Area Forecast Discussion
Issued by NWS Wakefield, VA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KAKQ 251932 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 332 PM EDT SUN SEP 25 2016 .SYNOPSIS... High pressure over New England will extend south across the Mid Atlantic region tonight and Monday. A strong cold front will cross the region Tuesday. An upper level low will track across the area later in the week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Cool air wedge in place across the area as high pressure drifts east across New England. Latest models not as bullish with the wdsprd moisture as drier air continues to filter south along the coast. TSCTNS indicating the moist E-SE flow off the ocean will keep BKN- OVC conditions across the piedmont with SCT clouds east to the Ches Bay/Tidewater/nrn Outer Banks to CLR skies along the eastern shore. Expect a dry evening. Some weak lift noted across the swrn most zones (FVX-AVC) for some spotty light rain/drizzle to develop after 06Z. Lows 55-60, 50-55 across the lwr Md eastern shore given a mstly clear sky. Some patchy fog possible in areas that do clear. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... The high moves off the New England coast Monday with the next front approaching from the west late. Upper ridge flattens which should slow the advance of the front and serve to break down the cool air wedge during the afternoon. TSCTNS show the BKN clouds hold firm west of I95 through much of the day with SCT-BKN clouds to the east. Pcpn wise, light rain/drizzle across the swrn zones early, a several hour break in pcpn chcs through 18z, then slght chc shwrs once again mainly west of I95 ahead of the approaching front. Highs in the mid to upr 70s. Models continue to show a strong cold front crossing the area late Monday night and Tuesday. Weak s/w energy progged along the boundary as it crosses sern zones Tuesday afternoon. Good feed of moisture along and ahead of it with PW`s climbing to around 1.75 inches. Instability is marginal, but kept low chcs for thunder with the actual fropa. Kept likely pops with the time frame for the most wdsprd pcpn coming late Mon nite and Tue morning. Models show drier air filtering across NWRN zones Tues afternoon to end pcpn. Kept high chc pops across the SE. Lows Mon nite in the 60s. Highs Tues in the 70s. QPF btwn 1/2 to 1 inch. Forecast for the mid week period becomes problematic and will all depend on the track and available moisture associated with a deep anomalous upper level low progged to drop south from the great lakes region. The cold front clears the coast Tues night so expect pcpn to wind down across the fa with chc pops lingering along the coast through the nite. Lows range from the mid-upr 50s across northern zones to the mi-upr 60s sern zones. Chc pops Wed for now with the highest pops across the SE. Highs in the 70s. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... Medium range guidance continues to indicate anomalous heights over Canada through the period, as well as over the western Atlantic. A deep/anomalous upper low drops over the eastern Great Lakes region Wednesday, under the upper ridge. Ensemble and deterministic guidance continues to struggle with a more progressive versus blocked flow over the eastern CONUS. The result is a relatively low confidence forecast, but have trended more toward GFS/GEFS solutions. Tuesdays cold front progged to stall along the coast in deep layer southwesterly flow across the Mid-Atlantic. POPs taper off inland Tuesday night, with chance POPs remaining across the southeast forecast area. A series of upper level disturbances will lift along the frontal boundary Wednesday. The combination of waves lifting along the front and strong upward vertical motion will bring solid chance POPs back to the southeast local area and slight chance to low end chance inland. The upper low locates in the vicinity of the Mid Atlantic region Thursday. While the best moisture pushes offshore, will keep mention of slight chance to chance POPs Thursday and Thursday night to account for uncertainty and potential light rain. Thereafter, the upper low likely begins to slowly lift northeastward as the upper ridge over the western Atlantic begins to break down. With the upper low lifting away from the region Friday and Saturday, large scale subsidence over the region will result in a drying trend. Will keep chance POPs northeast Friday and retain silent POPs on Saturday. Slightly below normal temperatures forecast through the period, with highs generally in the low to mid 70`s. Lows range from the low to mid 50`s inland to mid 60`s along the coast. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... Drier air from the north continues to filter south along the coast this afternoon. This is resulting in VFR conditions with only SCT SC along the Delmarva, SCT-BKN SC between 4-5K ft ivof the Ches Bay, BKN-OVC SC between 3-5K ft across the piedmont. Nearest MVFR cigs are across the mts. Models now showing only SCT clouds along the coast tonight with differing solutions for RIC. Given the lgt onshore flow and position of the high, decided to keep a BKN SC deck around 4K ft at RIC through the night with SCT SC elsewhere. Fog not expected to be a big issue tonight but can`t rule out some ptchy MVFR VSBYS toward sunrise in areas where it does CLR. Any pcpn is expected to be confined to the mts. OUTLOOK...The next chance for widespread precipitation arrives Monday night into Tuesday ahead of a strong cold front. Showers will linger through the mid week period as an upper level low tracks across the region. && .MARINE... Cold front has located south of the waters early this morning, as high pressure builds in from the north. North to northeast winds of 10 to 15 knots observed over the waters, with occasional gusts of 20 knots over the southern coastal waters. Have dropped SCA headlines for the lower Chesapeake Bay. Seas remain elevated thanks to distant tropical cyclone Karl and onshore flow, ranging from 3 to 5 feet. SCA headlines remain in effect for the coastal waters. Based on the latest guidance, have extended headlines through 1 pm this afternoon. Thereafter, seas subside to 3 to 4 feet. This mornings cold front lifts back to the north Monday as a cold front approaches from the northwest. Flow becomes south to southeast with marginal SCA conditions possible late Monday into Monday night. The front pushes across the region Tuesday, likely stalling along the coast Tuesday night and Wednesday. A weak pressure gradient progged over the region, but a cooler and drier air mass may result in at least marginal SCA conditions late Tuesday night. An upper level low is progged to drop into the region Wednesday and Thursday, resulting in unsettled weather conditions through the end of the week. Flow generally out of the north. && .HYDROLOGY... The Cashie River at Windsor remains in minor flood stage. The river is forecast to slowly fall below flood stage by late this afternoon. See FLSAKQ for details. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...MPR NEAR TERM...MPR SHORT TERM...MPR LONG TERM...MAS AVIATION...MPR MARINE...MAS HYDROLOGY... is the U.S. government's official web portal to all federal, state and local government web resources and services.