
Mesoscale Discussion 2236
NWS Storm Prediction Center Norman OK
1100 AM CST Thu Nov 27 2025
Areas affected...Northern Lower Michigan
Concerning...Heavy snow
Valid 271700Z - 272200Z
SUMMARY...Snowfall rates of 1-2 inch per hour remain possible
through mid/late afternoon.
DISCUSSION...A dominant snow band off of Lake Michigan, with
upstream connection to Lake Superior, continues early this afternoon
in northern Lower Michigan. Dual-pol data from KAPX shows higher KDP
values within this band suggesting 1-2 inch per hour snowfall rates
are possible. Given limited change in the large-scale environment
over the next few hours, this band is expected to persist through
the afternoon. High-resolution ensemble guidance suggests this as
well. The most intense snowfall rates will likely being to wane by
late afternoon as mid-level ascent from a shortwave trough moves
away from the region. As this occurs, there may be a slight
southward wobble in the band as 850-700 mb winds subtly take on a
more northerly component.
..Wendt.. 11/27/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...APX...
LAT...LON 44358438 44878534 45088560 45208556 45458547 44668384
44298383 44358438
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Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0139 PM CST Thu Nov 27 2025 Valid 272000Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast through tonight. ...20z Update... Only minor adjustments were made to the thunder line to account for ongoing trends across the Florida peninsula. Otherwise, no additional changes are needed. See previous discussion for more information. ..Thornton.. 11/27/2025 .PREV DISCUSSION... /ISSUED 1020 AM CST Thu Nov 27 2025/ ...Synopsis and Discussion... A large-scale upper trough encompassing much of the central/eastern CONUS will develop slowly eastward through the period. Isolated thunderstorm potential today will generally remain limited to parts of south FL and the Keys along/ahead of a southward-moving cold front. 11/12Z soundings from XMR/TBW/KEY show southwesterly winds strengthening with height at mid/upper levels. While sufficient deep-layer shear may exist to support a stronger thunderstorm or two this afternoon, especially along the Atlantic Coast in south FL, the presence of poor mid-level lapse rates and weak low-level winds should hinder the risk for organized severe thunderstorms over land. Isolated lightning flashes may also occur with snow bands occurring in western NY off of Lake Ontario.Read more

Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Thu Nov 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF EASTERN TEXAS AND SOUTHWESTERN LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible across portions of southeast Texas into western Louisiana Saturday afternoon or evening. ...Synopsis... The shortwave trough over the central Plains will move eastward as mid-level westerly flow intensifies from the Plains to the MS Valley and Midwest Saturday/Sunday. A surface low attendant to the trough will move from OK/KS to the southern Great Lakes as a strong cold front moves south from the Red River to the lower MS Valley. Moisture return ahead of the front will support scattered thunderstorms across eastern TX, the Sabine Valley and lower MS valley through early morning Sunday. ...Southeast TX to western LA... With southerly surface flow expected to develop ahead of the deepening surface cyclone over the Plains Saturday, low-level moisture advection should increase across coastal and southeast TX into LA. A warm front will slowly lift northward, stalling over southwest LA as it encounters a deep and cool air mass farther north. Continued low-level warm air advection (despite ongoing showers and remnant clouds) should allow for gradual destabilization Saturday afternoon. While overall forcing for ascent appears weak as the upper trough departs to the north, scattered thunderstorm development appears probable, both within the low-level warm advection regime and along the approaching cold front from the Northwest. Given expected mid to upper 60s F dewpoints beneath 7-8 C/km mid-level lapse rates, around 1000 J/kg MLCAPE could support a few stronger updrafts late Saturday through Sunday morning. Residual westerly flow aloft may also favor some storm organization with multicell lines or clusters and perhaps transient supercells capable of damaging gusts and hail. This is most likely from the TX coastal Plain to southwestern LA before the cold front moves offshore into the Gulf. ..Lyons.. 11/27/2025Read more

Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1240 PM CST Thu Nov 27 2025 Valid 281200Z - 291200Z The Elevated area was expanded slightly based on the most recent high-resolution forecast guidance. Locally elevated conditions remain likely in portions of the Florida Panhandle, southwest Georgia, and southeast Alabama outside of the Elevated area. Temperatures will likely be a bit cooler tomorrow than today, but after dry/breezy conditions today, fuels are likely to be even more receptive. ..Nauslar.. 11/27/2025 .PREV DISCUSSION... /ISSUED 1252 AM CST Thu Nov 27 2025/ ...Synopsis... A large upper-level trough over the Eastern CONUS will move offshore throughout the day, with enhanced zonal mid/upper level flow persisting in its wake. At the surface, a dry/breezy post-frontal airmass will remain in place across much of the Southeast. ...Central Florida and far Southern Georgia... A continuation of dry northerly low-level flow into the region along with diurnal heating will result in RH values falling into the teens during the afternoon. Despite somewhat enhanced upper-level flow, afternoon winds may approach 15-20 mph, at least in localized areas, resulting in Elevated fire-weather conditions. Fuels will remain quite receptive to large-fire spread amid a few days of persistent dry low-level advection. The Elevated area was expanded to the northwest based on wind/RH combos depicted in the latest high-resolution guidance and limited recent precipitation occurring across the region. ...Please see www.spc.noaa.gov/fire for graphic product...Read more

Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CST Thu Nov 27 2025 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible over the southern Plains and lower Missouri Valley Friday night into early Saturday morning. Severe thunderstorms are not currently expected. ...Synopsis... Mid-level ridging over the central US will shift eastward behind a departing trough over the East. A second trough will deepen over the Rockies encouraging lee cyclogenesis over the southern Plains Friday. As the surface low deepens, modest low-level moisture will advect northward with a 40-60 kt southerly low-level jet. Lift from the approaching trough and an attendant cold front will support isolated thunderstorms from the southern Plains to the lower MO Valley late Friday into early Saturday. ...Southern Plains into the lower Missouri Valley... Ahead of the lee low, strong low-level warm air advection will transport middling surface moisture northward over parts of central/north TX into southern OK ahead of the surging cold front. In the wake of the prior frontal passage, a persistent surface stable layer is likely to prevent substantial northward moisture return over the southern Plains. However, cold mid-level temperatures (H5 temps -24C) beneath the deepening upper trough will likely support some elevated buoyancy development late Friday, overnight into Saturday. Isolated thunderstorms are possible within the boarder warm advection band. While generally weak, (~250-500 J/kg MUCAPE) sufficient destabilization and strong flow aloft could support an occasional stronger storm capable of small hail from northeast TX into eastern OK and the Ozarks. But, given the limited thermodynamics, a sustained severe risk appears unlikely. ..Lyons.. 11/27/2025Read more

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1020 AM CST Thu Nov 27 2025 Valid 271630Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast through tonight. ...Synopsis and Discussion... A large-scale upper trough encompassing much of the central/eastern CONUS will develop slowly eastward through the period. Isolated thunderstorm potential today will generally remain limited to parts of south FL and the Keys along/ahead of a southward-moving cold front. 11/12Z soundings from XMR/TBW/KEY show southwesterly winds strengthening with height at mid/upper levels. While sufficient deep-layer shear may exist to support a stronger thunderstorm or two this afternoon, especially along the Atlantic Coast in south FL, the presence of poor mid-level lapse rates and weak low-level winds should hinder the risk for organized severe thunderstorms over land. Isolated lightning flashes may also occur with snow bands occurring in western NY off of Lake Ontario. ..Gleason/Wendt.. 11/27/2025Read more