textproduct: Gray - Portland

WHAT HAS CHANGED

Little change to the going forecast at this time as the next several days will be quiet.

KEY MESSAGES

1. Cool conditions persist for one more night, then a warm up gets underway starting on Tuesday.

2. Wednesday through Friday will feature mainly dry weather with warming temperatures. Chances for showers and thunderstorms increase some late Friday and over the weekend with a cold front.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Cool northerly flow continues through the afternoon and overnight hours as a small area of high pressure passes through overnight. Scattered showers this afternoon dissipate this evening, with clearing skies overnight. Clouds do then increase late tonight toward daybreak ahead of a weak cold front. This front keeps northern areas from reaching their full cooling potential tonight, but the more sheltered valleys around Berlin, Whitefield, and Fryeburg may get just cold enough for some patchy frost. Coverage isn't expected to be enough to warrant a frost advisory, but typically cooler spots and valleys could see one more night of patchy frost tonight as lows dip into the mid 30s.

The warm up then gets underway tomorrow, with highs warming into the low to mid 70s across most of the area, and mid to upper 60s across the north. The slow moving front passes offshore during the early afternoon hours, and may kick off some isolated showers as it does so along the MidCoast tomorrow afternoon. Elsewhere, the front's passage is marked by an uptick in cloud cover, followed by clearing for the late afternoon.

Tomorrow night looks milder than the last few as the warmer airmass continues to work into New England. Lows generally look to cool into the 40s, with mainly clear skies overnight.

KEY MESSAGE 2 DESCRIPTION...

Dry weather and warming temperatures are expected Wednesday through Friday morning. A cold front sagging southward from Quebec later Friday may provide enough forcing for ascent to aid in the development of a few showers and thunderstorms, especially in our northern zones. The threat for rain and some storms will continue into Saturday but ensemble guidance shows considerable spread in SFC and upper air features by the end of the weekend, so confidence in PoPs in low.

AVIATION /18Z MONDAY THROUGH SATURDAY/

Mainly VFR prevails through Tuesday night. Some valley fog is possible tonight, but overall looks less likely than last night.

Outlook:

Wednesday/Wednesday night: VFR with light winds.

Thursday/Friday: High pressure is favored with VFR conditions. However, a sagging cold front may bring a few showers and storms to the western ME mountains late Friday.

Saturday: Local MVFR conditions possible in sct showers and storms.

MARINE

A small area of high pressure crosses the waters tonight. A weak cold front then crosses the waters tomorrow afternoon. Broad high pressure then begins to build across the water by tomorrow night. Conditions remain below SCA levels through Tuesday night.

Fair weather is expected Tuesday through Friday with winds and seas remaining below SCA thresholds. Northerly winds may increase Sat or Sun depending on a cold front.

GYX WATCHES/WARNINGS/ADVISORIES

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