Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 250035 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 835 PM EDT Sat Oct 24 2020 .SYNOPSIS... A cold front crosses the area tonight. Canadian high pressure wedges down over the area behind the front with much cooler weather for Sunday. Another front will move into the area later Tuesday through Wednesday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 810 PM EDT Saturday... Latest sfc analysis shows the cold front is dropping SSE through the local area and is located invof the VA/MD border over the Eastern Shore and extends SW/WSW to the I-85 corridor. Other than an isolated thunderstorm in Mecklenburg, scattered showers along and behind the front will increase in coverage overnight with the highest PoPs in the piedmont. QPF amounts through this evening generally under a quarter inch from I-95 west, and lesser amounts as you head east towards the coast with the exception of a few locally heavier showers in the Middle Peninsula and Peninsula. After the cold front moves through, high pressure will begin to nudge back into the area from the north tonight, setting the stage for an overrunning CAD wedge setup, with likely light rain and drizzle late tonight and through much of tomorrow. Will transition ptype to stratiform rain after midnight with most areas seeing at least some light rain along with overcast conditions. Lows from the upr 40s NW to the low 60s SW. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... As of 340 PM EDT Saturday... High pressure will expand over the area on Sunday, helping to reinforce the CAD setup east of the mountains. Expect a mostly cloudy to overcast sky with some light rain and drizzle throughout the day over the piedmont. Temps will likely be their highest over the NW just after midnight late tonight/early Sunday, remaining steady or falling slowly through the morning. Meanwhile, SE portions of the area will see a little bit of a temp rebound during the day but still remaining cool. QPF has been kicked up slightly, as a southern stream shortwave moves across the SE coastal plain later Sun morning through Sunday aftn. This will result in more widespread rain across the central and eastern portions of the area, which exits the area from SW to NE Sunday evening. Overcast, cool, and raw, especially inland, with daytime highs Sunday in the upper 40s NW, upper 60s to low 70s over NE NC. lingering light rain and drizzle Sunday night, with lows to range from the mid 40s NW to around 60 SE. Drier conditions on Monday as the high to our north shifts to the east over the Canadian Maritimes, with another surface high building in over the local area. The flow will become southerly, albeit light, by Monday afternoon. This will allow the cool air wedge to break down gradually with a decent rebound in temps expected. Still did nudge cloud cover up and temps down far inland sections in anticipation of Wedge hanging on Mon morning before starting to break down late. High temps in the low-mid 60s inland, upper 60s to low 70s central, mid 70s NE NC. Sfc high lingers along/just offshore Tuesday, as a weakening front slowly drops across the northern mid-Atlantic toward the local area. Remaining dry and turning a bit milder, as any CAA holds off until later Tuesday night/Wed. Highs in the upper 60s to mid 70s inland, mid 70s to around 80 SE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 300 PM EDT Friday... Forecast period begins with previously referenced (weak) cold front dropping across the area later Tuesday into Tue night. Weakening forcing should ensure a mainly dry night Tuesday night, into the day on Wednesday, though slight chance PoP has been retained for a few stray showers Wed+. Model guidance still intent on developing an upper low over the desert southwest, eventually evolving into a cutoff low by the middle of next week. Considerable model differences remain, with the GFS still on the more progressive side of the guidance envelope, showing the system getting picked up and absorbed into the east coast mean trough. The 12z/24 CMC/12z ECMWF, like their respective ensemble means are a bit slower and more amplified. Have stayed away from the very high PoPs on the NBM for now given this uncertainty. Nevertheless do nudge rain chances up into high end chance range Wed night/Thursday morning with at least slight chance PoPs persisting through the remainder of the long term forecast period. Have capped PoPs in the 40-50% for the time being until a more solid model consensus is attainable. For temps, expect a slight cool down behind the front Wednesday and Thursday, with highs generally ranging from the mid 60s north to the low to mid 70s south. Early morning lows through the period generally range through the 50s to around far 60 SE. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 830 PM EDT Saturday... VFR conditions over all terminals continue through around 05-06z Sunday when MVFR ceilings around 3000 ft move into RIC and the piedmont. All terminals will see diminishing flight conditions through the day with ceilings lowering to MVFR between 06z to 10z Sunday and to IFR after 15z. From 18z through the remainder of the 00z taf, all terminals will be IFR. Visibilities will also begin to decrease through the afternoon to around 3-4 SM by around 18z. Recent models have trended even lower with visibilities, possibly to 2 SM or less at times after 18z. Light rain and drizzle will be possible through the day with a wedge setup in place. Fog will also be possible during Sunday evening as well. Winds will shift from SSW/SW 5 to 10 kt at ORF/PHF/ECG to NNE over the next few hours as the cold front drops south. A brief period of gustier winds (8-12 kt with gusts 15 to 20 kt) will be possible from 06 to 12z as the colder air advects into the region. Outlook...Wedge pattern with low ceilings and possibly low visibilities as well due to fog will remain in place through Sunday night with flight restrictions likely. Conditions should improve/dry out for Monday, although low clouds/fog may be an issue early on. && .MARINE... As of 340 PM EDT Saturday... Late this afternoon, Hurricane Epsilon is well offshore of the Northeast US coast and tracking away from the area, while a cold front is just to the NW of the local waters. Winds are generally W- SW at 5-10kt (with some areas seeing a sea breeze component to the wind). Seas remain elevated due to swell from Hurricane Epsilon, and are averaging around 5ft. Waves on the bay are ~1ft in most areas, with 2-3ft waves at the mouth of the Bay. The cold front is progged to cross the waters from N to S during the evening-early Sun AM before stalling near or just south of the NE NC coastal waters by 12z Sun. Winds will shift to the N then NE and will increase to around 20kt on the ocean N of the VA-NC border, Ches Bay, and Lower James River tonight into Sunday morning. Still expecting winds to be just below SCA criteria on the upper rivers and Currituck Sound, although a few gusts to 20kt are possible. On Sunday, a weak trough of low pressure establishes itself just offshore of the NC coast before moving NNE late Sunday into Sunday night as high pressure builds over central portions of VA/NC. Winds will likely average 15- 20kt over the Ches Bay and coastal waters N of Cape Henry through much of the day on Sun, with ~15kt winds across the Currituck Sound/far srn coastal waters. Winds diminish to 10-15kt and turn more to the NNW by Sun night/early Mon AM as the trough of low pressure slowly pulls away from the waters. Seas build to 5-7ft across most areas, with waves of 2-5ft on the Ches Bay (highest at the mouth). SCAs remain in effect through Sun night-early Mon AM for the ocean and mouth of the Ches Bay. Went ahead and extended SCAs through 1 PM Sunday for the remainder of the bay/Lower James River. It is possible that SCAs for the bay/Lower James may need to be extended into early Sun evening, but will let the next shift assess the latest trends. Still not enough confidence to issue an SCA for the Currituck Sound (frequent 20kt gusts likely stay just N of the sound), although one may be needed if the front stalls a bit further south than currently forecast. Weak high pressure settles across the area Monday and moves offshore by Monday night. Another weak cold front/CAA surge potentially arrives on Tuesday or Tuesday night. There is still some disagreement with the models with respect to timing, but the current forecast has conditions remaining a bit below SCA thresholds from Tue-Wed AM. An area of low pressure and a stronger cold front is progged to affect the marine area late this week. Another round of SCAs is likely sometime during the Thu-Sat timeframe. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 1 AM EDT Monday for ANZ634. Small Craft Advisory until 1 PM EDT Sunday for ANZ630>632-638. Small Craft Advisory until 6 AM EDT Monday for ANZ650-652-654- 656-658. && $$ SYNOPSIS...MAM NEAR TERM...MAM/RMM SHORT TERM...JDM/MAM LONG TERM...AJB/MAM AVIATION...RMM MARINE...AJZ is the U.S. government's official web portal to all federal, state and local government web resources and services.