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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...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 1155 AM CDT Tue Jul 01 2025 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Northern California... Isolated dry thunderstorm threat was extended farther south along the California coastal range with thunderstorm development expected just north of Napa Valley this afternoon. Similarly, thermodynamic profiles over the northern Sierra suggests convective development just north of Lake Tahoe later today, moving into northeastern California and southern Oregon through the afternoon and evening hours. ...Southern/Central Nevada... Critical fire weather conditions with sustained southerly winds of 15-20 mph and daytime relative humidity of 10-15% amid dry fuels will increase wildfire spread potential across central and southern Nevada today. Otherwise, previous forecast (see below) remains largely on track with additional high-based showers and thunderstorms with potential lightning ignitions amid receptive fuels over the higher terrain of northwest Arizona, central Utah into the Upper Snake River Plain and far southwest Wyoming. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0119 AM CDT Tue Jul 01 2025/ ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Tue Jul 1 16:31:02 UTC 2025.

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CDT Tue Jul 01 2025 Valid 011630Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. ..Mosier/Karstens.. 07/01/2025 Read more