textproduct: Gray - Portland

SYNOPSIS

Light rain will persist through this morning as low pressure tracks west of New England. A cold front crosses tonight into Thursday, bringing blustery conditions for Thanksgiving through the holiday weekend. Another cold front approaches later in the day on Sunday. Some mixed wintry precipitation is possible Sunday night across the portions of the interior as the next wave of low pressure arrives.

NEAR TERM /THROUGH TODAY/

615 AM Update...The bulk of the precipitation is pushing off the coast now with fog forming in areas where the rain has tapered off. The main focus of the update was to refine PoPs and use showery wording for the rest of the day. Otherwise, just loaded in the latest observations as the forecast remains on track.

Previous Discussion... Low pressure moving across the upper Great Lakes will continue to send a sfc warm front northward across New England this morning, allowing for continued light rain. This rain will become more showery in nature later today as the warm front lifts northward and an occluded front develops over the region. Skies will remain mainly cloudy but a few peaks of sunshine are possible this afternoon, mainly across southern locations. Patchy fog is likely across the interior. A wide range in high temperatures is expected with readings ranging from the 40s across the north and foothills to the 50s along the coast and in southern NH. A few spots could approach the 60 degree mark.

SHORT TERM /TONIGHT THROUGH THURSDAY/

Rain chances will increase again this evening through the first half of the night as a weak wave of low pressure rides along the lingering frontal boundary. This rain will gradually become mostly confined to the north and mountains after midnight with low temperatures into the 30s and 40s. A transition to snow is possible towards dawn on Thursday across the mountains and near the Canadian Border.

Cyclonic flow will prevail on Thursday with westerly wind gusts between 25-30 mph possible. It will otherwise be a mainly dry day with mainly cloudy skies across the north and partly cloudy skies further to the south. High temperatures will be into the 30s and 40s from north to south.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/

Key Messages: * Cold and breezy through the holiday weekend bringing cold wind chill temperatures * Potential for mixed precipitation across the interior on Sunday night * Watching the potential for another mixed precipitation storm that could impact coastal areas with the first widespread frozen precipitation of the season. Large model spread exists, but pattern evolution supports the potential.

Forecast Details: Upper level polar low over Quebec province pivots into New England on Friday, bring the core of the polar air and instability to the region. This will bring westerly backing to northwesterly upslope snow shower activity to the mountains with blustery conditions straight through Friday night. Pattern supports accumulating snow in the favorable mountain locations. Also expect wind chill temperatures down into the teens to single digits Friday night. Shortwave ridging expected on Saturday into Saturday night with surface high pressure bringing a nice cold day and no sensible weather impacts except for the cold. Return flow expected by Sunday as surface ridge quickly moves offshore, cold airmass in place, so an overrunning event looks likely at this point. Will be transitioning precipitation types on Sunday night, with a wintry mix in store before turning over to rain for most areas. Back to a polar airmass quickly on Monday with blustery conditions. What happens towards the end the extended forecast is still to be determined, but the flow will either be suppressed with the storm track across the Mid- Atlantic and very cold or there will be a coastal storm nearby and less cold. Will have to see how things trend.

AVIATION /11Z WEDNESDAY THROUGH SUNDAY/

Short Term...IFR-LIFR restrictions due to low ceilings and -RA will persist through at least this morning but MVFR-IFR restrictions will likely last through tonight in most locations due to continued low ceilings and light rain at times. Conditions will then improve on Thursday back to VFR, although MVFR CIGS could persist at KHIE with developing westerly flow. Westerly wind gusts up to around 25kts are possible on Thursday with light and variable flow today into tonight.

Long Term...VFR conditions Friday through Sunday for most TAF locations south of the mountains. Tempo IFR conditions are possible north of the mountains in snow shower activity on Friday. Do expect gusty conditions at all TAF terminals from the west and northwest. By Saturday winds will slacken and snow shower activity will come to an end. IFR conditions possible by Sunday night as the next warm front brings a period of mixed precipitation and low ceilings.

MARINE

Short Term...Southerly flow will persist today with gusts up to 30 kts outside of the bays through this morning. Seas of 2-4 ft are expected outside of the bays with 1-3 ft in the bays. Winds will become SW-W tonight into Thursday and increase with gusts up to around 35 kts possible outside of the bays with 25 kts in the bays. Seas will build to 3-7 ft across the outer waters with 1-3 ft in the bays.

Long Term...West to northwesterly gales are looking to continue Friday through the night as a tight pressure gradient sets up with low pressure to the north over Quebec. High pressure brings a brief period of improvement Saturday night and the first part of Sunday before a southerly flow increases ahead of a cold front that looks to cross Sunday night or early Monday. There may be a period at SCA on the southerly flow with possible gale conditions again by the beginning of next week.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory until 10 AM EST this morning for ANZ150- 152-154. Gale Watch from Thursday afternoon through Saturday morning for ANZ150-152-154.