textproduct: Gray - Portland

WHAT HAS CHANGED

Only update is to the aviation section for the 12Z TAFs.

KEY MESSAGES

1. Warm today and less breezy ahead of a cold front. This will bring light rain late this afternoon and into the overnight hours areawide.

2. After a modest cool down on Saturday, even warmer temperatures are possible early next week along with periodic chances for rain showers.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION... With a cold front stalled just to the west, thinner cloud cover should promote temperatures warmer than yesterday. Temperature trends have be slightly increasing the past few forecast cycles, with mid 50s to mid 60s forecast areawide. Confidence has increased in thinner cloud cover for the first half of the day, which should promote great warming from strong April sun. The exception may be towards the ME Midcoast where overnight low clouds may take a little longer to dissipate.

Clouds will thicken and lower in the afternoon, however. This comes as a shortwave moves along the approaching cold front from the west. The wave is forecast to continue strengthening as it moves into eastern ME and New Brunswick Saturday morning. The initially flat trajectory means a corridor of greater QPF amounts NW of the Whites and western ME mountains. Once the low is stronger, the cold front tends to press through the remainder of the forecast area rather quick and with less moisture. Thus the best chance for a wetting rain, or even a quarter to half inch, appears to be towards the mountains and US/CAN border. Lighter measurable amounts have been the trend for much of the interior, central NH, and the coast.

KEY MESSAGE 2 DESCRIPTION... A cooler and breezy day is in store for Saturday behind a cold front with partly to mostly sunny skies. High temperatures will be around 10 degrees cooler than those of Friday with readings into the 40s across the north with 50s south. Northwesterly wind gusts between 25-30 mph will make it feel cooler though. Afternoon RH may fall into the 20-30 percent range as well. Some radiational cooling is then likely on Saturday night as skies remain mainly clear and winds weaken. Lows into the 20s/30s can be expected. Surface high pressure will cross the region on Sunday as flow becomes southerly. Some increase in cloud cover is likely but it will be another dry day with high temperatures mainly into the 50s.

A series of frontal boundaries will then cross Sunday night into Monday, bringing scattered showers at times along with warming temperatures. Highs on Monday may approach the middle 60s across much of western ME south of the mountains with lower 70s possible in southern NH. Tuesday may be the warmest day of the stretch with more widespread readings into the 70s possible with perhaps a few spots in southern NH approaching the 80 degree mark. It is important to remember though that this time of the year not a lot has to change to spoil warmth but regardless, ensemble based guidance strongly favors above average temperatures through the end of the week. Scattered showers and perhaps even an isolated thunderstorm cannot be ruled out at times as well.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

Through 12z Saturday...Mainly VFR expected today with S to SW winds gusting to around 20-25 kt today with SHRA approaching from west towards the evening. MVFR/IFR cigs begin to move into western ME/northern NH this evening, with less coverage from the foothills to the mountains overnight. Expect NW winds to pick up after 06z tonight, continuing Saturday.

Outlook: Saturday and Sunday: VFR expected. NW gusts up to 35 kts across the interior Saturday. MVFR possible at HIE Saturday.

Monday and Tuesday: Restrictions possible due to showers.

MARINE

South winds continue on today as a cold front approaches and will reach SCA levels this afternoon and evening. Winds veer southwesterly overnight and then W to WNW toward daybreak Saturday behind the front.

NW wind gusts may approach 25 kts behind a cold front on Saturday with 2-5 ft (highest outside of the bays). Winds will become southerly Sunday night into Monday with gusts up to 30-35 kts possible through Monday night as seas build to 6-9 ft across the outer waters with 1-4 ft in the bays.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory from 2 PM this afternoon to 2 PM EDT Saturday for ANZ150-152-154.