Severe Storms

MD 0107 CONCERNING HEAVY SNOW FOR CENTRAL AND NORTHEASTERN ILLINOIS...WEST-CENTRAL AND NORTHWESTERN INDIANA...AND SOUTHWESTERN LOWER MICHIGAN
Mesoscale Discussion 0107 NWS Storm Prediction Center Norman OK 0711 AM CST Wed Feb 02 2022 Areas affected...central and northeastern Illinois...west-central and northwestern Indiana...and southwestern Lower Michigan Concerning...Heavy snow Valid 021311Z - 021815Z SUMMARY...Snowfall rates around 1" per hour are expected to continue through the morning from central and northeastern Illinois into southwestern lower Michigan. DISCUSSION...Weak short-wave troughing at mid levels is shifting into Missouri at this time, within southwesterly flow aloft on the eastern fringe of the larger, synoptic-scale trough over the West. As a result, maintenance of quasi-geostrophic ascent in the vicinity of the southward-moving cold front continues to support widespread precipitation from eastern Kansas to the Midwest. Within this broad area of precipitation, the heaviest snowfall is ongoing from central and northeastern Illinois northeastward. A temporary minimum in snowfall is indicated by radar across a portion of northwestern Indiana, but this is expected to be a transient situation as heavy snow spreads from southwest to northeast across the area. With time, snowfall will taper from the west, as the aforementioned short-wave trough advances. In the mean time however, snowfall rates of an inch per hour will continue through late morning. ..Goss.. 02/02/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...GRR...IND...LOT...ILX...LSX...DVN... LAT...LON 38929129 39799032 41288908 42148671 42498527 42428498 41938492 39868682 38848941 38929129 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Wed Feb 02 2022 Valid 021300Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected across the contiguous United States today and tonight. ...Synopsis/Discussion... The mid/upper-tropospheric pattern will be dominated this period by progressive, positively tilted troughing from the Hudson Bay region across the Rockies, to northwestern MX and the adjoining subtropical/tropical eastern Pacific. This high-amplitude troughing results from several fairly well-phased synoptic to subsynoptic troughs, including a strong shortwave perturbation evident in moisture-channel imagery over the Great Basin and western AZ. The latter feature will strengthen and move southeastward to AZ and northern Sonora by 00Z, spreading a strengthening plume of DCVA/ ascent aloft across parts of eastern AZ and central/southern NM, west of the frontal zone described below. Isolated thunder may occur in associated convection, with weak but sufficient low/middle-level moisture. The mid/upper perturbation should pivot eastward to southern CO and central/southern NM by 12Z tomorrow. Farther east, a strong surface cold front was analyzed from southern ON across central IN, to a weak low over northwestern AR, then across extreme southeastern OK, north-central TX, the Edwards Plateau, Davis Mountains area, and northwestward over central NM. The front should move relatively slowly through 00Z, reaching easternmost ON, southwestern OH, western portions of KY/TN, northern MS, northern LA, south-central to far west TX, and central/north- central NM. By 12Z, a weak frontal-wave low may develop along the front over the Gulf and move inland over southwestern LA, in response to the approaching trough. The front should extend from there northeastward to WV and eastern NY, and southwestward across the TX shelf waters to deep south TX. Isolated to widely scattered thunderstorms are possible in two initially separate plumes of lift that will offset in time: 1. A broad, somewhat triangular belt of low-level convergence today into early evening, amidst weak CINH, extending from the central Gulf north-northeastward across portions of MS/AL and southeastern LA. 2. A swath of low-level warm advection and moisture transport from the northwestern Gulf across south and east TX this evening, shifting eastward/inland and extending over parts of LA, AR and MS by 12Z. This area of ascent will be enhanced on its western rim by frontal processes as the baroclinic zone moves into the outlook area. The air mass inland remains cool and stable. However, modifying marine-layer air over the western Gulf (in the wake of the convection and the mid/upper wave from 24-36 hours ago) will advect northward/inland through the period, ahead of the cold front. Deep shear will increase over the western plume tonight, and a few cells (including low-end supercell potential) with small hail and strong gusts cannot be ruled out tonight over parts of LA, with small hail also possible from elevated/post-frontal convection over east TX. Temperatures and dew points in the low/mid 60s may reach parts of LA tonight ahead of the front, beneath weak low/middle-level lapse rates. At least a shallow stable layer will remain at the surface through most of the period, keeping any thunderstorm-gust or tornado potential too conditional and isolated for a categorical outlook area overnight. Though severe potential appears more unconditional and organized on day 2, some concern exists that surface-based parcels could reach areas of supercell potential in central LA the last couple hours of the overnight period. Moisture-return and prognostic trends will be monitored for a more-certain unconditional threat in subsequent outlooks. ..Edwards/Goss.. 02/02/2022 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0340 AM CST Wed Feb 02 2022 Valid 051200Z - 101200Z ...DISCUSSION... Severe thunderstorms are not expected during the Day 4-8 period. A surface cold front over the western Atlantic into central FL and eastern Gulf of Mexico will continue to shift east/southeast on Day 4/Saturday. This front will develop well south into the southern Gulf of Mexico/Caribbean vicinity. A series of mid/upper-level troughs will develop and track across the U.S. east of the Rockies during the period. Additionally, a couple surface cold fronts will sweep across much of the central/eastern U.S. through Day 8/Wednesday. This will keep Gulf moisture well offshore and generally dry/stable conditions will prevail, limiting thunderstorm potential. Read more

MD 0106 CONCERNING HEAVY SNOW FOR PORTIONS OF EASTERN KANSAS
Mesoscale Discussion 0106 NWS Storm Prediction Center Norman OK 0335 AM CST Wed Feb 02 2022 Areas affected...portions of eastern Kansas Concerning...Heavy snow Valid 020935Z - 021430Z SUMMARY...Snowfall rates of 1" per hour will occur over the next several hours across portions of the eastern Kansas vicinity. DISCUSSION...Latest surface analysis shows the surface cold front moving steadily southward -- south of the I-44 corridor in southwestern Missouri and Oklahoma. As this occurs, cold air filtering in behind the front has allowed temperatures to drop below freezing across east-central and parts of southeastern Kansas, where a band of locally heavy snowfall is evolving. The precipitation appears to be associated with a zone of QG ascent associated with a passing, subtle short-wave trough/vort max, expected to cross Missouri later this morning. Given its apparent association with this feature, the band of snow will shift east-northeastward with time, and eventually taper off from west to east. Prior to that, snowfall rates around 1" per hour are expected within this band of snow. ..Goss.. 02/02/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...TOP...ICT... LAT...LON 39209468 38739469 38189501 37399699 37079791 37459785 38119747 38909676 39329542 39499498 39209468 Read more

No watches are valid as of Tue Feb 1 21:29:01 UTC 2022.

No Mesoscale Discussions are in effect as of Tue Feb 1 21:29:01 UTC 2022.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0146 PM CST Tue Feb 01 2022 Valid 012000Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely over the contiguous United States through tonight. ...20Z Update... No changes have been made to the ongoing forecast. ..Gleason.. 02/01/2022 .PREV DISCUSSION... /ISSUED 1020 AM CST Tue Feb 01 2022/ ...LA... Morning water vapor imagery shows a well-defined shortwave trough moving slowly eastward across the northwest Gulf of Mexico. Scattered showers and thunderstorms have been occurring ahead of this system offshore of the LA coast. There remains a low probability of a few lightning flashes near the immediate coast this afternoon, but the bulk of the deep convection is expected to remain offshore. This potential will wane after 00z. Elsewhere, dry and stable conditions are expected to prelude organized thunderstorms today and tonight. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1221 PM CST Tue Feb 01 2022 Valid 021200Z - 031200Z ...NO CRITICAL AREAS... No changes have been made to the current outlook. See the prior discussion for more details. ..Lyons.. 02/01/2022 .PREV DISCUSSION... /ISSUED 0118 AM CST Tue Feb 01 2022/ ...Synopsis... A broad upper trough will eject into the Plains states tomorrow/Wednesday, further driving a surface cold front into the Gulf of Mexico. Behind the cold front, cold/wintry weather is expected across the central and southern Plains, limiting wildfire concerns. Strong, dry offshore flow is also expected tomorrow across southern California. While Critical meteorological surface conditions are expected to be in place, fuels remain too moist to support significant wildfire-spread potential, with no fire weather highlights introduced. ...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 1122 AM CST Tue Feb 01 2022 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the contiguous United States on Wednesday. ...Synopsis and Discussion... Large-scale upper troughing will extend from the northern Plains across the Rockies and into the Southwest Wednesday morning. This upper trough is expected to progress slowly eastward across the Upper Midwest and much of the Plains through the period. An arctic cold front will continue to advance southeastward across the southern Plains, Mid-South, and lower MS Valley through Wednesday night. Low-level moisture return ahead of the front should remain fairly modest through much of the day, with generally 50s to low 60s surface dewpoints prevalent. Eventually, slightly greater low-level moisture, characterized by surface dewpoints up to 64-66F, may advance inland across parts of coastal TX and LA Wednesday night. This gradual increase in low-level moisture will occur in tandem with a strengthening southerly low-level jet across east TX and the lower MS Valley, mainly after 06Z. Forcing for ascent associated with the upper trough should remain mostly displaced to the north and west of the surface warm sector. Still, increasing low-level warm/moist advection and the cold front itself will probably encourage convective development Wednesday evening/night from parts of central into east TX, and eventually the lower MS Valley. Most of these thunderstorms should be undercut by the front fairly quickly, with a large component of front-parallel flow present aloft. A low chance for surface-based storms may exist along immediate portions of the upper TX Coast into southwestern and central LA late Wednesday night. Across these areas, weak instability coupled with strong deep-layer shear suggest that there may be a chance for a strong thunderstorm or two. A fair amount of uncertainty remains in various model guidance regarding the quality of the low-level moisture return across this region, which will greatly impact the potential for surface-based convection. At this point, it appears that an appreciable increase in the threat for isolated severe thunderstorms should wait until the start of the Day 3 period (12Z Thursday) across parts of the central Gulf Coast. ..Gleason.. 02/01/2022 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0657 AM CST Tue Feb 01 2022 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely over the conterminous U.S. ...Synopsis/Discussion... A series of shortwaves at various latitudes will contribute to amplification of an extensive, yet progressive, trough from Arctic Canada across the western Hudson Bay region, then southwestward across the northern Plains to UT, southern CA and the Pacific west of Baja. Meanwhile, a southern-stream perturbation is devolving from a closed cyclone to open-wave trough over the northwestern Gulf. At the surface, 11Z analysis showed a cold front near a DSM-MKC-GAG-CVS line. By the end of the period, the front should extend near a line from DTW-IND-MVN-DAL, then southwestward over the Edwards Plateau, Trans-Pecos area of TX, and southeastern/central NM. Isolated to scattered thunderstorms will remain possible over the open Gulf east and southeast of the mid/upper perturbation for much of today, until it weakens and passes the area tonight. Activity should occur mainly in an arc of convection immediately ahead of the trough, and farther east in a zone of sustained low-level convergence, moisture transport and surface-based buoyancy. Isolated thunderstorms are evident moving northward across the central/eastern LA shelf waters in the latter regime, and cannot be ruled out over nearby coastal areas. Some model soundings' forecast mid/upper-level profiles show enough stability inland to cap convection to levels warmer than -20 C, as also evident in 12Z LCH/LIZ RAOBs. However, only 1-2 deg C cooler conditions in the 400-500-mb layer above the warm-advection plume -- or about that much warmer within the plume -- would be needed (compared to those models' soundings) to support an areal lightning threat over land. RAP CAPE profiles over land, by contrast, do briefly intrude into the bottom of icing layers suitable for lightning production, near and east of an MCV now located southwest of LFT. Buoyant layers over the Gulf also are deeper, given 30-40 kft echo tops observed with isolated cells over shelf waters over the past couple hours, with warm advection expected toward land. As such, a small general-thunder area has been added for daylight hours. ..Edwards.. 02/01/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Wed Jan 26 2022 Valid 261630Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of southern Florida today through early evening, although severe storms are not expected. ...Synopsis... A cold front will drift southward into south FL through the day and into tonight. Larger-scale forcing for ascent will be weak given only subtle perturbations within a zonal flow regime aloft, but storm coverage could be aided some by pockets of surface heating within cloud breaks this afternoon. Despite MLCAPE of 750-1000 J/kg this afternoon and effective bulk shear near 35 kt, poor midlevel lapse rates and weak low-level flow both suggest that severe storms are unlikely. ..Thompson/Weinman.. 01/26/2022 Read more

No Mesoscale Discussions are in effect as of Wed Jan 26 16:06:02 UTC 2022.

No watches are valid as of Wed Jan 26 16:06:02 UTC 2022.

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0919 AM CST Wed Jan 26 2022 Valid 261700Z - 271200Z ...NO CRITICAL AREAS... Morning surface observations and trends in latest guidance continue to suggest low fire weather potential for today across the CONUS. Dry and locally breezy conditions remain possible across the lower CO River Valley and coastal southern CA, but fuels remain too limited to support a more robust concern. See the discussion below for additional details. ..Moore.. 01/26/2022 .PREV DISCUSSION... /ISSUED 0119 AM CST Wed Jan 26 2022/ ...Synopsis... Flow aloft will become broadly cyclonic across a sizable portion of the country today. At the surface, high pressure will be present in the West and from the Gulf Coast into the Northeast. A strong surface cyclone in southern Canada will move eastward north of the international border, bringing gusty winds to parts of the northern Plains and upper Midwest. Fire weather concerns will remain minimal due to a combination of cool/cold conditions and unreceptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0656 AM CST Wed Jan 26 2022 Valid 261300Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of southern Florida today through early evening, although severe storms are not expected. ...South Florida... A weakening southern-stream shortwave trough continues to steadily progress offshore toward the Atlantic, with neutral/slightly rising heights today in its wake. Additional low-level moistening will continue to occur today into the southern Florida Peninsula near/south of a west/east-oriented front, and ahead of a weak surface wave that will transition from the eastern Gulf of Mexico toward off the southeast Peninsula by tonight. Mid-level subsidence may have a detrimental effect, but weak convergence near the front, perhaps aided by an east-coast sea breeze, will influence shower/thunderstorm development into this afternoon within an increasingly moist and modestly unstable air mass. A couple of stronger/sustained storms could materialize in the presence of 800-1000 J/kg MLCAPE and moderately long/semi-straight hodographs. However, the influences of weak convergence, weakening low-level winds, a lingering subsidence inversion aloft, and pseudo-adiabatic lapse rates are expected to temper updraft/downdraft intensity, likely keeping the potential for severe storms low. ..Guyer/Bentley.. 01/26/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0921 AM CST Tue Jan 25 2022 Valid 251700Z - 261200Z ...NO CRITICAL AREAS... No forecast changes are needed. Morning observations, guidance, and fuel analyses continue to suggest low fire weather potential for most of the CONUS today. Elevated conditions remain likely across the lower CO River Valley, but fuels remain too limited for a more substantial fire weather concern. See the discussion below for additional details. ..Moore.. 01/25/2022 .PREV DISCUSSION... /ISSUED 1224 AM CST Tue Jan 25 2022/ ...Synopsis... A shortwave trough will round the base of the larger-scale trough across the upper Midwest and Northeast today. This will push colder air into the Plains and force the cold front to near the Gulf Coast. Farther west, another shortwave trough will move through the Great Basin and into the Southwest. High pressure will similarly build at the surface in its wake across the Great Basin. Cold temperatures and areas of precipitation will generally keep fire weather concerns minimal. Dry and windy northerly/northeasterly winds will return to southern California and the lower Colorado River Basin. Winds of 15-20 mph and RH reductions to 15-20% are possible in some locations. Fuels are not particularly supportive of fire spread, however. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Tue Jan 25 15:24:01 UTC 2022.

MD 0091 CONCERNING HEAVY SNOW FOR PORTIONS OF NORTHEAST COLORADO AND NORTHWEST KANSAS
Mesoscale Discussion 0091 NWS Storm Prediction Center Norman OK 0752 AM CST Tue Jan 25 2022 Areas affected...Portions of northeast Colorado and northwest Kansas Concerning...Heavy snow Valid 251352Z - 251645Z SUMMARY...Snowfall rates in excess of 1 inch per hour are possible across northeast Colorado and northwest Kansas this morning into the early afternoon. DISCUSSION...A band of snow has developed from northeast Colorado to northwest Kansas in a region of strengthening mid-level frontogenesis. Expect this band to reach peak intensity during the mid-to-late morning hours and persist into the afternoon. The dendritic growth zone is sufficiently deep and saturated and is located near the strongest ascent near the mid-level frontogenesis. This will support larger flake sizes which also assist in snowfall accumulation. Overall, snowfall rates are expected to be around 0.5" per hour, but greater rates at or above 1 inch per hour are anticipated in strong banding near the Colorado/Kansas border. A regional radar loop shows a stronger band extending from Washington County, Colorado to western Kansas. This may be the beginning stages of the stronger band of snow which is anticipated to develop by 15 to 16Z. ..Bentley.. 01/25/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DDC...GLD...BOU... LAT...LON 40610421 40560319 39990188 39480071 38870005 38280060 38500139 38890232 39230298 39470346 39730392 40110423 40320431 40610421 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Tue Jan 25 2022 Valid 251300Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated weak thunderstorms are expected across portions of central and southern Florida tonight/early Wednesday. ...Florida... Thunderstorms are ongoing over the north-central Gulf of Mexico in the predawn hours, roughly 250+ miles south of Mobile, AL and 250+ miles west of Tampa Bay, FL. These storms are influenced by an eastward-moving/minimal-amplitude southern-stream shortwave trough over the Lower Mississippi Valley and northwest Gulf of Mexico, with this system expected to gradually deamplify as it reaches Florida and the coastal Southeast tonight. The downstream air mass across Florida is currently cool and dry, with some moistening expected across the Keys vicinity into the southern Florida Peninsula tonight through early Wednesday. This trend will allow for an increasing potential for elevated thunderstorms over the southern/central Peninsula tonight. The more organized/sustained storms are expected to remain over the open Gulf of Mexico, as the ongoing storms will outpace inland air mass modification and the aforementioned moistening that is expected tonight. While some stronger storms could approach the Lower Keys general vicinity tonight, the potential for organized severe storms is currently expected to remain low. ..Guyer/Bentley.. 01/25/2022 Read more

No watches are valid as of Mon Jan 24 14:29:01 UTC 2022.