Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 220324 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1024 PM EST Tue Feb 21 2017 .SYNOPSIS... A weakening frontal system will cross the area tonight. Low pressure moving east through southern Canada will push a cold front toward the region late Thursday. The front will be followed by high pressure through early Friday. A warm front will approach from the southwest late Friday and will lift north of the area Friday night. A coastal system may bring more widespread precipitation over the weekend. && .NEAR TERM /TONIGHT/... 1030PM UPDATE... Area of rain earlier over New York state has now moved into Vermont and now reaching into New Hampshire. However as it has arrived it has also weakened substantially and we struggle to find observations which show any of this is reaching the ground. At the same time, temperatures are still above freezing for most of the area, so confidence in any freezing rain tonight is decreasing. But will maintain a slight chance in the forecast in case a few spots pick up a sprinkle or two. No other significant changes were needed. 630PM UPDATE... Have updated the forecast based on latest observations and to reflect current forecast thinking. Area of rain noted on regional radar over far western New York state. Some radar echoes have shown up further east moving into Vermont, but these are falling from a very high cloud deck with significant low level dry air resulting in little if anything reaching the ground. Do not expect anything to be noted out of this as it moves into the area. The better chance of any precipitation would be with the heavier band of rain over eastern Lake Ontario at the moment, though this is forecast to break up and dissipate as it arrives. Even as it is, it is only producing very light rain with a mid level cloud base and no visibility restrictions noted. This supports the idea that this may not make it to our area tonight. Meanwhile, temperatures are cooler over Maine than they are over New Hampshire, but both areas have noted some minor cooling in the last few hours in spite of abundant high level clouds. Expect only minor cooling overnight due to the extensive cloud cover. Biggest change to overnight temperatures was to warm things up in northern areas where MOS forecasts tend to be well too cold on nights like this. Temperatures will ultimately be borderline, right around the freezing mark, as any remnant precipitation arrives. Expect precipitation type to be light rain or freezing rain depending on temperatures, but again, there is still not a lot of confidence that this will occur and if it does so amounts will be very light. ORIGINAL DISCUSSION... We have had a moderately warm day today with slightly above normal temperatures for most spots in NH and western Maine. High pressure currently straddling the coast will continue to move offshore tonight with increasing moisture moving northward and clouds thickening ahead of a cold front. Models have backed off on QPF for the frontal passage overnight with only a few hundredths in mainly elevated locations. Any precipitation that reaches the ground will be in the form of sleet or freezing rain...however it will be so sparse will not be issuing any headlines and will instead handle the situation with Special Weather Statement(s) when the time comes. Lows overnight will generally range through the 20s to lower 30 degrees along the coast. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... Cold front weakens and essentially washes out on Wednesday leaving the region in a warm southwesterly flow. High temperatures will push well above normal with most of the region topping out in the 40s to near 50 over southern New Hampshire and SW Maine. A warmer night will be on tap for Wednesday night with moisture still in place and a warm front lifting into the region overnight. Here we will likely see some light rain/freezing rain along the international border around daybreak, but again it looks very spotty. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Low pressure will move across southeast Canada Thursday and will drag a warm front northeast across the region. A few scattered showers are possible in the mountains with the warm frontal passage Thursday. As the low moves rapidly east into the maritimes Thursday night it will then drag a trailing weak and shallow cold front south across the region with weak high pressure building into the area behind the front late at night into early Friday with dry conditions. By late in the day the front moves north once again as a warm front with a very broad southerly flow developing late Friday and continuing through Saturday. Warmer daytime and nighttime lows are expected and reflected rather well in superblend guidance. By late Saturday a progressive upper trof moving through the Great Lakes will have a strong surface cold front associated with it and will allow showers to develop by late Saturday and become widespread Saturday night as the front and upper trof moves rapidly east across the area. On Sunday into Monday a return to a more zonal flow aloft with high pressure, colder temperatures, and dry conditions expected. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... Short Term...VFR likely through tonight, but MVFR ceilings possible early Wednesday morning mainly at Lebanon and Whitefield perhaps persisting into the day on Wednesday. Very slight chance of freezing rain in these areas tonight. Long Term...VFR conditions Thu into Thu night. MVFR conditions may develop Fri in a developing moist southerly flow with some scattered rain showers. Variable conditions expected early Saturday but with the approaching cold front late Sat and Sat night expected conditions to become MVFR to IFR in showers. && .MARINE... Short Term...A couple gusts to 25 kts will be possible over the outer waters tonight, but confidence is in the occurrence for more than a stray observation is too low for an advisory. Long Term...Winds and seas will remain below SCA thresholds thru the end of the week. A strong cold front will cross the waters over the weekend...and bring an extended period of SCA conditions to all waters. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM UPDATE...Kimble SHORT TERM...Hanes LONG TERM...Marine is the U.S. government's official web portal to all federal, state and local government web resources and services.