212 FXUS61 KGYX 012202 AFDGYX Area Forecast Discussion National Weather Service Gray ME 602 PM EDT Sat Apr 1 2023 .SYNOPSIS... A cold front will cross the region this evening bringing scattered showers and gusty thunderstorms. Very windy conditions will continue on Sunday before high pressure crests the East Coast Sunday night. A clipper crosses with some showers on Monday, followed by a another slow moving system with more rain showers Wednesday and Thursday. High pressure will build in late in the week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 6 PM Update...Convective line to our west across Upstate NY continues to weaken as SFC dewpoints have been in the 20s and 30s back there. Dewpoints are higher in southwestern NH, but limited heating instability is meager. At this point we expect some gusty showers with a few rumbles of thunder to move across western and southwestern NH with a few gusts up to 40 kt possible. Otherwise the warm front continues to stay put with cold/stable air in place at the SFC for much of the rest of the forecast area. Previously... A strong cold front will cross the region beginning by 00Z. The latest HRRR continues to indicate convection reaching western New Hampshire during this period and quickly moving to the east. Wind fields and instability ahead of this line may allow for strong storms to cross the region with very gusty winds and some hail. An isolated storm or two may become severe as well with SPC having southern portions of our forecast area in a marginal risk. Temperatures will be quite changeable this evening both ahead of and with the passage of the front. Have included a nondiurnal temperature curve for the first few hours of the near term portion of the forecast. Gradient winds will also align through an increasingly deep layer later tonight. Mixing profiles suggest wind gusts will run up to 40 mph. A light coating of snow will fall in the mountains tonight after the precipitation changeover to snow from rain. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Windy conditions will continue on Sunday as the surface low strengthens and moves out to sea. Strong cold air advection will support below average temperatures for this time of the year with highs only inn the 20s and 30s north to around 40 in the south. The surface high building into New England will crest over Maine and New Hampshire Sunday night. With light winds, mainly clear skies and low dew points, expect radiational cooling to set in. Overnight lows will fall quickly to the teens north to the 20s south. && .LONG TERM /MONDAY THROUGH SATURDAY/... Overview: Low pressure tracks north of the region Monday evening bringing the chance of rain and snow showers to the area, tapering Tuesday morning. High pressure will keep temps a bit cooler Tuesday, before return flow increases moisture into Wednesday. This comes ahead of another storm system that could bring more widespread precipitation mid-week. Details: Monday will see some increasing return flow ahead of low pressure. Despite marginal mid level lapse rates, moisture and forcing will be limited, and believe notable showers should hold off until the evening outside of the mountains. Snow chances remain within the northwestern mountains, with warmer sfc temps south to support mostly rain showers. Weakening low pressure crossing north of the CWA Monday night should be strong enough to drop a cold front through ME and NH by Tuesday morning. This will cool temps for the day under cloud cover as high pressure reinforces with NW winds. The next chance for widespread precipitation comes mid-week as large low pressure across the upper Midwest lofts moisture and forcing through the Great Lakes and into the Northeast. Uncertainty resides just how far east a possible occluded front reaches from this parent low. This would affect timing and QPF, especially if another area of sfc low pressure develops. This doesn't appear too likely given recent ensemble guidance, but these lows also seem to trend in the more short to medium range. Associated jet dynamics may also be too far west for more than a few embedded shortwave, but this leaves much of the eastern CONUS open for terrific moisture advection from the south. As a result, PWATs potentially climb to around 1 inch for the area. While QPF amounts remain close to two tenths, there does appear to be an extended amount of time with temperatures perhaps around 50 degrees for southern NH. So, will want to keep an eye on snowmelt combined with any increase in rainfall amounts via training or expansion of synoptic precip. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... Short Term...IFR and LIFR conditions during the mid afternoon hours will continue to improve from west to east late this afternoon. Thereafter, expect scattered showers and gusty thunderstorms this evening as a cold front sweeps through the region. Conditions then improve to VFR after midnight outside the mountains as a strong west to northwesterly gradient develops. VFR conditions expected Sunday and Sunday night. Gusty winds will relax Sunday night. Long Term...VFR Monday with MVFR becoming more likely in the evening for northern and western NH. VFR is likely outside of the mountains Tuesday, with intermittent MVFR ceilings possible in NH. && .MARINE... Short Term...Will be issuing gale warnings with this package. Winds may gust as high as 35 to 40 kts with the strongest winds along the outer waters. Gales will continue through Sunday. Long Term...A few gusts to gale force will be possible Monday evening as a cold front crosses the waters with low pressure to the north. Winds and seas should subside below SCA conditions Tuesday afternoon. Intermittent chances of SCA wind gusts will be possible through Thursday, where a large storm system will pass inland. && .HYDROLOGY... Rainfall and warm temps will lead to snowmelt this evening. The most significant snowpack loss will be in southern and central NH where the snowpack is ripe/isothermal and ready to melt out releasing additional runoff. The drawn out nature of the rain will help moderate mainstem river rises. Smaller rivers and creeks in SW NH could be vulnerable to rapid rises which could reach bankfull. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Gale Warning from 4 AM to 6 PM EDT Sunday for ANZ150-152-154. Gale Warning from 6 AM to 6 PM EDT Sunday for ANZ151-153. && $$ NEAR TERM...Ekster SHORT TERM...Cannon LONG TERM...Cornwell