Area Forecast Discussion
Issued by NWS Portland, ME

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235 FXUS61 KGYX 191049 AFDGYX Area Forecast Discussion National Weather Service Gray ME 649 AM EDT Thu Apr 19 2018 .SYNOPSIS... Low pressure passes to our south today bringing some light rain and snow, especially across southern NH and coastal ME. Things are looking up however as high pressure finally builds into New England over the weekend into early next week. After that the next chance of precipitation occurs next Wednesday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 645 AM Update...Forecast is going as planned as compared to radar imagery with the bulk of the light precipitation remaining south of the NH/MA border. This should continue to be the case for the most part, although some light snow and rain will likely fall north of the border over the next few hours. If the precip measures, it will be very light. Previously... SFC low pressure will pass well to our south today in association with a southern stream short wave trough. Deterministic models as well as ensembles have trended south with this feature which also means best forcing for ascent and associated precipitation shield has also trended south. Have therefore scaled back on precip amounts today as well as snowfall across the higher terrain of southern NH. There may still be a period of light precipitation across southernmost NH and southernmost ME this morning, but the expected light intensity of precipitation doesn`t portend to accumulating snowfall. At most, we expect up to an inch of snow in the highest elevations of the Monadnocks. In fact, a few mesoscale models keep any meaningful precipitation south of the NH/MA border, and that is a possibility as well. During the late morning and afternoon hours the northern stream closed low will move overhead. This is probably when most locations in the CWA have a chance to get wet, as instability showers are a good possibility. Therefore, the highest PoPs have been placed this afternoon. High temperatures are expected to generally be in the 40s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... NOrthwesterly flow and downsloping will be the rule tonight. This will mean clearing on the coastal plain with a good chance of upslope snow showers and plenty of clouds in the mountains. The same can be said for Friday, although clouds will likely fill in as cold cyclonic flow continues aloft aiding in instability. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... The deterministic model solutions remain in decent agreement on the long wave pattern through the middle of next week. We begin the period with an upper low centered to our northeast near Newfoundland. This upper low will maintain the cool cyclonic flow across the area for the start of the upcoming weekend. Clouds will linger Saturday across the higher terrain as well as our northern and eastern Maine zones with widely scattered showers confined to the higher terrain. Things then improve markedly for the second half of the weekend. On Sunday...ridging and rising heights will arrive with fair weather and a noticeable warming trend expected through the first half of the new work week. Over the past several runs...models have trended towards a slower and less progressive system for the second half of the work week as phasing occurs between northern and southern stream energy. This will result in several days of cooler and damper weather to wind out the work week. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Short Term...Mainly VFR conditions expected today, although areas of MVFR conds are likely in showers from time to time. VFR conditions are expected today and Friday except for MVFR conditions in snow showers in the mountains. Long Term... Sat...Sct MVFR in mtn -shra/-shsn. && .MARINE... Short Term...SCA conditions are possible later tonight into Friday as northwesterly winds kick in behind departing low pressure. Long Term... Sat...SCA`s are psb...especially outside the bays. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$

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