Area Forecast Discussion
Issued by NWS Wakefield, VA

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606 FXUS61 KAKQ 142046 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 346 PM EST Thu Dec 14 2017 .SYNOPSIS... High pressure builds over the area tonight, then moves off the Mid Atlantic coast Friday. Low pressure develops off the southeast coast Friday, then tracks northeast across the Vacapes Friday night. High pressure returns over the weekend. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Sfc high to the north slides east to a position near the NJ coast by 12Z Fri. Dry with more clouds after midnight. Lows in the 20s except lwr 30s SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... Sfc high slides offshore Fri morning with another clipper system and its associated moisture progged to track east staying well north of the area Fri nite. Tricky part of the forecast comes from the south as a wave of low pressure develops off the NC OBX Friday, then tracks NE across the Vacapes Fri nite. Latest data now shows the track of this low and assctd moisture closer to the coast Fri before lifting ne and away from the coast Fri night. NAM most aggressive throwing back moisture as far west as the I95 corridor while the GFS/SREF/ECMWF limit any measurable QPF to the nrn neck and ern shore areas. Bufkit sndgs suggest about a 4-6 hour period of pcpn between 18Z-00Z with pcpn lingering along the ern shore thru about 03Z Sat. Thermal profiles suggest mainly snow (across the lwr Md ern shore) with a buffer area of a rain/snow mix to snow across the nrn neck with just rain over the south mixing with or changing to a snow shwr before ending. Next concern will be sfc temps as they stay above freezing limiting snow accumls Fri before falling by sunset. After coord with WPC and neighboring offices, kept a dry forecast along and south of I64. Slght chc pops ramping up to high chc to low end likely across the lwr Md ern shore. For now, kept any snow accumls limited the lwr Md ern shore where the likely pops will be. Generally under one inch expected with the most ivof OXB. Highs Fri mid-upr 30s north, low- mid 40s south except nr 50 across the OB. Any lingering snow shwrs push of the coast before midnite Fri nite with decreasing clouds after midnite. Lows mid 20s NW to lwr 30s SE. High pressure builds over the sern states Sat then moves offshore Sun. Dry through this period except for a slght chc shwrs late Sun across wrn most zones. Highs Sat in the mid- upr 40s. Lows Sat nite mid 20s NW- mid 30s SE. Highs Sun upr 40s- mid 50s. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... A welcomed return to south-southwesterly flow on Sunday will bump temperatures into the middle 50s. High pressure slowly meanders offshore to the east on Sunday night and into Monday, allowing for an uptick in moisture advection across the south. The European is beginning to lean towards a drier, GFS-like solution for Monday. Better chances for measurable rainfall exist across our NC counties and extreme southeastern VA Monday aft/eve. Temperatures during the day will rise into the upper 50s, so no worries about any wintry precip. Tuesday`s temps will strive for the low 60s in the afternoon, with one caveat being cloud cover. The GFS and EURO begin to disagree during this timeframe, with the EURO being much drier at the mid levels than the GFS. As such, the GFS is more bullish on cloud cover and rain chances Tuesday afternoon and evening. Leaned more towards the EURO solution, trimming back PoPs Tuesday...will wait for better model agreement to increase confidence on Tuesday being any drier than currently forecast. The spigot abruptly shuts off early Wednesday morning as any moisture slides off the coast. Expect highs Wednesday and Thursday to be 7-10 degrees cooler than Tuesday. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... VFR conditions expected through the forecast period. SCT-BKN high mid level clouds this aftrn will dissipate this evening as high pressure builds over the area. The gusty WNW wind diminish this aftrn as well. Developing low pressure along the se coast will allow a BKN mid level deck to push north along coastal sections Fri morning. Any pcpn associated with this systm is expected to be after 18Z Fri and mainly along the eastern shore. OUTLOOK... Quick shot of snow and MVFR CIGS at SBY Fri aftrn and evening as coastal systm makes closest apprch. High pres returns to the area over the weekend. && .MARINE... Coastal low continues to exit into the western Atlantic while weak high pressure over the Ohio Valley continues to slide east and will be over the waters tonight into Early Friday. The next system will be a wave of low pressure that slides off the Carolina Coast and deepens quickly Friday afternoon. Expect an increase in winds across the southern waters late in the day, getting close to SCA levels late in the day for the southern bay and coastal waters. With the values being marginal SCA values of around 20 KT in the Bay and gust to 25 kt over the coastal waters, will not raise the SCA flag yet. But the model trend has been gradually getting stronger with this system and if that trend continues the SCA will be needed. Behind this wave, cold advection will increase after 6z on Sat through about 18z, which should cause more sca level winds, especially in the northern coastal waters. High pressure moves back over the area late Saturday afternoon and will remain in control of the regions weather through the weekend. This will allow for a period of light winds, going from a northerly direct Sat night to a southwest direction by Sunday afternoon. Winds will remain light on Monday, but expect a strong increase on Tuesday as a frontal boundary and developing surface low approach the area, followed by another shot of cold air for the midweek time frame. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Low Water Advisory until 6 PM EST this evening for ANZ637. Small Craft Advisory until 7 PM EST this evening for ANZ650- 652. && $$ SYNOPSIS...MPR NEAR TERM...MPR SHORT TERM...MPR LONG TERM...AJB/BMS AVIATION...MPR MARINE...ESS

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