Tag: convective

Official

SPC Dec 24, 2024 0100 UTC Day 1 Convective Outlook

SPC 0100Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0651 PM CST Mon Dec 23 2024 Valid 240100Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Discussion... Little lightning activity is ongoing this evening across the CONUS, with a few flashes noted just off the northern CA Coast earlier. Weak levels of elevated instability ahead of the primary upper trough may support sporadic flashes through tonight, mainly over northern CA. A greater chance of thunderstorms will occur over parts of OK and
Official

SPC Dec 23, 2024 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Mon Dec 23 2024 Valid 231300Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... Water-vapor imagery this morning shows a mid-level trough over AZ moving east and a northern stream trough over the Pacific Northwest. The northern mid-level trough will latitudinally expand southward into the central Rockies/south-central High Plains as a ridge amplifies over the Interior West in its wake. As this occurs, a partial phasing of mid-level trough
Official

SPC Dec 23, 2024 0100 UTC Day 1 Convective Outlook

SPC 0100Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0656 PM CST Sun Dec 22 2024 Valid 230100Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis... An upper trough currently exists along the coastal Pacific Northwest this evening, and height rises will occur tonight as the wave moves northeastward across OR and WA. In the near term, a few thunderstorms will remain possible over coastal northern CA, and farther north across western WA beneath the cooler air aloft. Most of the
Official

SPC Dec 22, 2024 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 22 2024 Valid 221300Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis... Water-vapor imagery this morning shows an upper trough over the eastern Pacific to the west of the Pacific Northwest coast. This upper feature will move east-northeast into British Columbia and WA/OR tonight. Cooling midlevel temperatures will result in weak buoyancy (100-200 J/kg MUCAPE) late today into tonight from portions of northern CA northward along the
Official

SPC Dec 22, 2024 0100 UTC Day 1 Convective Outlook

SPC 0100Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0653 PM CST Sat Dec 21 2024 Valid 220100Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected across the USA through tomorrow morning. The minimal thunderstorm threat has ended over parts of the Pacific Northwest as rapid warming aloft is underway behind a compact shortwave trough. Instability is not expected to materialize downstream into ID and MT, and as such all thunderstorm probabilities have been removed. Elsewhere, high pressure over the East and a dry air mass over land will maintain stable
Official

SPC Dec 21, 2024 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Sat Dec 21 2024 Valid 211300Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible this morning into early afternoon across parts of coastal Oregon and northern California. ...Coastal OR/northern CA... A potent mid to upper-level shortwave trough will move ashore the northern CA/OR coast and continue northeastward into the southern Canadian Rockies/northern Rockies vicinity through late tonight. Weak thunderstorm activity embedded within a warm-air advection rain shield will continue moving into the coastal range mountains this morning before
Official

SPC Dec 21, 2024 0100 UTC Day 1 Convective Outlook

SPC 0100Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 PM CST Fri Dec 20 2024 Valid 210100Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible along the northern California coast early morning Saturday. ...Northern CA coast... An amplified upper trough will move northeast and approach the Pacific Northwest coast through 12Z Saturday. This will yield a pronounced low-level warm conveyor to overspread the adjacent offshore waters. This forcing for ascent in conjunction with an ample buoyancy plume has supported scattered to widespread thunderstorms around 500-600 miles offshore. This buoyancy
Official

SPC Dec 20, 2024 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 AM CST Fri Dec 20 2024 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not forecast across the contiguous United States through tonight. ...Synopsis... Water-vapor imagery this morning shows an upper trough centered over the Great Lakes, with this feature forecast to move east into the Northeast and east of the Mid-Atlantic states by late tonight. Farther west, a mid-level ridge will reside over the Rockies with an upper trough over the eastern Pacific approaching the northern CA/Pacific Northwest
Official

SPC Dec 19, 2024 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 AM CST Thu Dec 19 2024 Valid 191300Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Synopsis/Discussion... The upper-tropospheric pattern is evolving back to an eastern mean trough and western ridge for a few days, as a series of shortwave troughs dig southeastward from the northern/central Plains and upstream parts of western/central Canada. Low-level cold frontal passage related to the eastern troughing will render the airmass east of the Rockies too dry and/or stable for thunderstorms over land for