textproduct: Gray - Portland

WHAT HAS CHANGED

Just a few minor changes to the going forecast early this Sunday morning but nothing major or really noteworthy.

KEY MESSAGES

1. Dangerous marine conditions continue with large breaking waves and a high risk for rip currents. Splash-over and minor coastal flooding are possible for several more high tide cycles through Sunday night, and possibly Monday afternoon.

2. This nor'easter will also lead to areas of widespread beneficial rain south of the mountains and gusty northeast winds through at least Monday along the coast and southern New Hampshire.

3. After the nor'easter moves away on Tuesday, conditions turn warmer and drier for the second half of next week.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

A nor'easter centered south of Long Island drifts northwestward and then westward towards Long Island and New Jersey today. After reaching peak intensity, the low gradually fills in and weakens as it slowly move across southern New England through Tuesday.

Storm surge values of 1.0 to 1.5 feet remain on track. While total water level forecasts come up just short of minor flood stage, the Coastal Flood Advisory remains for large wave action. Large near shore waves will bring ample splash over that will bring debris onto vulnerable coastal roadways through at least tonight's high tide cycle. In addition, dune erosion is expected and the most vulnerable locations will see the potential for some inundation.

Hazardous conditions at the beaches and over the waters continue through at least Sunday night. Near shore waves of 10 to 15 feet continue, with only a gradual decrease in height late today through Monday. The High Surf Advisory that runs through Sunday remains unchanged to cover the hazardous conditions from large waves and strong rip currents. It is important to note that the long duration of a long fetch will create opportunities for sneaker waves that will be larger embedded waves in a set and have potential to run farther into shore. Therefore, extra caution is encouraged for those venturing to the beach to observed the surf and avoid rock outcrops and jetties.

KEY MESSAGE 2 DESCRIPTION...

The well advertised nor'easter will continue to drift north for a little bit longer before stalling out somewhere off the coast of New Jersey by early today. The breadth of the storm is widening some and this is finally allowing our area getting into much needed rainfall. Bands of showers and steady rain, some heavy at times will continue to rotate onshore today with a rumble of thunder not completely out of the question. The most beneficial rainfall is expected across southern NH and coastal Maine. Further inland, the dry high pressure system to the north will occasionally ridge southward which will limit rainfall amounts, especially this afternoon and evening.

As far as winds go over land, we continue without any headlines. A few gusts on the coast and southeastern NH could reach 40 to 45 MPH today, but the low level jet will begin a weakening process by later this afternoon, so peak SFC winds should decrease by this evening into Monday.

Areas south of the mountains and along the coast should see a widespread 1 to 2 inches of rain while the latest HREF guidance suggests a potential for higher amounts over far southeast New Hampshire and far southwest Maine. Here, localized totals up to 4 inches will be possible through Monday. CAMs suggest that precipitation will likely come in waves with a convective component. Therefore, a stray bolt of lightning may not be impossible along the coast and over the waters. Embedded downpours will also be possible with P-wats in the 90th percentile or greater for this time of year. While most of the precipitation will start to taper off later in the day on Monday, the upper low will move overhead on Tuesday which may lead to some lingering areas of light rain.

KEY MESSAGE 3 DESCRIPTION...

After the nor'easter moves offshore, the 500mb pattern looks to favor the development of a ridge over the eastern US. With high pressure setting up south of New England, moderating temperatures are expected for mid to late week with mainly dry conditions. Some very weak instability could allow for a stray shower to generate on Wednesday or Thursday, but most people should stay dry.

Rain chances are a little higher on Friday, as a cold front is poised to move southward across New England. However rain chances are likely to remain in the slight-chance category, as the front is very weak and any instability will have to overcome a modest subsidence layer.

AVIATION /07Z SUNDAY THROUGH THURSDAY/

Through Monday...Widespread IFR to MVFR likely today, especially near the coast in rain. However, periods of improvement are possible outside of rain banding. Coastal terminals may see northeast surface gusts of 35 kt or more, especially towards PSM. LLWS possible through midday today.

Monday: Areas of MVFR or lower in rain/showers. North northeast surface gusts of 25 kt or more possible.

OUTLOOK:

Tuesday: Conditions gradually improving to at least MVFR.

Wednesday and Thursday: VFR expected.

Friday: VFR expected most places. Occl showers could lead to brief periods of MVFR at HIE.

MARINE

Developing nor'easter continues to build winds and seas over the coastal waters. The worst of the marine conditions are expected through this morning and possibly into the early afternoon today. Gale Warning remain in effect for all waters but the bays, with a strong SCA in the bays. Those conditions will last through Sunday before beginning to diminish during this afternoon. SCA conditions will linger into Tuesday evening before dropping below thresholds.

After the passage of the Nor'easter on Tuesday, winds and seas will gradually subside as high pressure moves in. Waves likely subside below 5ft by Wednesday. High pressure then brings mainly fair conditions for midweek, with the next cold front then possible on Friday.

GYX WATCHES/WARNINGS/ADVISORIES

ME...High Surf Advisory until 8 PM EDT Sunday for MEZ023>027. Coastal Flood Advisory until 11 PM EDT Sunday for MEZ023. NH...High Surf Advisory until 8 PM EDT Sunday for NHZ014. Coastal Flood Advisory until 11 PM EDT Sunday for NHZ014. MARINE...Gale Warning until 8 PM EDT Sunday for ANZ150-152-154-180-182- 184. Small Craft Advisory until 8 AM EDT Monday for ANZ151-153.