textproduct: Gray - Portland

WHAT HAS CHANGED

Have canceled the Winter Weather Advisory for New Hampshire as temperatures have risen above freezing and the threat for freezing rain has ended.

KEY MESSAGES

1. A cold front will cross the region today and bring rounds of showers to much of the area, but a wintry mix in the mountains of New Hampshire and western Maine.

2. This upcoming week is going to be bookended by chances for precipitation, with warmer temperatures and drier weather in between

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Forecast is largely on track as a surface warm front tries to lift into New England. Still not expecting that to make much progress into the forecast area. Based on current temps and dewpoints out there, the Winter Weather Advisories look to be in the right areas. The arrival of showers and steady moistening from the marine layer should allow temps to settle near the current wet bulbs. That may leave some areas south of the mtns 33 and rain, but I do not see too much of a freezing rain threat outside of the areas already under a headline. Even some of those locations in the downslope of the White Mtns may see locally warmer and drier conditions. Thru the morning I anticipate periods of showers, some of which may be pretty good downpours, but not really a steady rain. There may also be areas of fog that develop towards sunrise, especially near the coast. The best chance for steady rain will be along the advancing cold front. Ensemble guidance still showing that the majority of the forecast area is likely to see between 0.25 to 0.5 inches of liquid, with the higher amounts most likely over northern and eastern zones. The front will sweep out any remaining low level fog/clouds, but some upslope snow showers may linger in the mtns into Mon. Models do not have a great handle on that, so I have bumped PoP up to reflect that chance.

KEY MESSAGE 2 DESCRIPTION...

Tuesday is going to be the first widespread chances for precipitation next week as we get low pressure moving through the region on a cold frontal boundary, along with a 500 mb trough overhead. The timing of precipitation looks to follow the cold air filtering into the region so light snow is expected to be the dominant precipitation type. Hi-res guidance suggests more in the way of showers with little in the way of accumulation for the areas that see them. The higher peaks could see an inch or two, but outside of that a dusting to maybe a half inch at most looks like all we will get out of these. They move through in the afternoon, and move out before the evening is through. Temperatures behind the front will bottom out in the teens pretty much areawide Tuesday night.

High pressure follows with ridging aloft, so we will see temperatures steadily climb, with drier weather, into the first part of Saturday with nighttime temperatures generally staying above freezing as well. The 500 mb pattern switches to mean troughing on Friday, but high pressure still locked in at the surface should keep us dry. The next widespread chance for precipitation then looks to be Saturday as another frontal boundary moves through. This will be one of the warmer days of the week with temperatures nearing 60F in most locations, so this should be rain. As always this time of year we will have to keep a close eye on how this pattern evolves, particularly where high pressure sets up, for any potential for mixed precipitation in northern zones.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

MVFR conditions continue to work into the forecast area from the south and east. Conditions will continue to gradually deteriorate over the next few hours. CIGs are expected to lower across southern NH first, and expand northeastward into western Maine thru the early morning hours. Some areas of fog may also develop around sunrise and continue into midday. Periods of showers are expected thru the day until the cold front crosses the region. The only real threat of a wintry mix is around HIE, but gusty, downsloping winds are keeping precip light and temps warmer locally. By afternoon front/wind shift will be east of the forecast area and VFR conditions will return to the majority of the area. The exception will be in the mtns, where MVFR CIGs hang on and a few upslope rain or snow showers are possible.

Outlook...

Monday: VFR conditions expected.

Monday night: VFR conditions expected

Tuesday: Generally VFR with MVFR or lower conditions expected in light snow showers during the day.

Tuesday night-Thursday: VFR conditions are expected through much of next week as we see a period of quiet weather.

MARINE

Onshore winds will continue to build seas and gust to marginal SCA criteria thru morning. There may be a brief lull in which winds become light, but seas will generally remain at or above 5 ft outside of the bays. This will be the time period when areas of fog will be most likely. A cold front will cross the waters during the afternoon and winds will shift sharply to westerly. These winds may also gust to at or above 25 kt and additional SCA conditions are anticipated into Mon.

A period of sub-SCA conditions looks likely Monday night through the day Tuesday, but a period of wind gusts 25-30kts with bring that to an end Tuesday night as a front crosses the waters. Wednesday may also feature sub-SCA conditions as high pressure begins to build over the waters, but the pressure gradient tightening ramps wind gusts and waves up above SCA criteria Wednesday night through Thursday night. Waves might be a little slower to settle than winds, but conditions should improve on Friday with high pressure still in place. Another front crosses the waters Saturday with brief SCA conditions possible.

GYX WATCHES/WARNINGS/ADVISORIES

ME...Winter Weather Advisory until 10 AM EDT this morning for MEZ007>009. NH...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ150- 152-154. Small Craft Advisory until 11 AM EDT this morning for ANZ151- 153.