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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
633 FXUS61 KAKQ 201934 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 334 PM EDT Sun Aug 20 2017 .SYNOPSIS... High pressure becomes centered off the Mid Atlantic coast tonight through Tuesday. A cold front crosses the area late Wednesday. && .NEAR TERM /TONIGHT/... High pressure slides offshore allowing winds to become more srly. Pockets of moisture after midnight result in some fog development across srn and ern shore areas. Lows in the upr 60s-lwr 70s. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... Models track an area of low pressure north of the fa Mon. This combined the a trailing trof should be enough of a trigger for sct convection to develop across the mts then drift e-se across the northern most zones of the fa after 18Z. Will carry low chc pops mainly north of RIC for now. Otw, dry with highs upr 80s-lwr 90s except low-mid 80s at the beaches. Evening pops across the lwr MD ern shore Monday night, otw dry with lows 70-75. Hot/dry Tues ahead of the approaching cold front. 85-90 along the coast, 90-94 west of the bay. Dry most of Tues night except increasing moisture should lead to a few shwrs by daybreak across nrn most zones. Lows low-mid 70s. Frontal boundary a bit slower to traverse the fa Wed. This combined with a weak wave progged to move east along it will spread widespread moisture and support likely pops in the afternoon. Another round of mdt to hvy downpours possible ahead and along the fropa. Highs 85-90. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A cold front gradually drops through the area Wednesday night into Thursday morning. Modest ascent accompanies the front within the RRQ of a ~110kt jet over New England along with pw values around +1 st dev. The highest PoPs (high chc/likely) based on 27/12z data are forecast across srn VA/NE NC. PoPs across SE portions gradually diminish to 20-40% by Thursday aftn. Thunder will be maintained into Wednesday evening, with showers thereafter as stable NE flow prevails in the wake of the front. Drier air gradually filters in from the NW late Wednesday night into Thursday with partial clearing across the nrn tier counties. Lows Wednesday night range from the mid 60s NW to the low 70s SE, followed by highs Thursday in the upper 70s to low 80s. ~1025mb (+1 st dev) high pressure builds from the Great Lakes across the Saint Lawrence Valley and into New England Thursday nigh through Sunday. This will result in persistent onshore flow, which combined with a drier airmass will result in a series of pleasant days with highs in the upper 70s at the coast to low 80s inland, with lows in the upper 50s to low 60s inland, and mid/upper 60s along the coastlines. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... VFR conditions expected most of the forecast period with only sct CU btwn 3-4K FT over the next svrl hrs. Concern once again tonight is for patchy fog development as the winds become SSE. Kept vsbys in the MVFR range for now between 06Z-12Z, but some guidance suggests lcl IFR vsbys psbl across inland areas. Any morning fog burns off around 12Z Monday with VFR conditions to follow. OUTLOOK... The next cold front approaches the region Wed. Sub-VFR conditions and showers/tstms will be possible Wed, and may linger across SE terminals into Thu morning. && .MARINE... Latest surface analysis has a high pressure centered over the region. The high pressure moves off the coast Monday through Monday night and a cold front approaches the waters Tuesday night through Wednesday. The front pushes out of the area by Thursday with high pressure building back into the region for the remainder of the forecast period. Obs indicate generally NE/E winds of 5 to 10 knots over the waters with waves of 1 to 2 feet and seas of 2 feet. The flow becomes SE around 10 knots on Monday as high pressure moves offshore. Winds increase and become southerly ahead of the approaching cold front Tuesday through Tuesday night. Winds speeds may approach 15 to 20 knots over the bay and ocean with seas building to 3 to 4 feet, potentially up to 5 feet north/20nm out, and waves building to 2 to 3 feet. A Small Craft Advisory may be needed for the Chesapeake Bay Tuesday night. Winds shift to the N/NE behind the front on Wednesday through Thursday around 10 to 15 knots. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...MPR NEAR TERM...MPR SHORT TERM...MPR LONG TERM...AJZ AVIATION...MPR MARINE...AJB is the U.S. government's official web portal to all federal, state and local government web resources and services.