textproduct: Gray - Portland

WHAT HAS CHANGED

Thunderstorm activity has diminished with lingering showers through early this morning.

KEY MESSAGES

1. Low pressure crosses Maine today dragging a cold front across the area.

2. High pressure brings fair weather with rising temperatures Monday into Tuesday. Heat and humidity build the second half of next week posing a heat risk and chances for showers and thunderstorms.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION... A surface cold front and wave of low pressure will cross the area today as an H5 positively tilted trof axis swings through from the west. This will result in showers to move from north to south this morning through this afternoon with perhaps up to around 1/4 inch of rainfall possible in some locations. A rumble of thunder cannot be ruled out as well. Westerly winds early in the day will become northwesterly this afternoon and evening with gusts between 25-30 mph. Some late day clearing is possible but it will overall be a mostly cloudy day. High temperatures will range from the 60s across the north with 70s in most other locations. A few locations in southern NH may approach the 80 degree mark.

Skies will clear tonight with temperatures cooling into the lower 40s across the north with upper 40s/low 50s south. Northwesterly winds will persist, which will make it feel cooler.

KEY MESSAGE 2 DESCRIPTION...

High pressure builds in from the northwest Monday providing fair weather with a dry air mass in place. Light offshore flow will turn onshore along the coast during the afternoon with highs in the 70s to low 80s. High pressure will sink south Tuesday with return flow advecting warmer air into the area allowing highs to climb well into the 80s.

Heights build into Northeast Wednesday allowing for the heat to build along with increasing moisture. Latest available NWP guidance shows a weak wave riding the top of the building ridge that will help boost moisture as well bring chances for showers and thunderstorms. Highs will push into the low 90s with dew points into the low 60s. While ridging aloft generally prevails through the second half of the week, moisture will continue to increase with dew point potentially climbing into the mid to upper 60s. This moisture combined with temperatures in the upper 80s to low 90s will pose a heat risk. There will also be chance for showers and thunderstorms.

AVIATION /02Z SUNDAY THROUGH THURSDAY/

Through 06Z Monday... Thunderstorms have largely come to an end. HIE, AUG, and RKD stand the best chance to see IFR/LIFR conditions into the morning with showers and low ceilings. Ceilings improve through this morning, and then brief restrictions with scattered showers are likely from late morning at HIE, through the afternoon along coastal terminals. VFR then returns and likely prevails tonight. W-NW wind gusts up to 25 kts can ne expected.

Outlook... Monday-Tuesday: VFR conditions expected under mostly clear skies.

Wednesday-Thursday: Generally VFR conditions expected, but afternoon showers and/or thunderstorms may bring about TEMPO MVFR conditions.

MARINE

Low pressure crosses Maine today dragging a cold front across the waters this evening. Some seas to near 5ft are possible across the outer coastal waters today in S to SW flow around 20kt. Winds turn offshore tonight with gusts briefly climbing to 20-25 kts. Quiet conditions are expected on the waters Monday into the middle of next week as high pressure builds over the Gulf of Maine and only slowly moves eastward.

GYX WATCHES/WARNINGS/ADVISORIES

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