Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 141142 AFDGYX Area Forecast Discussion National Weather Service Gray ME 642 AM EST Tue Feb 14 2017 .SYNOPSIS... Weak high pressure builds south of the area Tuesday with mainly sunny skies and highs in the mid 20s to low 30s. Another strong upper trof of low pressure will move east to southeast from the upper Great Lakes Wednesday allowing a coastal low to rapidly intensify off the Maine coast by Wednesday night bringing potentially heavy snows across a good portion of Maine and New Hampshire. The system slowly exits into the Canadian maritimes Thursday but with lingering snow in the morning tapering to scattered snow showers. A more quiet pattern develops toward the weekend with high pressure accompanied by a warming trend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Update... Have updated the grids based on current conditions. Clouds have become trapped in the Connecticut River Valley and the northern mountains of Maine and New Hampshire. Also adjusted temperatures were vary greatly from location to location. Otherwise, little change to the current package. Prev Disc... A weak ridge of high pressure will quickly pass over the forecast area today. This will bring dry conditions to the region and relatively light winds compared to the last couple days. With some sunshine, temperatures will recover through the 20s during the day. This break in the active weather pattern ends as we head into Wednesday.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... A large upper level low pressure system will continue to be quick on the heels of the departing storm from yesterday. This energy is digging southeastward from northern Canada, a data sparse area. However, the 00Z model suite is relatively consistent from model to model in regards to the overall development of the next weather system. Cyclogenesis will occur south of the New England coastline Wednesday night in response to the digging trough and strong warm air advection well out over the open Atlantic. Low pressure will quickly deepend Wednesday night just east of the Gulf of Maine. In the meantime, a reflection of the upper trough in the form of an inverted trough will effect western Maine as well as Central and Northern New Hampshire. Snow will break out across the region, especially along and near the inverted trough axis. Northeasterly winds will funnel moisture in off the Gulf of Maine along with milder temperatures. There is a possibility that the snow will mix with rain for a period along coastal communities. Any rain/snow mix in coastal areas will transition to wet snow by Wednesday evening. The heavy wet snow may lead to isolated power outages. Also, the snow from a series of recent storms may lead to problems of weight on rooftops. The upper level low pressure system will cross the region Wednesday night. It appears that the H850 and H700 mb low will cross over central New Hampshire and southern Maine. Areas south of the track of the upper level features will have less in the way of precipitation. Due to the track of the system arriving out of central/northern Canada, the exact timing and path of the system is uncertain. Confidence level in the exact track and therefore potential snowfall amounts is not high at this time. && .LONG TERM /THURSDAY THROUGH MONDAY/... Low pressure in the Gulf of Maine early Thursday will slowly exit into the Canadian maritimes. In its wake the wraparound snows during the morning will gradually taper to snow showers Thursday followed by some partial clearing in the afternoon, especially over southern downsloping areas while the mountains may have afternoon scattered snow showers continuing. A broad surface/upper ridge of high pressure builds into the region Friday through early next week providing a quiet period of weather with a general warming trend. Used the superblend model for overall forecast of temps and trend. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Short Term...Expect mainly VFR conditions today and tonight with the exception of an isolated snow shower over the mountains early this morning. Conditions lowering to MVFR and IFR on Wednesday in developing snow. Some rain may mix in at PWM, RKD and PSM. IFR conditions expected in snow Wednesday night. Long Term...IFR conditions early Thursday will gradually improve to VFR from south to north. Generally VFR conditions expected Friday and through the weekend. && .MARINE... Short Term...SCAs will continue for the outer waters today, first for winds then continuing the rest of the day for seas. Long Term...SCA conditions are expected Thursday on a northwest flow as the low departs into the Canadian maritimes. Quiet conditions are expected Friday and through the weekend. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...Winter Storm Watch from Wednesday morning through Thursday morning for MEZ007>009-012>014-018>028. NH...Winter Storm Watch from Wednesday morning through Thursday morning for NHZ001>006-009-010. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ150- 152-154. && $$ NEAR TERM...Cannon SHORT TERM...Cannon LONG TERM...Marine is the U.S. government's official web portal to all federal, state and local government web resources and services.