Area Forecast Discussion
Issued by NWS Portland, ME

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137 FXUS61 KGYX 312152 AFDGYX Area Forecast Discussion National Weather Service Gray ME 552 PM EDT Fri May 31 2024 .SYNOPSIS... High pressure over the Great Lakes will settle off the east coast bringing and extended stretch of dry weather to the region with temperatures gradually warming through the weekend. The first half of next week is expected to continue the dry and mild stretch with unsettled weather likely to return late next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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Update... Winds will subside this evening with the loss of heating. Another cool night on tap as winds become relatively light. Partly cloudy conditions per 22Z satellite imagery and surface observations will become clear over the next couple hours. Therefore, expect good radiational cooling. Any remaining showers over far eastern sections will dissimpate shortly after sunset as well. Prev Disc...High Impact Weather Potential: Minimal. Pattern: Deep layer north-northwesterly flow is established across the region with H5 low centered over eastern Quebec and Labrador and the upstream ridge axis over the western Great Lakes. This trough/ridge pair will only very gradually move east through tonight. With high pressure nearby this spells little in the way of forecast concerns with forecast challenges centered on overnight low temperatures. Through this Evening: This afternoon/s robust cumulus development and isolated shower activity will continue for a time but should end by 8pm or shortly thereafter given waning llevel instability. Any showers that do develop through the evening may bring a quick gust of wind given inverted profiles in the llevels. Temperatures at 8pm will fall back to around 60 in the mountains while sitting in the 60s to the south. Tonight: Mesoscale ensembles painting a mostly clear night tonight...which should again allow for good radiational cooling conditions given very dry boundary layer conditions. Northerly gradient is pretty similar to last night with 1000 mb geostrophic magnitudes around 20kts. Last night...this allowed the valleys to decouple with a few kts of flow remaining at coastal locations and the hilltops /e.g. AUG/. Expect a similar story tonight which suggests leaning again towards the colder end of the statistical guidance envelope. This guidance is about 3-4F warmer than last night which...given overnight reports suggests some isolated mid 30s...but generally temperatures warm enough to preclude significant frost concerns and will hold off on any additional advisories for tonight. Beach hazard statement continues for sunny/mild/breezy conditions with ocean temperatures still in the 50s. Fully expect these headlines will be necessary through the weekend given continued dry and mild conditions.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... High Impact Weather Potential: Minimal. Pattern: A mid level ridge axis will pull into the region from the west as a cutoff low develops south of the Canadian maritimes. Gradually building heights and thickness values will bring a warming trend with dry northwesterly flow out of Canada suggesting little in the way of sensible weather impacts. Saturday: Dry...northwest flow aloft continues across the forecast area for the day on Saturday as mid level low closes off over the Canadian maritimes and shortwave ridging pulls east into PA/NY. Boundary layer moisture look to have only increased slightly from the day on Friday so expect afternoon dewpoints to fall into the upper 30s given deep mixing. At the top of the mixed layer northwest winds of 25 to 30kts are expected...which suggests surface based gusts of 20-25 mph. As for high temperatures...there will be a fairly tight thermal gradient from west to east...with T8s over NH reaching near the 10C mark...with T8s towards AUG around +8C. This should allow highs to crest above 80 for much of southern NH and a few inland points in western Maine with 70s elsewhere. Saturday Night: Surface ridge axis will be overhead with mid level shortwave ridging arriving from the west. Therefore...another quiet night with light winds is expected with the potential for some upper level cloudiness spilling over the mid level ridge. Temperatures should have no trouble falling into the 40s again given low afternoon dewpoints during the day Saturday...however concurrent warmer temperatures will keep lows a bit above Friday night/s readings. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A rather quiet weather pattern continues in the long term. An upper level ridge will shield the area from any significant precipitation through most of next week. In the dailies: On Sunday high pressure will be centered off the Southeast Coast. A weak warm front will lift north with a disturbance moving along it. This feature will pass south of the region Sunday Night into Monday. An area of mid and upper level clouds may cross the area in association with this feature. Behind this the east coast ridge builds back north and should dominate the weather through midweek. Can`t rule out some scattered diurnal shower activity mainly over the mountains and foothills but most of the time conditions should remain dry. A cutoff low over southern Canada just north of the Great Lakes will have a hard time making eastward progress. A cold front piviting around this system will approach Thursday and Friday increasing the chances of showers and possibly a few thunderstorms. The GFS is more aggressive than the ECMWF with this frontal feature. Given that we are in a rather blocky pattern, would favor a littler slower progression with this system so will go under GFS POPS and trend a little closer the the ECMWF. Have added patchy marine fog each night Monday Night through Wednesday Night. Temperatures will be on the warm side reaching somewhat above normal values ranging from the upper 70`s to mid 80`s Sunday and Monday and mid 70`s to low 80`s Tuesday through Friday. Expect afternoon seabreezes to cool the immediate coastal areas and islands. Low temperatures will generally be in 50`s. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... Short Term... Summary: High pressure will gradually build towards the region through the period bringing quiet weather conditions with moderate northwesterly winds. Restrictions: VFR conditions are expected to dominate through Saturday night. There is a low potential for a rain shower at AUG-RKD through this evening...but no restrictions are expected. Winds: Northwest winds 10g18kts will quickly diminish to calm/light- variable for the overnight hours. The only exception is at RKD where a seabreeze will turn winds onshore around 10kts into the evening. Any showers that develop this afternoon and evening could bring local wind gusts to 30-35 mph. On Saturday... northwest winds will again build to 10g18kts by late morning and through the afternoon before going calm/light-variable Saturday night. LLWS: LLWS is note expected through Saturday night. Lightning: Lightning is not expected through Saturday night. Long Term... Generally Expect VFR to MVFR throughout the period. && .MARINE... Short Term...With high pressure west of the region... northwesterly winds of 10-15kts are expected to continue through the period with wave heights of 1-3 feet. This afternoon and again Saturday afternoon...nearshore gusts will hit 20kts at times. Long Term...Wind and waves to remain below SCA conditions through the extended forecast period. Patchy fog mainly at night starting Monday Night. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Beach Hazards Statement until 8 PM EDT this evening for MEZ023>028. NH...Beach Hazards Statement until 8 PM EDT this evening for NHZ014. MARINE...None. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Beach Hazards Statement until 8 PM EDT this evening for MEZ023>028. NH...Beach Hazards Statement until 8 PM EDT this evening for NHZ014. MARINE...None. && $$ NEAR/SHORT TERM...Cannon LONG TERM...Lulofs