283 FXUS61 KCAR 130218 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 1018 PM EDT Wed Jun 12 2019 .SYNOPSIS... High pressure will exit across the Maritimes overnight through early Thursday. Low pressure approaches from the west Thursday with secondary development over southern New England bringing widespread rain to the area later Thursday through Thursday night. && .NEAR TERM /THROUGH THURSDAY/... Update... High pressure will exit across the Maritimes overnight, with clear/mostly clear skies across the forecast area. Low temperatures will range from the lower to mid 40s north, to the mid to upper 40s Downeast. Have updated the forecast to adjust for current conditions along with overnight temperatures. Previous Discussion... Skies rmn clr tonight and hv delayed increase in clds by 3-6 hrs as guidance is trending slower with eventual system. Temps likely to be warmest acrs the north and east tomorrow as this area wl be the last to see clouds and rainfall fm sfc system. LLJ will begin to bring in PW values of 1.5 inches to Downeast late in the pd. Med range guidance conts to show heaviest pcpn along the Downeast coast tomorrow evng while 12z GFS takes it more offshore. Hv trended twd persistence as still unclear what effect the new FV3 core in the GFS has had on mvmnt of systems at this point. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... Upper-level trough will begin to tilt negatively over the eastern Great Lakes into the Northeast Thursday night. Sfc low will form and pivot along the St. Lawrence, tracking NE before getting captured by northerly flow towards the parent upper low just west of Hudson Bay. The strong mid-level jet oriented along the east coast will help by shunting the low from it’s easterly component. Rain will be ongoing as the low lifts north, with it high PWATs mentioned in near term along coastal Downeast. Much of Maine will be placed in the warm sector and moist air will quickly invade much of the FA. Patchy fog will develop into the evening hours. Kept timing and coverage originally set by night crew, with areas of fog in coastal waters and immediate coastal Downeast, patchy inland and across the north. Focus for daytime Friday becomes chance for thunder in afternoon. Generally, more going against organized development than for. Environment destabilization seems limited, and lapse rates have flattened to 5-7 C/km for mid and low levels as cooling aloft is slow to reach the area due to winds shifting later as trough passes. Thus, greatest chance for thunder will be across the north where this advection will take place earlier, combined with best forcing and higher CAPE values, 200-600j/kg. Shear continues to be in a good place for storms, however at 70kts of deep layer shear may tear updrafts apart before becoming sustaining. At this time storm mode would be single cell pulse, with main threats being winds and hail. Clouds hampering daytime heating will be an additional factor, however expect this area to be fairly clouded over during the morning. Precip chances will decrease Friday night before another wave approaches along a stalled frontal position near the CWA. Rain shower chances increase during the afternoon across the north with much of the forecast area reaching the lower 70s for highs. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... The weak boundary will remain settled across the Northeast through much of early next week. This would bring at least the mention for some rain showers daily. Break for dry weather would fall towards Tuesday night/Wednesday as most guidance suggests high pressure nosing in from the northwest. Even in this regime, cool NW winds could bring daytime isolated showers. Given the persistent SW flow, daily temperatures will run warm, with potential to approach the mid-70s through Wednesday. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... NEAR TERM: VFR conditions are expected across the region overnight through early Thursday. Conditions will then lower to MVFR/IFR levels north, IFR/LIFR levels Downeast, Thursday afternoon with developing rain. Low level wind shear, southeast around 40 knots at 2000 feet, is expected across Downeast areas later Thursday afternoon through early Thursday night. SHORT TERM: IFR conditions are expected Friday morning with rain. Patchy fog will dissipate in the morning along with rising ceilings. MVFR is likely through the afternoon before the chance for storms in the later afternoon/evening, mainly across the north. Conditions will trend towards VFR overnight into Saturday after passage of cold front, earlier towards BGR and BHB...later towards the northern terminals. MVFR could return with general showers through Sunday and Monday as a boundary stalls over the Northeast. && .MARINE... NEAR TERM: Winds/seas will remain below small craft advisory levels overnight through early Thursday. A Small Craft Advisory then remains in effect starting later Thursday afternoon. Visibilities will lower in rain Thursday afternoon. SHORT TERM: Small Craft Advisory conditions warranted on Thursday night through early morning Friday with waves building 5-7ft and winds 20kts with gusts approaching 30kts. Winds and waves will begin to come down mid Friday morning, but remain around 5-6 ft and gusts around 15-20kts through Sunday night. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory from 4 PM Thursday to 8 AM EDT Friday for ANZ050>052. && $$ Near Term...Norcross/Farrar Short Term...Cornwell Long Term...Cornwell Aviation...Norcross/Cornwell Marine...Norcross/Cornwell