Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 250755 AFDGYX Area Forecast Discussion National Weather Service Gray ME 255 AM EST Sat Feb 25 2017 .SYNOPSIS... An unseasonably warm and moist airmass will remain across the area today. A strong cold front will sweep across the region this evening accompanied by showers and a few thunderstorms. A drier and colder air mass follows this front for Sunday into Monday. A disturbance will approach from the west late Monday and Monday night. && .NEAR TERM /THROUGH TODAY/... At 07z...a 994 millibar low was over Lake Huron with a warm front extending eastward through northern New England and a trailing cold front southward into the Ohio valley. NWS Doppler radar mosaic showed scattered return to the north of the warm front. Otherwise it was mostly cloudy across the forecast area with areas of fog and patchy drizzle in light southerly flow over our rapidly shrinking snowpack. For today...strengthening southerly flow should boost temperatures into the 50s and 60s with record highs to be challenged if not exceeded once again. Todays record highs include 63F in Concord set in 2016, 53F in Portland set in 2016, and 57F in Augusta set in 1984. We should see a few scattered showers in the warm sector today. The shortwave impulse evident in GOES water vapor over the western Great Lakes will go negative tilt later today with strong surface cold front racing eastward into New England towards dusk. We should see a line of convection along and just ahead of this front with a few embedded thunderstorms. The convection should weaken tonight as it enters the forecast area...but can`t rule out a few strong wind gusts over the Connecticut valley with enhanced wording added there. && .SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/... The line of convection will sweep east with the cold front this evening before quickly exiting the coast. We`ll see post frontal clearing in all but the higher terrain as drier and colder air flows into the region on a downslope northwest flow. The mountains should hold on to the clouds and a few snow showers as the column cools. Lows will range from the upper 20s to mid 30s. It`ll be blustery and cooler on Sunday with a weak secondary cold front/surface trough crossing the area. we`ll see clouds and a few upslope snow showers in the mountains...with partly sunny skies elsewhere. Highs will be in the 30s across the mountains and international border and in the lower to mid 40s elsewhere. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... The overall upper level pattern will be rather unmarked by any system of amplitude through at least mid week. Upper level flow will be zonal and fast with a sheared out and weakened trof moving through on Monday. This will increase cloud cover across the north and may bring a few light showers to the higher terrain. Temperatures will continue to be above normal with highs in the upper 30s north to near 50 south. A warm front lifts north on Tuesday night into Wednesday and northern New England will be in a strong WAA regime through Thursday. Have gone considerably higher than guidance during this time frame for temperatures as we should see readings soar on Wednesday and Thursday (not too dissimilar to what we had happen earlier this week, which guidance also performed poorly on). Have already gone a good 10+ degrees above guidance but still feel highs may top out above what is in the forecast (currently 50 to 55 degrees). The warm front will trigger numerous showers- mostly plain rain with the chance for higher elevations snows initially and overnight. A surface low deepens to about 975 mb or lower as it crosses northern NH and ME late Thursday bringing an end to widespread precipitation as a cold front sweeps through. Given the warm temperatures convection/lightning and thunderstorms will be possibly especially on Thursday as the best dynamics swing through. The front may stall to the south and could possibly move back north as a warm front to bring some showers for coastal zones late Friday into Saturday morning...however it seems like this baroclinic zone will have enough push to clear the Gulf of Maine. High pressure and more seasonable/cooler air- highs in the 20s to near 40- arrives by Friday behind the front, with even cooler temperatures for the weekend. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... Short Term /through Sunday/...IFR/LIFR in areas of fog and low clouds improving to MVFR today in -shra. A line of -shra and embedded -tsra will cross the area this evening ahead of a strong cold front. Winds will shift to NW behind the front and gust up to 25 kt with conditions improving to VFR in all but mtn locations where MVFR ceilings will linger in -shsn. NW sfc winds will continue to gust up to 25 kt on Sunday. Long Term...Generally VFR on Monday with a chance for MVFR ceilings for HIE in -SHSN. -SHRA increasing from SW to NE Tuesday and increasing in likelihood Wednesday with a possible -SHSN for HIE and LEB. Gusty SW winds Monday and gusty S winds Wednesday. && .MARINE... Short Term /through Sunday/...Southerly winds will increase today ahead of a cold front with small craft winds and seas likely later today and much of tonight. Following the cold frontal passage...northwest winds may approach gales outside the bays late tonight and into the day on Sunday. An SCA for all waters this afternoon into tonight with a Gale Watch for late tonight and Sunday. Long Term...SCA conditions to continue through Monday in strong westerly flow. Winds and seas diminish Monday night through Tuesday before increasing once again on Wednesday to near gales as low pressure deepens north of the Gulf of Maine. && .HYDROLOGY... The flood watch remains posted for interior portions of Maine and new Hampshire through 00Z Monday. Daytime temperatures will soar into the 50s and lower 60s again today. The cold front moves through this evening with 0.50 to 0.75 inch of rain possible. The warmth will continue to ripen and melt the snowpack with rivers and streams responding through Sunday. Rainfall will add to the runoff through Saturday night. At the current time, the main threat is ice jam flooding. The threat is higher in New Hampshire where temperatures will be warmest and the precipitation will be heaviest. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Flood Watch through Sunday evening for MEZ007>009-012>014-020- 021. Dense Fog Advisory until 7 AM EST this morning for MEZ007>009- 012>014-019>021. NH...Flood Watch through Sunday evening for NHZ001>009-011-012-015. Dense Fog Advisory until 7 AM EST this morning for NHZ001>006. MARINE...Gale Watch from late tonight through Sunday evening for ANZ150>154. Small Craft Advisory from noon today to 4 AM EST Sunday for ANZ150>154. && $$ Schwibs/Hanes is the U.S. government's official web portal to all federal, state and local government web resources and services.