Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0121 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather potential appears limited for Thursday for much of the country, though regional concerns may materialize across southern New Mexico into Southwest Texas. The upper low currently off the CA coast is forecast to reach the Four Corners region by Thursday morning with an attendant surface low over central NM. A trailing Pacific cold front should sweep through southern NM and southwest TX through the afternoon. Ensemble guidance shows reasonably good agreement in sustained winds above 15 mph, possibly gusting as high as 30-35 mph. Little in the way of temperature reductions are currently anticipated behind the front, and the westerly flow regime should promote downslope warming/drying. However, most solutions hint at isolated to scattered showers and thunderstorms along the front, which may negate recent days of modest drying. Furthermore, scattered cloud cover may also modulate RH reductions. While the potential for elevated fire weather conditions is noted, uncertainties regarding rain chances and cloud cover preclude highlights. ..Moore.. 01/03/2024 ...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 0121 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather potential appears limited for Thursday for much of the country, though regional concerns may materialize across southern New Mexico into Southwest Texas. The upper low currently off the CA coast is forecast to reach the Four Corners region by Thursday morning with an attendant surface low over central NM. A trailing Pacific cold front should sweep through southern NM and southwest TX through the afternoon. Ensemble guidance shows reasonably good agreement in sustained winds above 15 mph, possibly gusting as high as 30-35 mph. Little in the way of temperature reductions are currently anticipated behind the front, and the westerly flow regime should promote downslope warming/drying. However, most solutions hint at isolated to scattered showers and thunderstorms along the front, which may negate recent days of modest drying. Furthermore, scattered cloud cover may also modulate RH reductions. While the potential for elevated fire weather conditions is noted, uncertainties regarding rain chances and cloud cover preclude highlights. ..Moore.. 01/03/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 0001 CONCERNING HEAVY SNOW FOR THE SIERRA NEVADA...FROM WEST OF TAHOE INTO AREAS SOUTHEAST OF YOSEMITE
Mesoscale Discussion 0001 NWS Storm Prediction Center Norman OK 0926 PM CST Tue Jan 02 2024 Areas affected...the Sierra Nevada...from west of Tahoe into areas southeast of Yosemite Concerning...Heavy snow Valid 030326Z - 030800Z SUMMARY...Heavy snow rates in excess of 2 inches per hour may begin impacting the I-80 corridor west of Tahoe by 9-10 PM PST, if not earlier, before developing southward along the western slopes of the Sierra Nevada, across and southeast of Yosemite by midnight-1 AM PST. DISCUSSION...Cloud tops have been cooling the past few hours, inland of the San Francisco Bay area toward the Sierra Nevada to the west of Tahoe. This is occurring downstream of a vigorous short wave trough, which is forecast to continue gradually pivoting across and inland of the central California coast through 06-09Z., accompanied by considerable further strengthening of large-scale ascent. Models indicate that strongest lift will focus along a frontal zone already in the process of advancing inland, south/east of the Bay area and into the northern Sierra Nevada, and within an increasing upslope flow component across the western slopes of the northern into southern Sierra Nevada by late evening. Coupled with saturating thermodynanmic profiles, including precipitable water in excess of .4 to .5 inches, strengthening lift through through mid-levels with favorable cold temperatures for large dendritic ice crystal growth (roughly between 700-600 mb in forecast soundings) appears likely to yield intensifying snow rates. By 05-06Z, if not before, guidance generally indicates that this may include rates in excess of 2 inches per hour near the Interstate 80 corridor, where cold advection may result in snow levels falling to near or below 4000 feet. As the strengthening lift develops southward along the mountains into and southeast of the Yosemite vicinity through 08-09Z, snow levels are likely to be higher (on the order of 4500 to 5000+ feet), at least initially, before gradually falling overnight. However, somewhat higher moisture content may support heavier peak rates approaching or exceeding 3 inches per hour. ..Kerr.. 01/03/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...REV...HNX...STO... LAT...LON 39282034 38832002 38131950 37361936 37671975 38162027 38772070 39082082 39282034 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 AM CST Wed Jan 03 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... ...Synopsis... Minimal fire weather concerns are expected today. Latest fuel guidance reveals some recent drying from the southern High Plains into the central and northern High Plains. However, early-morning surface observations show a cold front pushing southward through the Northern Plains that should usher in cooler temperatures by this afternoon. Similarly, surface high pressure over the southern Plains after a recent frontal passage will favor cool and fairly calm conditions this afternoon. ..Moore.. 01/03/2024 ...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 1251 AM CST Wed Jan 03 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... ...Synopsis... Minimal fire weather concerns are expected today. Latest fuel guidance reveals some recent drying from the southern High Plains into the central and northern High Plains. However, early-morning surface observations show a cold front pushing southward through the Northern Plains that should usher in cooler temperatures by this afternoon. Similarly, surface high pressure over the southern Plains after a recent frontal passage will favor cool and fairly calm conditions this afternoon. ..Moore.. 01/03/2024 ...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 1251 AM CST Wed Jan 03 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... ...Synopsis... Minimal fire weather concerns are expected today. Latest fuel guidance reveals some recent drying from the southern High Plains into the central and northern High Plains. However, early-morning surface observations show a cold front pushing southward through the Northern Plains that should usher in cooler temperatures by this afternoon. Similarly, surface high pressure over the southern Plains after a recent frontal passage will favor cool and fairly calm conditions this afternoon. ..Moore.. 01/03/2024 ...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 1251 AM CST Wed Jan 03 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... ...Synopsis... Minimal fire weather concerns are expected today. Latest fuel guidance reveals some recent drying from the southern High Plains into the central and northern High Plains. However, early-morning surface observations show a cold front pushing southward through the Northern Plains that should usher in cooler temperatures by this afternoon. Similarly, surface high pressure over the southern Plains after a recent frontal passage will favor cool and fairly calm conditions this afternoon. ..Moore.. 01/03/2024 ...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 1251 AM CST Wed Jan 03 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... ...Synopsis... Minimal fire weather concerns are expected today. Latest fuel guidance reveals some recent drying from the southern High Plains into the central and northern High Plains. However, early-morning surface observations show a cold front pushing southward through the Northern Plains that should usher in cooler temperatures by this afternoon. Similarly, surface high pressure over the southern Plains after a recent frontal passage will favor cool and fairly calm conditions this afternoon. ..Moore.. 01/03/2024 ...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 1251 AM CST Wed Jan 03 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... ...Synopsis... Minimal fire weather concerns are expected today. Latest fuel guidance reveals some recent drying from the southern High Plains into the central and northern High Plains. However, early-morning surface observations show a cold front pushing southward through the Northern Plains that should usher in cooler temperatures by this afternoon. Similarly, surface high pressure over the southern Plains after a recent frontal passage will favor cool and fairly calm conditions this afternoon. ..Moore.. 01/03/2024 ...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 1251 AM CST Wed Jan 03 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... ...Synopsis... Minimal fire weather concerns are expected today. Latest fuel guidance reveals some recent drying from the southern High Plains into the central and northern High Plains. However, early-morning surface observations show a cold front pushing southward through the Northern Plains that should usher in cooler temperatures by this afternoon. Similarly, surface high pressure over the southern Plains after a recent frontal passage will favor cool and fairly calm conditions this afternoon. ..Moore.. 01/03/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears generally low. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with two possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. A separate area of thunderstorms also appears possible late Thursday night into early Friday morning across portions of coastal TX, as greater low-level moisture begins to return northward and weak MUCAPE develops across this area. ..Gleason.. 01/03/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears generally low. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with two possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. A separate area of thunderstorms also appears possible late Thursday night into early Friday morning across portions of coastal TX, as greater low-level moisture begins to return northward and weak MUCAPE develops across this area. ..Gleason.. 01/03/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears generally low. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with two possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. A separate area of thunderstorms also appears possible late Thursday night into early Friday morning across portions of coastal TX, as greater low-level moisture begins to return northward and weak MUCAPE develops across this area. ..Gleason.. 01/03/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears generally low. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with two possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. A separate area of thunderstorms also appears possible late Thursday night into early Friday morning across portions of coastal TX, as greater low-level moisture begins to return northward and weak MUCAPE develops across this area. ..Gleason.. 01/03/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears generally low. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with two possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. A separate area of thunderstorms also appears possible late Thursday night into early Friday morning across portions of coastal TX, as greater low-level moisture begins to return northward and weak MUCAPE develops across this area. ..Gleason.. 01/03/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears generally low. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with two possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. A separate area of thunderstorms also appears possible late Thursday night into early Friday morning across portions of coastal TX, as greater low-level moisture begins to return northward and weak MUCAPE develops across this area. ..Gleason.. 01/03/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Wed Jan 03 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears generally low. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with two possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. A separate area of thunderstorms also appears possible late Thursday night into early Friday morning across portions of coastal TX, as greater low-level moisture begins to return northward and weak MUCAPE develops across this area. ..Gleason.. 01/03/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1139 PM CST Tue Jan 02 2024 Valid 031200Z - 041200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today through tonight. ...Synopsis... Thunderstorm potential for today and tonight will primarily be driven by two upper lows as they traverse the northern Gulf Coast and the lower Colorado River Valley regions. Meager buoyancy is expected to modulate the potential for organized convection for most locations, with perhaps the exception of the FL west coast. ...Gulf Coast/FL West Coast.. The first of these waves is noted in water-vapor imagery over central TX with an attendant surface low beginning to deepen off the TX Gulf Coast. Objective analyses and surface observations show a broad baroclinic zone - the remnants of a prior frontal intrusion into the Gulf/FL peninsula - draped to the east/southeast. The surface low is forecast to propagate along this effective warm front across the northern Gulf over the next 24 hours, reaching the FL west coast by early Thursday morning. Robust convection attendant to the low appears probable over the Gulf given strong (45-55 knots at 500 mb) flow aloft and recent radar trends. However, 00 UTC soundings across FL sampled an anomalously dry air mass (PWAT values well below the 10th percentile for early January) as a result of the recent frontal intrusion. While some moistening is expected to occur through the day ahead of the approaching low, establishing a quality warm sector inland prior to the arrival of stronger ascent seems unlikely. This idea is reflected in latest CAM ensemble guidance as convective signatures diminish with landfall, suggesting that the potential for organized convection over land is low. That said, a few forecast soundings hint that adequate low-level theta-e may materialize along the immediate FL west coast (including the Tampa Bay area) to support strong, surface-based convection. Given the aforementioned kinematics, this suggests a conditional threat for an organized cell or two. This potential remains too limited to introduce probabilities, but low-level theta-e trends will be monitored. ...California into AZ/NM... Cooler temperatures aloft and strong ascent associated with the upper low over the eastern Pacific are currently supporting sporadic lightning flashes off and along the northern CA coast. Steepening mid-level lapse rates due to differential temperature advection and broadscale ascent, coupled with a modest influx of mid-level maritime moisture, is expected to support marginal instability in the vicinity of the upper trough as it shifts to the east/southeast over the next 24 hours. Consequently, isolated lightning flashes seem probable along the CA coast, across parts of southern NV, and over AZ/western NM through early Thursday morning. ..Moore.. 01/03/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1139 PM CST Tue Jan 02 2024 Valid 031200Z - 041200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today through tonight. ...Synopsis... Thunderstorm potential for today and tonight will primarily be driven by two upper lows as they traverse the northern Gulf Coast and the lower Colorado River Valley regions. Meager buoyancy is expected to modulate the potential for organized convection for most locations, with perhaps the exception of the FL west coast. ...Gulf Coast/FL West Coast.. The first of these waves is noted in water-vapor imagery over central TX with an attendant surface low beginning to deepen off the TX Gulf Coast. Objective analyses and surface observations show a broad baroclinic zone - the remnants of a prior frontal intrusion into the Gulf/FL peninsula - draped to the east/southeast. The surface low is forecast to propagate along this effective warm front across the northern Gulf over the next 24 hours, reaching the FL west coast by early Thursday morning. Robust convection attendant to the low appears probable over the Gulf given strong (45-55 knots at 500 mb) flow aloft and recent radar trends. However, 00 UTC soundings across FL sampled an anomalously dry air mass (PWAT values well below the 10th percentile for early January) as a result of the recent frontal intrusion. While some moistening is expected to occur through the day ahead of the approaching low, establishing a quality warm sector inland prior to the arrival of stronger ascent seems unlikely. This idea is reflected in latest CAM ensemble guidance as convective signatures diminish with landfall, suggesting that the potential for organized convection over land is low. That said, a few forecast soundings hint that adequate low-level theta-e may materialize along the immediate FL west coast (including the Tampa Bay area) to support strong, surface-based convection. Given the aforementioned kinematics, this suggests a conditional threat for an organized cell or two. This potential remains too limited to introduce probabilities, but low-level theta-e trends will be monitored. ...California into AZ/NM... Cooler temperatures aloft and strong ascent associated with the upper low over the eastern Pacific are currently supporting sporadic lightning flashes off and along the northern CA coast. Steepening mid-level lapse rates due to differential temperature advection and broadscale ascent, coupled with a modest influx of mid-level maritime moisture, is expected to support marginal instability in the vicinity of the upper trough as it shifts to the east/southeast over the next 24 hours. Consequently, isolated lightning flashes seem probable along the CA coast, across parts of southern NV, and over AZ/western NM through early Thursday morning. ..Moore.. 01/03/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1139 PM CST Tue Jan 02 2024 Valid 031200Z - 041200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today through tonight. ...Synopsis... Thunderstorm potential for today and tonight will primarily be driven by two upper lows as they traverse the northern Gulf Coast and the lower Colorado River Valley regions. Meager buoyancy is expected to modulate the potential for organized convection for most locations, with perhaps the exception of the FL west coast. ...Gulf Coast/FL West Coast.. The first of these waves is noted in water-vapor imagery over central TX with an attendant surface low beginning to deepen off the TX Gulf Coast. Objective analyses and surface observations show a broad baroclinic zone - the remnants of a prior frontal intrusion into the Gulf/FL peninsula - draped to the east/southeast. The surface low is forecast to propagate along this effective warm front across the northern Gulf over the next 24 hours, reaching the FL west coast by early Thursday morning. Robust convection attendant to the low appears probable over the Gulf given strong (45-55 knots at 500 mb) flow aloft and recent radar trends. However, 00 UTC soundings across FL sampled an anomalously dry air mass (PWAT values well below the 10th percentile for early January) as a result of the recent frontal intrusion. While some moistening is expected to occur through the day ahead of the approaching low, establishing a quality warm sector inland prior to the arrival of stronger ascent seems unlikely. This idea is reflected in latest CAM ensemble guidance as convective signatures diminish with landfall, suggesting that the potential for organized convection over land is low. That said, a few forecast soundings hint that adequate low-level theta-e may materialize along the immediate FL west coast (including the Tampa Bay area) to support strong, surface-based convection. Given the aforementioned kinematics, this suggests a conditional threat for an organized cell or two. This potential remains too limited to introduce probabilities, but low-level theta-e trends will be monitored. ...California into AZ/NM... Cooler temperatures aloft and strong ascent associated with the upper low over the eastern Pacific are currently supporting sporadic lightning flashes off and along the northern CA coast. Steepening mid-level lapse rates due to differential temperature advection and broadscale ascent, coupled with a modest influx of mid-level maritime moisture, is expected to support marginal instability in the vicinity of the upper trough as it shifts to the east/southeast over the next 24 hours. Consequently, isolated lightning flashes seem probable along the CA coast, across parts of southern NV, and over AZ/western NM through early Thursday morning. ..Moore.. 01/03/2024 Read more