textproduct: Gray - Portland

SYNOPSIS

High pressure will persist over the Northeast into Friday. A weak system will cross Friday night bringing chances for rain and snow showers across the north. High pressure briefly returns late Saturday into Sunday before another weak system crosses Sunday night. Another area of high pressure builds in Monday and Tuesday with the pattern turning more active towards the middle of next week.

NEAR TERM /THROUGH TONIGHT/

High pressure drifts to the east into this evening. Winds will remain light and variable but gradually become more from the SW as the night goes on. Will see some cirrus drift overhead at times, but shouldn't be enough to deter some radiational cooling through the night.

HREF ceiling probabilities do hint at the arrival of a lower deck after midnight into southern NH and far southern ME. This could decrease the rate of cooling here, thus a bulk of decreasing temps could take place later this evening.

SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/

Cold front nears the forecast area during the day Friday. Moisture has continued to decrease with this system, and showers now look to avoid much of the interior and coast. Terrain in western NH and ME will help to dry out the downslopes, further decreasing shower coverage. QPF is even lighter for the mountainous regions to the west.

Will still see some southern stream moisture move across southern New England Friday night, and some light rain could result in the southern half of the CWA. The center of this low has pushed south in guidance, well south of the Cape Cod region. While these northern peripheries are typically whittled away by dry northern air, we'll still be seeing moisture associated with the exiting cold front. Thus this precip shield may still bring light showers to the southern forecast area.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Overview: A low amplitude northern stream pattern will persist through this weekended into early next week. The pattern will become more amplified towards the middle of next week when some southern stream energy merges with the northern stream resulting in a broad trough over the central US. A weak front will be pushing offshore Saturday morning with high pressure briefly building in through Sunday morning. Another weak system crosses late Sunday into Monday bringing mainly snow showers to the mountains. High pressure returns late Monday into Tuesday. Chances for widespread precipitation increase late Tuesday through Wednesday as the trough over the central US migrates eastward.

Impacts: *No strong signal for significant weather impacts through the period.

Details: Saturday will feature a mix of sun and clouds in the wake of a departing cold front. Post frontal winds will be tame with gusts topping out around 20 mph. Highs will range from the 30s north to 40s south. Mostly clear skies and a colder air mass in place will allow for lows into the teens and 20s Saturday night. Brief high pressure shifts south Sunday as the next short wave dives SE out of Canada. This moisture starved system will bring some chances for snow showers to the mountains Sunday night into Monday.

High pressure builds in late Monday through Tuesday for mostly fair weather. High pressure shifts south Tuesday night as broad troughing translates east across the Ohio Valley. A warm air advection pattern develops into Wednesday bringing increasing chances for precipitation to the region. The antecedent airmass does not look overly cold suggesting rain may be the dominant precipitation type south of the mountains. The trough will be slow to move east and may bring additional chances of precipitation to the region through the holiday.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Short Term...VFR. SKC or high cirrus conditions through this evening and midnight. Some guidance has been hinting at the reinforcement of low level moisture in southern NH to form SCT MVFR for southern NH terminals. Exactly how much of the sky this covers is uncertain at this time, but it is expected to be around 3000ft. Better moisture over the coastal waters may aid in lower and thicker ceilings, and these may near coastal terminals like PSM, PWM, and RKD later tonight and Friday morning. A cold front will pass over the area Friday afternoon, bringing some MVFR ceilings and maybe virga or light rain showers. SHSN possible in the mountains and towards the US/CAN border, as well as MVFR/IFR ceilings.

Long Term...Outside of occasional mountain clouds and snow showers at KHIE, mainly VFR is expected across the area through the period.

MARINE

Short Term...High pressure drifts south and east tonight through Friday morning. A cold front will pass over the waters Friday afternoon, increasing gusts to around 20 kts. Can't rule out a brief period of 25 kts as winds shift SW to W. Wind wave will be slow to react, becoming 1 to 3 ft Friday night.

Long Term...Winds and seas will generally stay below SCA thresholds through the period. A couple of cold fronts will cross the waters with one Saturday morning and another Sunday night.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...None.