Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KGYX 061300 AAA AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 800 AM EST Wed Dec 6 2017 .SYNOPSIS... Weak high pressure will gradually build into the region today through Friday with fair weather expected for most of the forecast area. A coastal low will develop offshore Saturday and possibly deliver a little light snow to the coastal plain through Saturday night. Thereafter, we will have to watch for another coastal low developing offshore, especially midweek, that could deliver some snow to the region but confidence is currently low. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Update...No significant changes to the forecast. ORIGINAL DISCUSSION... Cold front is making its way through New Hampshire at this hour and will continue its push eastward early this morning. Winds right along the front could gust to about 40 MPH with an abrupt temperature drop expected. Cold advection today will mean daytime high temperatures should be the early morning temperatures with temperatures holding steady or falling through the 30s during the day. With a tight pressure gradient, a fast flow above the surface, and deep mixing to about 850 MB expected today, it will continue to be breezy today. Wind gusts to 25 MPH will be common.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... Forecast soundings indicate that the atmosphere will remain well mixed in the low levels tonight, so temperatures will not fall as much as they otherwise could. Lows will generally be in the 20s, with some colder temperatures possible in well protected valleys. Westerly flow continues on Thursday with temperatures near normal, in the upper 30s and low 40s. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... The main focus in the extended period of the forecast is whether or not measurable snowfall will occur in association with an east coast trough this weekend through mid next week. At the beginning of the long term forecast, the region will be in an area of weak high pressure, with fair and seasonably chilly weather Thursday night through Friday night. Thereafter, a strong upper level trough over the Great Lakes will very gradually move southeastward. The main question over the last few days has been will the baroclinic zone offshore be able to produce low pressure close enough to the coast to allow for a measurable snowfall in our region. As of this time, 00z deterministic model data along with latest ensemble information indicates that the coastal plain may be grazed with a little light snow later Saturday into early Sunday. Some solutions are well offshore, but others are far enough west to allow the coastal plain to pick up a couple inches of snow. Either way, a big event does not appear to be in the cards during this time. Have gone with a chance of snow on the coastal plain Saturday and Saturday night to account for the possibility of a more western track. Thereafter, the next best shot for snow looks to be the Tue/Wed time frame. However, there are still too many questions about the strength, orientation, and degree of amplification of the northeastern trough and associated baroclinic zone to have any sort of confidence on chances for a meaningful snow event at this time. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... Short Term...Winds shift to the west behind a cold front this morning. After an initial burst of wind gusts to 30 or 35 KT, winds today should generally gust to 20 KT with conditions rapidly improving to VFR behind the front this morning. Winds diminish a bit tonight with gusts to 20 KT again on Thursday. Long Term...Mainly VFR conditions are expected Thursday night through Saturday. Thereafter, there will be a low probability of light snowfall on the coastal plain and southern NH Saturday night into early Sunday which could bring conditions down to MVFR. && .MARINE...
-- Changed Discussion --
Short Term...Have dropped gale warning for all waters...with a SCA in place in the bays thru the early afternoon...and outside the bays thru this evening. Winds shift to the west behind a cold front this morning. Generally expect these winds to top out at around 30 to 35 KT and gradually diminish as the day goes on. Still expect a stiff west wind on Thursday as well, but possibly below advisory levels. Wave heights will take some time to subside, but could fall below 5 FT as early as tonight. Long Term...Westerly flow behind a cold front remains near advisory levels for the outer waters into early Friday. Model forecasts are inconsistent on timing and track of low pressure offshore of New England this weekend, so current forecast represents a blend of model guidance. It is possible that advisory level winds could occur again depending on the track of the low pressure areas come early next week
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING... Winds will shift to offshore this morning, so there should be very little issues with the high tide around 1230PM today. This tide is higher, at about 11.6 FT in Portland, but the surge will be on its way out, preventing significant issues. && .GYX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
ME...None. NH...None. MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ151- 153. Small Craft Advisory until 7 PM EST this evening for ANZ150- 152-154.
-- End Changed Discussion --
&& $$ NEAR TERM...Legro

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.