Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 271030 AAA AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 630 AM EDT Thu Jun 27 2019 .SYNOPSIS... A few showers will drift offshore this morning as an upper level disturbances passes through. Another disturbance drops down from the north tonight and may bring another round of showers and thunderstorms mainly to northern areas. After brief high pressure on Friday, low pressure moves in from the west on Saturday with more widespread showers. Upper level low pressure drops in from the north on Sunday keeping the threat for showers in the forecast along with cool conditions. && .NEAR TERM /THROUGH TONIGHT/... 630 AM Update... Currently some dense fog out there which will improve quickly as the morning ensues. Made a few changes to dew points and to input overnight temperatures. Otherwise forecast is on track. Previous discussion... Some residual showers are moving offshore from about Portland southward, along a inverted trough that has developed off of low pressure south of the Gulf of Maine. This should be the end of the rainfall tonight, The marine layer still covers much of the region, with widespread fog developing as well. Will keep an eye out for any visibilities below a quarter mile. This should lift between 8 and 10 AM. Expecting sunny skies for southern and western sections, with clouds and the threat of showers still in play for the mountains and eastern Maine. Highs will reach the mid 70s north and east and the 80s west and south. && .SHORT TERM /FRIDAY/... A short wave arrives later tonight along with another surface trough. This will arrive after the heat of the day, with thunderstorms arriving from the west for a few hours tonight. 500mb temperatures around -16 degrees C supports gusty winds and small hail wording in the zones. Precipitation clears out soon after midnight tonight, allowing clouds to thin from the west. Overnight lows will be in the mid 50s to lower 60s. Although high pressure builds in Friday, another disturbance will be arriving from the west Friday night, increasing rain chances once again across the whole area. Highs will range from the upper 70s in the mountains to the upper 80s across southern NH. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Ensemble and deterministic model solutions are now in good agreement on the long wave pattern through late next week. We begin the period with a low amplitude flow and a series of impulses embedded in the mean jet position near the international border. The flow quickly buckles with an evolving upper trough for the upcoming weekend. By Monday...the upper trough shifts offshore with brief ridging before troughing returns for the middle of next week. However...the numerical solutions suggest that upper trough will quickly shear out and be replaced by rising heights and ridging for the tail end of the week. In the dailies...a weak disturbance crosses the area Friday night and Saturday accompanied by another round of convection. The system slides offshore and slows down Saturday night and Sunday in response to digging shortwave and close proximity of upper low. The upper low and a secondary cold front should produce another round of convection for Sunday. A weak trough crosses the area Monday and may touch off a brief shower in northern and eastern sections. A brief break between systems Monday night and early Tuesday. By late Tuesday...unsettled weather returns as another disturbance approaches from the Great Lakes. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Short Term...Area of IFR to MVFR ceilings persists across central coastal Maine and will also impact coastal Maine and coastal New Hampshire during the overnight. Expect widespread IFR or LIFR conditions in this maritime air mass along with some areas of dense fog. This will improve greatly after 14Z with MVFR or better expected most of the day. A few thunderstorms may affect northern areas this evening, with KHIE the most likely to see impacts. Long Term... Fri night - Sun...Areas of MVFR in -shra/-tsra with lcl IFR in night time stratus and fog. && .MARINE... Short Term...Although low pressure is over the Gulf of Maine the pressure gradient is quite light and will keep winds and seas rather low. Fog continues to be expected over the waters however. Long Term... Mon...Winds could approach SCAs in gusts outside the bays. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Hanes SHORT TERM...Hanes LONG TERM...Schwibs is the U.S. government's official web portal to all federal, state and local government web resources and services.