SPC Forecast Products
Current Mesoscale Discussions
SPC - No watches are valid as of Tue Dec 5 07:24:02 UTC 2023
No watches are valid as of Tue Dec 5 07:24:02 UTC 2023.
SPC - No MDs are in effect as of Tue Dec 5 07:24:02 UTC 2023
No Mesoscale Discussions are in effect as of Tue Dec 5 07:24:02 UTC 2023.
SPC Dec 5, 2023 0600 UTC Day 1 Convective Outlook
SPC 1200Z Day 1 OutlookDay 1 Convective Outlook NWS Storm Prediction Center Norman OK 1116 PM CST Mon Dec 04 2023 Valid 051200Z - 061200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected across the contiguous United States. ...Discussion... Large-scale pattern will prove unfavorable for thunderstorms today across the CONUS. Offshore flow will prevail across most of the Atlantic/Gulf Coasts and any appreciable buoyancy has been shunted well south and east of the United States. Across the western US, warm conveyor will gradually sag south along the west Coast, but the primary upper trough will hold well offshore. Weak instability may be noted within the conveyor, but primarily west of -125 longitude. Even within this corridor, elevated convection should remain too shallow/weak to warrant any meaningful risk for lightning. ..Darrow.. 12/05/2023Read more
SPC Dec 5, 2023 0700 UTC Day 2 Convective Outlook
SPC 0700Z Day 2 OutlookDay 2 Convective Outlook NWS Storm Prediction Center Norman OK 1142 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Discussion... Thunderstorm potential will remain negligible across much of the CONUS. Sporadic lightning flashes are possible over a portion of northern CA to coastal OR, mainly during the late afternoon and evening on Wednesday. A shortwave trough over the northeast Pacific will move inland across northern CA and the Northwest. In the wake of trough passage, cooler mid-level temperatures amid an expanding plume of steep lapse rates will overspread much of the Pacific Northwest. As this occurs, scant surface-based buoyancy should develop along coastal OR into a portion of northern CA towards late afternoon. 00Z HREF guidance suggests scattered low-topped convection will become common in this time frame, with the deepest convection capable of producing sporadic lightning flashes. ..Grams.. 12/05/2023Read more
SPC Dec 5, 2023 0830 UTC Day 3 Severe Thunderstorm Outlook
SPC 0830Z Day 3 OutlookDay 3 Convective Outlook NWS Storm Prediction Center Norman OK 0121 AM CST Tue Dec 05 2023 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...Discussion... Thunderstorm potential will be negligible across much of the CONUS on Thursday. The lone exception will be over the Pacific Northwest, where sporadic lightning flashes are possible, mainly during the first half of the period near the coast. The next in a series of shortwave troughs will impinge on the Pacific Northwest coast on Thursday, before digging towards the northern Great Basin by Thursday night. Already steep 700-500 mb lapse rates in the wake of a trough passage on D2/Wednesday, will steepen further between 8 to 8.5 C/km as cold 500-mb temperatures from -30 to -35 C become common. This should compensate for gradually decreasing boundary-layer moisture with low 40s surface dew points holding along the coast through Thursday afternoon. Scant surface-based buoyancy is anticipated with multiple rounds of scattered low-topped convection. Similar to D2, sporadic lightning flashes will be possible, although focused somewhat farther north along the OR/WA coast and mainly in the morning to afternoon. ..Grams.. 12/05/2023Read more
SPC Day 1 Fire Weather Outlook
SPC Day 1 Fire Weather OutlookDay 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1120 PM CST Mon Dec 04 2023 Valid 051200Z - 061200Z ...NO CRITICAL AREAS... ...Synopsis... An upper-level ridge will shift eastward over the Divide today. At the surface, high pressure will strengthen in the Plains as it moves southeastward with time. Surface high pressure will also remain within the Great Basin into the Western Slope. Fire weather concerns throughout the CONUS should remain low given generally unreceptive fuels and light winds. Some stronger offshore winds are likely in southern California. These winds will peak this morning before weakening through the day. Though fuels are not overly receptive and the lowest RH will not phase well with the strongest winds, locally elevated conditions would be possible where pockets of dry fuels exits within the terrain. ..Wendt.. 12/05/2023 ...Please see www.spc.noaa.gov/fire for graphic product...Read more
SPC Day 2 Fire Weather Outlook
SPC Day 2 Fire Weather OutlookDay 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1122 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO CRITICAL AREAS... ...Synopsis... The upper-level ridge will continue to shift eastward into the Missouri/Mississippi Valley regions on Wednesday. A trough will begin to develop into the West once again, but will be relatively ill-defined initially. At the surface, a combination of a modestly intensifying surface high in the Southeast and broad surface low pressure in the northern Rockies southward into the High Plains will increase the pressure gradient within parts of the Plains. Gusty south/southwest winds are possible from the southern High Plains into the central Plains and parts of the Upper Midwest. Temperatures should remain rather cool farther north and keep RH elevated. Warmer temperatures are expected farther south and within areas of stronger downslope winds. Pockets of locally elevated fire weather are possible in the southern High Plains and perhaps parts of southeast Wyoming should sufficiently dry fine fuels exist. ..Wendt.. 12/05/2023 ...Please see www.spc.noaa.gov/fire for graphic product...Read more