Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1114 AM CDT Thu Oct 06 2022 Valid 061700Z - 071200Z ...NO CRITICAL AREAS... No changes; fire weather concerns are low. ..Lyons.. 10/06/2022 .PREV DISCUSSION... /ISSUED 1201 AM CDT Thu Oct 06 2022/ ...Synopsis... Surface high pressure and associated cooler air will surge southward across the Plains/MS Valleys amid deep-layer northwesterly flow aloft today. Given cooler or wetter conditions expected across the central and western U.S., wildfire spread threats (if any exist) should be very brief and localized, confined to where fuels are most receptive to fire spread, namely the southern Plains. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Wed Oct 5 17:44:01 UTC 2022.

No Mesoscale Discussions are in effect as of Wed Oct 5 17:44:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1152 AM CDT Wed Oct 05 2022 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are unlikely on Thursday. ...Synopsis... A broad mid/upper trough will envelop much of the eastern half of the CONUS on Thursday. Several shortwave troughs embedded within this larger-scale system will pivot across the Upper Midwest, Great Lakes and Northeast. While some enhancement to westerly midlevel flow will accompany these shortwave troughs, vertical shear will generally remain weak. At the surface, low pressure will develop over southern Quebec and the Northeast. A cold front associated with the low will develop south/southeast across the central Plains, mid/upper MS Valley and OH Valley vicinity through the period. Cooler midlevel temperatures will support modestly steep midlevel lapse rates and contribute to weak instability. However, a seasonally dry airmass will be in place ahead of the cold front across much of the Plains/Midwest/Northeast, limiting stronger destabilization. A few instances of thunderstorms will still be possible ahead of the front across parts of NE, the Lake Michigan vicinity and parts of New England, though severe thunderstorm potential is not expected. Diurnal thunderstorm activity is also expected again across portions of the Southwest where steep midlevel lapse rates will contribute to weak instability amid abundant midlevel moisture. Weak vertical shear and modest instability will limit severe potential here as well. ..Leitman.. 10/05/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1139 AM CDT Wed Oct 05 2022 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... No changes have been made to the ongoing forecast. Dry conditions (RH values below 30%) are possible over much of the mid Mississippi Valley, but the lack of stronger winds will keep any fire weather concerns localized. ..Lyons.. 10/05/2022 .PREV DISCUSSION... /ISSUED 0129 AM CDT Wed Oct 05 2022/ ...Synopsis... Deep-layer northwesterly flow will become prevalent across the central U.S. today as a surface cold front sags southward across the Plains. Dry, occasionally breezy conditions may precede the cold front, with wildfire-spread potential remaining localized and limited overall. The best chance for any brief, localized wildfire concerns would likely be over the central and southern Plains states, where fuels are most receptive to fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1136 AM CDT Wed Oct 05 2022 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... CORRECTED FOR TSTM LINES ...SUMMARY... Scattered thunderstorms are possible today across parts of the southwestern U.S, the mid to upper Mississippi Valley, and in the vicinity of southern New England. Severe thunderstorms are unlikely. ...Synopsis/Forecast... Thunderstorms are expected today into tonight including across the southern Rockies/west Texas in proximity to an upper low, in addition to parts of the Midwest related to an east/southeastward-moving shortwave trough from Iowa into northern Illinois. While a couple of strong thunderstorms could occur this afternoon in areas such as southeast New Mexico/far west Texas and/or south-central Iowa, organized severe thunderstorms are unlikely owing to modest buoyancy and relatively weak vertical shear. ..Guyer/Thornton.. 10/05/2022 Read more

No watches are valid as of Tue Oct 4 17:41:02 UTC 2022.

No Mesoscale Discussions are in effect as of Tue Oct 4 17:41:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Oct 04 2022 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered afternoon storms are most likely across parts of New Mexico and Arizona, and portions of the Upper Mississippi Valley on Wednesday. Severe thunderstorms appear unlikely. ...AZ/NM... A weak shortwave trough will be in place over the southern Rockies vicinity on Wednesday, with a more amplified upper ridge oriented across CA and the Pacific Northwest. Deep-layer flow will remain weak, resulting in poor vertical shear. Weak destabilization will be driven by cool midlevel temperatures and steep lapse rates atop modest surface heating. Scattered thunderstorms are expected by afternoon, though severe potential will be negated by weak shear/instability. ...Upper MS Valley Vicinity... Isolated thunderstorm are expected during the afternoon/early evening as a mid/upper shortwave trough and surface cold front migrate across the region. An antecedent dry airmass over the Midwest will preclude better-quality boundary-layer moisture ahead of the surface front. This will limit instability despite cool midlevel temperatures and modest lapse rates. Vertical shear also will remain modest, with effective shear magnitudes around 20-25 kt forecast. A couple stronger cells could produce gusty winds and perhaps small hail, though severe storms are not expected. ..Leitman.. 10/04/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Tue Oct 04 2022 Valid 041630Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast across the contiguous United States today. ...Synopsis... Morning water vapor imagery depicts a mid/upper-level trough tracking slowly eastward across the northern/central Plains, preceded by a belt of moderate west-southwesterly midlevel flow and modest midlevel height falls/large-scale ascent. An attendant weak cold front will shift eastward from the central Plains into the Upper/Middle MS Valley through the period. Farther south, a convectively enhanced, low-latitude midlevel impulse will continue drifting east-southeastward across southern AZ, with related large-scale ascent overspreading southeastern AZ into western NM. ...Central Plains... Along/behind the weak cold front/wind shift and ongoing band of shallow frontal convection, filtered diurnal heating/destabilization of a plume of recycled boundary-layer moisture (lower/middle 50s dewpoints) beneath cold midlevel temperatures will support isolated to widely scattered convective development this afternoon into the evening. Over parts of NE, the enhanced west-southwesterly midlevel flow should yield 25-35 kt of effective shear, which coupled with marginal surface-based instability could favor a loosely organized cluster or two capable of locally strong gusts and/or small hail. ...Desert Southwest... Differential heating along the edges of ongoing shallow convection and cloud debris across southeastern AZ coupled with orographic circulations should result in additional surface-based convective development over the area this afternoon -- aided by large-scale ascent ahead of the midlevel cyclonic impulse. While generally weak deep-layer flow/shear should limit convective organization/longevity, steep midlevel lapse rates atop marginal low-level moisture could support a few strong updrafts capable of locally strong gusts and/or marginal hail. This will especially be the case for any multicell clusters that intercept steep low-level lapse rates over southeastern AZ and southwestern NM where stronger diurnal heating is expected. ..Weinman/Thornton/Thompson.. 10/04/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Tue Oct 04 2022 Valid 041700Z - 051200Z ...NO CRITICAL AREAS... No changes, fire weather concerns are minimal. ..Lyons.. 10/04/2022 .PREV DISCUSSION... /ISSUED 0150 AM CDT Tue Oct 04 2022/ ...Synopsis... A mid-level trough will traverse the northern Plains while a surface cold front sags southward across the central Plains today. While brief bouts of locally dry and breezy conditions may occur ahead of the front around afternoon peak heating, widespread significant wildfire-spread potential should remain limited, with no fire weather highlights introduced. Localized wildfire-spread potential may also exist across the central Mississippi Valley into the Ohio Valley given the presence of a dry low-level airmass overlapping modestly receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Mon Oct 3 17:44:02 UTC 2022.

No Mesoscale Discussions are in effect as of Mon Oct 3 17:44:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Mon Oct 03 2022 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast across the contiguous United States on Tuesday. ...Synopsis... A mid-level low over the Mid-Atlantic states will slowly move east into the adjacent Atlantic during the period as a mid-level low shifts slowly east across the Dakotas. An extension of the mid-level trough over the north-central U.S. will protrude farther southwest into NM. A plume of modest moisture and heating will promote isolated to scattered showers/thunderstorms from the Desert Southwest north-northeastward into parts of the Upper Midwest. A few lightning flashes cannot be ruled out near the immediate coast from NJ to Cape Cod. ..Smith.. 10/03/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Mon Oct 03 2022 Valid 031700Z - 041200Z ...Central and Southern Plains... The previous forecast generally remains on track with only minor adjustments. Higher than expected humidity recoveries have developed farther north across portions of northeastern NE and eastern SD. Low-level drying may be somewhat delayed resulting in RH values above 25% this afternoon. Locally gusty winds may still support a few hours near-elevated fire weather concerns within very dry fuels, but widespread elevated conditions are no longer expected. Dry and breezy conditions conducive to sustained fire weather concerns are most likely across portions of western KS near the lee trough this afternoon. ..Lyons.. 10/03/2022 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Oct 03 2022/ ...Synopsis... A mid-level trough will impinge on the northern Plains today, encouraging the persistence of surface lee troughing and associated dry southerly flow. Across the central Plains, a narrow corridor exists where Elevated dry and windy conditions will overspread receptive fuels in the absence of rainfall. Elevated highlights have been maintained in this corridor, mainly for early afternoon into early evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Mon Oct 03 2022 Valid 031630Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN ARIZONA... ...SUMMARY... A few strong to locally severe thunderstorms may occur over northern Arizona through early evening. ...Northern Arizona... A positive-tilt upper trough centered over southern Nevada will continue east-southeastward toward the Four Corners area through tonight. Steep mid-level lapse rates accompany the trough-related mid-level cold core (-14C at 500 mb). As further boundary layer heating/destabilization occurs into this afternoon, some stronger storms may develop and persist even with relatively weak winds aloft. A few of these storms could episodically produce hail to near severe levels through the afternoon before weakening by around sunset. ...North-central High Plains... Isolated stronger storms may also form later today over the Black Hills and the Nebraska Panhandle. Stronger winds aloft will promote some risk of more persistent structures, but limited low-level moisture will keep CAPE values rather low today. Nevertheless, small hail or gusty winds cannot be ruled out in a storm or two. ..Guyer/Wendt.. 10/03/2022 Read more

No watches are valid as of Sun Oct 2 18:10:02 UTC 2022.

MD 1855 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR NORTHERN AZ INTO SOUTHERN/EASTERN UT AND WESTERN CO
Mesoscale Discussion 1855 NWS Storm Prediction Center Norman OK 0108 PM CDT Sun Oct 02 2022 Areas affected...far northern AZ into southern/eastern UT and western CO Concerning...Severe potential...Watch unlikely Valid 021808Z - 022115Z Probability of Watch Issuance...20 percent SUMMARY...Sporadic strong thunderstorms may produce hail and strong gusts through the afternoon from far northern AZ into southern/eastern UT and western CO. DISCUSSION...Convection is beginning to develop near the higher terrain of southern/central UT and northern AZ at midday as lower elevation temperatures warm into the 60s and 70s. Thunderstorms should slowly increase in coverage and intensity over the next few hours. Effective shear magnitudes around 25-35 kt and steepening low/midlevel lapse rates will support at least periodically organized cells, with some high-based supercell structures possible. Meager boundary-layer moisture will limit instability, resulting in transient stronger cells through the afternoon. Sporadic severe hail and strong outflow gusts will be possible as convection shifts east/northeast. Given the transient and isolated nature of any more intense convection, a watch is not expected at this time. ..Leitman/Guyer.. 10/02/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GJT...FGZ...SLC...VEF... LAT...LON 37931380 39651140 40890925 40960865 40900802 40460765 39650768 38060857 37010992 36641179 36591335 36901359 37421377 37931380 Read more

No Mesoscale Discussions are in effect as of Sun Oct 2 17:53:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sun Oct 02 2022 Valid 031200Z - 041200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast for Monday across the contiguous United States. ...Synopsis... A weak mid- to upper-level trough will migrate slowly east across MT/WY into the Dakotas through Tuesday morning. A surface trough will extend from the Dakotas southward into the central High Plains while high pressure influences weather conditions across much of the central and eastern U.S. Near the surface trough, a narrow plume of modest moisture (surface dewpoints in the 40s and lower 50s) and heating will yield MLCAPE around 750 J/kg from SD into NE along the wind shift, beneath relatively weak midlevel southwesterlies below 30 kt. Scattered convection is likely to form off the Front Range, producing small hail and locally gusty winds. Given the relatively dry air mass and weak low-level winds, it appears convection will be sub severe. Farther southwest in the Four Corners, primarily diurnal storm activity will result in widely scattered to scattered storms during the afternoon to early evening. ..Smith.. 10/02/2022 Read more