No watches are valid as of Fri Dec 26 23:44:02 UTC 2025.MD 2276 CONCERNING HEAVY SNOW FOR UPSTATE NY TO EASTERN LONG ISLAND...INCLUDING PARTS OF SOUTHERN NEW ENGLAND
Mesoscale Discussion 2276
NWS Storm Prediction Center Norman OK
0541 PM CST Fri Dec 26 2025
Areas affected...Upstate NY to eastern Long Island...including parts
of southern New England
Concerning...Heavy snow
Valid 262341Z - 270545Z
SUMMARY...Heavy snow bands will spread/develop southeast across
upstate NY toward southern New England over the next few hours. Snow
rates of 1-1.5"/hr are expected.
DISCUSSION...Low-amplitude short-wave trough is progressing
southeast across western NY/PA early this evening. Latest
water-vapor imagery depicts a notable midlevel vort max southwest of
Syracuse, and this is reflected well in radar data. Multiple heavy
snow bands have developed ahead of this vort max, strongly
influenced by low-level warm advection, extending across upstate NY
into the lower Hudson Valley. Boundary layer moistening supports
this with dew points now rising into the mid teens (F) where snow
rates are increasing. Over the next few hours snow rates are
expected to increase downstream across western CT and Long Island,
largely in response to this well-defined short wave digging toward
the northern Middle Atlantic. Snow rates of 1-1.5"/hr can be
expected prior to the short wave passage.
..Darrow.. 12/26/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BOX...OKX...ALY...PHI...BGM...
LAT...LON 40917449 41497505 42417571 42857574 43277537 43347441
43037362 41847235 41217180 40677192 40367243 40347311
40527380 40917449
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0146 PM CST Fri Dec 26 2025
Valid 262000Z - 271200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not forecast across the contiguous United
States through tonight.
...20Z Update...
The general thunderstorm forecast was updated in the Lower Great
Lakes region on account of the shortwave trough progression. The
remainder of the forecast remains valid and is unchanged. See the
previous discussion for additional information.
..Wendt.. 12/26/2025
.PREV DISCUSSION... /ISSUED 1026 AM CST Fri Dec 26 2025/
...Synopsis and Discussion...
An upper trough will continue to progress eastward over the western
CONUS today. With cool temperatures at mid levels supporting weak
MUCAPE, isolated thunderstorms may occur across parts of CA into the
Great Basin and northern Rockies through the period as large-scale
ascent associated with the upper trough spreads inland. Mid-level
flow and related deep-layer shear should remain strong enough to
support some updraft organization across these areas, but limited
low-level moisture, cool surface temperatures, and overall weak
instability will likely hinder a meaningful severe threat from
materializing today. Elsewhere, isolated lightning flashes may occur
with elevated convection in a strong low-level warm advection regime
over portions of the Great Lakes into the Mid-Atlantic and southern
NY as a mid-level shortwave trough advances east-southeastward
across these areas.
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0130 PM CST Fri Dec 26 2025
Valid 281200Z - 291200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE MID MISSISSIPPI AND OHIO VALLEYS...
...SUMMARY...
Isolated severe thunderstorms are possible Sunday into Sunday night
from the Southern Great Lakes into parts of the Ohio and Mid
Mississippi Valleys.
...Mid MS to the OH Valleys...
An initially broad and multi-faceted positive-tilt upper trough over
the central US is forecast to undergo substantial amplification as
it moves eastward toward the Great Lakes Sunday and Sunday night.
The corresponding surface low will quickly intensify as it moves
eastward from KS/MO across northern IL. A trailing cold front will
also strengthen, with low-level moisture transport ahead of the
front (50s and 60s F surface dewpoints) aiding in modest
destabilization Sunday evening.
Elevated convection is likely to be ongoing over the MO valley
vicinity early in the period associated with the strong low-level
theta-E advection. This convection may remain elevated for much of
the day as it tracks along a stalled frontal zone from northern
MO/IL vicinity eastward into OH/IN and southern lower MI. Still,
some elements may eventually become near-surface based with weak
MUCAPE (100-200 J/kg) potentially supporting a few stronger gusts
near the surface.
Additional surface-based storms will likely develop within the
moistening warm sector over the northern Ozarks and mid MS valley
late Sunday afternoon. A low-topped convective band could organize
along the front as it moves east/southeast from the MS/OH Valleys
toward the northern Gulf Coast. As the trough and surface low
deepen, flow aloft will also increase. A strong (45-55+ kt)
low-level jet will develop from the Mid South to the southern Great
Lakes, rapidly strengthening low and mid-level shear profiles. While
buoyancy will be marginal (250-500 J/kg MUCAPE), this should be
sufficient for stronger linear segments to organize along the
surging cold front. Isolated damaging gusts and perhaps a brief
tornado or two are possible as the line moves quickly eastward over
the Mid MS and eventually the OH Valley Sunday night.
..Lyons.. 12/26/2025
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0126 PM CST Fri Dec 26 2025
Valid 271200Z - 281200Z
Some dry, downslope westerly winds are possible across portions of
northeastern Colorado during the day on Saturday ahead of a surface
cold front. Given the receptive fuels in the area, this may lead to
some brief Elevated fire weather risk during the afternoon. However,
uncertainty on the degree to which mid- and upper-level cloud cover
will impact mixing, and therefore the RH and wind strength, preclude
adding any highlights at this time. Otherwise, the previous forecast
remains largely on track with only minor adjustments made to the
Elevated highlights over the Texas Panhandle.
..Supinie.. 12/26/2025
.PREV DISCUSSION... /ISSUED 1228 AM CST Fri Dec 26 2025/
...Synopsis...
An upper-level ridge will remain in place along with an embedded
speed max across the central/southern Plains. The combination of lee
troughing and mixing should allow for sustained winds of 15-20 mph
to develop during the afternoon across the OK/TX Panhandles and
vicinity. Despite somewhat marginal RH values, perhaps approaching
the low to mid 20s, persistent dry conditions have led to
dry/receptive fuels, which will promote a few hours of Elevated
fire-weather conditions for this region.
...Please see www.spc.noaa.gov/fire for graphic product...
|
