Aggregator

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN OREGON INTO FAR NORTHEAST CALIFORNIA AND FAR NORTHWEST NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST OREGON INTO SOUTHWEST IDAHO...NORTHEAST NEVADA...AND FAR NORTHWEST UTAH... ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO WESTERN SOUTH DAKOTA... ...Synopsis... An active fire weather day is anticipated across the High Plains and Pacific Northwest/northern Great Basin. Fire weather concerns across the West will be associated with a progressive upper wave currently moving onshore along the northern CA coast, which is forecast to migrate into the interior Pacific Northwest over the next 24 hours. As this occurs, strengthening low-level winds will support dry/windy conditions, and lift ahead of the wave will promote isolated to scattered thunderstorms. To the east, flow across the northern to central Rockies is forecast to strengthen slightly within the apex of an upper ridge. This will result in modest surface pressure falls along the High Plains, which when juxtaposed with a building surface high over the Midwest will yield strong southerly winds and dry conditions. Fuels across both regions remain very dry (ERCs at or above the 90th percentile) after multiple days of dry conditions, which will support the fire weather concerns. ...Pacific Northwest/Great Basin... Regional VWPs along the West Coast are beginning to observe the influence of the approaching wave with winds in the lowest few kilometers slowly strengthening since 00 UTC. Further intensification of the low-level wind field is anticipated, which will strengthen downslope flow off the central to northern Sierra Nevada. Dry conditions are already in place and will be maintained within the augmented downslope regime. Latest ensemble guidance continues to show a strong signal for afternoon RH values to fall into the teens with 15-25 mph winds. The strongest winds (and highest probability for sustained critical conditions) are expected from northeast CA into southern OR and far northwest NV as the mid-level jet max passes overhead around peak heating. Over the past several days, a plume of monsoonal moisture has been tracked from southern AZ into northern NV and central to eastern OR. The 00 UTC MFR sounding sampled this air mass well, which is characterized by sufficient mid-level moisture to support weak convection, but a very dry boundary layer favorable for dry thunderstorms. Over the past two days, thunderstorms within this air mass across the Great Basin have been predominantly dry, and are expected to mainly be dry once again today for much of the region (one exception is from the Blue Mountains in northeast OR to the Salmon River Mountains in central ID where orographic ascent should support more prolonged convection with a higher probability for wetting rainfall). Stronger synoptic-scale forcing for ascent should result in greater thunderstorm coverage compared to previous days, warranting a scattered dry thunderstorm risk area from eastern OR into ID, northeast NV, and far northwest UT where latest CAM guidance shows the best convective signal. ...High Plains... A recent frontal intrusion into the Plains/Midwest has shunted seasonally rich moisture southward into the southern Plains. A strong surface high in the wake of the front will shift east through the day concurrent with the deepening of a weak lee trough. A dry return flow regime will become established through the day as winds become more southerly. Latest deterministic and ensemble solutions show a fairly strong signal for 20-25 mph winds (gusting to 35 mph) across western NE into western SD with RH values falling into the low 20s to teens. Consequently, confidence in sustained critical conditions over an appreciable area has increased enough to warrant introducing a Critical risk area. ..Moore.. 09/02/2024 ...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 0150 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN OREGON INTO FAR NORTHEAST CALIFORNIA AND FAR NORTHWEST NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST OREGON INTO SOUTHWEST IDAHO...NORTHEAST NEVADA...AND FAR NORTHWEST UTAH... ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO WESTERN SOUTH DAKOTA... ...Synopsis... An active fire weather day is anticipated across the High Plains and Pacific Northwest/northern Great Basin. Fire weather concerns across the West will be associated with a progressive upper wave currently moving onshore along the northern CA coast, which is forecast to migrate into the interior Pacific Northwest over the next 24 hours. As this occurs, strengthening low-level winds will support dry/windy conditions, and lift ahead of the wave will promote isolated to scattered thunderstorms. To the east, flow across the northern to central Rockies is forecast to strengthen slightly within the apex of an upper ridge. This will result in modest surface pressure falls along the High Plains, which when juxtaposed with a building surface high over the Midwest will yield strong southerly winds and dry conditions. Fuels across both regions remain very dry (ERCs at or above the 90th percentile) after multiple days of dry conditions, which will support the fire weather concerns. ...Pacific Northwest/Great Basin... Regional VWPs along the West Coast are beginning to observe the influence of the approaching wave with winds in the lowest few kilometers slowly strengthening since 00 UTC. Further intensification of the low-level wind field is anticipated, which will strengthen downslope flow off the central to northern Sierra Nevada. Dry conditions are already in place and will be maintained within the augmented downslope regime. Latest ensemble guidance continues to show a strong signal for afternoon RH values to fall into the teens with 15-25 mph winds. The strongest winds (and highest probability for sustained critical conditions) are expected from northeast CA into southern OR and far northwest NV as the mid-level jet max passes overhead around peak heating. Over the past several days, a plume of monsoonal moisture has been tracked from southern AZ into northern NV and central to eastern OR. The 00 UTC MFR sounding sampled this air mass well, which is characterized by sufficient mid-level moisture to support weak convection, but a very dry boundary layer favorable for dry thunderstorms. Over the past two days, thunderstorms within this air mass across the Great Basin have been predominantly dry, and are expected to mainly be dry once again today for much of the region (one exception is from the Blue Mountains in northeast OR to the Salmon River Mountains in central ID where orographic ascent should support more prolonged convection with a higher probability for wetting rainfall). Stronger synoptic-scale forcing for ascent should result in greater thunderstorm coverage compared to previous days, warranting a scattered dry thunderstorm risk area from eastern OR into ID, northeast NV, and far northwest UT where latest CAM guidance shows the best convective signal. ...High Plains... A recent frontal intrusion into the Plains/Midwest has shunted seasonally rich moisture southward into the southern Plains. A strong surface high in the wake of the front will shift east through the day concurrent with the deepening of a weak lee trough. A dry return flow regime will become established through the day as winds become more southerly. Latest deterministic and ensemble solutions show a fairly strong signal for 20-25 mph winds (gusting to 35 mph) across western NE into western SD with RH values falling into the low 20s to teens. Consequently, confidence in sustained critical conditions over an appreciable area has increased enough to warrant introducing a Critical risk area. ..Moore.. 09/02/2024 ...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 0150 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN OREGON INTO FAR NORTHEAST CALIFORNIA AND FAR NORTHWEST NEVADA... ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST OREGON INTO SOUTHWEST IDAHO...NORTHEAST NEVADA...AND FAR NORTHWEST UTAH... ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO WESTERN SOUTH DAKOTA... ...Synopsis... An active fire weather day is anticipated across the High Plains and Pacific Northwest/northern Great Basin. Fire weather concerns across the West will be associated with a progressive upper wave currently moving onshore along the northern CA coast, which is forecast to migrate into the interior Pacific Northwest over the next 24 hours. As this occurs, strengthening low-level winds will support dry/windy conditions, and lift ahead of the wave will promote isolated to scattered thunderstorms. To the east, flow across the northern to central Rockies is forecast to strengthen slightly within the apex of an upper ridge. This will result in modest surface pressure falls along the High Plains, which when juxtaposed with a building surface high over the Midwest will yield strong southerly winds and dry conditions. Fuels across both regions remain very dry (ERCs at or above the 90th percentile) after multiple days of dry conditions, which will support the fire weather concerns. ...Pacific Northwest/Great Basin... Regional VWPs along the West Coast are beginning to observe the influence of the approaching wave with winds in the lowest few kilometers slowly strengthening since 00 UTC. Further intensification of the low-level wind field is anticipated, which will strengthen downslope flow off the central to northern Sierra Nevada. Dry conditions are already in place and will be maintained within the augmented downslope regime. Latest ensemble guidance continues to show a strong signal for afternoon RH values to fall into the teens with 15-25 mph winds. The strongest winds (and highest probability for sustained critical conditions) are expected from northeast CA into southern OR and far northwest NV as the mid-level jet max passes overhead around peak heating. Over the past several days, a plume of monsoonal moisture has been tracked from southern AZ into northern NV and central to eastern OR. The 00 UTC MFR sounding sampled this air mass well, which is characterized by sufficient mid-level moisture to support weak convection, but a very dry boundary layer favorable for dry thunderstorms. Over the past two days, thunderstorms within this air mass across the Great Basin have been predominantly dry, and are expected to mainly be dry once again today for much of the region (one exception is from the Blue Mountains in northeast OR to the Salmon River Mountains in central ID where orographic ascent should support more prolonged convection with a higher probability for wetting rainfall). Stronger synoptic-scale forcing for ascent should result in greater thunderstorm coverage compared to previous days, warranting a scattered dry thunderstorm risk area from eastern OR into ID, northeast NV, and far northwest UT where latest CAM guidance shows the best convective signal. ...High Plains... A recent frontal intrusion into the Plains/Midwest has shunted seasonally rich moisture southward into the southern Plains. A strong surface high in the wake of the front will shift east through the day concurrent with the deepening of a weak lee trough. A dry return flow regime will become established through the day as winds become more southerly. Latest deterministic and ensemble solutions show a fairly strong signal for 20-25 mph winds (gusting to 35 mph) across western NE into western SD with RH values falling into the low 20s to teens. Consequently, confidence in sustained critical conditions over an appreciable area has increased enough to warrant introducing a Critical risk area. ..Moore.. 09/02/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION AND GREAT BASIN... ...SUMMARY... Scattered strong/a few severe storms capable of producing damaging wind gusts, and possibly marginal hail, are expected from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... As a large-scale upper trough continues to vacate the northeastern U.S. Tuesday, a second/short-wave trough initially situated over the Pacific Northwest will advance eastward across the northern Intermountain region/Great Basin. At the surface, a cold front will shift eastward across the northwestern quarter of the country, in conjunction with the advancing upper trough, while westerly flow aloft will maintain a High-Plains lee trough. Meanwhile, a remnant baroclinic zone will linger from the southern Atlantic coastal area westward across the Gulf Coast/northern Gulf of Mexico through the period, as a large area of high pressure prevails north of the front, across the central and eastern U.S., through the period. ...Montana to the western Dakotas, and southward to northwestern Colorado and Utah... As the upper system advances eastward across Idaho/western Montana and the Great Basin during the afternoon, daytime heating/mixing will eventually result in 500 to 1000 J/kg mixed-layer CAPE atop a deep/dry boundary layer. This will support development of scattered thunderstorms from western Montana/eastern Idaho southward across Utah and adjacent portions of eastern Nevada. The strongest storms are expected to evolve from southwestern Montana south to northern Utah, where CAPE should be maximized ahead of the trough, and a belt of 30 to 40 kt west-southwesterly mid-level flow on the southeastern periphery of the upper trough should reside. Here, a couple of the strongest -- potentially rotating -- storms will be capable of producing both strong/severe outflow winds and possibly marginal hail. Surrounding this area, where instability and/or shear should remain a bit weaker, the primary risk will be isolated strong wind gusts. Through late afternoon and into the evening, convection -- and local risk for strong/damaging winds -- will spread eastward toward/into the High Plains, before weakening into the overnight hours. ..Goss.. 09/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION AND GREAT BASIN... ...SUMMARY... Scattered strong/a few severe storms capable of producing damaging wind gusts, and possibly marginal hail, are expected from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... As a large-scale upper trough continues to vacate the northeastern U.S. Tuesday, a second/short-wave trough initially situated over the Pacific Northwest will advance eastward across the northern Intermountain region/Great Basin. At the surface, a cold front will shift eastward across the northwestern quarter of the country, in conjunction with the advancing upper trough, while westerly flow aloft will maintain a High-Plains lee trough. Meanwhile, a remnant baroclinic zone will linger from the southern Atlantic coastal area westward across the Gulf Coast/northern Gulf of Mexico through the period, as a large area of high pressure prevails north of the front, across the central and eastern U.S., through the period. ...Montana to the western Dakotas, and southward to northwestern Colorado and Utah... As the upper system advances eastward across Idaho/western Montana and the Great Basin during the afternoon, daytime heating/mixing will eventually result in 500 to 1000 J/kg mixed-layer CAPE atop a deep/dry boundary layer. This will support development of scattered thunderstorms from western Montana/eastern Idaho southward across Utah and adjacent portions of eastern Nevada. The strongest storms are expected to evolve from southwestern Montana south to northern Utah, where CAPE should be maximized ahead of the trough, and a belt of 30 to 40 kt west-southwesterly mid-level flow on the southeastern periphery of the upper trough should reside. Here, a couple of the strongest -- potentially rotating -- storms will be capable of producing both strong/severe outflow winds and possibly marginal hail. Surrounding this area, where instability and/or shear should remain a bit weaker, the primary risk will be isolated strong wind gusts. Through late afternoon and into the evening, convection -- and local risk for strong/damaging winds -- will spread eastward toward/into the High Plains, before weakening into the overnight hours. ..Goss.. 09/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION AND GREAT BASIN... ...SUMMARY... Scattered strong/a few severe storms capable of producing damaging wind gusts, and possibly marginal hail, are expected from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... As a large-scale upper trough continues to vacate the northeastern U.S. Tuesday, a second/short-wave trough initially situated over the Pacific Northwest will advance eastward across the northern Intermountain region/Great Basin. At the surface, a cold front will shift eastward across the northwestern quarter of the country, in conjunction with the advancing upper trough, while westerly flow aloft will maintain a High-Plains lee trough. Meanwhile, a remnant baroclinic zone will linger from the southern Atlantic coastal area westward across the Gulf Coast/northern Gulf of Mexico through the period, as a large area of high pressure prevails north of the front, across the central and eastern U.S., through the period. ...Montana to the western Dakotas, and southward to northwestern Colorado and Utah... As the upper system advances eastward across Idaho/western Montana and the Great Basin during the afternoon, daytime heating/mixing will eventually result in 500 to 1000 J/kg mixed-layer CAPE atop a deep/dry boundary layer. This will support development of scattered thunderstorms from western Montana/eastern Idaho southward across Utah and adjacent portions of eastern Nevada. The strongest storms are expected to evolve from southwestern Montana south to northern Utah, where CAPE should be maximized ahead of the trough, and a belt of 30 to 40 kt west-southwesterly mid-level flow on the southeastern periphery of the upper trough should reside. Here, a couple of the strongest -- potentially rotating -- storms will be capable of producing both strong/severe outflow winds and possibly marginal hail. Surrounding this area, where instability and/or shear should remain a bit weaker, the primary risk will be isolated strong wind gusts. Through late afternoon and into the evening, convection -- and local risk for strong/damaging winds -- will spread eastward toward/into the High Plains, before weakening into the overnight hours. ..Goss.. 09/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION AND GREAT BASIN... ...SUMMARY... Scattered strong/a few severe storms capable of producing damaging wind gusts, and possibly marginal hail, are expected from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... As a large-scale upper trough continues to vacate the northeastern U.S. Tuesday, a second/short-wave trough initially situated over the Pacific Northwest will advance eastward across the northern Intermountain region/Great Basin. At the surface, a cold front will shift eastward across the northwestern quarter of the country, in conjunction with the advancing upper trough, while westerly flow aloft will maintain a High-Plains lee trough. Meanwhile, a remnant baroclinic zone will linger from the southern Atlantic coastal area westward across the Gulf Coast/northern Gulf of Mexico through the period, as a large area of high pressure prevails north of the front, across the central and eastern U.S., through the period. ...Montana to the western Dakotas, and southward to northwestern Colorado and Utah... As the upper system advances eastward across Idaho/western Montana and the Great Basin during the afternoon, daytime heating/mixing will eventually result in 500 to 1000 J/kg mixed-layer CAPE atop a deep/dry boundary layer. This will support development of scattered thunderstorms from western Montana/eastern Idaho southward across Utah and adjacent portions of eastern Nevada. The strongest storms are expected to evolve from southwestern Montana south to northern Utah, where CAPE should be maximized ahead of the trough, and a belt of 30 to 40 kt west-southwesterly mid-level flow on the southeastern periphery of the upper trough should reside. Here, a couple of the strongest -- potentially rotating -- storms will be capable of producing both strong/severe outflow winds and possibly marginal hail. Surrounding this area, where instability and/or shear should remain a bit weaker, the primary risk will be isolated strong wind gusts. Through late afternoon and into the evening, convection -- and local risk for strong/damaging winds -- will spread eastward toward/into the High Plains, before weakening into the overnight hours. ..Goss.. 09/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION AND GREAT BASIN... ...SUMMARY... Scattered strong/a few severe storms capable of producing damaging wind gusts, and possibly marginal hail, are expected from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... As a large-scale upper trough continues to vacate the northeastern U.S. Tuesday, a second/short-wave trough initially situated over the Pacific Northwest will advance eastward across the northern Intermountain region/Great Basin. At the surface, a cold front will shift eastward across the northwestern quarter of the country, in conjunction with the advancing upper trough, while westerly flow aloft will maintain a High-Plains lee trough. Meanwhile, a remnant baroclinic zone will linger from the southern Atlantic coastal area westward across the Gulf Coast/northern Gulf of Mexico through the period, as a large area of high pressure prevails north of the front, across the central and eastern U.S., through the period. ...Montana to the western Dakotas, and southward to northwestern Colorado and Utah... As the upper system advances eastward across Idaho/western Montana and the Great Basin during the afternoon, daytime heating/mixing will eventually result in 500 to 1000 J/kg mixed-layer CAPE atop a deep/dry boundary layer. This will support development of scattered thunderstorms from western Montana/eastern Idaho southward across Utah and adjacent portions of eastern Nevada. The strongest storms are expected to evolve from southwestern Montana south to northern Utah, where CAPE should be maximized ahead of the trough, and a belt of 30 to 40 kt west-southwesterly mid-level flow on the southeastern periphery of the upper trough should reside. Here, a couple of the strongest -- potentially rotating -- storms will be capable of producing both strong/severe outflow winds and possibly marginal hail. Surrounding this area, where instability and/or shear should remain a bit weaker, the primary risk will be isolated strong wind gusts. Through late afternoon and into the evening, convection -- and local risk for strong/damaging winds -- will spread eastward toward/into the High Plains, before weakening into the overnight hours. ..Goss.. 09/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION AND GREAT BASIN... ...SUMMARY... Scattered strong/a few severe storms capable of producing damaging wind gusts, and possibly marginal hail, are expected from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... As a large-scale upper trough continues to vacate the northeastern U.S. Tuesday, a second/short-wave trough initially situated over the Pacific Northwest will advance eastward across the northern Intermountain region/Great Basin. At the surface, a cold front will shift eastward across the northwestern quarter of the country, in conjunction with the advancing upper trough, while westerly flow aloft will maintain a High-Plains lee trough. Meanwhile, a remnant baroclinic zone will linger from the southern Atlantic coastal area westward across the Gulf Coast/northern Gulf of Mexico through the period, as a large area of high pressure prevails north of the front, across the central and eastern U.S., through the period. ...Montana to the western Dakotas, and southward to northwestern Colorado and Utah... As the upper system advances eastward across Idaho/western Montana and the Great Basin during the afternoon, daytime heating/mixing will eventually result in 500 to 1000 J/kg mixed-layer CAPE atop a deep/dry boundary layer. This will support development of scattered thunderstorms from western Montana/eastern Idaho southward across Utah and adjacent portions of eastern Nevada. The strongest storms are expected to evolve from southwestern Montana south to northern Utah, where CAPE should be maximized ahead of the trough, and a belt of 30 to 40 kt west-southwesterly mid-level flow on the southeastern periphery of the upper trough should reside. Here, a couple of the strongest -- potentially rotating -- storms will be capable of producing both strong/severe outflow winds and possibly marginal hail. Surrounding this area, where instability and/or shear should remain a bit weaker, the primary risk will be isolated strong wind gusts. Through late afternoon and into the evening, convection -- and local risk for strong/damaging winds -- will spread eastward toward/into the High Plains, before weakening into the overnight hours. ..Goss.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

000
ABPZ20 KNHC 020526
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sun Sep 1 2024

For the eastern North Pacific...east of 140 degrees west longitude:

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

$$
Forecaster Blake

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Sun Sep 01 2024 Valid 020100Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms will continue into the late evening and overnight hours from the Mid-Atlantic region into the southern CONUS, Four Corners region, and Pacific Northwest. ...Summary... Isolated to scattered thunderstorms are expected to persist into the early morning hours across parts of the Mid-Atlantic, but the overall severe threat appears sufficiently low to remove risk probabilities. ...Mid-Atlantic... Thunderstorms across the Mid-Atlantic region have shown signs of steady weakening over the past hour based on regional reflectivity imagery, MRMS echo-top heights, and cloud-top temperatures. 00 UTC soundings along the East Coast, and downstream from ongoing multicell clusters, sampled around 500-1000 J/kg MLCAPE with around 20 knots of mid-level flow. A sporadic strong updraft or two will remain possible this evening along the outflow boundaries of ongoing convection given these environmental conditions. However, the onset of nocturnal cooling will continue to modulate mixed-layer buoyancy (with an attendance increase in inhibition), which should maintain the overall weakening trend. Latest CAM solutions support this scenario with increasingly sparse thunderstorm coverage heading into the early morning hours. Consequently, the overall severe potential appears sufficiently low to warrant removing risk probabilities. ..Moore.. 09/02/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Sun Sep 01 2024 Valid 020100Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms will continue into the late evening and overnight hours from the Mid-Atlantic region into the southern CONUS, Four Corners region, and Pacific Northwest. ...Summary... Isolated to scattered thunderstorms are expected to persist into the early morning hours across parts of the Mid-Atlantic, but the overall severe threat appears sufficiently low to remove risk probabilities. ...Mid-Atlantic... Thunderstorms across the Mid-Atlantic region have shown signs of steady weakening over the past hour based on regional reflectivity imagery, MRMS echo-top heights, and cloud-top temperatures. 00 UTC soundings along the East Coast, and downstream from ongoing multicell clusters, sampled around 500-1000 J/kg MLCAPE with around 20 knots of mid-level flow. A sporadic strong updraft or two will remain possible this evening along the outflow boundaries of ongoing convection given these environmental conditions. However, the onset of nocturnal cooling will continue to modulate mixed-layer buoyancy (with an attendance increase in inhibition), which should maintain the overall weakening trend. Latest CAM solutions support this scenario with increasingly sparse thunderstorm coverage heading into the early morning hours. Consequently, the overall severe potential appears sufficiently low to warrant removing risk probabilities. ..Moore.. 09/02/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Sun Sep 01 2024 Valid 020100Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms will continue into the late evening and overnight hours from the Mid-Atlantic region into the southern CONUS, Four Corners region, and Pacific Northwest. ...Summary... Isolated to scattered thunderstorms are expected to persist into the early morning hours across parts of the Mid-Atlantic, but the overall severe threat appears sufficiently low to remove risk probabilities. ...Mid-Atlantic... Thunderstorms across the Mid-Atlantic region have shown signs of steady weakening over the past hour based on regional reflectivity imagery, MRMS echo-top heights, and cloud-top temperatures. 00 UTC soundings along the East Coast, and downstream from ongoing multicell clusters, sampled around 500-1000 J/kg MLCAPE with around 20 knots of mid-level flow. A sporadic strong updraft or two will remain possible this evening along the outflow boundaries of ongoing convection given these environmental conditions. However, the onset of nocturnal cooling will continue to modulate mixed-layer buoyancy (with an attendance increase in inhibition), which should maintain the overall weakening trend. Latest CAM solutions support this scenario with increasingly sparse thunderstorm coverage heading into the early morning hours. Consequently, the overall severe potential appears sufficiently low to warrant removing risk probabilities. ..Moore.. 09/02/2024 Read more

389
ABPZ20 KNHC 012315
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sun Sep 1 2024

For the eastern North Pacific...east of 140 degrees west longitude:

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

$$
Forecaster Pasch