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 290326 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 1026 PM EST Mon Nov 28 2016 .SYNOPSIS...
-- Changed Discussion --
High pressure centers offshore tonight. A complex weather system approaches the region from the west for midweek...bringing an increased chance of rain to the region. A cold front will push through the area early Thursday.
-- End Changed Discussion --
-- Changed Discussion --
Based on latest radar trends and hi-res guidance, have opted to pull back on POPs a few hours late tonight. 29/00Z KRNK and KLWX RAOBs still indicate relatively dry air below 600-650mb as high pressure remains centered off the Mid-Atlantic coast. Blended total precipitable water product indicates the best moisture still remains west of the mountains this evening. Expect moisture to increase across the Piedmont late tonight as the upper ridge axis pushes offshore and a warm front lifts over the region. A low level jet will begin to advect better moisture into the region as dewpoints quickly warm from the 30`s to low 40`s into the low to mid 50`s by daybreak. NAM12/RAP 295-300K surfaces indicate the best isentropic lift along the lifting warm front will remain over the Piedmont into central Virginia. Have maintain the highest POP`s over that region, but have pushed the best POPs back until after 4 AM. Rainfall amounts less than one half inch expected. Sky becomes mostly cloudy to cloudy late tonight. Low temperatures are occurring, or have already occurred, at many locations this evening. Temperatures are forecast to warm into the mid 50`s by daybreak. Southerly winds increase to 10-15 mph.
-- End Changed Discussion --
&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... The primary upper trough will continue to sharpen and dig south over the Plains Tue and Wed. Models are in continued agreement suggesting showers tuesday morning into the afternoon mainly along and north of I-64 (including MD) as the first weak upper wave moves through. Even in areas (across southeast VA and northeast NC) where there is less shower activity skies will remain mostly cloudy. There will be a break/lull in the overall shower activity Tue night and Wed morning before the main push with the upper trough and attending cold front come through late Wed. POPS increase once again Wed afternoon as forcing increases ahead of the front with likely to categorical POPS expected across the entire region Wed afternoon into Wed night as the system pushes from west to east. Given the warm/moist airmass in place and forcing there is a risk for a few thunderstorms and SPC has the area in a Marginal Risk for severe storms. Total (average) QPF Tue-Wed 0.50-0.75" NW to 0.20-0.35" SE.Everything pushes off the coast Thursday morning as much cooler air rushes in behind the front. Strong pre-frontal WAA will make for a couple of very mild to warm days Tue and Wed. Highs Tue in the upper 60s well inland to lower 70s SE VA- NE NC. Highs Wed in the near 70 well inland mid 70s in SE VA- NE NC. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... The extended period is expected to begin with cool high pressure gradually building across the Southeast Conus. This will result in dry conditions, with temperatures slightly below seasonal averages, but within -1 st dev. Sky cover is expected to be mostly clear, however, increasing high clouds are possible Saturday. Forecast lows Friday morning range from the mid 30s to around 40, followed by highs Friday in the low/mid 50s. Slightly cooler Friday night and Saturday with lows ranging from the low 30s inland to the mid/upper 30s along the coast, and highs around 50. There is the potential for highs to remain in the 40s Saturday if thicker high clouds arrive earlier. GFS/ECMWF diverge Saturday night through Sunday night, with the GFS depicting a progressive nrn stream wave tracking across the region, while the ECMWF shows a phased system lifting ne through the Ohio Valley. At this time forecast PoPs are ~30%, which is slightly above climo. Model differences continue into Monday, but the consensus is for a drier pattern. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Surface high pressure has centered just offshore early this evening, with VFR conditions prevailing across the local area. Scattered to broken mid level clouds with decks 4-6k feet AGL persist over the Piedmont, with generally high clouds elsewhere. Surface winds are generally southeasterly at or below 10 knots. High pressure slides farther offshore tonight as a storm system approaches from the west. An increasing low level jet tonight will result in strong winds 1-2k feet AGL late tonight across the Piedmont into central Virginia. Have included LLWS in the RIC TAF late tonight into early Tuesday morning. Expect ceilings to drop to MVFR late tonight over the Piedmont into central Virginia, but do not anticipate IFR conditions at the TAF sites (like the MET/NAM indicates) due to mixing. Light showers become likely KRIC and KSBY early Tuesday morning. Light showers expected to persist through Tuesday morning, with the best chances KRIC northward. Lower confidence in the southeast. MVFR ceilings anticipated to persist, with MVFR visibilities at times. Showers taper southeast to northwest during the afternoon. Breezy, with southerly gusts of 20 knots inland and 25 to 30 knots near the coast. Periodic sub-VFR conditions are expected through midweek with another (better) chance of rain Wed/Wed night. && .MARINE... High pressure slides offshore tonight ahead of a trough pushing through the Ohio Valley. Southerly flow is expected to increase later tonight into Tuesday with wind speeds reaching 15- 25kt, with gusts up to 30 kt over the ocean. Waves in the Bay build to 3-4ft, with 5-7ft (highest n) in the ocean. The trough lifts newd through New England Tuesday night with the wind becoming sw and diminishing to 10-15kt. Waves in the Bay subside to 2-3ft. However, seas likely remain 4-6ft. SCAs for the Bay/ocean/sound remain as is, and an SCA flag has been raised for the rivers from 12z-21z. A cold front is expected to push through the Ohio Valley Wednesday and then push off the Mid-Atlantic Coast late Wednesday night. The wind should shift bay to south Wednesday into Wednesday evening and increase to 15-25kt. It is likely that another round of SCAs will be necessary for the Bay/Sound/rivers, while seas may not drop below 5ft (especially n) between the two events. The wind becomes westerly at 10-15kt (minimal CAA) behind the front late Wednesday night into Thursday as the front shifts offshore. A nw wind of 10-15kt should prevail Friday into Saturday as high pressure builds across the Southeast Conus. Seas subside from 3-4ft to 2-3ft, with ~2ft waves in the Bay. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 7 AM to 4 PM EST Tuesday for ANZ635>638. Small Craft Advisory from 4 AM to 7 PM EST Tuesday for ANZ630>634. Small Craft Advisory from 7 AM Tuesday to 6 AM EST Wednesday for ANZ650-652-654-656-658. && $$ SYNOPSIS...ALB/JAO NEAR TERM...SAM SHORT TERM...ALB/JAO LONG TERM...AJZ AVIATION...MAS/SAM MARINE...AJZ/JDM is the U.S. government's official web portal to all federal, state and local government web resources and services.