655 FXUS61 KGYX 111018 AFDGYX Area Forecast Discussion National Weather Service Gray ME 618 AM EDT Fri Apr 11 2025 .SYNOPSIS... A cutoff low will stall south of New England today through the weekend, bringing an extended period of cool and unsettled weather conditions. The system then moves away by Monday with a return to drier and warmer conditions early next week as high pressure returns. A cold front approaches from the west Tuesday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 615 AM Update... Minor changes to reflect latest observational trends. Light rain and snow persist across portions of the area at this hour but webcams and road sensors indicate that there is little to no accumulation across roadways. This precipitation will persist for the next hour or two before ending later this morning. Previously... Northeast radar mosaic early this Friday morning shows precipitation streaming from southwest to northeast in association with low pressure located to our southwest and a trof of low pressure situated over the Northeast. ASOS and MPING reports indicate that light rain and snow has begun across much of southern NH with the general theme being that most locations are starting as rain and then through wet bulbing they are quickly transitioning to snow. DOT road temperature sensors indicate that roads are mainly into the middle to upper 30s across the region, which is helping to limit snow accumulations to mainly non-paved surfaces. This can also be seen through area webcams. Latest hi-res guidance and upstream observations do indicate that a brief period of heavier snowfall rates is possible within an hour or so either side of 12Z though and this could temporarily allow for some slushy roads. Little in the way of precipitation is likely over much of western ME this morning as forcing for ascent is expected to quickly dissipate once it exits NH but despite this some light snow remains possible with a coating in some spots. It will otherwise remain a cloudy and chilly morning with lows bottoming out into the 20s and 30s. Light snow mixed with rain will end by mid-morning across the area as the vort max exits to our north and some slightly drier air moves into the mid-levels. Skies will remain mainly cloudy through the day though as we remain under broad trofing and easterly flow will limit high temperatures to mainly the 40s. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... Tonight will feature cool and damp conditions but there will likely not be much in the way of precipitation until after midnight across extreme southern NH and then towards dawn elsewhere. Low temperatures will be into the 20s and 30s. A more organized wave of moisture from cutoff low pressure to our south looks to arrive on Saturday morning. Latest forecast guidance indicates a growing potential that a band of strong h7/h85 frontogenesis along with strong omega within a saturated dendritic growth zone will lift northward across the area between roughly 7am to 2pm on Saturday. Should this occur then a period of moderate to heavy snowfall rates would be likely with localized rates between 1-2"/hr not out of the question. This potential can now be seen through the WPC Snowband Probability Tracker (SPT) using both the latest HREF and HRRR. Some guidance is more bullish than others, however, with both the placement and magnitude of this potential front end thump of snow with some indicating the forcing will weaken as it lifts north. Nevertheless, based on this new guidance did increase QPF and snow amounts some with totals now approaching advisory criteria in portions of southwestern NH. It is possible these amounts will need to be raised further in other locations but given the wobbling of guidance the last few days, did not want to make complete wholesale changes yet. Winter Weather Advisories may later be needed for portions of the area depending on later forecasts. Following this initial shot of strong forcing, by the afternoon forcing looks to decrease with some drier air moving into the -12C to -18C layer. This will decrease precipitation intensity and likely allow for a changeover to rain or at least a rain/snow mix in areas outside of the mountains. High temperatures will be mainly into the middle to upper 30s. Rain and snow will end from west to east on Saturday night with low temperatures primarily into the 30s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Long Term Update... Little change from the previous forecast. Previously... Another area of low pressure passes off the coast that may continue precipitation chances for coastal areas Sunday. Monday appears dry with brief high pressure, before another low across central Quebec brings a cold front through Tuesday. The region will continue to experience effects of this broad upper low through to Wednesday. Timing and spatial differences continue into Sunday as a low further off the coast follows northward. Deterioration of the initial low south of New England will expand the influence of cyclonic flow, resulting in a period of greater moisture content off the coast. How far inland this influences either precipitation or just cloud cover differs. Kept a chance of rain in the forecast for the coast and parts of the interior through Sunday given this uncertainty. Will need to keep an eye on if dry continental air is more readily advected south across the forecast area to keep this moisture off the coast. Greater consensus is given Monday into Monday evening as high pressure quickly passes through the area. This could be the bright(er) spot of the forthcoming week before a cold front arrives and the region experiences unsettled weather under an upper low through mid to late week. && .AVIATION /10Z FRIDAY THROUGH TUESDAY/... Short Term...MVFR to IFR CIGs due to -SNRA/low ceilings will persist through mid- day before mostly improving back to VFR. The exceptions could be at KLEB and KHIE where MVFR restrictions could linger through much of the day. Winds will be out of the east at 5-10 kts. Light and variable winds will prevail tonight along with mainly VFR conditions. A period of moderate SN and low ceilings is then possible from 12Z-18Z on Saturday with IFR to LIFR restrictions possible. SN will then transition to mainly RA later in the day but low ceilings will cause lingering restrictions with northeast flow prevailing. No LLWS is currently anticipated. Long Term...Precipitation shrinks to the coast Sunday, with MVFR ceilings continuing and possible IFR near or just offshore. Conditions trend to VFR Monday under high pressure. && .MARINE... Short Term...High pressure exits to the northeast of the waters through tonight with low pressure arriving on Saturday. This will result in increased northeasterly winds and building seas... leading to SCA conditions. Long Term...Wave heights may remain 5 to 6 ft until Monday when high pressure moves overhead. A cold front will approach the waters Tuesday morning. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory from noon Saturday to 8 PM EDT Sunday for ANZ150-152-154. && $$ NEAR TERM...Tubbs SHORT TERM...Tubbs LONG TERM...Cornwell