Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 131646 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1146 AM EST Mon Feb 13 2017 .SYNOPSIS... Low pressure centered in the Gulf of Maine this morning will continue intensifying rapidly with northerly winds increasing during the day causing widespread blowing snow and near blizzard conditions. Snow ends from west to east during the day as the low moves east, though the strong winds will last into tonight. Expect a brief break on Tuesday as a narrow area of high pressure crosses the region. Another low pressure system will bring more snow on Wednesday, with the heaviest accumulations in the east. Below normal temperatures continue through the end of the week as high pressure builds in from the west. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Update...The winter storm continues to rage this central pressures fall into the 970s in the Gulf of ME. The nearly stationary deformation band has continued to pump out consistent 2 to 4 inch per hour snowfall rates...and so I have tried to keep pace with storm totals. There will be several reports of 2 plus feet when all is said and done. Farther W...the more elevated and narrow H7 to H5 frontogenesis continues to force a band of occasionally heavy snow from just N of IZG down towards Cape Cod. I have upped PoP along the NH border down to PSM...and increased afternoon snowfall totals slightly for this area. Also...with a little sunshine and CAA increasing the mixing depth I will issue a wind advisory for Srn NH. HRRR has mid level winds increasing to 50 or 55 kts thru this afternoon...and gusts to 40 kts seem likely enough. Even though it is marginal...significant impacts are expected from the blowing and drifting snow. Prev Disc...Have updated the grids based on current conditions and mesoscale models. Bands of very heavy snow continue over southwestern Maine, while little in the way of snow is falling over New Hampshire. Beginning to receive several reports of over a foot of snow in the region with up to 17.5 inches now in Starks our new max total. Will be adjusting snowfall totals over the next hour, likely bringing accumulations upwards in Maine and adjusting slightly downwards in New Hampshire. Prev Disc... Comma head in place and heavy snow continues across portions of the forecast area, especially the coast where locally 2 to 4 inches an hour snowfall rates will occur. Have increased snowfall amounts for the White Mountains where reports of 10 to 15 inches of snowfall have occurred. Left many areas in the 18 to 24 inch range along and near the Midcoast region. Lowered temperatures several degrees as temperatures continue to fall or hold steady in many areas with the coastal front now back off the coast. Winds will be on the increase early this morning. Near blizzard conditions expected for the remainder of the coastline. Three consecutive hours of visibilities below a quarter mile may be challenging for the southwest coast of Maine, but it will be close. Snow ends from southwest to northeast today. Have adjusted (shortened) some of the warning ending times to better match our ongoing gridded forecast, mainly over New Hampshire. Blizzard warnings will remain in effect until 00Z. Even if the precip stops, blowing and drifting will make for very low visibilities at times along the Midcoast.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Skies begin to slowly clear, mainly over downslope regions tonight. Winds will keep the atmosphere from decoupling with overnight lows mainly in the single numbers north to the teens south. Tuesday is the calm before the next storm. A weak ridge of high pressure will allow for partly sunny conditions across the forecast area. Winds will be light, allowing for New Englanders to continue to dig out from our latest storm and prepare for the next potential snowfall. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A deep upper trof will dig southeast through the Great Lakes Tue night and then move east toward New England Wednesday. Models are forecasting this trof to become negatively tilted which allows coastal low pressure to develop rapidly somewhere off the New England coast, exactly where will be critical to the forecast for Wednesday. Models differ on placement which will make for a tough forecast on placement of highest storm totals. For now it appears central and eastern areas of Maine will have highest amounts. There could briefly be a mix with rain along the immediate coast but any changeover would be brief. Plenty of cold air will be in place and thus lowered max temps on Wednesday. Overall prefer the EURO solution for now in forecasting this system. Significant accumulations are possible with this system depending on exactly where mid level low tracks. The upper low will be slow to exit so scattered snow showers can be expected on Thursday with even some light additional accumulations possible. A more quiet and warmer pattern will set up for the weekend as a more zonal flow aloft develops. Expect temperatures near to above normal with dry conditions for the weekend. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Short Term...LIFR conditions expected this morning in heavy snow and blowing snow. SFC wind gusts up to 40 kt likely today. Cigs and vsbys improve in southern NH by mid morning, with improvement foreseen further east during the late morning and afternoon hours. VFR conditions are expected Monday night but blowing snow will still be an issue. Long Term...Expect conditions to lower to IFR by Wednesday with developing snow. Conditions are likely to become LIFR over central and eastern portions of Maine Wednesday afternoon into Wednesday night. Should see a return to VFR on Thursday, outside of some isolated snow showers. && .MARINE... Short Term...Dangerous conditions are expected on the waters today as storm force winds are expected (except for Casco Bay where gales are in place). Seas will likely reach 20 ft early today. An improvement in conditions is expected tonight as winds slowly diminish and seas gradually subside. Long Term...Another coastal low pressure system may develop over the gulf of Maine Wednesday and Wednesday night possibly producing Gale force winds. A northwest flow will continue in the storms wake with SCA conditions possible for Thursday into Friday. && .TIDES/COASTAL FLOODING... Received reports of flooding on Eastern Avenue in Saco as well as splash-over developing at and just after high tide. Will continue the Coastal Flood Advisory for the next hour or so. About a 1 foot storm surge will accompany the 10.3 foot astronomical high tide in Portland at midday. This will likely be down a tad from the peak of 1.7 foot surge during last night`s high tide. The surge will decrease due to an offshore wind shift to the northwest. However, having said that, models tend to overdue this wind shift affect. Also, large battering waves may keep the surge up to around a foot today. Large, battering waves are expected at high tide which is 1240 pm in Portland. Nearshore waves as will be around 15 feet at high tide. This will likely lead to fairly widespread splash- over in many locations south of Portland. This will include several of the beaches in York and Rockingham counties. Some splash-over expected closer to the storm center over the Midcoast as well. Have therefore expanded the advisory for this region as well. && .GYX WATCHES/WARNINGS/ADVISORIES...
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ME...Winter Storm Warning until 7 PM EST this evening for MEZ007>009-012>014-018>021-023-024. Coastal Flood Advisory until 2 PM EST this afternoon for MEZ023>028. Blizzard Warning until 7 PM EST this evening for MEZ022- 025>028. NH...Wind Advisory until 4 PM EST this afternoon for NHZ008-010- 012>015. Coastal Flood Advisory until 2 PM EST this afternoon for NHZ014. MARINE...Gale Warning until 11 PM EST this evening for ANZ153. Storm Warning until 11 PM EST this evening for ANZ150>152-154.
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