Area Forecast Discussion
Issued by NWS Wakefield, VA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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. --
000 FXUS61 KAKQ 270049 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 849 PM EDT Wed Oct 26 2016 .SYNOPSIS... High pressure remains near the local area through tonight. A cold front approaches from the northwest Thursday afternoon and crosses the area Thursday night. High pressure returns Friday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Early evening analysis features ~1034mb Sfc hi pres centered from Near James Bay and central Quebec...with a surface ridge extending south from New England to along the Mid-Atlantic coast. Sfc Low pres continues to slide from the Mid Ms Valley toward the Ohio Valley this evening. Temperatures have once again fallen off quickly this evening with light winds and clear sky, with temps already in the 40s at 00z over much of the local area. As with last HRRR and RAP have a good handle on this trend and have trended forecast in its direction overnight. Sfc ridge will continue to pivot offshore overnight, as sfc low pressure tracks E toward the lower Great Lakes. Look for BKN- OVC mid to high clouds to slide across the FA (mainly nrn portion) tonight, reaching SW sections by late tonight. Winds become more S through the night...and increase a bit...especially at the coast. Combined with the increasing clouds, this will allow temps to level off a bit, especially after midnight, with the end result being a relatively milder night than last night. Look for early morning lows to settle into the u30s to around 40 on the eastern shore...low to mid 40s elsewhere (upper 40s to around 50 immediate for SE coastal sections). && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... Lo pres continues E into New England by late Thu/Thu eve...w/ its trailing cold front arriving Thu eve/night. Period of higher moisture and at least weak forcing result carrying chc PoPs most places by late Thu afternoon into the eve...then tapering off W to E after midnight Thu night. Highest PoPs (40-55%) from Nrn Neck VA to the MD Eastern...w/ 15-30% elsewhere. QPF through 12z/28 from T to about .25". Highs Thu m60s N to l70s se. The front pushes offshore late Thu night into early Fri morning with sfc hi pres returning by aftn. Clouds are expected to decrease rather quickly Friday...w/ most of the area becoming sunny by late morning and aftn. Lows Thu night from around 50F NW to the u50s SE. Highs Fri in the low 60s to around 70F. Sfc hi pres slides S of the region Sat w/ zonal flo aloft. Deep layered WSW flo leads to substantial warming by Sat afternoon. Mainly skc Fri night-Sat. Lows Fri night ranging through the 40s. Highs Sat from the u60s-around 70F on the ern shore to the l-m70s inland. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Another low pressure system skirts north of the area (primarily along the St Lawrence River Valley) and drags a weak sfc front across the area Sat night. There are some model discrepancies regarding shortwave energy passing through the region behind the front on Sunday with a weak sfc low developing in the lee of the Appalachians late in the day. Tried to split the difference regarding precip placement and limited to 15% POPs since the end result may be more clouds than precip Sunday aftn/evening. Otherwise, high pressure will persist over the Mid Atlantic Region Sunday into most of next week. Warm Sat/Sun nights with temps running 5-10 degrees above normal (lows in the 50s) and highs on Sun 5-7 degrees above normal (highs in the 70s). Expect a slight cool down Mon-Tue with highs in the mid 60s to lower 70s. Lows Mon/Tue nights in the upper 40s to mid 50s. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... High pressure will slowly move out of the region tonight while a cold front approaches during the overnight and Thursday. The front will move through the area during the evening hours and off the coast by early Friday. The front will bring a chance for a few showers during the afternoon and evening. Some guidance suggests that a brief period of MVFR stratus clouds will affect the region Thursday morning. This is likely the affect of E-SE flow ahead of a weak warm frontal boundary. As the boundary moves north of the area and winds shift to the south, those ceilings should lift and winds increase with gusts to 20-25 kts. The chance for -Ra will increase into the evening. Outlook: High pressure and VFR conditions builds into the region for Friday and Saturday. Another cold front approaches from the west on Sunday. && .MARINE... SCA flags raised Thu aftn through Fri aftn/evening. High pressure slides offshore this evening and pushes ewd overnight as a sfc low moves across the Ohio Valley. NE-E winds aob 10kt will veer around to a more SE direction Thu morning as the Ohio Valley low pressure system tracks along the St Lawrence River Valley. The sfc pressure gradient tightens up as the day progresses and most especially as a cold front gets dragged through the region Thu evening and across the waters after midnight Thu night. Expect winds to be SE-S 10-15kt in the morning...becoming more S by Thu aftn. Solid SCA conditions develop as early as Thu aftn as wind speeds increase to 15-20kt with gusts of 25-30kt Bay/coastal waters Thu aftn through Thu night...followed by Currituck Sound/mouth of James River with speeds of 15-20kt Thu evening and overnight. The mouth of the York River may experience gusts around 20kt for a few hours late Thu evening, however this timeframe is not long enough to justify SCA flags here at this time. Seas build to 3-5ft/waves 3-4ft on the Bay. The cold front exits the coast by Fri morning, however SCA conditions will persist during the daytime hours until winds start to diminish Fri aftn and seas drop below 5ft early Thu evening. Expect breezy NW winds 15-20kt Fri morning...diminishing to NW 10-15kt by Thu evening. High pressure builds over the Ohio Valley on Fri and then slides over the SE States by Sat. Another low pressure system skirts north of the area (once again along the St Lawrence River Valley) and drags a weak sfc front across the waters Sat night. A brief SW surge may be possible, however speeds remain aob 15kt at this time. High pressure will then persist over the Mid Atlantic Region Sun into most of next week. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 2 PM Thursday to 1 PM EDT Friday for ANZ630>632-634. Small Craft Advisory from 8 PM Thursday to 6 AM EDT Friday for ANZ633-638-654-656. Small Craft Advisory from 4 PM Thursday to 6 PM EDT Friday for ANZ650-652. && $$ SYNOPSIS...AJB/JDM NEAR TERM...AJB/MAM SHORT TERM...AJB LONG TERM...BMD AVIATION...AJB/JEF MARINE...BMD is the U.S. government's official web portal to all federal, state and local government web resources and services.