SPC Severe Thunderstorm Watch 628

11 months ago
WW 628 SEVERE TSTM AR MO OK 162035Z - 170400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 628 NWS Storm Prediction Center Norman OK 335 PM CDT Fri Aug 16 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest Arkansas Extreme southwest Missouri Northern Oklahoma * Effective this Friday afternoon and evening from 335 PM until 1100 PM CDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail likely with isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Multiple areas of thunderstorm development are possible along and south of the Kansas/Oklahoma border through late evening, in a storm environment favoring organized clusters and supercells. The more intense storms will be capable of producing very large hail up to 2.5 inches in diameter, as well as severe outflow winds up to 75 mph. The severe thunderstorm watch area is approximately along and 35 statute miles north and south of a line from 40 miles west southwest of Alva OK to 30 miles south southeast of Monett MO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 627... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 600. Mean storm motion vector 30025. ...Thompson Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

11 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN OREGON AND FAR NORTHERN NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTH-CENTRAL NEVADA AND EAST-CENTRAL CALIFORNIA... ...Update... A few adjustments were made to the Critical and Elevated areas for Saturday, along with the introduction of a narrow corridor of isolated dry thunderstorms across the western Columbia Basin of OR and WA. ...Dry/Windy... Breezy southerly surface winds are still expected to develop Saturday afternoon near two surface lows, and combine with low-teens RH. The first area of concern will be across portions of southeastern OR and far northern NV, influenced by a tightening surface pressure gradient. Here, sustained surface wind speeds as high as 20-25 mph with gusts up to 35 to 40 mph will be possible. Further south, across south-central NV and near the White and Inyo Mountains of CA, slightly higher wind speeds under the influence of a mid-level jet will be possible in conjunction with RH in the single digits to low teens. The southern extent of the Critical area across OR and northern NV was reduced slightly, since it appears the duration of critical wind-speed thresholds will remain below 3 hours there. However, the Critical area further south was expanded north and south to account for a broader region of critical speeds overlapping receptive fuels. ...Dry Thunderstorms... A mid to upper-level shortwave trough, within a broader Pacific upper trough, will impact OR and WA Saturday afternoon through late Saturday evening. Ascent associated with this feature, along with sufficient moisture, will support widely scattered thunderstorm development during this time. Most of this activity will result in wetting rainfall just west of the Cascades, but isolated dry lightning strikes appear possible within a narrow corridor mainly over the western Columbia Basin of OR on the eastern fringe of the deeper mid-level moisture axis. In addition, outflow winds associated with a cluster of thunderstorms could result in severe gusts later in the evening perhaps somewhere near the OR/WA border/Columbia Gorge. ..Barnes.. 08/16/2024 .PREV DISCUSSION... /ISSUED 0132 AM CDT Fri Aug 16 2024/ ...Synopsis... On Saturday, a mid-level shortwave trough is forecast to approach the northern California and Oregon coasts, with a fairly strong mid-level jet of 60-70 kts forecast to move northward from the San Francisco Bay area into southeastern Oregon. This trough and associated jet streak will bring critical fire-weather conditions across portions of southeastern Oregon and northern Nevada, as well as southwestern Nevada and the White/Inyo mountains of California. ...Dry/Windy... Two primary areas for critical fire-weather conditions are anticipated -- one over portions of northern Nevada and southern Oregon, and the other over southwestern Nevada and the White/Inyo mountain ranges of California. The strongest winds will likely be beneath the strongest flow of the mid-level jet streak and near the surface low in Oregon, forecast to be as high as 20-25 MPH with gusts up to 35 MPH possible. These winds will overlap with relative humidity values of 10-15% and ERC fuels near the 90th annual percentile. Some recent wetting rainfall has occurred over south-central Oregon, though modestly dry/windy conditions on Friday should result in at least some drying of fuels before Saturday. In southwestern Nevada and portions of the White/Inyo mountains in California, sustained winds of 20-25 MPH and relative humidity values of 10-15% will overspread fuels at or exceeding the 95th annual percentile, resulting in critical fire-weather conditions. Modifications to these areas may be needed with updated fuels and meteorological guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Aug 16, 2024 2000 UTC Day 1 Convective Outlook

11 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0233 PM CDT Fri Aug 16 2024 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON TO EARLY TONIGHT FROM SOUTHERN KANSAS/NORTHERN OKLAHOMA INTO FAR SOUTHWEST MISSOURI AND NORTHWEST ARKANSAS.... ...SUMMARY... Scattered severe thunderstorms are possible for central/southern Kansas into northern Oklahoma and into northwest Arkansas. Very large hail up to 2.5 inches in diameter and severe gusts up to 75 mph are the expected hazards with the stronger thunderstorms. ...KS into OK/AR/MO through tonight... A cluster of storms has persisted into the afternoon with most of the activity on the cool side of a frontal zone. However, a leading supercell has maintained its intensity into southern Kansas were temperatures are in the mid 90s and dewpoints in the mid 70s with SPC mesoanalysis indicating MLCINH has mostly eroded. Therefore, additional intensification of this storm and additional development on the trailing outflow to its west is possible. For additional information, see MCD #1921. ...TN/OH Valley this afternoon/evening... Thunderstorms are ongoing within a broad region of moderate to strong instability and weak shear from Arkansas to Tennessee and southern Kentucky. Given the instability, isolated damaging wind gusts are possible, but the lack of shear and better storm organization should preclude any organized severe-weather threat. ...WI to Lower MI this afternoon into early tonight... Thunderstorms have started to develop across eastern Wisconsin within a pocket of greater instability west of Lake Michigan. See MCD #1920 for more discussion of the threat across this region. ..Bentley.. 08/16/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Aug 16 2024/ ...KS into OK through tonight... Elevated thunderstorms have formed/strengthened since 14-15z from west central into southwest KS in a zone of low-midlevel warm advection downstream from an embedded speed max aloft. There is still some uncertainty regarding the longevity of these morning storms. However, if the ongoing storms persist into early-mid afternoon when surface temperatures warm into the 90s F, convective inhibition will diminish and the storms will become fully rooted at the surface. Given the conditionally favorable thermodynamic (MLCAPE >2000 J/kg) and vertical shear (effective bulk shear in excess of 40 kt) environment expected across southern KS/northern OK by this afternoon, will maintain the SLGT risk for large hail up to 2.5 inches in diameter and severe outflow gusts up to 75 mph. ...TN/OH Valleys this afternoon/evening... A closed midlevel low will move generally eastward over WI/MI through Saturday morning, as embedded perturbations rotate around the southern periphery of the low. Elevated convection has been slowly weakening through the morning across KY/southern OH, with other storms located farther southwest into western TN. This convection farther south will have more direct access to the moist/unstable warm sector, and there will be some potential for an increase in both storm coverage and intensity this afternoon from middle/eastern TN into northern AL/northwest GA. Occasional downbursts with wind damage will be the main concern with multicell clusters, given the relatively weak deep-layer flow/shear. ...WI to Lower MI this afternoon into early tonight... Scattered thunderstorms are expected to form across WI this afternoon and spread eastward into early tonight, along and ahead of a surface cold front, and in advance of the midlevel closed low. Moisture/buoyancy will be sufficient for strong storms capable of producing isolated large hail near 1 inch and isolated wind damage, but modest vertical shear suggests primarily multicell storms. Read more

SPC Aug 16, 2024 2000 UTC Day 1 Convective Outlook

11 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0233 PM CDT Fri Aug 16 2024 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON TO EARLY TONIGHT FROM SOUTHERN KANSAS/NORTHERN OKLAHOMA INTO FAR SOUTHWEST MISSOURI AND NORTHWEST ARKANSAS.... ...SUMMARY... Scattered severe thunderstorms are possible for central/southern Kansas into northern Oklahoma and into northwest Arkansas. Very large hail up to 2.5 inches in diameter and severe gusts up to 75 mph are the expected hazards with the stronger thunderstorms. ...KS into OK/AR/MO through tonight... A cluster of storms has persisted into the afternoon with most of the activity on the cool side of a frontal zone. However, a leading supercell has maintained its intensity into southern Kansas were temperatures are in the mid 90s and dewpoints in the mid 70s with SPC mesoanalysis indicating MLCINH has mostly eroded. Therefore, additional intensification of this storm and additional development on the trailing outflow to its west is possible. For additional information, see MCD #1921. ...TN/OH Valley this afternoon/evening... Thunderstorms are ongoing within a broad region of moderate to strong instability and weak shear from Arkansas to Tennessee and southern Kentucky. Given the instability, isolated damaging wind gusts are possible, but the lack of shear and better storm organization should preclude any organized severe-weather threat. ...WI to Lower MI this afternoon into early tonight... Thunderstorms have started to develop across eastern Wisconsin within a pocket of greater instability west of Lake Michigan. See MCD #1920 for more discussion of the threat across this region. ..Bentley.. 08/16/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Aug 16 2024/ ...KS into OK through tonight... Elevated thunderstorms have formed/strengthened since 14-15z from west central into southwest KS in a zone of low-midlevel warm advection downstream from an embedded speed max aloft. There is still some uncertainty regarding the longevity of these morning storms. However, if the ongoing storms persist into early-mid afternoon when surface temperatures warm into the 90s F, convective inhibition will diminish and the storms will become fully rooted at the surface. Given the conditionally favorable thermodynamic (MLCAPE >2000 J/kg) and vertical shear (effective bulk shear in excess of 40 kt) environment expected across southern KS/northern OK by this afternoon, will maintain the SLGT risk for large hail up to 2.5 inches in diameter and severe outflow gusts up to 75 mph. ...TN/OH Valleys this afternoon/evening... A closed midlevel low will move generally eastward over WI/MI through Saturday morning, as embedded perturbations rotate around the southern periphery of the low. Elevated convection has been slowly weakening through the morning across KY/southern OH, with other storms located farther southwest into western TN. This convection farther south will have more direct access to the moist/unstable warm sector, and there will be some potential for an increase in both storm coverage and intensity this afternoon from middle/eastern TN into northern AL/northwest GA. Occasional downbursts with wind damage will be the main concern with multicell clusters, given the relatively weak deep-layer flow/shear. ...WI to Lower MI this afternoon into early tonight... Scattered thunderstorms are expected to form across WI this afternoon and spread eastward into early tonight, along and ahead of a surface cold front, and in advance of the midlevel closed low. Moisture/buoyancy will be sufficient for strong storms capable of producing isolated large hail near 1 inch and isolated wind damage, but modest vertical shear suggests primarily multicell storms. Read more

SPC Aug 16, 2024 2000 UTC Day 1 Convective Outlook

11 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0233 PM CDT Fri Aug 16 2024 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON TO EARLY TONIGHT FROM SOUTHERN KANSAS/NORTHERN OKLAHOMA INTO FAR SOUTHWEST MISSOURI AND NORTHWEST ARKANSAS.... ...SUMMARY... Scattered severe thunderstorms are possible for central/southern Kansas into northern Oklahoma and into northwest Arkansas. Very large hail up to 2.5 inches in diameter and severe gusts up to 75 mph are the expected hazards with the stronger thunderstorms. ...KS into OK/AR/MO through tonight... A cluster of storms has persisted into the afternoon with most of the activity on the cool side of a frontal zone. However, a leading supercell has maintained its intensity into southern Kansas were temperatures are in the mid 90s and dewpoints in the mid 70s with SPC mesoanalysis indicating MLCINH has mostly eroded. Therefore, additional intensification of this storm and additional development on the trailing outflow to its west is possible. For additional information, see MCD #1921. ...TN/OH Valley this afternoon/evening... Thunderstorms are ongoing within a broad region of moderate to strong instability and weak shear from Arkansas to Tennessee and southern Kentucky. Given the instability, isolated damaging wind gusts are possible, but the lack of shear and better storm organization should preclude any organized severe-weather threat. ...WI to Lower MI this afternoon into early tonight... Thunderstorms have started to develop across eastern Wisconsin within a pocket of greater instability west of Lake Michigan. See MCD #1920 for more discussion of the threat across this region. ..Bentley.. 08/16/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Aug 16 2024/ ...KS into OK through tonight... Elevated thunderstorms have formed/strengthened since 14-15z from west central into southwest KS in a zone of low-midlevel warm advection downstream from an embedded speed max aloft. There is still some uncertainty regarding the longevity of these morning storms. However, if the ongoing storms persist into early-mid afternoon when surface temperatures warm into the 90s F, convective inhibition will diminish and the storms will become fully rooted at the surface. Given the conditionally favorable thermodynamic (MLCAPE >2000 J/kg) and vertical shear (effective bulk shear in excess of 40 kt) environment expected across southern KS/northern OK by this afternoon, will maintain the SLGT risk for large hail up to 2.5 inches in diameter and severe outflow gusts up to 75 mph. ...TN/OH Valleys this afternoon/evening... A closed midlevel low will move generally eastward over WI/MI through Saturday morning, as embedded perturbations rotate around the southern periphery of the low. Elevated convection has been slowly weakening through the morning across KY/southern OH, with other storms located farther southwest into western TN. This convection farther south will have more direct access to the moist/unstable warm sector, and there will be some potential for an increase in both storm coverage and intensity this afternoon from middle/eastern TN into northern AL/northwest GA. Occasional downbursts with wind damage will be the main concern with multicell clusters, given the relatively weak deep-layer flow/shear. ...WI to Lower MI this afternoon into early tonight... Scattered thunderstorms are expected to form across WI this afternoon and spread eastward into early tonight, along and ahead of a surface cold front, and in advance of the midlevel closed low. Moisture/buoyancy will be sufficient for strong storms capable of producing isolated large hail near 1 inch and isolated wind damage, but modest vertical shear suggests primarily multicell storms. Read more