Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 271039 AFDGYX Area Forecast Discussion National Weather Service Gray ME 639 AM EDT Thu Apr 27 2017 .SYNOPSIS... A weakening area of low pressure centered over Cape Cod will continue to drift northeast into the Gulf of Maine today into tonight. This will prolong the cool damp conditions over all but far western and northern New Hampshire today into tonight. A front accompanied by showers will move across the region Friday morning and will help to sweep out the cool and wet conditions with warmer temperatures Friday afternoon and into the weekend. That may be short lived cooler air tries to slip back in from the north Sunday into Monday while low pressure approaches from the south. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 635 am update: ESTF update to ingest latest mesonet data. Only very minor tweaks needed to temps and dewpoints needed at this time otherwise no other changes. Previous Discussion: The weakening of low pressure centered over Cape Cod will continue to slowly drift to the northeast today into the Gulf of Maine. This will prolong a cloudy damp and cool air mass over southern and eastern areas today into tonight. Some partial sun may occur over far western and northern NH. The low levels will remain saturated elsewhere since no mechanism is available to ventilate the low levels. Patchy drizzle and fog may occur especially along the coast. High temps will be warmest across NH and the western Maine mountains reaching into the 60s while over maine portions temps will remain in the 50s with coolest temps along the coast. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Tonight most areas remain cloudy and damp. Some patchy drizzle and fog may reform over eastern and southern areas of Maine due to a very light moist onshore flow. A front approaches from the west late tonight and moves across the region from west-east Friday morning. Scattered showers and isolated thunderstorms will accompany this fast moving front. Also this will be the much needed mechanism to force mixing and clearing of the trapped low level moisture during the afternoon allowing a return to partly to mostly sunny skies and warmer temps across all areas as winds shift to southwest. Temps will be in the 70s over all southern and central areas Friday but 60s in the mountains and even cooler along the midcoast areas where temps will be in the mid 50s to mid 60s. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Not too much change to the extended forecast this morning as much of the 00z guidance suite is in agreement with the big picture over the next week. A strong short wave trough is expected to move eastward fairly quickly across southern Canada Friday night and Saturday. This will act to drive a cold front southward across our CWA on Saturday. While Saturday looks to get quite warm and potentially somewhat unstable, the front looks to be pretty moisture starved and the timing of the short wave trough energy looks a bit too fast for much in the way of showers and thunderstorms. Can`t rule out a couple, but the day may very well end up being dry. Strong high pressure dives in from the NW Saturday night and Sunday and will bring with it cool and dry weather. Sunday should be a winner of a day with strong higher pressure settling overhead. Light winds should be the theme in the afternoon along with highs around 60. Some high clouds may move in late. The high quickly moves off to the east Sunday night allowing for a WAA pattern to develop. This may mean another couple-day period of rainy, drizzly, and cool weather for our region Monday and Tuesday. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Short Term... Widespread IFR conditions will continue today into tonight across eastern interior and coastal areas. Over far western and northern areas conditions will improve during the day to vfr or MVFR. MVFR conditions in scattered showers and isolated thunderstorms expected Friday morning over western areas while eastern areas start out IFR and then slowly improve to vfr during the afternoon behind the FROPA. Long Term...A series of warm fronts will try and lift into Nrn New England thru the weekend. This will most likely lead to periods of widespread cloud cover. Significant periods of MVFR CIGs are likely...and areas of IFR could form in the overnights in onshore flow. Any IFR conditions would be most likely near the coast...with LEB and HIE being least likely to see significant impacts. && .MARINE... Short Term... The persistent light onshore flow will continue through Friday. So will continue the SCA for Hazardous Seas through Friday for the outer waters. Seas will remain 5-7 ft over the outer waters through Friday and only 2-4 ft in the bays. Long Term...Marginal SCA seas on the ocean waters will subside Friday night. A cold front crosses the waters on Saturday. The CAA regime behind this front could allow for a period of SCA winds Saturday and Saturday night. && .FIRE WEATHER... Cool damp conditions with light winds will continue today into tonight as weakening low pressure moves through the Gulf of Maine. A front will move through Friday with scattered morning showers and even an isolated thunderstorm possible with its passage. Clearing and warmer weather returns Friday afternoon into Saturday although a few widely scattered mountain showers will be possible. && .TIDES/COASTAL FLOODING... A Coastal Flood Advisory is in effect for later this evening through early Friday morning due to the persistent light onshore flow combining with the highest astronomical high tides of this cycle. High tide at Portland is 11.7ft at 12:42am Friday. Storm surge will run near a half foot at time of high tide. Some splash over and beach erosion will be possible through the early morning hours. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Coastal Flood Advisory from midnight tonight to 3 AM EDT Friday for MEZ023-024. NH...Coastal Flood Advisory from midnight tonight to 3 AM EDT Friday for NHZ014. MARINE...Small Craft Advisory for hazardous seas until 8 PM EDT Friday for ANZ150-152-154. && $$ NEAR TERM...Marine SHORT TERM...Marine LONG TERM...Ekster is the U.S. government's official web portal to all federal, state and local government web resources and services.