textproduct: Gray - Portland

WHAT HAS CHANGED

Issued a Coastal Flood Advisory for tonight's high tide for coastal areas from Portland and points south.

KEY MESSAGES

1. Minor coastal flooding remains possible, especially during the Monday morning high tide cycle.

2. Radiational cooling will keep low temperatures cold tonight and especially tomorrow night as high pressure sits over the area.

3. A relative warm up brings temperatures close to average early to midweek. Then, another cool down is expected by late in the week and into the weekend.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

High astronomical tides combined with between 1.5-2.0 ft of storm surge from distant low pressure over the open North Atlantic will bring total water levels to near minor flood stage both tonight and Monday morning.

The tide is expected to rise near minor flood stage tonight, but higher wave action (especially south of Portland) will allow for some splashover and beach erosion across beaches in southern NH/ME. A Coastal Flood Advisory was issued for tonight's high tide. Tomorrow's high tide is expected to see less wave action, but the water levels will be a little higher, with splashover and minor coastal flooding impacts possible along the entire coastline. Ice movement in marshier areas along the coast could block some drains and create some ponding.

KEY MESSAGE 2 DESCRIPTION...

High pressure overhead tonight and Monday night should allow for good radiational cooling conditions. Partly cloudy skies will mitigate this concern tonight, though low temperatures are still expected to bottom out in the single digits above/below zero in most spots.

Conditions look to be mostly clear and very calm across the area Monday night. Low temperatures are likely to be near or below 0F across most of the interior, and can't rule out some localized double digit below 0F readings in the upper Connecticut and Androscoggin River valleys (Littleton, Berlin, Fryeburg being places most prone to colder temperatures).

KEY MESSAGE 3 DESCRIPTION...

A ridge of high pressure builds eastward early this week, bringing a relative warm up to the region after an extended cold stretch. While certainly not warm, temperature rise back to near average for much of the week. Highs in the upper 20s to low 30s are expected south of the mountains through at least Wednesday.

On Wednesday, a front approaches from the north, but is looking more likely to wash out before crossing through New England. This brings the chance for some snow showers across the mountains late Wednesday. If the front doesn't clear New England, highs around freezing likely continue through Friday. A stronger front then approaches late in the week, with another shot of cold air more likely by this weekend.

AVIATION /00Z MONDAY THROUGH FRIDAY/

00Z TAF Update:

Thin high altitude (~25 k ft) cirrus will persist through tonight, bringing no flight restrictions. Gusty N winds of around 20 kts will persist through around midnight before diminishing some overnight into early Monday morning. VFR conditions will persist Monday into Monday night with N winds of 5-10 kts. LLWS is not anticipated.

Outlook:

Tuesday - Tuesday Night: VFR Expected.

Wednesday - Wednesday night: MVFR and snow showers possible north, VFR likely elsewhere.

Thursday - Friday: VFR expected south, MVFR possible north.

Friday Night- Saturday: MVFR and snow showers possible.

MARINE

Gale force northerly winds will continue this evening, with seas of 4-10ft expected. These conditions are expected until tomorrow afternoon, northwesterly winds lower to sub-SCA levels and seas decrease to 3-7ft by early Tuesday morning. High pressure extends across the waters for much of the week, with the next cold front likely on Friday.

GYX WATCHES/WARNINGS/ADVISORIES

ME...Coastal Flood Advisory from 10 PM this evening to 1 AM EST Monday for MEZ023-024. NH...Coastal Flood Advisory from 10 PM this evening to 1 AM EST Monday for NHZ014. MARINE...Gale Warning until 7 AM EST Monday for ANZ150>154.