Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 221558 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1158 AM EDT Mon May 22 2017 .SYNOPSIS... A weak cold front will approach from the west today before pushing east through the region tonight. Weak high pressure will build over the area on Tuesday and will hold over the region through Wednesday. Low pressure will slowly move northeast out of the Ohio Valley Thursday and pass through southern New England on Friday. Low pressure will shift east into the maritimes Friday night. High pressure will build over the area Saturday through Sunday. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... 1155 AM...Minor ESTF update to reflect current radar trends, HRRR output, and the latest mesonet values. Prev Disc... 910 AM...minor ESTF update to ingest the current mesonet values into near term grids. Prev Disc... 640 AM Update...Little change to the going forecast. Rain/showers continue to move eastward across the region this morning. The HRRR has been doing a good job with the trends in PoP so we continued to blend it in heavily through the afternoon. There should be a break in the rain by late morning into the early afternoon hours. Otherwise, no changes to the forecast for today. Previously... A warm frontal boundary will push toward our region today. Cloud weather is therefore expected, with some rain early on this morning. Forcing becomes weak later this morning through early afternoon and therefore we should be dry for several hours during that period. Thereafter a cold front or occlusion should approach later in the afternoon with an increase in shower activity. Today will not be a washout by any means, but clouds and temperatures in the 50s and perhaps 40s will not make it a great day. There is also a chance of drizzle, especially on the coastal plain, this afternoon. && .SHORT TERM /8 PM THIS EVENING THROUGH 6 PM TUESDAY/... Frontal system moves offshore tonight and allows for any showers or drizzle to end from west to east, with some clearing following thereafter. Tuesday should be a much better day than Monday with high pressure moving overhead helping to boost temperatures back into the upper 60s to lower 70s. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure will build over the region Tuesday night as a weak area of low pressure tracks northeast off the New England coast. Expect high clouds over southern zones during the evening hours before clearing after midnight. Lows will range from the mid 40s north to the lower 50s south. High pressure will gradually weaken over the area on Wednesday but should provide one more nice day. High temperatures will top out in the upper 60s to mid 70s away from the coast. An afternoon sea breeze will cap temperatures in the lower to mid 60s along the coast. Vertically stacked area of low pressure over the Ohio Valley will slowly lift northeast Wednesday night and Thursday. Mostly clear skies Wednesday evening will give way to high clouds by daybreak Thursday. Lows overnight will bottom out in the lower to mid 50s. Low pressure will gradually approach from the southwest on Thursday. Weak over-running ahead of this system will result in variable clouds with perhaps a stray shower. Increasing onshore flow will likely bring ocean stratus into southern zones by late in the day. Highs will generally range through the 60s. Vort lobe swinging around upper low will intensify over-running over the region Thursday night as surface low shifts east into southern New England. Expect a steady rain to develop over the region overnight. Lows will be fairly uniform in the lower to mid 50s. Low pressure will continue northeast into the Gulf of Maine on Friday. Steady rain will persist through the morning and will gradually taper to showers in the afternoon. Highs will range through the 60s. Showers will gradually end Friday night as low pressure pulls off to the northeast. Looking for clearing skies after midnight. Lows will range from the mid 40s to mid 50s. Upper level ridging will bring weak high pressure to the region for the weekend. Looking for a mix of sun and clouds with seasonable highs. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... Short Term...VFR conditions for the most part through mid morning will deteriorate to MVFR late morning or early afternoon before becoming IFR later this afternoon and evening. IFR conditions will improve to VFR early Tuesday morning. Long Term...VFR Tuesday night through Thursday. IFR/LIFR ceilings/vsby Thursday night and Friday. && .MARINE... Short Term...A brief period of marginal SCA conditions will be possible on the ocean waters late this afternoon and evening. Otherwise relatively tranquil conditions are expected today through Tuesday. Long Term...SCA`s May be needed Thursday night and Friday. && .FIRE WEATHER... Cool and wet conditions are expected today with some drying likely Tuesday and Wednesday before the next low pressure system brings rain Thursday and Friday. && .TIDES/COASTAL FLOODING... High astronomical tides Thursday night (11.8 ft mllw forecast for Portland), will combine with onshore flow possibly resulting in minor coastal flooding. Another high tide on Friday night (12.0 ft mllw forecast) will likely again result in minor coastal flooding although winds may be offshore by that time. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ ES is the U.S. government's official web portal to all federal, state and local government web resources and services.