textproduct: Gray - Portland

WHAT HAS CHANGED

Have dropped the winter headlines as snow comes to an end across the area.

No significant changes to the extended forecast at this time. Models continue to be in general agreement with dry and cold weather through the rest of the work week. Will continue to monitor for coastal storm development for this weekend.

KEY MESSAGES

1. Well below normal temperatures continue thru the second half of the week. While apparent temperatures will get below zero, it does not appear it will be cold enough for any headlines. 2. Cold but mainly dry weather continues through the rest of the the work week with the potential for a bit of a warmup over the weekend. Signals for another coastal storm are appearing for this weekend but model spread continues to be rather wide with low confidence in the forecast arising due to that.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

NWP continues strong agreement for below normal temps for the foreseeable future. Generally looking at 5 to 10 degrees below normal, which is well below normal but unlikely to set any records. There will also be breezy northwest winds off and on for much of the week. This will drop wind chills overnight below zero, as cold as 10 or 15 below in the mtns. During the day those values may climb into the single digits or low teens, but it will certainly feel very cold out there.

Occasional reinforcing cold fronts will arrive with shortwave trofs pinwheeling around the larger upper low, and we do have our eye on one for this afternoon. As it swings thru snow showers are likely to become more widespread. I will maintain some mention of snow showers in the afternoon forecast despite the NBM have low or no PoP inland. Bufkit soundings have the snow growth zone near saturated and in the very low levels, so any lift in that layer should produce some flakes. Unlike this past evening where the upper levels were saturated as well, they will be drier this afternoon. So any accumulation will be more like a dusting.

KEY MESSAGE 2 DESCRIPTION...

Cold weather continues for the rest of the work week but not brutally cold. There may be snow showers from time to time mid to late week under mean troughing but impacts will be minimal. We continue to monitor the potential for a coastal storm for this weekend. However, ensemble spread is much too wide at this juncture to have much confidence in any significant weather impacts here. A large portion of the guidance currently relegates this storm to the southeast and mid atlantic coasts with minimal impacts here. However, there is still plenty of time for this to change and we will obviously continue to monitor.

AVIATION /02Z TUESDAY THROUGH SATURDAY/

Widespread IFR conditions driven mainly by light snow and lower VIS. Gradually this will improve from west to east and generally lift to VFR as winds turn northwesterly and downslope off the mtns. The exception will be north of the White Mtns around HIE, where lingering MVFR CIGs are possible. VFR conditions are expected most of the day until the upper low moves overhead during the afternoon. Scattered snow showers and local IFR or lower conditions are possible.

Outlook:

Wednesday: VFR conditions expected.

Thursday-Saturday: VFR should prevail at most terminals as no significant weather is expected through the second half of the week. HIE could see brief periods of MVFR ceilings and Vsbys in snow showers.

MARINE

With the upper trof swinging thru the region a secondary cold front will cross the waters this morning. Winds turn northwesterly and increase. Marginal gale force gusts are possible well outside the bays thru sunrise. With cold temps in place, periods of moderate freezing spray are possible thru midday as well. As the core of the cold air aloft moves overhead this afternoon, snow showers will become more numerous over the waters. Local visibility below 1 mile is possible. Otherwise SCA to near SCA conditions are expected to prevail thru Wed.

Long term...Sub-SCA conditions are expected into Saturday but a period of SCA conditions will be possible Thursday night. Otherwise, higher wind gusts and seas may not return until Sunday and will be dependent on the track of a coastal low pressure system.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Gale Warning from 1 AM to 7 AM EST Tuesday for ANZ150-152-154. Freezing Spray Advisory from 1 AM to 10 AM EST Tuesday for ANZ150>154. Small Craft Advisory until 7 AM EST Tuesday for ANZ151-153.