textproduct: Gray - Portland

WHAT HAS CHANGED

No major changes for this forecast package other than to tweak precipitation chances through the rest of tonight/early today based on the latest radar observations and high resolution guidance trends.

KEY MESSAGES

1. Some light snow remains possible over the Midcoast and across the mountains through this morning, then mainly dry conditions prevail until at least Saturday.

2. Seasonable temperatures are likely through the end of the week and into the weekend, with above average temperatures possible next week.

3. A potential system late this weekend and early next week continues to waffle back and forth on recent model runs, but remains an item of focus. Currently limited threat for an impactful system.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

An upper low and associated surface low move up into the Canadian Maritimes this morning as an inverted trough extends to the west of the surface low and rotates down into the Midcoast. Thus, we can expect some more light snow here through around 12z or so, but only a light coating of additional accumulation is expected. The mountains and vicinity will also see some lingering snow showers through the morning given upslope flow, but this activity should diminish by later this morning as upper ridging starts to nudge in. Mainly dry conditions are then expected until at least Saturday when another quick moving upper low may lead to some more light snow depending on the eventual track.

KEY MESSAGE 2 DESCRIPTION...

Temperatures will mainly be seasonal through the rest of the week and into the weekend. Highs through Saturday will generally range from the upper teens to mid 20s north, to the low to mid 30s south. It then appears that a more substantial warmup will commence Sunday into next week with readings possibly back into the 40s by Monday. Widespread values in the 40s are then looking more possible by midweek. Lows will generally remain slightly below normal through at least the weekend with a decent snowpack in place.

KEY MESSAGE 3 DESCRIPTION...

Attention remains on a potential system for Sunday and Monday. Models and ensemble members have continued to show a widespread array of solutions for storm track. The general consensus appears to be a more out to sea track, but confidence remains very low.

The main source of uncertainty pertains to how quickly a shortwave in the northern jet stream branch merges with a moisture-rich wave in the southern branch. Models will likely continue to wobble back and forth with the timing of this convergence, with a clearer picture unlikely to emerge until at least late Thursday.

AVIATION /06Z THURSDAY THROUGH MONDAY/

Periods of MVFR ceilings will remain possible this morning at HIE, LEB, RKD, and AUG. A brief dip into MVFR to IFR visibilities will also be possible at these terminals if a heavier snow shower moves over ahead this morning. Ceilings will lift into VFR categories through the afternoon, except MVFR lingers at HIE. Elsewhere, expect VFR conditions through Thursday night.

Outlook:

Friday - Sunday AM: VFR prevails.

Sunday - Monday: Restrictions with snow are possible. Should the storm miss to the south, VFR would prevail.

Tuesday: VFR most likely.

MARINE

Low pressure deepens across Atlantic Canada through the day as high pressure builds in from the west. SCA conditions continue through the day in northwesterly flow and will likely linger into early Friday. High pressure then builds across the waters into the weekend, with conditions mostly below SCA levels late Friday and into the weekend. Low pressure likely then tracks south of the Gulf of Maine on Sunday and Monday.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory until 7 AM EST Friday for ANZ150-152-154. Small Craft Advisory until 7 AM EST Friday for ANZ151.