited inhibition should promote scattered to widespread thunderstorms by 19-21 UTC. Damaging downbursts will be possible with this activity - especially where surface temperatures can warm into the upper 80s and low 90s. Based on recent ensemble guidance, this appears most probable from southern PA into the New England region. While deep-layer shear will be fairly weak, very weak surface winds under 20-25 knot mid-level flow may provide adequate deep-layer wind shear for a few persistent, more robust cells and/or clusters. ..Moore/Hart.. 08/13/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears probable across parts of the central Plains this evening and overnight. Scattered thunderstorms across the Mid-Atlantic/Northeast may produce sporadic damaging winds this afternoon. ...Synopsis... Strong to severe thunderstorm chances today will primarily be focused across the Mid-Atlantic/Northeast and across the central Plains. Early-morning water-vapor imagery depicts a broad upper-level trough across eastern Canada and Great Lakes region with a diffuse surface front draped from the Midwest southwestward into the Plains. This wave and its attendant surface front will spread east through the day, reaching the Mid-Atlantic by around peak heating when conditions should be adequately unstable for thunderstorms. Further west, a deepening upper trough will progress rapidly across the Pacific Northwest and northern Rockies over the next 24 hours. Ascent ahead of this wave overspreading a dry, but buoyant, air mass will promote scattered thunderstorms with robust convection anticipated across the Plains later this evening/overnight as lift impinges on a more moist/buoyant air mass. ...Central Plains... 05 UTC surface observations show modest moisture return ongoing across the Plains in the wake of a recent frontal passage. Through the afternoon, a deepening of the lee trough will promote stronger moisture return just as lift ahead of the approaching wave and high-based convection emanating off the central Rockies spreads east. Deep, well-mixed boundary layers to the west of the surface trough will promote strong to severe downbursts winds as well as outflow dominant storms. Most CAM guidance suggest cold pool consolidation will be adequate for upscale growth of at least one convective cluster across the High Plains by mid/late evening. This activity will likely intensify as it encounters richer moisture within a moderately sheared environment (35-40 knots of effective shear). This scenario appears to be the most probable based on ensemble consensus, and hints that strong to severe winds will likely overspread much of southern SD and northern NE through the overnight hours. While CAMs show reasonably good agreement on the trajectory of this system, the exact corridor of propagation remains uncertain. A few solutions hint at more cellular development across portions of SD after roughly 02 UTC as isentropic ascent over an effective warm frontal zone increases with a strengthening of the nocturnal jet. Cells developing within the warm advection regime may evolve into supercells with an attendant risk for large hail given strong veering between 1-3 km and moderate effective shear. A propagating cluster may emerge out of this regime, but ensemble support for this scenario is comparatively weak. ...Mid-Atlantic/Northeast... 00z soundings across the region sampled rich low-level moisture as well as poor mid-level lapse rates. However, west/southwesterly flow aloft will advect steeper mid-level lapse rates over the next 12-18 hours. The combination of steepening lapse rates and diurnal heating of a moist air mass should result in a modestly buoyant, but weakly capped, environment across the Mid-Atlantic. Focused forcing along the front coupled with limited inhibition should promote scattered to widespread thunderstorms by 19-21 UTC. Damaging downbursts will be possible with this activity - especially where surface temperatures can warm into the upper 80s and low 90s. Based on recent ensemble guidance, this appears most probable from southern PA into the New England region. While deep-layer shear will be fairly weak, very weak surface winds under 20-25 knot mid-level flow may provide adequate deep-layer wind shear for a few persistent, more robust cells and/or clusters. ..Moore/Hart.. 08/13/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears probable across parts of the central Plains this evening and overnight. Scattered thunderstorms across the Mid-Atlantic/Northeast may produce sporadic damaging winds this afternoon. ...Synopsis... Strong to severe thunderstorm chances today will primarily be focused across the Mid-Atlantic/Northeast and across the central Plains. Early-morning water-vapor imagery depicts a broad upper-level trough across eastern Canada and Great Lakes region with a diffuse surface front draped from the Midwest southwestward into the Plains. This wave and its attendant surface front will spread east through the day, reaching the Mid-Atlantic by around peak heating when conditions should be adequately unstable for thunderstorms. Further west, a deepening upper trough will progress rapidly across the Pacific Northwest and northern Rockies over the next 24 hours. Ascent ahead of this wave overspreading a dry, but buoyant, air mass will promote scattered thunderstorms with robust convection anticipated across the Plains later this evening/overnight as lift impinges on a more moist/buoyant air mass. ...Central Plains... 05 UTC surface observations show modest moisture return ongoing across the Plains in the wake of a recent frontal passage. Through the afternoon, a deepening of the lee trough will promote stronger moisture return just as lift ahead of the approaching wave and high-based convection emanating off the central Rockies spreads east. Deep, well-mixed boundary layers to the west of the surface trough will promote strong to severe downbursts winds as well as outflow dominant storms. Most CAM guidance suggest cold pool consolidation will be adequate for upscale growth of at least one convective cluster across the High Plains by mid/late evening. This activity will likely intensify as it encounters richer moisture within a moderately sheared environment (35-40 knots of effective shear). This scenario appears to be the most probable based on ensemble consensus, and hints that strong to severe winds will likely overspread much of southern SD and northern NE through the overnight hours. While CAMs show reasonably good agreement on the trajectory of this system, the exact corridor of propagation remains uncertain. A few solutions hint at more cellular development across portions of SD after roughly 02 UTC as isentropic ascent over an effective warm frontal zone increases with a strengthening of the nocturnal jet. Cells developing within the warm advection regime may evolve into supercells with an attendant risk for large hail given strong veering between 1-3 km and moderate effective shear. A propagating cluster may emerge out of this regime, but ensemble support for this scenario is comparatively weak. ...Mid-Atlantic/Northeast... 00z soundings across the region sampled rich low-level moisture as well as poor mid-level lapse rates. However, west/southwesterly flow aloft will advect steeper mid-level lapse rates over the next 12-18 hours. The combination of steepening lapse rates and diurnal heating of a moist air mass should result in a modestly buoyant, but weakly capped, environment across the Mid-Atlantic. Focused forcing along the front coupled with limited inhibition should promote scattered to widespread thunderstorms by 19-21 UTC. Damaging downbursts will be possible with this activity - especially where surface temperatures can warm into the upper 80s and low 90s. Based on recent ensemble guidance, this appears most probable from southern PA into the New England region. While deep-layer shear will be fairly weak, very weak surface winds under 20-25 knot mid-level flow may provide adequate deep-layer wind shear for a few persistent, more robust cells and/or clusters. ..Moore/Hart.. 08/13/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Wed Aug 13 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears probable across parts of the central Plains this evening and overnight. Scattered thunderstorms across the Mid-Atlantic/Northeast may produce sporadic damaging winds this afternoon. ...Synopsis... Strong to severe thunderstorm chances today will primarily be focused across the Mid-Atlantic/Northeast and across the central Plains. Early-morning water-vapor imagery depicts a broad upper-level trough across eastern Canada and Great Lakes region with a diffuse surface front draped from the Midwest southwestward into the Plains. This wave and its attendant surface front will spread east through the day, reaching the Mid-Atlantic by around peak heating when conditions should be adequately unstable for thunderstorms. Further west, a deepening upper trough will progress rapidly across the Pacific Northwest and northern Rockies over the next 24 hours. Ascent ahead of this wave overspreading a dry, but buoyant, air mass will promote scattered thunderstorms with robust convection anticipated across the Plains later this evening/overnight as lift impinges on a more moist/buoyant air mass. ...Central Plains... 05 UTC surface observations show modest moisture return ongoing across the Plains in the wake of a recent frontal passage. Through the afternoon, a deepening of the lee trough will promote stronger moisture return just as lift ahead of the approaching wave and high-based convection emanating off the central Rockies spreads east. Deep, well-mixed boundary layers to the west of the surface trough will promote strong to severe downbursts winds as well as outflow dominant storms. Most CAM guidance suggest cold pool consolidation will be adequate for upscale growth of at least one convective cluster across the High Plains by mid/late evening. This activity will likely intensify as it encounters richer moisture within a moderately sheared environment (35-40 knots of effective shear). This scenario appears to be the most probable based on ensemble consensus, and hints that strong to severe winds will likely overspread much of southern SD and northern NE through the overnight hours. While CAMs show reasonably good agreement on the trajectory of this system, the exact corridor of propagation remains uncertain. A few solutions hint at more cellular development across portions of SD after roughly 02 UTC as isentropic ascent over an effective warm frontal zone increases with a strengthening of the nocturnal jet. Cells developing within the warm advection regime may evolve into supercells with an attendant risk for large hail given strong veering between 1-3 km and moderate effective shear. A propagating cluster may emerge out of this regime, but ensemble support for this scenario is comparatively weak. ...Mid-Atlantic/Northeast... 00z soundings across the region sampled rich low-level moisture as well as poor mid-level lapse rates. However, west/southwesterly flow aloft will advect steeper mid-level lapse rates over the next 12-18 hours. The combination of steepening lapse rates and diurnal heating of a moist air mass should result in a modestly buoyant, but weakly capped, environment across the Mid-Atlantic. Focused forcing along the front coupled with limited inhibition should promote scattered to widespread thunderstorms by 19-21 UTC. Damaging downbursts will be possible with this activity - especially where surface temperatures can warm into the upper 80s and low 90s. Based on recent ensemble guidance, this appears most probable from southern PA into the New England region. While deep-layer shear will be fairly weak, very weak surface winds under 20-25 knot mid-level flow may provide adequate deep-layer wind shear for a few persistent, more robust cells and/or clusters. ..Moore/Hart.. 08/13/2025 Read more

184
ABPZ20 KNHC 130530
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Tue Aug 12 2025

For the eastern and central North Pacific east of 180 longitude:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Henriette, located in the subtropical Central Pacific well to
the north-northwest of the Hawaiian Islands.

Tropical cyclone formation is not expected over the next 7 days.

$$
Forecaster Kelly

Parts of the Big Island varied from being dry to being in extreme drought with some areas seeing wildfires. Those relying on water catchments were urged to monitor their supplies and not run out of water. Honolulu Star Advertiser (Hawaii), Aug 12, 2025