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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1046 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. today through tonight. ...Discussion... Ridging to the north of the blocking mid-level high centered over the mid-latitude eastern Pacific is rebuilding, as an initially suppressing short wave perturbation progresses inland across British Columbia. The latter feature is forecast to dig through the northern U.S. Rockies and adjacent Great Plains by 12Z Wednesday, reinforcing large-scale troughing now encompassing much of central and eastern North America. As this occurs, a pair of initially digging downstream short wave perturbations will be forced east-northeastward, into and through strong, confluent flow between a prominent mid-level ridge centered over the subtropical western Atlantic and a broad cyclonic circulation centered over the far northeastern Canadian provinces. Although down slope flow may contribute to moderating temperatures across the northern and central Great Plains, seasonably cold air associated with surface ridging entrenched across much of the southern Great Plains through Atlantic Seaboard will generally be maintained. It appears that the shallow leading edge of this cold air mass will remain south and east of the Florida Peninsula and Keys, with little in the way of surface frontal wave development across the west central through southeastern Gulf of Mexico due to lack of mid/upper support. ...Northwestern Gulf coast... In the presence of steepening mid-level lapse rates associated with differential thermal advection, it still appears that elevated moisture return will contribute to weak destabilization (rooted in the 800-700 mb layer) as far northwest as upper Texas/Louisiana coastal areas by 12-15Z this morning. This probably will provide support for a period of increasing convective development, with thermodynamic profiles possibly become conducive to at least some lightning production before diminishing by early afternoon. There remains substantive spread concerning this potential, however, and thunderstorm probabilities will be maintained at less than 10 percent, based on objective calibrated guidance from both the NCEP SREF and HREF. ..Kerr.. 01/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1046 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. today through tonight. ...Discussion... Ridging to the north of the blocking mid-level high centered over the mid-latitude eastern Pacific is rebuilding, as an initially suppressing short wave perturbation progresses inland across British Columbia. The latter feature is forecast to dig through the northern U.S. Rockies and adjacent Great Plains by 12Z Wednesday, reinforcing large-scale troughing now encompassing much of central and eastern North America. As this occurs, a pair of initially digging downstream short wave perturbations will be forced east-northeastward, into and through strong, confluent flow between a prominent mid-level ridge centered over the subtropical western Atlantic and a broad cyclonic circulation centered over the far northeastern Canadian provinces. Although down slope flow may contribute to moderating temperatures across the northern and central Great Plains, seasonably cold air associated with surface ridging entrenched across much of the southern Great Plains through Atlantic Seaboard will generally be maintained. It appears that the shallow leading edge of this cold air mass will remain south and east of the Florida Peninsula and Keys, with little in the way of surface frontal wave development across the west central through southeastern Gulf of Mexico due to lack of mid/upper support. ...Northwestern Gulf coast... In the presence of steepening mid-level lapse rates associated with differential thermal advection, it still appears that elevated moisture return will contribute to weak destabilization (rooted in the 800-700 mb layer) as far northwest as upper Texas/Louisiana coastal areas by 12-15Z this morning. This probably will provide support for a period of increasing convective development, with thermodynamic profiles possibly become conducive to at least some lightning production before diminishing by early afternoon. There remains substantive spread concerning this potential, however, and thunderstorm probabilities will be maintained at less than 10 percent, based on objective calibrated guidance from both the NCEP SREF and HREF. ..Kerr.. 01/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1046 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. today through tonight. ...Discussion... Ridging to the north of the blocking mid-level high centered over the mid-latitude eastern Pacific is rebuilding, as an initially suppressing short wave perturbation progresses inland across British Columbia. The latter feature is forecast to dig through the northern U.S. Rockies and adjacent Great Plains by 12Z Wednesday, reinforcing large-scale troughing now encompassing much of central and eastern North America. As this occurs, a pair of initially digging downstream short wave perturbations will be forced east-northeastward, into and through strong, confluent flow between a prominent mid-level ridge centered over the subtropical western Atlantic and a broad cyclonic circulation centered over the far northeastern Canadian provinces. Although down slope flow may contribute to moderating temperatures across the northern and central Great Plains, seasonably cold air associated with surface ridging entrenched across much of the southern Great Plains through Atlantic Seaboard will generally be maintained. It appears that the shallow leading edge of this cold air mass will remain south and east of the Florida Peninsula and Keys, with little in the way of surface frontal wave development across the west central through southeastern Gulf of Mexico due to lack of mid/upper support. ...Northwestern Gulf coast... In the presence of steepening mid-level lapse rates associated with differential thermal advection, it still appears that elevated moisture return will contribute to weak destabilization (rooted in the 800-700 mb layer) as far northwest as upper Texas/Louisiana coastal areas by 12-15Z this morning. This probably will provide support for a period of increasing convective development, with thermodynamic profiles possibly become conducive to at least some lightning production before diminishing by early afternoon. There remains substantive spread concerning this potential, however, and thunderstorm probabilities will be maintained at less than 10 percent, based on objective calibrated guidance from both the NCEP SREF and HREF. ..Kerr.. 01/21/2025 Read more

MD 0042 CONCERNING HEAVY SNOW FOR PORTIONS OF FAR WESTERN NEW YORK
Mesoscale Discussion 0042 NWS Storm Prediction Center Norman OK 0713 PM CST Mon Jan 20 2025 Areas affected...portions of far western New York Concerning...Heavy snow Valid 210113Z - 210415Z SUMMARY...Heavy snow should develop through tonight with an approaching lake-effect snow band. 2-3 inch/hour snowfall rates are likely, at least on an intermittent basis. DISCUSSION...While heavy snow has recently been reported by the KART ASOS, the ongoing snow-band should shift several miles southward over the next couple of hours, as indicated by KTYX regional radar data. The CWQP surface observation along the Ontario shoreline showed an abrupt wind-shift and brief increase in speed as the snow-band shifted to the south of this location, indicating potential appreciable low-level convergence. The strong convergence associated with the approaching snow-band, amid 8+ C/km 0-3 km lapse rates, suggest that the snowfall is likely associated with low-topped convection. The low-topped convection will benefit from a long fetch of Lake Ontario moisture as low-level flow parallels the lake axis this evening. Heavy lake-effect snow should begin soon, and given convective banding with 90 percent RH in the dendritic growth zone, production efficiency may be high enough to support at least 2 inch/hr snowfall rates, perhaps reaching 3 inches/hr at times. ..Squitieri.. 01/21/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BUF... LAT...LON 43867632 43927582 43917548 43787548 43697575 43687615 43757627 43867632 Read more

MD 0041 CONCERNING HEAVY SNOW FOR PORTIONS OF FAR WESTERN NEW YORK
Mesoscale Discussion 0041 NWS Storm Prediction Center Norman OK 0439 PM CST Mon Jan 20 2025 Areas affected...portions of far western New York Concerning...Heavy snow Valid 202239Z - 210245Z SUMMARY...Instances of heavy lake-effect snow should continue through the evening, with 2 inch/hour snowfall rates possible, especially over Erie County, New York. DISCUSSION...Deep-layer flow (especially closer to the surface) has become more aligned with the long axis of Lake Erie over the past couple of hours given the passing of a weak surface trough. The long fetch of appreciable low-level moisture off of the lake waters will support lake effect snow into the evening hours. 6-7 C/km low-level lapse rates (evident via 22Z mesoanalysis) will support continued heavier snowfall (as was recently observed at the DKK ASOS), with snowfall rates potentially approaching 2 inches/hour at times. ..Squitieri.. 01/20/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BUF... LAT...LON 42667911 42767897 42817890 42907887 42927861 42777847 42617851 42527878 42517889 42577899 42667911 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

No watches are valid as of Mon Jan 20 23:46:02 UTC 2025.

MD 0041 CONCERNING HEAVY SNOW FOR PORTIONS OF FAR WESTERN NEW YORK
Mesoscale Discussion 0041 NWS Storm Prediction Center Norman OK 0439 PM CST Mon Jan 20 2025 Areas affected...portions of far western New York Concerning...Heavy snow Valid 202239Z - 210245Z SUMMARY...Instances of heavy lake-effect snow should continue through the evening, with 2 inch/hour snowfall rates possible, especially over Erie County, New York. DISCUSSION...Deep-layer flow (especially closer to the surface) has become more aligned with the long axis of Lake Erie over the past couple of hours given the passing of a weak surface trough. The long fetch of appreciable low-level moisture off of the lake waters will support lake effect snow into the evening hours. 6-7 C/km low-level lapse rates (evident via 22Z mesoanalysis) will support continued heavier snowfall (as was recently observed at the DKK ASOS), with snowfall rates potentially approaching 2 inches/hour at times. ..Squitieri.. 01/20/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BUF... LAT...LON 42667911 42767897 42817890 42907887 42927861 42777847 42617851 42527878 42517889 42577899 42667911 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more