MD 0029 CONCERNING HEAVY SNOW FOR DOWNWIND OF LAKE ONTARIO


Mesoscale Discussion 0029
NWS Storm Prediction Center Norman OK
0824 PM CST Mon Jan 19 2026

Areas affected...Downwind of Lake Ontario

Concerning...Heavy snow 

Valid 200224Z - 200830Z

SUMMARY...A lake effect snow band will gradually intensify tonight,
with rates eventually approaching 2-4 inches per hour downwind of
Lake Ontario.

DISCUSSION...The latest radar imagery from KTYX shows gradually
organizing lake effect snow bands extending downwind of Lake
Ontario. This is in response to subtle veering of uni-directional
boundary-layer flow (sampled by KTYX VWP) and a favorable fetch
developing across the long axis of Lake Ontario. This trend will
continue over the next few hours, as a low-level cyclone and
southward-extending surface trough continue advancing
east-northeastward across Quebec. Additionally, cooling temperatures
aloft (around -31C at 700 mb) will result in a deepening convective
boundary layer -- further aiding in the intensification of lake
effect snow bands extending across the Tug Hill Plateau and
vicinity. Heavy snowfall rates of around 2-4 inches per hour are
expected to begin in the 04-06Z time frame, and should continue
through the early morning hours.

..Weinman.. 01/20/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...ALY...BGM...BUF...

LAT...LON   43947626 43977539 43857511 43537507 43387524 43387618
            43467640 43667642 43947626

SPC 0100Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0653 PM CST Mon Jan 19 2026

Valid 200100Z - 201200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are not forecast across the U.S. today or tonight.

...DISCUSSION...
A large-scale cyclonic flow pattern will remain in place across the
U.S. this evening and tonight. At the surface, a cold and dry
airmass within a large area of high pressure will be in place over
much of the nation. As a result, thunderstorms will not develop
across the continental U.S. through daybreak on Tuesday.

..Broyles.. 01/20/2026