MD 0045 CONCERNING HEAVY SNOW FOR PORTIONS OF FAR WESTERN NEW YORK
Mesoscale Discussion 0045
NWS Storm Prediction Center Norman OK
1030 PM CST Mon Jan 20 2025
Areas affected...portions of far western New York
Concerning...Heavy snow
Valid 210430Z - 211030Z
SUMMARY...At least 2-3 inch/hour snowfall rates should continue past
sunrise with an intense lake-effect snow band.
DISCUSSION...MRMS mosaic and KTYX radar imagery show an intense,
steady-state lake-effect snow band persisting across Jefferson and
Lewis Counties in far western NY. This snow-band is benefiting from
an optimal fetch of moisture off of Lake Ontario, where 8+ C/km 0-3
km lapse rates are in place. As such, convective snowfall within
this lake-effect band should persist past sunrise, as shown by the
latest high-resolution guidance consensus. Furthermore, given the
convective nature of the band, and degree of saturation in the
dendritic growth zone, snowfall rates at least in the 2-3 inch/hour
range are expected through the remainder of tonight.
..Squitieri.. 01/21/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BUF...
LAT...LON 43977634 44027567 43947519 43697514 43547540 43587581
43617612 43647630 43977634
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MD 0044 CONCERNING HEAVY SNOW FOR PORTIONS OF FAR WESTERN NEW YORK
Mesoscale Discussion 0044
NWS Storm Prediction Center Norman OK
1016 PM CST Mon Jan 20 2025
Areas affected...portions of far western New York
Concerning...Heavy snow
Valid 210416Z - 210815Z
SUMMARY...Heavy lake-effect snow should continue into the early
morning hours, with 3 inch/hour intermittent snowfall rates likely.
DISCUSSION...The lake-effect snow-band has taken a more
southwest-to-northeast orientation over the past hour or so, with
heavy snow recently reported as far south as the Dunkirk Airport.
04Z mesoanalysis shows increased boundary-layer convergence and
moistening along a northern Chautaugua to Erie County line, which
will support continued heavy snowfall rates within the main band.
Snowfall accumulations over very short time periods via reports
suggest that near 3 inch/hour snowfall rates may be occurring with
this snow band. With the 04Z mesoanalysis showing 7.5 C/km 0-3 km
lapse rates present over water (where a long moisture fetch is in
place), 2-3 inch/hour snowfall rates may continue into the early
morning hours, as also suggested by latest high-resolution guidance
consensus.
..Squitieri.. 01/21/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BUF...
LAT...LON 42467965 42677916 42857882 42937844 42827827 42577845
42407890 42337923 42357944 42357954 42467965
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MD 0043 CONCERNING WINTER MIXED PRECIPITATION FOR PORTIONS OF SOUTH INTO SOUTHEAST AND EASTERN TEXAS
Mesoscale Discussion 0043
NWS Storm Prediction Center Norman OK
1000 PM CST Mon Jan 20 2025
Areas affected...portions of south into southeast and eastern Texas
Concerning...Winter mixed precipitation
Valid 210400Z - 210800Z
SUMMARY...Wintry precipitation rates should increase through tonight
across southeastern portions of Texas, with sleet and freezing rain
accumulations likely to continue.
DISCUSSION...700 mb WAA continues to increase atop a sub-freezing
airmass over southeastern TX as a positively tilted mid-level trough
glances the region to the north. Meanwhile, the dry low-levels
support wet-bulb temperatures well below freezing given ample
evaporative cooling/sublimation potential. Over the next couple of
hours, continued cooling of the surface-850 mb layer, due to both
925 mb CAA and evaporative cooling, should support an increased
potential for wintry precipitation (as evident based on recent
reports of ice accretion and sleet accumulations).
The greatest near-term potential for freezing rain/ice accretion
will be along a zone roughly from Wilson to Tyler Counties, where
surface observations show surface temperatures already cooled below
32 F. Latest high-resolution guidance shows sleet/freezing rates
peaking sometime after 06Z, including over portions of deep-south
TX. With time, at least moderate snowfall rates may eventually be
observed closer to the southeast TX coastline.
..Squitieri.. 01/21/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LCH...SHV...HGX...CRP...EWX...
LAT...LON 28789686 27639811 27479862 28629842 29729812 30359727
30899592 31199473 31259398 30999377 30489386 29879437
29819506 28789686
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