Aggregator

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CST Tue Dec 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Medium-range guidance is in good agreement that a shortwave trough will move from the central Rockies through the central Plains on D4/Friday. An associated surface low will take a similar track just ahead of the parent wave, with an attendant cold front pushing eastward across the southern/central Plains. Some modest moisture return will precede this front, and thunderstorms appear possible from east TX into the Lower MO Valley D4/Friday night into D5/Saturday morning. A few strong storms are possible, but overall buoyancy will likely remain modest due to warm mid-level temperatures, and the highest dewpoints are expected to remain displaced south of the better forcing. This shortwave and attendant cold front will likely continue eastward on into the MS Valley on D5/Saturday and through the remainder of the eastern CONUS on D6/Sunday. Thunderstorms are possible over portions of the Lower MS Valley and Mid-South on D5/Saturday and the Carolinas on D6/Sunday. Limited buoyancy should keep any severe-weather threat isolated. Another shortwave trough is expected to move across CA and the Great Basin on D6/Sunday and through the central Plains and Mid MS Valley on D7/Monday. Similar to the earlier shortwave, the strongest forcing for ascent with this shortwave is expected to remain displaced north of the better low-level moisture and buoyancy, likely tempering the overall severe potential. Even so, thunderstorms are possible, and greater moisture return (and buoyancy) is possible if the preceding cold front remains weak over the southern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CST Tue Dec 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Medium-range guidance is in good agreement that a shortwave trough will move from the central Rockies through the central Plains on D4/Friday. An associated surface low will take a similar track just ahead of the parent wave, with an attendant cold front pushing eastward across the southern/central Plains. Some modest moisture return will precede this front, and thunderstorms appear possible from east TX into the Lower MO Valley D4/Friday night into D5/Saturday morning. A few strong storms are possible, but overall buoyancy will likely remain modest due to warm mid-level temperatures, and the highest dewpoints are expected to remain displaced south of the better forcing. This shortwave and attendant cold front will likely continue eastward on into the MS Valley on D5/Saturday and through the remainder of the eastern CONUS on D6/Sunday. Thunderstorms are possible over portions of the Lower MS Valley and Mid-South on D5/Saturday and the Carolinas on D6/Sunday. Limited buoyancy should keep any severe-weather threat isolated. Another shortwave trough is expected to move across CA and the Great Basin on D6/Sunday and through the central Plains and Mid MS Valley on D7/Monday. Similar to the earlier shortwave, the strongest forcing for ascent with this shortwave is expected to remain displaced north of the better low-level moisture and buoyancy, likely tempering the overall severe potential. Even so, thunderstorms are possible, and greater moisture return (and buoyancy) is possible if the preceding cold front remains weak over the southern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CST Tue Dec 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Medium-range guidance is in good agreement that a shortwave trough will move from the central Rockies through the central Plains on D4/Friday. An associated surface low will take a similar track just ahead of the parent wave, with an attendant cold front pushing eastward across the southern/central Plains. Some modest moisture return will precede this front, and thunderstorms appear possible from east TX into the Lower MO Valley D4/Friday night into D5/Saturday morning. A few strong storms are possible, but overall buoyancy will likely remain modest due to warm mid-level temperatures, and the highest dewpoints are expected to remain displaced south of the better forcing. This shortwave and attendant cold front will likely continue eastward on into the MS Valley on D5/Saturday and through the remainder of the eastern CONUS on D6/Sunday. Thunderstorms are possible over portions of the Lower MS Valley and Mid-South on D5/Saturday and the Carolinas on D6/Sunday. Limited buoyancy should keep any severe-weather threat isolated. Another shortwave trough is expected to move across CA and the Great Basin on D6/Sunday and through the central Plains and Mid MS Valley on D7/Monday. Similar to the earlier shortwave, the strongest forcing for ascent with this shortwave is expected to remain displaced north of the better low-level moisture and buoyancy, likely tempering the overall severe potential. Even so, thunderstorms are possible, and greater moisture return (and buoyancy) is possible if the preceding cold front remains weak over the southern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CST Tue Dec 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Medium-range guidance is in good agreement that a shortwave trough will move from the central Rockies through the central Plains on D4/Friday. An associated surface low will take a similar track just ahead of the parent wave, with an attendant cold front pushing eastward across the southern/central Plains. Some modest moisture return will precede this front, and thunderstorms appear possible from east TX into the Lower MO Valley D4/Friday night into D5/Saturday morning. A few strong storms are possible, but overall buoyancy will likely remain modest due to warm mid-level temperatures, and the highest dewpoints are expected to remain displaced south of the better forcing. This shortwave and attendant cold front will likely continue eastward on into the MS Valley on D5/Saturday and through the remainder of the eastern CONUS on D6/Sunday. Thunderstorms are possible over portions of the Lower MS Valley and Mid-South on D5/Saturday and the Carolinas on D6/Sunday. Limited buoyancy should keep any severe-weather threat isolated. Another shortwave trough is expected to move across CA and the Great Basin on D6/Sunday and through the central Plains and Mid MS Valley on D7/Monday. Similar to the earlier shortwave, the strongest forcing for ascent with this shortwave is expected to remain displaced north of the better low-level moisture and buoyancy, likely tempering the overall severe potential. Even so, thunderstorms are possible, and greater moisture return (and buoyancy) is possible if the preceding cold front remains weak over the southern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CST Tue Dec 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Medium-range guidance is in good agreement that a shortwave trough will move from the central Rockies through the central Plains on D4/Friday. An associated surface low will take a similar track just ahead of the parent wave, with an attendant cold front pushing eastward across the southern/central Plains. Some modest moisture return will precede this front, and thunderstorms appear possible from east TX into the Lower MO Valley D4/Friday night into D5/Saturday morning. A few strong storms are possible, but overall buoyancy will likely remain modest due to warm mid-level temperatures, and the highest dewpoints are expected to remain displaced south of the better forcing. This shortwave and attendant cold front will likely continue eastward on into the MS Valley on D5/Saturday and through the remainder of the eastern CONUS on D6/Sunday. Thunderstorms are possible over portions of the Lower MS Valley and Mid-South on D5/Saturday and the Carolinas on D6/Sunday. Limited buoyancy should keep any severe-weather threat isolated. Another shortwave trough is expected to move across CA and the Great Basin on D6/Sunday and through the central Plains and Mid MS Valley on D7/Monday. Similar to the earlier shortwave, the strongest forcing for ascent with this shortwave is expected to remain displaced north of the better low-level moisture and buoyancy, likely tempering the overall severe potential. Even so, thunderstorms are possible, and greater moisture return (and buoyancy) is possible if the preceding cold front remains weak over the southern Plains. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... A mid/upper cyclone is forecast to be over the Ontario/Quebec vicinity early Thursday morning, with cyclonic flow throughout its base extending from the northern/central Plains through the Northeast. This cyclone is expected to gradually shift eastward through Quebec, with the associated cyclonic flow shifting northward and eastward as well. Farther west, a low-amplitude shortwave trough is expected to progress across the Great Basin into the Four Corners region while enhanced mid-level westerly flow associated with it spreads from southern CA across the Southwest. At the surface, extensive ridging is expected from the northern Plains into much of the eastern CONUS, promoting dry and stable conditions. Modest lee troughing is anticipated across the High Plains ahead of the approaching shortwave. However, scouring of the low-level moisture by an antecedent frontal passage will limit moisture advection, with stable conditions prevailing across the central and southern Plains as well. ..Mosier.. 12/10/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... A mid/upper cyclone is forecast to be over the Ontario/Quebec vicinity early Thursday morning, with cyclonic flow throughout its base extending from the northern/central Plains through the Northeast. This cyclone is expected to gradually shift eastward through Quebec, with the associated cyclonic flow shifting northward and eastward as well. Farther west, a low-amplitude shortwave trough is expected to progress across the Great Basin into the Four Corners region while enhanced mid-level westerly flow associated with it spreads from southern CA across the Southwest. At the surface, extensive ridging is expected from the northern Plains into much of the eastern CONUS, promoting dry and stable conditions. Modest lee troughing is anticipated across the High Plains ahead of the approaching shortwave. However, scouring of the low-level moisture by an antecedent frontal passage will limit moisture advection, with stable conditions prevailing across the central and southern Plains as well. ..Mosier.. 12/10/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... A mid/upper cyclone is forecast to be over the Ontario/Quebec vicinity early Thursday morning, with cyclonic flow throughout its base extending from the northern/central Plains through the Northeast. This cyclone is expected to gradually shift eastward through Quebec, with the associated cyclonic flow shifting northward and eastward as well. Farther west, a low-amplitude shortwave trough is expected to progress across the Great Basin into the Four Corners region while enhanced mid-level westerly flow associated with it spreads from southern CA across the Southwest. At the surface, extensive ridging is expected from the northern Plains into much of the eastern CONUS, promoting dry and stable conditions. Modest lee troughing is anticipated across the High Plains ahead of the approaching shortwave. However, scouring of the low-level moisture by an antecedent frontal passage will limit moisture advection, with stable conditions prevailing across the central and southern Plains as well. ..Mosier.. 12/10/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... A mid/upper cyclone is forecast to be over the Ontario/Quebec vicinity early Thursday morning, with cyclonic flow throughout its base extending from the northern/central Plains through the Northeast. This cyclone is expected to gradually shift eastward through Quebec, with the associated cyclonic flow shifting northward and eastward as well. Farther west, a low-amplitude shortwave trough is expected to progress across the Great Basin into the Four Corners region while enhanced mid-level westerly flow associated with it spreads from southern CA across the Southwest. At the surface, extensive ridging is expected from the northern Plains into much of the eastern CONUS, promoting dry and stable conditions. Modest lee troughing is anticipated across the High Plains ahead of the approaching shortwave. However, scouring of the low-level moisture by an antecedent frontal passage will limit moisture advection, with stable conditions prevailing across the central and southern Plains as well. ..Mosier.. 12/10/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... A mid/upper cyclone is forecast to be over the Ontario/Quebec vicinity early Thursday morning, with cyclonic flow throughout its base extending from the northern/central Plains through the Northeast. This cyclone is expected to gradually shift eastward through Quebec, with the associated cyclonic flow shifting northward and eastward as well. Farther west, a low-amplitude shortwave trough is expected to progress across the Great Basin into the Four Corners region while enhanced mid-level westerly flow associated with it spreads from southern CA across the Southwest. At the surface, extensive ridging is expected from the northern Plains into much of the eastern CONUS, promoting dry and stable conditions. Modest lee troughing is anticipated across the High Plains ahead of the approaching shortwave. However, scouring of the low-level moisture by an antecedent frontal passage will limit moisture advection, with stable conditions prevailing across the central and southern Plains as well. ..Mosier.. 12/10/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... A mid/upper cyclone is forecast to be over the Ontario/Quebec vicinity early Thursday morning, with cyclonic flow throughout its base extending from the northern/central Plains through the Northeast. This cyclone is expected to gradually shift eastward through Quebec, with the associated cyclonic flow shifting northward and eastward as well. Farther west, a low-amplitude shortwave trough is expected to progress across the Great Basin into the Four Corners region while enhanced mid-level westerly flow associated with it spreads from southern CA across the Southwest. At the surface, extensive ridging is expected from the northern Plains into much of the eastern CONUS, promoting dry and stable conditions. Modest lee troughing is anticipated across the High Plains ahead of the approaching shortwave. However, scouring of the low-level moisture by an antecedent frontal passage will limit moisture advection, with stable conditions prevailing across the central and southern Plains as well. ..Mosier.. 12/10/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... A mid/upper cyclone is forecast to be over the Ontario/Quebec vicinity early Thursday morning, with cyclonic flow throughout its base extending from the northern/central Plains through the Northeast. This cyclone is expected to gradually shift eastward through Quebec, with the associated cyclonic flow shifting northward and eastward as well. Farther west, a low-amplitude shortwave trough is expected to progress across the Great Basin into the Four Corners region while enhanced mid-level westerly flow associated with it spreads from southern CA across the Southwest. At the surface, extensive ridging is expected from the northern Plains into much of the eastern CONUS, promoting dry and stable conditions. Modest lee troughing is anticipated across the High Plains ahead of the approaching shortwave. However, scouring of the low-level moisture by an antecedent frontal passage will limit moisture advection, with stable conditions prevailing across the central and southern Plains as well. ..Mosier.. 12/10/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ..Moore.. 12/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ..Moore.. 12/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ..Moore.. 12/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ..Moore.. 12/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ..Moore.. 12/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...Synopsis... Critical to extremely critical fire weather conditions are expected today along the southern CA coast, posing a high-end fire weather threat. 06 UTC surface observations within the southern CA coastal mountains are showing widespread RH reductions into the low to mid teens with sustained winds between 25-35 mph and frequent gusts upwards of 40-50 mph (occasionally gusting to 60-75 mph in a few locations). Other observed trends across the region suggest that winds will increase through the early to mid-morning hours (most likely peaking during the 12-17 UTC period). Surface pressure obs across northeast NV are reporting a 1036 mb surface high with further pressure rises to around 1037-1039 mb expected through 15 UTC. Additionally, latest upper-air analyses show a low to mid-level cold front pushing south into southern CA. The arrival of the cooler/more dense air mass and stronger mid-level flow, accompanied by further surface pressure rises, should result in strengthening winds through the morning hours. The observed LAX-DAG pressure gradient has also been trending lower (i.e. stronger) than depicted by most deterministic solutions, but guidance that has captured recent trends well shows increasingly widespread 60+ mph wind gusts within the Sierra Madre, San Gabriel, and San Jacinto mountains by mid-morning. Single-digit RH values will also become more common by the afternoon hours, given the duration of the downslope wind event coupled with the diurnal heating cycle. The prolonged nature of the event is also promoting rapid drying of 1- and 10-hour fuels, which will increase the fire weather threat through the day. Extremely critical wind speeds will gradually begin to abate after roughly 20 UTC, as the surface high over the Great Basin begins to weaken. However, widespread critical fire weather conditions should still persist well into early Wednesday morning. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...Synopsis... Critical to extremely critical fire weather conditions are expected today along the southern CA coast, posing a high-end fire weather threat. 06 UTC surface observations within the southern CA coastal mountains are showing widespread RH reductions into the low to mid teens with sustained winds between 25-35 mph and frequent gusts upwards of 40-50 mph (occasionally gusting to 60-75 mph in a few locations). Other observed trends across the region suggest that winds will increase through the early to mid-morning hours (most likely peaking during the 12-17 UTC period). Surface pressure obs across northeast NV are reporting a 1036 mb surface high with further pressure rises to around 1037-1039 mb expected through 15 UTC. Additionally, latest upper-air analyses show a low to mid-level cold front pushing south into southern CA. The arrival of the cooler/more dense air mass and stronger mid-level flow, accompanied by further surface pressure rises, should result in strengthening winds through the morning hours. The observed LAX-DAG pressure gradient has also been trending lower (i.e. stronger) than depicted by most deterministic solutions, but guidance that has captured recent trends well shows increasingly widespread 60+ mph wind gusts within the Sierra Madre, San Gabriel, and San Jacinto mountains by mid-morning. Single-digit RH values will also become more common by the afternoon hours, given the duration of the downslope wind event coupled with the diurnal heating cycle. The prolonged nature of the event is also promoting rapid drying of 1- and 10-hour fuels, which will increase the fire weather threat through the day. Extremely critical wind speeds will gradually begin to abate after roughly 20 UTC, as the surface high over the Great Basin begins to weaken. However, widespread critical fire weather conditions should still persist well into early Wednesday morning. ..Moore.. 12/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more