SPC Nov 6, 2022 1730 UTC Day 2 Convective Outlook

2 years 8 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1116 AM CST Sun Nov 06 2022 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast on Monday. ...Synopsis... An upper low is forecast to progress gradually southward along the Pacific Northwest coast on Monday. Several shortwave troughs will rotate around this low, including one expected to move from northern CA northeastward through the northern Rockies during the day Monday and another that is expected to approach the central CA coast early Tuesday morning. Persistent forcing for ascent amid cold mid-level temperatures will support isolated lightning flashes across the Pacific Northwest coast throughout the day and overnight. A few flashes are also possible across more inland areas of northern and central CA as the previously mentioned shortwave trough moves through late Monday night/early Tuesday morning. Downstream of this deepening Pacific Northwest/CA upper low, shortwave ridging is expected to amplify across the Plains. As it does, persistent southwesterly flow aloft will gradually strengthen and surface lee troughing will become more defined. In response, low-level southerly flow will strengthen, fostering moisture advection across the southern and central Plains. By early Tuesday morning, mid 60s dewpoints may be as far north as central OK, with uppers 60s/low 70s along the TX Gulf Coast. Isolated thunderstorms are anticipated within this warm-air advection regime, likely beginning the day in an arc from south TX through the Arklatex into southern AR. This corridor is expected to gradually shift northwestward throughout the day and overnight, possibly reaching from the TX Panhandle into central KS by early Tuesday morning. Severe potential will be mitigated by limited buoyancy. ..Mosier.. 11/06/2022 Read more

SPC Day 1 Fire Weather Outlook

2 years 8 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1057 AM CST Sun Nov 06 2022 Valid 061700Z - 071200Z Expanded the Elevated delineation slightly farther east across southeast Minnesota and northern Iowa. Fuels are not as receptive in this region, but winds of 25-30 mph and relative humidity in the teens appears likely. Therefore, despite the less receptive fuels, the intensity of the winds and dryness warrants expansion of the elevated. ..Bentley.. 11/06/2022 .PREV DISCUSSION... /ISSUED 0120 AM CDT Sun Nov 06 2022/ ...Synopsis... A weak cold front will continue to push southward across the Dakotas into Nebraska and into the central Plains/Midwest by Sunday afternoon. Much drier air will filter in behind this feature with strong west northwesterly flow and sustained winds around 15-20 mph (locally stronger around 20-25 mph with gusts up to 45 mph), across portions of South Dakota east into the Minnesota River Valley and south into northeastern Iowa and northern Nebraska. The previous Day 2 Elevated area was expanded further southward into Nebraska and Iowa in agreement with continued stronger winds in hi-res guidance. Sounding analysis across the Elevated region shows boundary-layer max winds could approach 20-35 kts during peak afternoon mixing. While temperatures will be cool (in the mid to upper 50s F), afternoon relative humidity looks to be around 15-20 percent with modestly dry fuels. Areas of critical fire weather conditions may be possible at times. Due to expected cooler temperatures, have kept with Elevated delineation for now. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Nov 6, 2022 1630 UTC Day 1 Convective Outlook

2 years 8 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1017 AM CST Sun Nov 06 2022 Valid 061630Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are possible over parts of the Northeast, Southeast, Texas to Mid-South overnight, and across the Pacific Northwest. ...Synopsis... Mid-morning upper air analyses and surface observations show a weak/diffuse cool front draped from the lower Great Lakes southwestward into the Southeast. An onshore flow regime along the Atlantic coast will continue to advect mid to upper 60s dewpoints into the southeastern Appalachians and Northeast through the afternoon. Thunderstorm development is expected through the afternoon and evening across these regions along the diffuse boundary. Cold temperatures aloft/steep mid-level lapse rates associated with a strong upper wave approaching the Pacific Northwest have yielded sporadic lightning flashes over the northeast Pacific over the past several hours. These thermodynamic conditions will overspread the WA/OR coasts over the next 24 hours. A lightning flash or two east of the Cascades will be possible overnight, but the better lightning potential will reside west of the terrain. ...Northeast... Regional radar mosaics reveal low-topped convection developing over parts of northern NY. Despite poor low and mid-level lapse rates, modified 12 UTC soundings from BUF and ALB suggest that temperatures in the low 70s with upper 50s/low 60s dewpoints are adequate for weak surface-based convection. The poor thermodynamic environment aloft coupled with broken cloud cover will limit the degree of diurnal destabilization, but enough buoyancy may be present for a few lightning flashes as isolated/scattered convective cells develop along the diffuse boundary. This activity will likely mix down 30-40 knot low-level winds, and may lead to sporadic strong to damaging gusts. However, given low confidence in robust destabilization, the severe potential remains too low to introduce wind probabilities. ..Moore/Hart.. 11/06/2022 Read more

SPC Nov 5, 2022 1730 UTC Day 2 Convective Outlook

2 years 8 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Sat Nov 05 2022 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast on Sunday. ...Synopsis... A belt of predominately zonal westerly flow aloft will stretch across the northern and central CONUS early Sunday morning. Several shortwave troughs will be embedded within this westerly flow, including one initially over the Canadian Prairie Provinces and northern Plains and another dropping into the Pacific Northwest. The northern Plains shortwave is forecast to progress eastward throughout the period, moving through much of Ontario and the Upper Great Lakes by Monday morning. A cold front will accompany this wave, but limited low-level moisture will preclude thunderstorm development across the Plains and Mid MS Valley. strong forcing for ascent and cold mid-level temperatures associated with the Pacific Northwest shortwave support a few isolated thunderstorms along the immediate coastal areas. Low-level convergence along a weakening cold front will likely support isolated thunderstorms from western VA across Carolinas and into GA. Isolated storms are possible amid the low- to mid-level westerly flow across FL as well. Lastly, isolated thunderstorms may also occur late Sunday night into early Monday morning across parts of central/northeast TX into the lower MS Valley, as low-level moisture returns northward in a modest low-level warm advection regime. Weak instability across all regions with convective potential is expected to limit any appreciable severe risk. ..Mosier.. 11/05/2022 Read more

SPC Nov 5, 2022 1630 UTC Day 1 Convective Outlook

2 years 8 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CDT Sat Nov 05 2022 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to widely scattered thunderstorms are expected from parts of the Gulf Coast to the Great Lakes. Organized severe-thunderstorm potential appears minimal. A cold front currently extends from WI/IL southward into MS. Weak instability exists ahead of the line - mainly from the OH valley southward to the Gulf Coast. This area may continue to see scattered thunderstorms this afternoon and evening. While an isolated damaging wind gust or two cannot be ruled out over southern MS/AL this afternoon, no organized severe thunderstorms are expected. Farther north, a narrow line of low-topped showers extends along the front from northern IL into WI. Very strong surface winds in the warm sector ahead of the front, and within showers associated with the front, will produce gusty and occasionally damaging winds. Since very little lightning is anticipated with this activity and the intensity of winds in the line is not significantly stronger than the regional gradient flow out ahead, will not introduce severe probabilities at this time. Refer to MCD#1927 for further details. ..Hart/Moore.. 11/05/2022 Read more

SPC Day 1 Fire Weather Outlook

2 years 8 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1026 AM CDT Sat Nov 05 2022 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... The strongest winds still appear to remain over areas where recent rain/snowfall has occurred across southeast Wyoming and the Nebraska Panhandle. Therefore, no fire weather highlights are necessary. ..Bentley.. 11/05/2022 .PREV DISCUSSION... /ISSUED 0104 AM CDT Sat Nov 05 2022/ ...Synopsis... As an upper-level low lifts northeast across the Great Lakes region Saturday, a band of enhanced upper-level westerly flow upstream will begin to spread across the Rockies and into the Plains with surface lee troughing across eastern Colorado and the panhandle of Nebraska. Surface gradients will remain strong, with winds sustained from the southwest around 15-20 mph across northwest Texas into the Oklahoma/Texas Panhandles north into western Kansas. Dry desert air will be translated eastward in this downslope flow regime with afternoon relative humidity around 15-20 percent. Temperatures are expected to be much cooler across much of the central Plains, owing to the strong cold frontal passage Friday. Temperatures will be a bit warmer further west into northwest Texas. Overall, fuels are wet from recent rainfall/snowfall with generally below-normal ERCs. This will preclude the need for an Elevated delineation across Texas/Oklahoma/Southern Kansas. A few stations in eastern Colorado and northwestern Kansas may briefly see elevated to near critical fire-weather conditions amid more supportive fuels and similar dry and windy conditions. Portions of this region did see light rain/snowfall on Friday. Temperatures will also be a bit warmer in these regions, especially where the best downslope warming occurs. Overall, the threat looks to be brief and localized in nature. This will preclude the need for any Elevated or Critical delineations at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Tornado Watch 560

2 years 8 months ago
WW 560 TORNADO AR OK TX 041800Z - 050100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 560 NWS Storm Prediction Center Norman OK 100 PM CDT Fri Nov 4 2022 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northwest Arkansas Eastern and Southern Oklahoma North Central and Northeast Texas * Effective this Friday afternoon and evening from 100 PM until 800 PM CDT. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Scattered damaging winds and isolated significant gusts to 80 mph likely Scattered large hail and isolated very large hail events to 2 inches in diameter possible SUMMARY...Thunderstorms will continue to increase in coverage and intensity this afternoon, with scattered severe storms expected. Strong winds aloft and a moist environment will pose a risk of tornadoes and damaging wind gusts in the strongest cells. The tornado watch area is approximately along and 80 statute miles east and west of a line from 50 miles northwest of Fayetteville AR to 25 miles east of Temple TX. 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. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 24035. ...Hart Read more

SPC Nov 4, 2022 1730 UTC Day 2 Convective Outlook

2 years 8 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Fri Nov 04 2022 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL GULF COAST STATES AND OH VALLEY... ...SUMMARY... Isolated strong to severe thunderstorms appear possible mainly Saturday morning across parts of the central Gulf Coast states. Occasional damaging winds should be the main threat. ...Synopsis... A strong shortwave trough is expected to extend from western IA south-southwestward into east TX early Saturday morning. An expansive area of moderate to strong mid-level flow will accompany this wave, stretching from central TX through the Upper Great Lakes Saturday morning. Expectation is for this wave to quickly move northeastward through the mid MS Valley, Upper Great Lakes, and eastern Ontario throughout the period, while deepening and becoming more negatively tilted. Surface low associated with this shortwave is forecast to be over the IA/WI/IL border intersection vicinity early, before also moving northeastward and occluding. An attendant cold front will extend southward from this low, and will move quickly eastward/northeastward as the parent system moves northeastward. By 00Z Sunday, this front is expected to extend from eastern MI south-southwestward through Middle TN, central MS, and southeast LA. The northern portion of the front will likely remain progressive as it moves across the upper OH Valley Saturday evening and overnight. The southern portion of the front is expected to stall as surface pressure lowers across the Plains ahead of the next wave. ...Central Gulf Coast into central MS/AL... Numerous showers and thunderstorms are expected to be ongoing from the Mid-South through the Lower MS Valley along and ahead of the front Saturday morning. This front is expected to continue pushing eastward throughout the day while the main wave and forcing for ascent becoming increasingly displace north/northeast of the region. The air mass ahead of the front across the central Gulf Coast and central MS/AL will likely feature upper 60s dewpoints and moderate buoyancy, despite poor lapse rates. This moisture/buoyancy should support a persistence of the ongoing storms as they move through the region. The strongest low to mid-level flow will stay attendant to the main wave, with shear gradually decreasing throughout the day across the region as a result. These factors should increasingly limit the severe potential throughout the day, with the highest potential anticipated across southeast LA and southern MS early Saturday. Expectation is that a few storms may become strong enough to produce damaging gusts. ...Mid/Upper OH Valley...Upper Great Lakes... Robust low/mid-level flow will spread across the region during the afternoon and evening as the strong shortwave trough quickly advances from the mid MS Valley across the OH Valley and Upper Great Lakes. Mid-level lapse rates and daytime heating should remain fairly modest, keeping instability quite meager. Still, strong forcing for ascent is expected to result in a low-topped convective line by Saturday afternoon. Consequently, the enhanced low-level flow may reach the surface and produce strong/gusty winds as the line moves through. ..Mosier.. 11/04/2022 Read more

SPC Center Public Severe Weather Outlook (PWO)

2 years 8 months ago
Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 AM CDT FRI NOV 04 2022 ...Severe thunderstorms expected over parts of the Ark-La-Tex region this afternoon and tonight... * LOCATIONS... Northeast Texas Southwest Arkansas Southeast Oklahoma Northwest Louisiana * HAZARDS... Widespread damaging winds, some hurricane force Several tornadoes, a few intense Isolated large hail * SUMMARY... A threat for tornadoes, severe gusts and large hail exists today and tonight over parts of central, north and east Texas, southeastern Oklahoma, southern/western Arkansas, and northern Louisiana. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Moore.. 11/04/2022 Read more

SPC Nov 4, 2022 1630 UTC Day 1 Convective Outlook

2 years 8 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Fri Nov 04 2022 Valid 041630Z - 051200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHEAST OKLAHOMA...NORTHEAST TEXAS...SOUTHWEST ARKANSAS...AND NORTHWEST LOUISIANA.... ...SUMMARY... A threat for tornadoes, severe gusts and large hail exists today and tonight over parts of central, north and east Texas, southeastern Oklahoma, southern/western Arkansas, and northern Louisiana. ...OK/TX/AR/LA... Morning water vapor imagery shows a large upper trough moving across NM, with an 80-90 knot mid level jet rotating eastward into west TX. At the surface, a cold front is sagging southward across western OK with strong southerly low-level winds aiding moistening in the warm sector over central/east TX/OK. Widespread low clouds will hinder daytime heating/destabilization over much of the warm sector today. However, dewpoints in the mid 60s to lower 70s will yield afternoon MLCAPE values of 1000-2000 J/kg ahead of the cold front. Present indications are that the mid level capping inversion shown on the 12z FWD raob is weakening rapidly, with a nearly saturated boundary-layer and little convective inhibition expected throughout the afternoon. Persistent large-scale forcing ahead of the approaching trough will lead to scattered fast-moving thunderstorm development in the warm sector before 19z. Forecast soundings show very favorable low-level and deep-layer shear profiles for updraft rotation and tornadoes (including strong tornadoes). The main forecast question is whether activity will become widespread early, rapidly weakening the available instability. Even if this occurs, a transition to bowing structures seems likely with the potential for widespread damaging winds. For these reasons, have upgraded to MDT risk for parts of the Arklatex region. Storms will persist well into the night, tracking across much of LA/AR and into western MS. ...IA/IL/WI... A surface cold front currently extends from southern WI into eastern IA and northern MO. A few strong and fast-moving thunderstorms are affecting areas along/ahead of this front. Given the strong winds aloft and sufficient CAPE, isolated strong/damaging wind gusts could occur with this activity. ..Hart/Moore.. 11/04/2022 Read more

SPC Day 1 Fire Weather Outlook

2 years 8 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1109 AM CDT Fri Nov 04 2022 Valid 041700Z - 051200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 11/04/2022 .PREV DISCUSSION... /ISSUED 0115 AM CDT Fri Nov 04 2022/ ...Synopsis... An upper-level trough will continue across the Front Range into the central/southern Plains on Friday. A strong surface low will continue to deepen across south-central Oklahoma/northwest Texas with an attendant surface cold front tracking across the south-central US. After the cold frontal passage across western Texas, strong west to northwesterly surface winds (around 25-30 mph gusting 40+ mph) and infiltration of much drier air will begin. Though afternoon minimum relative humidity will be around 15-20 percent with gusty winds, recent rainfall and ERCs that are below seasonal average will preclude the need to include Elevated areas. Across southern California, offshore flow will allow for a period of elevated fire weather in the afternoon, with relative humidity around 15-20 percent across the coastal mountains and valleys (lowest in favored downslope regions). Due to the localized and brief nature, no Elevated delineation has been included. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Nov 3, 2022 1730 UTC Day 2 Convective Outlook

2 years 9 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Nov 03 2022 Valid 041200Z - 051200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF EASTERN/NORTHEASTERN TEXAS...SOUTHEAST OKLAHOMA...SOUTHWEST ARKANSAS...AND NORTHERN LOUISIANA... ...SUMMARY... Severe thunderstorms are likely Friday into Friday night centered over parts of northern and eastern Texas, eastern Oklahoma, southwest Arkansas and western Louisiana. Several tornadoes are possible over Texas with damaging winds spreading into Arkansas and Louisiana overnight. A strong tornado or two may occur from late afternoon into early evening. ...Synopsis... An upper trough over NM will deepen and pivot northeastward across northern TX, OK and KS during the day, then toward the mid MS Valley by 12Z Saturday. Coincident with this wave will be a strengthening mid and upper-level speed max with strong cooling aloft from the TX Panhandle into KS. At the surface, a cold front should extend roughly from eastern IA into southeast KS and to a low over southwest OK at 12Z Friday, with gradual deepening of the surface trough from MO into northeast TX through 00Z. Southerly surface winds ahead of the cold front as well as a broad zone of 40-50 kt southwesterly 850 mb winds will aid moisture advection, with 68-72 F dewpoints south of the Red River, and low 60s F into southern MO. The end result will be a region of favorable instability, shear and lift from eastern TX and OK into western AR and LA, with a threat of several tornadoes and damaging winds. ...TX...OK...AR...LA... Scattered storms are expected to be ongoing near and north of a cold front from northwest OK into eastern KS, with strong deep-layer shear and cold temperatures aloft favoring hail. Given the front-parallel nature to the winds aloft, these storms may become elevated as the front undercuts the convection. Isolated damaging gusts could occur immediately along the boundary. To the south, moisture and instability will increase throughout the day ahead of the cold front in TX. As pressures fall, boundary-layer winds will become increasingly confluent along the I-35 corridor, with deepening moist profiles. Forecast soundings indicate that the capping inversion will not be very strong. As a result, increasing large-scale lift will likely lead to pre-frontal storms after 19-20Z over much of northern TX into southeast OK. Strong deep-layer shear and MLCAPE of 1500-2000 J/kg will favor discrete cells, a few of which may mature into tornadic supercells as SRH increases to around 300 m2/s2 by 00Z. Other isolated supercells are possible farther southwestward into central TX as the cold front approaches the instability axis. Low-level shear will not be as strong farther south, but supercells will still be possible, including the threat of locally damaging hail. During the evening and overnight, the cold front will merge with any existing warm sector activity, with a severe squall line forecast. Damaging winds and brief tornadoes will be possible over eastern TX, western LA and AR, and eastern OK. Other severe storms may occur from northern AR into southern MO, where shear will be very strong, but instability minimal. Sporadic wind damage may occur overnight in these areas. ..Jewell.. 11/03/2022 Read more

SPC Nov 3, 2022 1630 UTC Day 1 Convective Outlook

2 years 9 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Nov 03 2022 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EASTERN TX PANHANDLE TO CENTRAL KS... ...SUMMARY... Potential exists late tonight for a tornado along with isolated to perhaps scattered severe wind and hail from the eastern Texas Panhandle into central Kansas. ...Central/southern Great Plains... An amplified shortwave trough over the Lower CO Valley will shift east across the Southwest through early Friday. Associated lee surface cyclone over southeast CO will drift east before accelerating late tonight into the eastern TX/OK Panhandles. A southwest to northeast-oriented cold front will push southeast across the central Great Plains and Mid-MO Valley. A north to south-oriented Pacific cold front will eventually merge with the southern High Plains dryline. Low-level moisture largely characterized by low to mid 60s surface dew points will continue to spread north through tonight from central/east TX into KS ahead of the fronts. This will support gradual destabilization in the warm sector which will remain capped until later tonight. Scattered thunderstorm initiation appears likely between 06-12Z along/to the cool side of the front in KS and near/south of the cyclone when the Pacific cold front merges with the dryline, as mid-level height falls overspread these boundaries. Convection is expected to be rooted near or just above the surface, in an environment of modest buoyancy with MLCAPE of 500-1500 J/kg and moderate mid-level lapse rates. Rather elongated straight-line hodographs, largely due to robust speed shear above 700 mb, will foster organized updrafts. Flow alignment paralleling the front and the undercutting nature of the boundary in KS should subdue the overall severe wind and hail threat. A tornado is possible given storms will be rooted near the surface, though low-level hodograph curvature is forecast to diminish along the cold front by the time storms form overnight. ..Grams/Moore.. 11/03/2022 Read more
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