textproduct: Gray - Portland

SYNOPSIS

Light snow will grace the area to start the new year. While most locations will only see around 1 inch, closer to Penobscot Bay may be shoveling 2 to 4 inches of the white stuff. Despite the turning of the calendar the colder than normal weather continues. Once a cold front crosses the area this morning, expect temperatures to remain below normal through at least Monday. Snow showers will stay mainly in the mountains, but high temperatures will remain in the 20s or colder.

NEAR TERM /THROUGH THURSDAY/

Light snow continues to overspread the forecast area early this first day of 2026. Generally speaking it will be quite light, with most areas seeing around an inch. However from Casco Bay through the Midcoast and north to the lower Kennebec Valley there may be enough late development of the coastal low pressure to throw back precip thru the late morning or midday hours. This will generally lead to 2 to 4 inches of snow, but very close to Penobscot Bay there may be some totals around 6 inches. There is also some indication from hi-res guidance that along the cold front snow showers may organize into a line of briefly heavy or squally precip. This would be most likely over the more populated areas of southern NH and southwestern Maine, so any early New Years Day travel may be impacted. By late morning this activity should largely be over the Gulf of Maine. The afternoon will see falling temps and gusty winds behind the front. I cannot rule out some gusts as high as 30 to 35 mph.

SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/

Surface ridging tries to nose into the region tonight, which may be enough to allow winds to relax for most sheltered locations. Once again with fresh snow, albeit light, that may allow for stronger radiational cooling than model guidance indicates. Will blend in a little 25th percentile NBM guidance to account for this.

Fri will bring a return to colder weather, with high temps in the teens and 20s. Winds at the top of the mixed layer remain around 25 to 30 kt, so gusts of 25 mph certainly seem possible and will make it feel much colder than the actual air temp. Upslope snow showers will be possible as well, and a few of those may continue downstream of the mtns as flurries.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/

Overview: Below normal temps expected thru next week. Below average chance of precip thru late next week.

Key Messages:

-Temps well below normal thru early next week. High temps run about 10 degrees below normal, with wind chills in the teens and single digits during the day for much of the area.

Forecast Details: The primary concern thru the extended will be a return to well below normal temps. Temps look unlikely to climb out of the 20s at best thru the weekend and into Mon. In fact Mon may struggle to reach even 20 degrees. There will also be a pretty solid pressure gradient thru the weekend as well, meaning breezes may not completely die overnight. That will introduce at least a low confidence threat of wind chills dropping to 20 below in the mtns. Elsewhere apparent temps in the single digits below zero overnight seem likely. The only adjustment I see is that surface high pressure settles into the region Mon morning, and NBM guidance is typically too warm under these scenarios. Will blend in the 25th percentile guidance for now, as there may be enough cloud cover approaching from the west to prevent the most ideal radiational cooling.

That brings me to the precip chances thru the middle of next week. They will primarily be driven by upslope flow over the higher terrain. At least Sat this looks to be unblocked flow in cold air advection, so I anticipate that some flurry activity is possible downwind of the mtns.

Otherwise I am watching the window around Mon night as high pressure slides east. Warm air advection ahead of a weak trailing shortwave trof may provide enough frontogenesis along the edge of the departing cold dome to produce some light precip thru New England. Currently guidance varies on the spacing between the stronger shortwave driving the cold front on Mon and the trailing feature. Too close and it will get squashed and leave no real mechanism for generating lift, but with enough spacing we can get that warm advection developed enough. The NBM already has some slight chance to chance PoP in this window, so I do not really see a need for adjustment at this time.

AVIATION /03Z THURSDAY THROUGH MONDAY/

Short Term...Mostly VFR conditions currently, but light snow is on the doorstep. At least a few hours of IFR or lower conditions are anticipated at all TAF sites thru morning. Will also see southerly winds increase to 30 to 40 kt around 2000 ft tonight for all terminals across southern NH and coastal western ME. I do not anticipate enough of a wind shift to call this LLWS, but some mechanical turbulence on takeoff/landing is possible. Farther east there will be some enhancement of snow and IFR conditions may linger thru midday at AUG and RKD. Then a cold front sweeps thru and westerly surface winds will gust between 20 and 30 kt into the evening. VFR continues Fri but westerly gusts of 20 to 25 kt are expected again.

Long Term...Largely VFR conditions expected in the extended. Gusty westerly winds will lead to surface gusts around 20 kt Sat before diminishing Sun. Upslope flow may bring local MVFR CIGs to the area around HIE thru the weekend before CIGs scatter out.

MARINE

Short Term...Still anticipating a cold front to cross the waters today and bring a return to gusty offshore winds. Gale warnings remain in effect for all waters thru tonight. Once colder air arrives that will combine with gusty winds to create areas of moderate freezing spray into Fri morning.

Long Term...Westerly winds remain gusty thru the weekend as colder air continues to pour over the Gulf of Maine. SCA conditions are expected for all waters at the start of the period. By later Sat winds and seas will be gradually diminishing, but continued SCA are anticipated thru Sun.

GYX WATCHES/WARNINGS/ADVISORIES

ME...Winter Weather Advisory from 1 AM to 7 PM EST Thursday for MEZ022-025>028. NH...None. MARINE...Gale Warning from 1 PM Thursday to 7 AM EST Friday for ANZ150>152-154. Freezing Spray Advisory from 10 PM Thursday to 1 PM EST Friday for ANZ150>154.