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 231849 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 249 PM EDT Fri Mar 23 2018 .SYNOPSIS... High pressure will build down into and over the area later today and tonight. Low pressure moves east from the Mississippi Valley Saturday, then across the Carolinas Saturday night. The low moves offshore Sunday, as high pressure builds in from the north. && .NEAR TERM /THROUGH TONIGHT/... A shortwave trough will drop SE and acrs the region this aftn, producing SCT-BKN SC and a partly to mostly sunny sky. Highs will range fm the upper 40s/near 50 over the ern shore, to the mid 50s south of I64, along with a NW wind at 10-20 mph. Went lwr than guidance on dew point temps this aftn, especially acrs the Piedmont, where readings will likely drop into the teens given the nw wind flow. This puts relative humidity values in the lower to mid 20s during peak heating hrs. && .SHORT TERM /SATURDAY THROUGH MONDAY/... 1040mb sfc high ivof Hudson Bay will build into the region tonight in the wake of the upper trough. Mstly clear and cold with lows from the upr 20s nw to mid 30s se. The high remains anchored north of the region Sat. Meanwhile, low pressure tracks across the Miss Valley toward the Tenn Valley with an extension of the high nosing down the Mid Atlntc coast. Drier air associated with the high progged to hold off pcpn through 21Z. Still noting some timing differences wrt the onset of pcpn when models show enuf support for some pcpn to break out across the wrn zones. Will carry chc pops btwn 18-21Z across wrn most zones then extend the chc pops farther east 21Z-00Z. Likely pops swrn most zones late. Pcpn type to be mostly in liquid form but some mixing is psbl ivof AVC by sunset. Highs 45-50, but falling into the upr 30s to nr 40 across the west once the pcpn arrives. Low pressure progged to track across the srn Carolinas Sat night, a bit farther south than previous forecasts. Models struggling to determine just how far north the pcpn gets due to the drier air in place from the high to the north. The NAM is an outlier and followed more of a GFS/ECMWF soln with this forecast package. A rather sharp QPF cutoff is noted on where significant pcpn occurs. Another challenge will be sfc temps as readings will remain aoa freezing for most of the evening when most of the pcpn is expected to fall. The exception here being the extreme sw zones ivof fvx-avc where pcpn should quickly go over to snow during the hvyst pcpn intensity. Otw, expect that a rain/snow mix will occur a bit later into the evening hrs before going over to snow. In a nutshell, expect any snow accumls will be limited to the wrn piedmont (south of I64 and west of I95). Thus, have cut back accumls even further with less than an inch except a 1-2 inch swath from near FVX-AVC. No headlines as this appears to be an advsry level event at most across xtreme swrn zones Sat night. Pops range from categorical across the sw to nothing across the ne. Pcpn begins to taper off across the north after midnight as the support for any sgnfcnt pcpn pushes south into the Carolinas. No measurable QPF expected north of I64 with up to 1/2 in ivof AVC. Lows from the upr 20s NW to mid 30s se. Pcpn quickly ends across the se Sun morning as high pressure builds into the area from the north. Skies bcmg mstly sunny but remaining chilly due to a brisk ne wind. Highs in the mid 40s. Mstly clr and cold Sun night. Lows mid 20s nw to upr 30s se. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... The extended part of the forecast starts out cool then temperatures moderate mid-late next week. Ridge aloft and sfc hi pres will be aligned N-S invof E coast Mon night-Tue...then gradually weaken as deep layered SW flow develops from the Plains states to the mid-Atlantic region. Used blend of GFS/ECMWF/WPC through the period wrt timing return of cloudiness and increased PoPs. Dry wx hangs on through Tue night/early Wed...then PoPs expected to increase Wed afternoon-Fri along w/ VRB clouds/mostly cloudy conditions. Lows Mon night in the u20s W to the m-u30s at the coast. Highs Tue in the m-u40s at the coast (w/ still a bit of a ENE breeze). Lows Tue night from the m30s inland to around 40F at the immediate coast. Highs Wed 50-55F at the coast to the l60s inland. Lows Wed night ranging through the 40s. Highs Thu in the m-u50s at the coast to the m-u60s in central VA to interior NE NC. Highs Fri 55-60F at the coast to the l-m60s in central VA and the u60s across interior srn VA-NE NC. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... VFR conditions continue through the forecast period as high pressure builds across the sern states. Another s/w trof moves across the area producing sct-bkn CU during peak heating hrs. Nw winds gust btwn 15-20 kts. Only sct clouds expected tonight. Outlook: Low pressure approaches from the W Saturday and pushes across the Carolinas Saturday night. This could produce flight restrictions with a mix of rain and snow at PHF/ORF/ECG and light snow at RIC. High pressure becomes anchored over New England, with VFR conditions expected from Monday through the middle of next week. && .MARINE... Have cancelled the Small Craft Advisory for the coastal waters north of Cape Charles as winds and seas have diminished below SCA criteria. NW winds over the Bay may continue to gust in excess of 20 knots after sunrise, thus extended the SCA until 10 am. Also went ahead and extended the SCA over the southern coastal waters into the afternoon as seas may linger around 5 feet. Expect a gradual diminishing trend in winds and seas this morning as low pressure moves up into the northern Atlantic waters. Winds will likely increase to 15-20 knots over the Bay after sunset, leading to the potential for another round of SCAs overnight. Low pressure passes south of the waters tomorrow into Sunday, but poor mixing will keep any SCA potential limited. Winds and seas increase Sunday as low pressure deepens off the coast, thus another round of SCAs will likely be needed Sunday into early next week. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ658. Small Craft Advisory from 10 PM this evening to 6 AM EDT Saturday for ANZ630>632-634. && $$ SYNOPSIS...MPR/TMG NEAR TERM...MPR/TMG SHORT TERM...MPR LONG TERM...ALB AVIATION...MPR MARINE...AJB is the U.S. government's official web portal to all federal, state and local government web resources and services.