Area Forecast Discussion
Issued by NWS Wakefield, VA

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790 FXUS61 KAKQ 221421 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 1021 AM EDT Thu Mar 22 2018 .SYNOPSIS... Low pressure tracks northeast and away from the area today. High pressure to the west will build into the area tonight through Friday. Low pressure moves east from the Mississippi Valley Saturday and tracks through the Carolinas Sunday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Current wv imagery shows a strong upper low SE of Cape Cod and this will be slow to depart to the NE today as high pressure builds into the KY/TN valley. Models show a couple of s/w trofs moving across the region today through Friday. Tsctns show periodic moisture at different levels so instead of any prolonged clrg, think skies remain variable cloudy once the late March sun goes to work. Any remaining snow should melt as highs range from the mid to upr 40s north, 50-55 south. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... Fair to pt cldy tonight and continued cold. Lows upr 20s-lwr 30s except mid 30s sern cstl areas. More of the same Fri with skies becoming pt to mstly cldy at times. Highs mid-upr 40s ern shore areas, 50-55 west of the bay. Friday night starts off mstly clr as the ridge axis moves overhead then offshore after midnight. Clouds incrs across the Piedmont late. Dry with lows mid-upr 20s north, low to mid 30s south. Winter not over just yet as the next s/w rapidly apprchs from the west. Current models are showing a nearly perfect track for an accumulating snow event mainly south of I64 away from the water. A 1040+ mb high will be slow to track across ern Canada over the weekend providing the cold air as the center of the low tracks se across KY late Sat then across the Carolinas Sat night before moving offshore Sun. QPF and sfc temps will be the forecast challenge since partial thicknesses support a rain changing to snow event for the region. Models still not in complete agreement in timing or moisture fields attm, so stay tuned. Grid/forecast wise, undercut MOS guid Sat with rain overspreading the area west-east after 18Z. Highs 40-45. Rain/snow mix basically north of a FVX-RIC-XSA line by 21Z with temps falling into the 30s. Little if any accumls expected thru 00Z Sun. Sat night will be the main event with a rain/snow mix changing over to all snow except for sern cstl area with rain or a rain/snow mix. Lows 30-32 except mid 30s sern cstl areas. Accumls this far out are tentative at best, but given forecasted QPF`s btwn 1/4 to 1/3 inch suggests the ptntl for a 2-4 inch event across the Piedmont with a 1-2 inch buffer zone arnd that. Still plenty of time to adjust these values as the events gets closer. The system is slow to depart Sunday with lingering snow in the morning then decreasing clouds as the systm moves offshore. Addntl accumls psbl into Sun morning across the south. Highs in the 40s. Gusty NNE winds...esp at the coast will make it feeling colder). && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... Deep/anomalous trough aloft hangs near/just off the E coast Sun night into Tue before shifting E and a high amplitude upper level ridge builds into the region. Dry and clearing wx Sun night through Tue. By Wed...lo pres to track through the Great Lakes states pushing some moisture into the mid- Atlantic region. Brought increasing clouds into the local area Wed...but left PoPs aob 10%. Lows Sun night in the u20s W to the m- u30s at the coast. Highs Mon in the m40s at the coast...u40s-around 50F inland. Lows Mon night in the u20s W to the m-u30s at the coast. Highs Tue in the u40s at the coast to the m50s inland. Highs Wed in the u40s- l50s at the coast to the 60-65F inland. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... CIGS finally lifting into the VFR range at 12Z as the east coast low slowly departs to the ne. Clouds may SCT out for a while today but then come back as a BKN SC deck this aftrn as the March sun combines with the cool air aloft. High level clouds thru the rest of the frcst period. NW winds 10-15 Kts. Outlook: Low pressure approaches from the West late Saturday, with a period of sub-VFR flying conditions Saturday night into Sunday in both rain and snow. High pressure returns early next week. && .MARINE... Low pressure located off the New Jersey coast will continue to track northeast on Thursday and move into the northern Atlantic waters by Friday. Winds will continue to remain stirred up this morning into Friday due to the pressure gradient between the departing low pressure and strong high pressure over Canada. As a result of this and recent guidance, went ahead and extended the Small Craft Advisory for the Bay into Friday morning. There may be a brief lull in the winds later this afternoon and evening before ramping back up overnight. Generally expect NW winds of 15 to 25 knots with a few gusts to 30 knots early this morning and again tonight. Seas at or above 5 feet are also expected to linger into early Friday. Winds slowly diminish during the day on Friday as high pressure briefly builds into the region. Winds may briefly gust to 20 knots again Friday night. Another low pressure system looks to impact the waters late Saturday into Sunday. The gradient tightens Sunday which will allow for winds and seas to increase again. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 1 PM EDT this afternoon for ANZ633- 635>638. Small Craft Advisory until 7 AM EDT Friday for ANZ630>632-634- 650-652-654-656-658. && $$ SYNOPSIS...MPR NEAR TERM...AJZ/MPR SHORT TERM...AJZ/MPR LONG TERM...ALB/MPR AVIATION...MPR MARINE...AJB is the U.S. government's official web portal to all federal, state and local government web resources and services.