Area Forecast Discussion
Issued by NWS Wakefield, VA

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336 FXUS61 KAKQ 240800 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 400 AM EDT Mon Jul 24 2017 .SYNOPSIS... A weakening cold front will gradually push across the area on Monday and stall across the Carolinas through the middle of the upcoming week. Temperatures will cool down to near normal levels by Wednesday. && .NEAR TERM /THROUGH TONIGHT/... Current analysis reveals weak sfc low pressure pushing along a wavy frontal boundary over the Delmarva just north of the local area. Aloft, broad upper level trough continues to dig E-SE across the Ohio/Tn River Valleys, with W-NW flow aloft. Coverage of showers/tstms has gradually diminished this morning. Weak front will gradually be forced south into the local area today. Pre-frontal Southerly flow will bring another warm, humid day across the local area. However, lingering clouds should keep southern tier of the area at least a category cooler. CAMs not nearly as generous with convective potential today, largely a result of drier air nudging in from the NW. Thus, have gone no higher than a 20% POP for most of Richmond Metro area. Farther south, better deep layer moisture and lift, as well as a more tangible convective trigger (upper height falls) warrant low end chance POP across SE VA/NE NC zones. However, slightly cooler temperatures mean convective temperatures will likely be met until later in the day. Have therefore delayed onset of POP until after 18z. Expect most locations remain dry today. Warm but not quite as hot and slightly less humid over the NW CWA. Highs Mon in the low to mid 90s (where clearing occurs earliest), upper 80s to near 90 SE. This will result in heat indices around 100 degrees across South Central and Southeast VA into NC this afternoon, and in the 90s to around 100 in Metro Richmond (lower Td values), and therefore should preclude the need for additional heat headlines. surface front slowly drops across the area tonight, before stalling along/south of the VA/NC border by morning. Showers quickly wane with minimal shear and waning instability. Slightly cooler and a bit more comfortable with early morning lows in the upper 60s to low 70s in the piedmont...low to mid 70s elsewhere. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... Front stalls across E NC Tue, with mainly diurnal tstms possible again over the S (20-35%), and 10-15% N (mainly south of US-460. Seasonable highs upper 80s to lower 90s. Wednesday still looks to be the nicest day we`ve seen in awhile temperature-wise. Sfc high pressure traverses New England with max temps only reaching the the mid/upr 80s with somewhat lower humidity levels. Stalled frontal boundary to our south will still keep a chance of mainly aft/eve showers/tstms in the forecast over our southern FA (PoPs 20-40%, again mainly central and southern zones). && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... The Mid-Atlantic region will generally be situated between a trough off the Carolina Coast and trough digging through the Great Lakes and Ohio Valley Wednesday night and Thursday. The Great Lakes/Ohio Valley trough gradually drops into the region Thursday night and Friday as an associated cold front approaches from the NW. PoPs are mainly aob 20% Wednesday night/Thursday and then increase to 30-40% chc for showers/tstms Friday ahead of the approaching front. Highs Thursday/Friday are mainly in the upper 80s to around 90, with mid 80s at the immediate coast, and overnight lows in the low/mid 70s. The trough is progged to settle over the region by Saturday/Sunday with the cold front pushing through Friday night into Saturday, before stalling off the Carolina coast. Forecast PoPs for showers/tstms are ~40% Friday night, and then generally 20-30% NW to 30-40% SE next weekend. High temperatures trend down into the mid 80s as the trough settles overhead with lows in the upper 60s to low 70s. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... Conditions have recovered to VFR at most sites early this morning, with heavier showers and convection waning and shifting NNE of the area terminals. Some patchy fog is possible across the Piedmont during the overnight but am not expecting any significant impact to TAF sites at this time. Isolated to widely sct tsra possible this afternoon, mainly at ORF/ECG. Confidence in areal coverage remains low and have held out mention attm. Any convection quickly wanes tonight, with VFR conditions expected overnight into Tuesday. Outlook: Convective continues for south central VA and NC for Tuesday. VFR should dominate through this period, with periods of sub-VFR possible in heavier showers/TSRA. A weak cold front pushes into the area for the mid week period. && .MARINE... W-SW gusting between 20-25kt over Ches Bay expected to diminish around sunrise as an area of weak low pressure tracks ENE of the Delmarva. Otherwise, a sfc thermal trough remains over cntrl VA today as a cold front drops down from the NNW. The front is expected to slowly cross the waters late tonight into Tue morning. Isolated to scattered aftn/evening thunderstorms will be possible once again with locally strong wind gusts, heavy rainfall, and frequent lightning being the main impacts. Winds generally SW aob 15kt today/tonight. Decided to put up Small Craft Advisory for the Chesapeake Bay, Currituck Sound and for the lower James River. Winds have picked up over the waters due to increasing pressure gradient. Expect this to be a short term event until around 4 am. Seas will be 2 feet nearshore and up to 4 feet 20 nm. Showers and thunderstorms will affect the lower bay and Atlantic coastal waters til around midnight. Winds will remain mostly SW on Monday but expected to be below SCA criteria. A frontal boundary crosses the area early Tuesday bringing a windshift to the E-NE. Winds are expected to generally remain around 15 knots behind the frontal boundary. Seas will range from 2 to 4 feet with some areas to around 5 feet at 20 nm in the far northern zones. The extended marine period will be dominated by mainly weak onshore flow as a frontal boundary stalls across the region. Afternoon showers and thunderstorms will remain possible through the forecast period.ight with seas averaging 2-4ft north/2-3ft south and waves 1-2ft during this time. The cold front gradually stalls out just south of the area by late Tue night/Wednesday morning with high pressure building north of the region. This will limit aftn/evening thunderstorms to srn waters invof the weak trough and/or seabreeze boundaries. Conditions generally dry on Thu. Then low pressure and an upper level shortwave are expected to swing through the region Thu night/Fri...bringing the next best chance for rain to the waters. Wind speeds aob 15kt the rest of the week. Wind direction veers to the north on Tue (behind the cold front)...onshore/NE-E Tue night through Wed...E-SW Wed night into Thu...then S-SW Thu night/Fri. Seas average 2-4ft; waves 1-2ft. && .CLIMATE... Did not set any records over the past few days (even with the 101 degree temperature reached at RIC on Sat). * Date: Sun(7/23) * RIC: 103/1952 (actual 97) * ORF: 103/2011 (94) * SBY: 103/2011 (88) * ECG: 104/1952 (91) && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...MAM NEAR TERM...LKB/MAM SHORT TERM...JDM/MAM LONG TERM...AJZ AVIATION...MAM/JEF MARINE...BMD CLIMATE... is the U.S. government's official web portal to all federal, state and local government web resources and services.