Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 130142 AFDGYX Area Forecast Discussion National Weather Service Gray ME 942 PM EDT Sat Aug 12 2017 .SYNOPSIS... Low pressure will drag a trailing cold front through New England Sunday morning. This will bring a few rounds of showers and thunderstorms...before drier air works back into the region on Sunday. Quiet and mild weather is expected for Monday and Tuesday of next week with high pressure centered south of the region. A cold front will move through northern New England late Tuesday into Wednesday followed by a ridge of high pressure. Low pressure will approach from the Great Lakes late Thursday into Friday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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940 pm Update: Strong Thunderstorms continue across northern NH and the western mountains of Maine. Also another area of storms moving across southern NH at this time. Will make some minor adjustments to POPs otherwise no changes. Temps were adjusted slightly based on latest obs data. 630 pm Update: A line of organized strong convection has developed N-S from easter NY and is now moving into VT. It will move into NH this evening so increased POPs across that area. Some of the storms are rather strong so will continue the enhanced wording for possible strong gusty winds and small hail with some of the storms through about 02z. Later this evening most of the activity should diminish. Previous Discussion: Southerly flow ahead of an approaching cold front will keep humid conditions in place across northern New England tonight. Expect some fairly widespread valley fog to develop after dark as well. Thunderstorm potential this afternoon and evening will be best over the mountains and western New Hampshire. Current activity over New York state will take some time to work it`s way eastward this afternoon. As the upper level support begins to move eastward, expect storms to become more numerous over our CWA. As mentioned in the previous discussion, it looks like at best the storms should have around 1000j/kg of CAPE to work with. Expect primary threat to be gusty winds and perhaps some small hail. There could be one or two isolated severe cells, but convection should primarily remain below severe limits. Storms should be moving quick enough also that flash flooding concerns should be limited.
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&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Cold front will move across the region with some residual showers and isolated thunderstorms possible over the mountains. Most locations should be dry though. Expect high temperatures to climb into the upper 70s to mid 80s. Drier air doesn`t move into the region until Sunday night. As dewpoints drop Sunday night, so will overnight temperatures. Pretty much everyone should see overnight lows in the 50s. && .LONG TERM /MONDAY THROUGH SATURDAY/... The models are in decent agreement on the long wave pattern through late next week. An omega block will be centered across the Canadian Prairies with the eastern anchor trough over eastern Canada and New England. As we head through the extended period... the numericals begin to break down the block with timing and strength differences adding increased uncertainty to sensible weather details after mid week. In the dailies...weak ridging should provide quiet weather Monday into Tuesday. Late Tuesday and Tuesday night....a cold front will drop south across the area followed by a ridge of high pressure. Low pressure approaches from the Great Lakes late Thursday into Friday. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... Short Term... Expect primarily VFR conditions. However, valley fog will drop favored TAF locations to IFR/LIFR conditions tonight. Conditions should improve rapidly tomorrow after sunrise and VFR conditions should prevail for the remainder of the short term. Long Term... Tue PM - Wed AM...areas of MVFR in -shra/-tsra. && .MARINE... Short Term... No flags expected. Long Term... Mon and Wed...Winds and seas may briefly approach small craft outside the bays. && .EQUIPMENT... The weather radar at Gray (GYX) will be down for maintenance for approximately two to three days, beginning August 13th. During that time technicians will be installing important upgrades. This work has been scheduled to minimize any potential impacts to office operations. During the outage, radar coverage is available from adjacent radar sites including Burlington-Vermont (KCXX), Taunton- Massachusetts (KBOX), and Hodgdon-Maine (KCBW). Also, the radar at Albany (KENX) suffered a failure last night (Friday night) that has been attributed to azimuthal motor/gear issues. It is expected to be down through early next week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Marine SHORT TERM...Marine

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