textproduct: Gray - Portland

WHAT HAS CHANGED

Precipitation continues to taper off this morning and most sites in the Winter Weather Advisory have warmed to above freezing. Thus, we will go ahead and cancel the advisory a little bit early. Otherwise, no major changes were needed for this update other than to freshen up the aviation forecast.

KEY MESSAGES

1. Slippery travel possible with mixed precipitation early this morning in the Western Maine Mountains. Winter Weather Advisories remain in effect. Heaviest rain ends early this morning across central and southern zones but smaller streams may rise to bankfull. Ponding of water likely for the morning commute.

2. Low pressure brings another chance for a wintry mix Thursday night into early Friday over portions the area. There is higher confidence from foothills northward seeing a wintry mix with less certainty to the south.

3. Above normal temperatures likely for most of the area Friday into the weekend with widespread rainfall likely going into Sunday.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Light icing and light snow amounts will be likely early this morning in the western ME mountains which may allow for slippery travel. A winter weather advisory remains in effect until 8am. Thereafter drier weather arrives for Wednesday daytime.

Farther south, periods of heavy showers and a few thunderstorms across central and southern zones will come to an end early this morning. While SFC temperatures will be cold, moisture aloft will aid in heavier rainfall totals - perhaps an inch or two in some areas. A few smaller streams may rise to around bankfull, but ponding of water is more likely for the morning commute even with the rain ending. This will be especially possible across central and southern NH.

Today appears dry for the most part. However, with low level moist airmass lingering, especially in the morning, periods of drizzle and fog cannot be ruled out. Temperatures will gradually warm during the day as a warm front slowly works north. However, will have to watch for a slowing of the warmth since these colder low level air masses are notoriously tough to dislodge.

Some guidance points to a return of showers across southern zones tonight but there remains uncertainty here with several pieces of guidance remaining south with this activity.

Thursday looks dry and relatively cold. However, a warm front approaching may allow for some mixed precipitation by late in the day.

KEY MESSAGE 2 DESCRIPTION...

A warm front will lift northward across the region Thursday night, bringing the potential for some spotty light precipitation. Despite temperatures aloft rising above 0C overnight, a lack of mechanical mixing may allow temperatures to wet bulb near or a little below freezing across portions of western NH as well as from the Lakes Regions of ME and NH and points northward. This may allow for some light wintry precipitation with rain along the coast and in southern NH. Any lingering slick spots will quickly melt on Friday morning as temperatures warm to well above freezing and the high April sun angle makes its appearance. Temperatures will rise into the 50s across much of western ME with 60s in NH.

KEY MESSAGE 3 DESCRIPTION...

Saturday will feature mainly dry conditions as an H5 s/wv ridge arrives from the west. Highs will generally be into the 50s and 60s but a few spots in southern NH may approach the 70 degree mark. Rain chances will then increase towards Sunday as a trof of low pressure crosses the region, likely bringing a period of widespread beneficial rainfall. Mainly dry conditions look to then return early next week with temperatures a little above average.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

Through Thursday daytime...Improvements will gradually improve through the morning with most terminals MVFR to VFR after 18Z. Southern terminals such as MHT and PSM may begin to see MVFR again tonight as precipitation attempts to moves back into the region. MVFR to IFR likely Thurs.

Outlook...

Thursday night...LIFR to IFR restrictions and widespread precipitation possible. Mostly rain is expected, except a wintry mix is possible at HIE and AUG.

Friday: Lingering low ceilings, drizzle, or fog possible in the morning with gradual improvement to VFR, especially in NH. Improvement is more questionable in western ME with AUG and RKD possible holding on to low ceilings all day.

Saturday: VFR possible early in the day with restrictions possible later in the day. Confidence is low.

Saturday night-Sunday: Increasing chances for fog, low ceilings, and precipitation with IFR possible as a cold front approaches. Precipitation type is expected to be rain across all TAF sites, although a brief period of wintry precipitation is possible at KHIE Saturday night.

MARINE

SCA conditions today as low pressure moves over the waters. This is mainly for building wave heights as wind gusts are expected to generally stay below 25 knots. Northwesterly winds flip to southwesterly as a front crosses the waters by this afternoon. The front then moves south this evening flipping winds back northeasterly for tonight.

Thursday-Early Next Week...Easterly flow Thursday will become more southerly Thursday night into early Friday as a warm front lifts to the north. South to southwest flow then likely increases to SCA levels on Friday ahead of a cold front that looks to cross the waters Friday night. Another cold front approaches on Sunday as low pressure tracks north of the region. South to southwest winds again increase to SCA levels, and there may gusts to gale force ahead of the front. SCA conditions probably continue into Monday or Monday night as winds turn west to northwest behind the front, but high pressure should bring subsiding winds and seas by Tuesday.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory until 8 AM EDT Thursday for ANZ150>152- 154.