Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 180805 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 405 AM EDT Tue Oct 18 2016 .SYNOPSIS... High pressure settles just off the southeast coast overnight. The high slides southeast of the area through midweek...bringing warm and dry conditions to the local area through the work week. A cold front crosses the region Friday, bringing near seasonable temperatures back to the region for the upcoming weekend. && .NEAR TERM /THROUGH TONIGHT/... latest wx analysis features ~1018mb Surface High pressure offshore of the SE coast. Aloft, upper level ridging extends NE from the Gulf Coast into the TN River Valley, with persistent area of upper level low pressure now meandering near The Bahamas. Very similar day weatherwise across the region today. Heights build over the local area as the strong/anomalous upper ridge builds across the Carolinas into the Mid-Atlantic Today. Building heights and 850Mb temps warming to +15-17C (+1 standard deviation) will push highs up about a category from yesterday`s maxima. Highs today generally in the low to mid 80`s (slightly cooler immediate coastal zones) under a clear to mostly clear sky. These temps will be challenge daily record max temps at our local climate sites. See Climate section below. Continued clear and mild tonight, with lows ranging through the 60s. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... The upper high becomes centered from the southeast into the Mid-Atlantic on Wednesday, resulting in the warmest day of the period. Record temperatures appear possible with highs climbing into mid 80`s inland, again cooler along the coast. These forecast highs are generally ~15 degrees above normal. A frontal boundary drops into the northern Mid-Atlantic region Wednesday afternoon. Higher dewpoints pool along the boundary to the north, resulting in some marginal instability nudging south across the Maryland Eastern Shore. However, with the upper ridge over the region, warm temperatures aloft should suppress any convection Wednesday afternoon across the northeast forecast area, and have maintained a dry forecast. Mild again Wednesday night with lows generally in the mid 60`s. Upper trough digs from the High Plains into the Mid Mississippi River Valley on Thursday...nudging the associated Sfc cold front east to the Appalachians by Thursday night, and to just west of the local area on Friday morning. Heights and 850mb temperatures begin to decrease across the local area on Thursday ahead of the cold front. Thus while temperatures will remain above normal, expect temperatures to be about a category lower than those of Wednesday. Highs u70s to l80s. Increasing clouds late and continued mild Thu night. Lows around 60. Front crosses the area on Friday, before pushing offshore Friday evening. Typical timing differences persist with the frontal passage, though continue to favor the more progressive ECMWF/EPS solution to the slower/deeper GFS solution. Still, given uncertainty, have nudged rain chances upward but kept in the slight to low end chance for now. Also worth monitoring is the previously referenced disturbance near the Bahamas. Incoming upper trough will interact with this system, lifting the disturbance north- Northeast, keeping it offshore of the SE coast up toward New England Thursday night through Friday night, before the system ejects into Atlantic Canada over the weekend. Best lift and moisture remain removed to the north, nearest to a wave of low pressure that will develop along the boundary along the Eastern Great Lakes. Nonetheless, a period of rain appears an increasingly good bet across the area Friday morning into the afternoon as the front crosses into the area. Daytime temperatures still several degrees above normal Friday, with highs generally in the 70s. && .LONG TERM /SATURDAY THROUGH MONDAY/... A return to more seasonable conditions expected from the weekend into early next week. Lingering rain chances drop off on Sat as drying WNW flow takes over. Cooler and dry wx Sat afternoon through Mon. Low Fri night from the l50s W to u50s at the coast. Highs Sat from the l60s W to u60s E. Lows Sat and Sun nights from the m40s (well) inland to the l50s at the coast. Highs Sun/Mon mainly in the m-u60s. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... As of 07Z...Surface high pressure remains in place along/just off the Southeast coast with upper level ridging in place from the southern Great Plains to the Tennessee Valley. VFR conditions in place over area terminals expected to remain in place through the 06z Taf period w/mainly clear skies and a light southwesterly flow. Anticipating mostly clear skies overnight. As with the previous couple of nights, some patchy fog may develop over inland locations closer to sunrise. Introduced a tempo MVFR for visibility at RIC/SBY where patchy fog is most likely. Wind should limit any fog near coastal locations. All fog should dissipate shortly after sunrise and we will return to VFR conditions for Tuesday. Outlook: Little change is expected in the overall pattern tonight through Wednesday, as upper level ridge builds from the Lower Mississippi Valley to the Carolinas. Dry weather/VFR conditions are expected to persist through Thursday. The next chance for showers arrives Friday as a cold front crosses the area. Dry weather returns for the weekend. && .MARINE... Sfc high pressure will reside near the Mid Atlantic waters into early Fri. S-SW winds aob 10kt through this morning with seas 2-4ft/waves 1-2ft. Meanwhile, a sfc low located just north of the Upper Great Lakes will push across SE Canada today/tonight. The sfc cold front associated with this system is expected to cross the waters on Wed but weaken as it does so. The end result will be a brief tightening of the sfc pressure gradient this aftn and overnight with a slight increase in S-SW winds to 10-15kt all waters. Seas continue to average 2-4ft/waves 1-2ft during this surge. High pressure briefly rebounds over the Carolinas Wed through Thu as another upper trough/sfc cold front approaches the Mid Atlantic Region from the west. Winds will remain sly around 10kt with seas 2-3ft/waves 1-2ft. The cold front is expected to cross the waters Fri late aftn/early evening. Meanwhile, a coastal low well off the Southeast coast (possibly becoming a tropical cyclone) stays well off of Cape Hatteras as it gets pushed out to sea by the front. The interaction of the cold front, coastal low, and cold Canadian high pressure located behind the front will significantly tighten the sfc pressure gradient beginning Fri aftn and persisting through at least the first half of Sun before winds gradually start to diminish. Expect solid SCA conditions (coastal waters/Bay/Sound/mouth of James River) to develop quickly Fri evening with NW winds 20-25kt due to the presence of strong cold air advection. In addition, building seas/swell from the nearby low should be anticipated Fri through at least Sun morning. Expect seas up to 4-6ft and waves of 3-4ft during strongest period of winds Fri night (with the initial cold air surge). Another sfc low pressure (similar to an Alberta Clipper) dives across the nrn waters Sun night into Mon...allowing low-end SCA conditions to persist during this time. Winds/seas/waves finally diminish Mon night into early next week as high pressure returns to the area from the SW and cold air advection processes wane. Winds generally W-WNW aob 15kt (15-20kt coastal waters) with seas becoming 2-4ft/waves 1-3ft. && .TIDES/COASTAL FLOODING... The experimental total water level hydrographs remain unavailable at this time. We hope to have the information back online later today. In the meantime, please refer to VIMS or MDL tidal data. && .CLIMATE... Very warm conditions this week with the possibility of challenging some records listed below: * Record Highs * Tue (10/18) Wed (10/19) Thu (10/20) * RIC 88 (1938) 87 (1938) 89 (1984) * ORF 86 (2011) 87 (2007) 87 (1984) * SBY 86 (1908) 84 (1938) 84 (1984) * Record high Mins: * Tue (10/18) Wed (10/19) Thu (10/20) * RIC 67 (1980) 73 (2007) 68 (1916) * ORF 68 (1980) 73 (2007) 70 (1916) * SBY 70 (1975) 71 (2007) 68 (1916) && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAM/SAM LONG TERM...ALB AVIATION...AJB/MAM MARINE...ALB TIDES/COASTAL FLOODING... CLIMATE... is the U.S. government's official web portal to all federal, state and local government web resources and services.