textproduct: Buffalo

SYNOPSIS

While low clouds will remain stubborn to clear over much of the region this Boxing Day...high pressure centered over the Saint Lawrence Valley will support fair dry weather through at least Friday. While this weekend will very likely feature April like warmth...the above normal temperatures in the 50s will be accompanied by rainy weather.

NEAR TERM /THROUGH FRIDAY/

Low clouds will remain firmly locked in throughout the region through the morning hours...as a very robust subsidence inversion will keep a wealth of low level moisture trapped beneath 3kft.

High pressure anchored over the St Lawrence valley this Boxing Day will maintain fair dry weather through Friday. The fair weather SHOULD finally be accompanied by some clearing...as the low clouds that have shrouded the western counties the past few days will gradually thin and give way to some sun this afternoon.

Temperatures will be close to seasonal normals today...then as we will start our warm up with the mercury lifting to near 40 across the western counties for Friday. Meanwhile...areas east of Lake Ontario will reach into the mid 30s.

SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/

Multiple shortwaves will impact the area bringing unsettle weather to the region beginning late Friday night and then lasting through this entire period. The first of these mid-level shortwaves, currently found over the panhandle of TX as of 06Z Thursday, is advertised to cut across the mid-Mississippi Valley on Friday. This shortwave will continue to head northeast towards Wisconsin-Upper Great Lakes where it will get absorbed by a trailing shortwave. As these shortwaves near....a warm frontal segment will lift northeast into and across the region with increasing chances for showers (30%- 40%) as we head into Saturday. P-type will mainly be 'rain' for most locales...the only area of concern would be across the St. Lawrence Valley. There, northeast flow may keep some cold air trapped in the lowest levels to allow for a bit of -FZRA. That said...confidence in this occuring at this point is low. As the sfc low heads northward across Lake Superior Saturday and then into Canada we should see a decrease in showers behind the front Saturday afternoon through Saturday night.

The next shortwave wave arrives Sunday which will bring a better chance of widespread 'rain', no issue regarding p-type this go around. The track of the sfc low is a bit in question but will'not' change p-type as a very mild airmass will already be in place. Speaking of which...temps will continue to modify over the weekend and by Sunday we should be looking at highs in the upper 40s to low/mid 50s. This may even be a bit conservative...there is some guidance pointing towards upper 50s to near 60F in spots. This would be at the top end of guidance, with low potential (< 10%) of reaching 60F.

Given the anticipated warm-up and 'rainfall' amounts (0.50" to 1.0") coming on Sunday/Sunday night we should see much of the remaining snow pack melt off. Current SWE values in the snowpack range from 1" up to 4" across the forecast area. A look at latest NAEFS, GEFS, and HEFS simulations most creeks and rivers across our HSA stay well below action stage...except on the Black River. The snowpack across the North County (Tug Hill) is much deeper and the potential for higher rainfall amounts exists. Even so...flooding is 'NOT' expected at this point but will need to keep an eye on it.

..An Important Pattern Change on the way

Surface low pressure will continue to pull away from the Lower Lakes Monday to our north and northeast. This will result in ongoing rain showers to gradually taper off throughout the day. Brief surface high pressure will slide across the area Tuesday, supporting a subtle drying trend. However, the next shortwave will slide another area of low pressure east across the Ohio Valley towards the Mid- Atlantic and support chances for precipitation to return for the start of the new year.

Temperatures Monday through Wednesday will remain above average, though a cooling trend will begin. It won't be until after the new year that temperatures really begin to turn 'colder' with the deep trough developing over the eastern CONUS which funnels much cold air into the eastern Great Lakes region.

Looking further ahead into the start of 2025...

A BIG change in our weather can be expected immediately after the New Year. The relatively low amplitude Pacific based flow that will have dominated the Lower 48 the past week or so with above normal temperatures will be replaced by a high amplitude...coupled +PNA/- NAO pattern that will feature our first cross polar flow in at LEAST two years. Boiling this down... it simply means that there is HIGH confidence that our temperatures will plunge back to well BELOW normal...with the potential for this change to persist at least a week.

The first signal of this dramatic change back to mid winter weather was a fairly significant stratospheric warming event that took place some 10 to 14 days ago. Sudden warming above 10mb usually results in a change in the arctic jet that translates into significant changes to the Arctic oscillation along with the corresponding North Atlantic oscillation. Within two to three weeks...this change in the high latitude flow will lead to an impressive surge of cold air that will make its way across eastern Canada and the northeastern portion of the Lower 48. Supporting this compelling change to mid winter conditions is agreement among many of the ensembles that anomalously strong ridging will be found along the West Coast (+PNA) while broad ridging will also build across Greenland and the North Atlantic (- NAO). This coupled pattern has a very high correlation to below normal temperatures throughout the Great Lakes region.

The proverbial 'icing on the cake' for this event is that many ensembles also suggest that a cross polar flow will develop. This will allow arctic air to settle southwards across eastern Canada where H85 temps in the -20s C will be common. Fortunately...the source region for this event does is not especially cold at this time...or the event could be more noteworthy.

AVIATION /09Z THURSDAY THROUGH MONDAY/

MVFR cigs will be found throughout the region through this morning...then drier air should erode our strato-cu to allow for the return to VFR weather later this Boxing Day through tonight.

Outlook...

Friday...VFR. Saturday...VFR/MVFR. Showers moving in. IFR in low clouds and fog at higher terrain. Sunday...MVFR/IFR. Rain likely. Monday...VFR/MVFR. A chance of rain showers.

MARINE

High pressure across the Saint Lawrence Valley will result in only gentle to moderate breezes and negligible wave action through Friday.

BUF WATCHES/WARNINGS/ADVISORIES

NY...None. MARINE...None.