textproduct: Gray - Portland

WHAT HAS CHANGED

Adjusted temperatures across some of the northern valleys where efficient radiational cooling allowed temperatures to fall below zero. Temperatures should level off or even come up a couple of degrees with clouds moving in.

KEY MESSAGES

1. Mild temperatures around or above seasonal averages are expected through this weekend with even warmer temperatures likely through midweek next week.

2. A frontal boundary moves through on Sunday, bringing isolated, low impact chances of snow showers. The long term pattern supports active weather next week, with the potential for more widespread precipitation later in the week.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

An upper low will gradually move down from central Quebec this morning, to around the crown of Maine by this evening. After this low moves off into the Atlantic on Sunday, the pattern will transition to mean zonal flow aloft with little ripples of low amplitude troughing and ridging here and there through much of the the work week. This will mean that temperatures should remain at or just above seasonal averages for this time of year today and Sunday with even warmer conditions expected through at least mid week. Highs today and Sunday will mainly range from the low to mid 20s north, to the mid 30s south. By Monday, we could see some afternoon highs in the lower 40s creeping in across southern New Hampshire and coastal Maine. Tuesday should then see widespread highs in the 40s with a few lower 50s even possible over southern New Hampshire or southwest Maine. Above normal temperatures then continue through midweek with a potential cool down returning at the end of the week.

KEY MESSAGE 2 DESCRIPTION...

A upper-level trough will deepen over the northeast this weekend as a frontal boundary moves southward across eastern Maine. The low will allow for some snow showers and perhaps a snow squall to develop over central Maine Saturday night.

By the end of next week, a weak system looks to move across the northeast from northwest to southeast. Storm track remains uncertain, but guidance is showing a general consensus of a southerly track across southern New England. This track would put NH and Maine in the colder and drier section of the low, with the most snowfall appearing to fall across southern and western NH. Storm timing is still fairly uncertain as well, with some members showing the low could arrive as early as Wednesday night and as late as Thursday afternoon. Either way, it should be a quick moving system and it is not likely people will see notable impacts from the aforementioned low.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

Through 12z Sunday: Clouds will continue to fill in early this morning. Ceilings should remain in VFR categories, but HIE could see some lower ceilings with low SHSN chances through this afternoon. Brief IFR visibilities will be possible under any heavier shower that moves overhead. This activity should taper this evening. VFR tonight.

Outlook...

Sunday: VFR

Sunday night-Monday night: Some light snow showers may bring localized brief MVFR/IFR conditions Sunday night into Monday with MVFR ceilings common during this time as well. This is more likely at western TAF sites.

Tuesday: SHSN possible with MVFR/IFR.

Wednesday-Thursday: A disturbance may bring SN to the region, potentially lowering restrictions at terminals over southern NH. Confidence is low.

MARINE

High pressure continues to nose into the region this morning, with a cold front expected to arrive by this evening. This will result in SCA conditions tonight through Sunday morning with some gusts across the outer waters up to 30 knots. Conditions may remain below SCA through early next week, but disturbances arriving mid to late week look to bring an uptick in winds and thus seas that may require additional headlines.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory from 1 AM to 1 PM EST Sunday for ANZ150- 152-154.