Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1034 AM CST Sun Jan 15 2023 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Monday. ...Mid-MS Valley vicinity... A compact mid/upper shortwave trough and developing upper low will lift northeast from the central Plains to the upper Great Lakes on Monday. A surface low attendant to the shortwave trough will be located over southeast NE early Monday, while tracking northeast into WI by early Tuesday. Strong southwesterly deep-layer flow will overspread the Lower MO/Mid-MS Valleys into the upper Great Lakes vicinity, while southerly low-level flow facilitates minor boundary-layer moistening into IL/IA and vicinity. Quite a bit of spread exists in forecast guidance regarding surface temps/dewpoints. The HRRR is the most aggressive with low 50s T/Tds into central IA/northwest IL. The other end of the spectrum is the NAM with temps and dewpoints about 10-13 degrees cooler. Given that dewpoints in the 50s are still in the vicinity of the TX Coast as of Sunday morning, it appears unlikely the HRRR solution will be realized as substantial airmass modification would be needed. As a result, destabilization is expected to be very weak with little if any surface-based instability expected. Furthermore, some areas across the southeast MN/northern IA vicinity still have quite a bit of snow pack. Additionally, timing of the ejecting wave appears ill-timed with peak heating, with strongest ascent likely during the morning and early afternoon before spreading northeast. Given large model spread, little signal amid machine learning/ensemble guidance and very low probability of surface-based convection, the Marginal risk has been removed. ..Leitman.. 01/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1019 AM CST Sun Jan 15 2023 Valid 151630Z - 161200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast through tonight. ...Discussion... A quiet pattern for lightning production is expected to persist through tonight, with thunderstorm probabilities appearing to be less than 10 percent. A lightning flash or two is possible this afternoon in lower elevations around the Four Corners area attendant to a shortwave trough ejecting towards the southern Rockies. Amplification of this wave is anticipated tonight as it ejects across the central Great Plains towards the Lower MO Valley. Given the poor low-level moisture sampled by 12Z soundings this morning over the central states to the western Gulf Coast, elevated thunder potential in the warm conveyor region ahead of the wave will likely hold off until after 12Z. Low-topped convection will also redevelop tonight ahead of yet another shortwave trough impinging on the central CA coast. Instability is expected to remain negligible through early morning and casts doubt on lightning occurring along the coast prior to 12Z. ..Grams/Wendt.. 01/15/2023 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0136 PM CST Sat Jan 14 2023 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR A PORTION OF THE SAN JOAQUIN VALLEY... ...SUMMARY... A couple low-topped supercells are possible in the San Joaquin Valley of central California between about 5 to 9 PM PST, and may yield a brief weak tornado. ...20z Update... The ongoing forecast remains on track and no changes are necessary with the 20z update. A couple of briefly strong/severe storms will be possible late this afternoon/evening. For more details, see the previous discussion below. ..Leitman.. 01/14/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Sat Jan 14 2023/ ...San Joaquin Valley... A broad rain swath across the Central Valley to the central CA coast will shift east within the warm conveyor region ahead of a shortwave trough that is west of the CA/OR border area. In its wake, a short-duration period of weak boundary-layer heating coupled with cooling mid-level temperatures/steepening lapse rates will aid in scattered low-topped convection redeveloping by early evening. Low-level winds during this time frame should be in the process of weakening while also becoming veered towards the west, but marginally adequate 0-1 km SRH may persist in the eastern portion of the valley. Speed shear above 800 mb may prove adequate for a couple discrete cells with weak mid-level updraft rotation. A funnel cloud or two, with potential for a brief weak tornado, along with small hail are the most likely hazards. Read more

No watches are valid as of Sat Jan 14 19:40:01 UTC 2023.

No Mesoscale Discussions are in effect as of Sat Jan 14 19:40:01 UTC 2023.

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sat Jan 14 2023 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN HIGH PLAINS... The primary change with this update was to expand the Elevated highlights northeastward across southwest and central KS to I-70, where below-average precipitation has supported drying of fine fuels (60th-75th percentile ERCs). While widespread mid/high-level cloud coverage will limit boundary-layer heating/mixing to an extent, strong deep-layer west-southwesterly downslope flow should compensate for this, and 20-25 percent minimum RH is possible. Given the potential for these dry boundary-layer conditions and 35-45 mph gusts, the Elevated highlights are warranted. Elsewhere, only minor adjustments were made to the Elevated and Critical highlights based on the latest high-resolution guidance. ..Weinman.. 01/14/2023 .PREV DISCUSSION... /ISSUED 0107 AM CST Sat Jan 14 2023/ ...Synopsis... Lee cyclogenesis will intensify across southeast Colorado during the day Sunday as the mid-level trough advances into the Plains. As this occurs, strong winds will develop across the southern High Plains. Sustained winds of 25 to 30 mph are expected across portions of the southern High Plains where heating and deeper mixing is maximized. Upper-level clouds may stunt heating somewhat and keep relative humidity somewhat higher. However, guidance is consistent enough with relative humidity of 15 to 20 percent. These meteorological conditions combined with dormant, dry fine fuels will support critical fire weather conditions. ...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 1058 AM CST Sat Jan 14 2023 Valid 141700Z - 151200Z ...Southern Plains... A small expansion of the Elevated area was made into southwest KS, western OK, and northwest TX. Mostly clear skies (outside of thin cirrus clouds) and at least a component of downslope flow off the southern Rockies should support around 25 percent minimum RH over these areas. These dry conditions, coupled with strengthening southerly surface winds (sustained near 20 mph) atop modestly receptive fuels will favor elevated conditions. ...East-central into Southeast FL... An Elevated area was added along the FL east coast roughly from Melbourne southward through Homestead, where rainfall has been below average over the last month. Water vapor and visible satellite imagery show a dry, post-frontal airmass over the Peninsula. Clear skies/efficient boundary-layer mixing and continued north-northwesterly (down-Peninsula) flow should yield 30-40 percent minimum RH. Given breezy/gusty surface winds amid the drying boundary layer, elevated conditions are expected. While locally elevated conditions are also possible farther north into northern FL this afternoon, these conditions appear too brief for highlights. ..Weinman.. 01/14/2023 .PREV DISCUSSION... /ISSUED 0106 AM CST Sat Jan 14 2023/ ...Synopsis... Lee cyclogenesis will lead to strengthening winds across portions of the central and southern Plains on Saturday. These strong winds will overlap relative humidity of 15 to 20 percent across portions of eastern New Mexico, west Texas, the TX/OK Panhandle and far western Oklahoma. Winds around 20 mph with relative humidity of 15 to 20 percent amid somewhat receptive fuels supports an Elevated delineation across this region. Some dry and breezy conditions are expected with down-peninsula flow in Florida. However, relative humidity and fuels are only marginally receptive. Therefore, no Elevated area is warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1034 AM CST Sat Jan 14 2023 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast on Sunday. ...Synopsis... A mid/upper trough over the western U.S. Sunday morning will shift east into the Plains by early Monday morning. This will lead to deepening lee cyclogenesis over the central High Plains, with the low tracking northeast toward the MO Valley overnight. Resulting southerly return flow will transport modest Gulf moisture northward, but 60s F dewpoints will mainly be confined to the TX coast vicinity. Nevertheless, modest boundary-layer moisture beneath cooling temperatures aloft, and increasing ascent with the ejecting mid/upper trough could foster a few lightning flashes near the surface low across northwest MO/southwest IA and vicinity during the overnight hours into early Monday morning. Warm temperatures just above 850 mb will maintain a capping inversion during the period, and despite moderate to strong deep-layer southwesterly flow, severe thunderstorm potential will remain very low. Isolated thunderstorms also will be possible Sunday morning/afternoon across parts of the Four Corners as the mid/upper trough ejects eastward. Another midlevel shortwave impulse and surface low will impinge on the CA coast by early Monday morning, and a few lightning flashes are possible as a front approaches the coast toward the end of the forecast period. ..Leitman.. 01/14/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Sat Jan 14 2023 Valid 141630Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS A PORTION OF THE SAN JOAQUIN VALLEY... ...SUMMARY... A couple low-topped supercells are possible in the San Joaquin Valley of central California between about 5 to 9 PM PST and may yield a brief weak tornado. ...San Joaquin Valley... A broad rain swath across the Central Valley to the central CA coast will shift east within the warm conveyor region ahead of a shortwave trough that is west of the CA/OR border area. In its wake, a short-duration period of weak boundary-layer heating coupled with cooling mid-level temperatures/steepening lapse rates will aid in scattered low-topped convection redeveloping by early evening. Low-level winds during this time frame should be in the process of weakening while also becoming veered towards the west, but marginally adequate 0-1 km SRH may persist in the eastern portion of the valley. Speed shear above 800 mb may prove adequate for a couple discrete cells with weak mid-level updraft rotation. A funnel cloud or two, with potential for a brief weak tornado, along with small hail are the most likely hazards. ..Grams/Wendt.. 01/14/2023 Read more

No watches are valid as of Fri Jan 13 17:12:02 UTC 2023.

No Mesoscale Discussions are in effect as of Fri Jan 13 17:12:02 UTC 2023.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Fri Jan 13 2023 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast on Saturday. ...Synopsis... An upper trough will be oriented over the Atlantic coast states Saturday morning, with a ridge over the Plains and another trough over the eastern Pacific/West Coast vicinity. This pattern will be fairly progressive, with the wave train shifting east through the period. This will bring a trough inland over the western U.S., with a fairly intense jet streak oriented over southern CA into the Lower CO Valley vicinity by Sunday morning. As the Pacific trough moves inland, cooling midlevel temperatures will offer meager instability over parts of CA, and isolated thunderstorms will be possible during the late morning into the evening. Severe thunderstorms are not expected at this time. ..Leitman.. 01/13/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1024 AM CST Fri Jan 13 2023 Valid 131630Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Northern/central CA... A modest-amplitude shortwave trough will shift inland across CA this afternoon and into the northern Great Basin tonight. Cooler mid-level temperatures and steepening lapse rates may support very isolated thunderstorms during the late afternoon and evening. Scant buoyancy is expected owing to boundary-layer dew points only peaking in the upper 40s to low 50s along the coast and into the Central Valley. This in combination with increasingly veered low-level flow should mitigate potential for organized convection. ...South FL... Relatively low-topped convection persists in a pre-frontal convective band. Weak mid-level lapse rates in the 12Z observed and forecast soundings suggest convection will struggle to deepen in the absence of appreciable height falls this afternoon. It is plausible that no additional lightning will occur before convection shifts east/south of the peninsula this evening. ..Grams/Wendt.. 01/13/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1025 AM CST Fri Jan 13 2023 Valid 131700Z - 141200Z ...NO CRITICAL AREAS... No changes were made to the outlook. For details, see the previous discussion below. ..Weinman.. 01/13/2023 .PREV DISCUSSION... /ISSUED 1256 AM CST Fri Jan 13 2023/ ...Synopsis... High pressure will build across the central CONUS today with cool conditions for much of the eastern CONUS. Farther west, persistent troughing along the West Coast will continue to bring cool, wet conditions. Some warm and dry conditions are expected across the southern High Plains, but winds should remain light today. Therefore, fire weather concerns will be minimal across the CONUS today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0020 Status Updates
STATUS REPORT ON WW 20 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 NW GPT TO 35 NW MOB TO 40 WSW SEM TO 20 NW SEM. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0055 ..THORNTON..01/12/23 ATTN...WFO...BMX...MOB... STATUS REPORT FOR WT 20 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC001-003-013-025-035-039-041-047-051-053-085-097-099-101-129- 131-122040- AL . ALABAMA COUNTIES INCLUDED ARE AUTAUGA BALDWIN BUTLER CLARKE CONECUH COVINGTON CRENSHAW DALLAS ELMORE ESCAMBIA LOWNDES MOBILE MONROE MONTGOMERY WASHINGTON WILCOX FLC033-113-122040- FL . FLORIDA COUNTIES INCLUDED ARE ESCAMBIA SANTA ROSA MSC039-131-122040- Read more

WW 20 TORNADO AL FL MS CW 121620Z - 122300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 20 NWS Storm Prediction Center Norman OK 1020 AM CST Thu Jan 12 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern Alabama Florida Panhandle Southeast Mississippi Coastal Waters * Effective this Thursday morning and afternoon from 1020 AM until 500 PM CST. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...Storms will continue to spread east-northeastward and tend to intensify into this afternoon, with at least some potential for several storms including a tornado risk. The tornado watch area is approximately along and 60 statute miles north and south of a line from 45 miles west northwest of Mobile AL to 30 miles south southeast of Montgomery AL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 16...WW 17...WW 18...WW 19... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24025. ...Guyer Read more

WW 0019 Status Updates
STATUS REPORT ON WW 19 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 W RMG TO 25 E CHA TO 10 ESE TYS. ..THORNTON..01/12/23 ATTN...WFO...FFC...MRX... STATUS REPORT FOR WT 19 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS GAC015-057-085-111-115-123-129-187-213-227-291-122040- GA . GEORGIA COUNTIES INCLUDED ARE BARTOW CHEROKEE DAWSON FANNIN FLOYD GILMER GORDON LUMPKIN MURRAY PICKENS UNION NCC039-122040- NC . NORTH CAROLINA COUNTIES INCLUDED ARE CHEROKEE TNC139-122040- TN . TENNESSEE COUNTIES INCLUDED ARE POLK Read more

WW 19 TORNADO GA NC TN 121600Z - 122200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 19 NWS Storm Prediction Center Norman OK 1100 AM EST Thu Jan 12 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northern Georgia Far western North Carolina Southeast Tennessee * Effective this Thursday morning and afternoon from 1100 AM until 500 PM EST. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...A fast-moving line of storms will pose a risk for damaging winds and/or a tornado through early/mid-afternoon. The tornado watch area is approximately along and 40 statute miles north and south of a line from 25 miles south southwest of Chattanooga TN to 65 miles east of Chattanooga TN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 16...WW 17...WW 18... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 23040. ...Guyer Read more

MD 0056 CONCERNING SEVERE POTENTIAL...TORNADO WATCH LIKELY FOR SOUTHEASTERN ALABAMA AND THE WESTERN FLORIDA PANHANDLE
Mesoscale Discussion 0056 NWS Storm Prediction Center Norman OK 0119 PM CST Thu Jan 12 2023 Areas affected...southeastern Alabama and the western Florida Panhandle Concerning...Severe potential...Tornado Watch likely Valid 121919Z - 122115Z Probability of Watch Issuance...80 percent SUMMARY...Tornado threat will increase through the afternoon. Watch issuance likely needed soon. DISCUSSION...As of 19z, an established line of thunderstorms was ongoing across portions of Alabama, with more discrete cells located ahead of and south of the line in southwestern Alabama and Mississippi. Across southeastern Alabama into the Florida Panhandle, air mass destabilization from daytime heating has led to surface based CAPE values around 1500 J/kg. KEOX (Ft. Rucker) has seen an increase in 0-1km and 0-3 km storm relative helicity in the last few hours as 850 mb flow has increased to around 40-50 kts. 0-1km storm relative helicity is currently around 230 m2/s2. This environment is expected to persist and will support the risk for tornadoes, especially within any discrete cells that can maintain supercell characteristics ahead of the main line. ..Thornton/Guyer.. 01/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FFC...TAE...BMX...MOB... LAT...LON 30618677 30988662 31288623 31608584 31978532 32168497 32228469 32188440 31958424 31578422 31208419 30908424 30598447 30388465 30238484 30128503 30048541 29998586 30208641 30618677 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0111 PM CST Thu Jan 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire-weather concerns are minimal. See the previous discussion for more info. ..Lyons.. 01/12/2023 .PREV DISCUSSION... /ISSUED 0145 AM CST Thu Jan 12 2023/ ...Synopsis... The southern Plains will be in northwesterly flow aloft throughout the day tomorrow, which will promote surface high pressure across the region. Guidance suggests diurnal mixing will drive RH into the 15-25% range across eastern New Mexico and west Texas during the afternoon atop dry 1- and 10-hr fuels. However, generally weak winds around the surface anticyclone prevent the introduction of any Elevated areas this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more