Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 291110 AFDAKQ Area Forecast Discussion National Weather Service WAKEFIELD VA 710 AM EDT Wed Mar 29 2017 .SYNOPSIS... A cold front pushes farther offshore this morning. High pressure builds across the northeast today, before it retreats to the northeast on Thursday. A strong system is expected to impact the region Friday and Friday night. Dry weather returns for the weekend. && .NEAR TERM /THROUGH TONIGHT/... Latest upper air analysis reveals a dampening upper level trough now oriented offshore of the Mid-Atlantic/Northeast coast. In its wake, shortwave ridging continues to build northeast from the Mississippi River Valley into the OH/TN Valleys. Farther west, a strong closed low continues to slowly cross the Southern High Plains this morning. At the surface, surface trough now aligned just offshore, with ~1034+ mb sfc high pressure centered from Hudson Bay down into Western Ontario and now dropping south across the Upper Great Lakes. As expected, have noted some patchy fog across South Central VA into Interior NE NC over locations that received between 0.5 and 1" of rainfall Tuesday aftn. As post-frontal NNE flow continues this morning, expect areal coverage to remain limited, but have accounted for lingering low stratus/patchy fog early this morning. Otherwise, look for clouds to eventually give way to a partly/mostly sunny sky as drier air moves in from the N. Somewhat cooler, but still expecting temperatures near to a little above average with highs 60-65F near the coast and in the upper 60s to lower 70s well inland. Upper ridging pulls overhead tonight as upper trough lifts across KS/OK late tonight. At the surface, high pressure nudges south from Eastern Canada/New England tonight, with low level flow becoming E-NE and increasing. Lows in the mid 30s to near 40 across far northern zones, low to mid 40s farther south...mid to upper 40s along far SE coastal zones. Sky begins mainly clear, but expect some increasing mid to high clouds toward morning. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Dry Thursday, with upper ridge in place overhead. However, WAA aloft atop the stable onshore flow will likely result in partly to mostly cloudy sky Thursday and model BUFR soundings continue to suggest mostly cloudy to overcast conditions inland by 18z Thu (partly sunny eastern sections). Given weak/low mixing and the increase in clouds, expect a much cooler day with highs mainly ranging from the lower to mid 50s near the coast to the upper 50s over interior eastern VA/northeast NC. Models coming into increasing agreement with handling of previously mentioned upper low currently pushing slowly across the Southern High Plains. 00z NAM has come into better agreement with the GFS/ECMWF solutions, which all feature a strong closed low lifting across the Missouri Valley, and taking on a negative tilt as it lifts across IN/OH by Friday morning. Good model agreement exists with respect to onset of showers and embedded t-storms late Thursday night/Friday Morning from west to east. Similarly good agreement with respect to potential for widespread showers/tstms and potential for heavy rain during Fri, which makes sense given the negative tilt, PW values in the 1.25-1.5" range (>150% of normal) and flow aloft parallel to the encroaching frontal boundary. quickly expand pops just before sunrise west of I-95 before increasing to 80% to 90% all areas during Fri morning. Categorical pops continue Friday aftn as the upper low tracks east across the mountains Friday afternoon and night. There remains every indication that we`ll have the chance for some strong to locally severe storms once again during this time frame. Given the trend towards the quicker solution, storms will move out quicker and there will be less time for diurnal destabilization, so it is certainly a conditional threat. That said, strong 0-6km shear values, Lifted Indices of <-4 deg C coincident with timing of best forcing onset Friday aftn would at least argue favorably for continued mention of thunder in grids, especially across the southern 2/3 of the area. Lowered pops Friday night given quicker timing, with clearing into Sat morning. as front crosses the area late Friday. Highs in the 60s to near 70. Lows Sat morning in the low to mid 50s, with some upper 40s across our far northern tier of counties. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Low pressure and associated surface cold front cross the area Friday night then moves off the coast. Dry wx and high pressure returns for Sat thru at least Mon morning. Yet another system will bring the chc for showers back to the area late Mon thru Tue. Highs in the mid 60s to lower 70s Sat, in the 60s to near 70 Sun and Mon, and in the 60s to lower 70s Tue. Lows in the upper 40s to mid 50s Fri night, in the 40s Sat night and Sun night, and in the mid 40s to lower 50s Mon night. && .AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
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Predominate VFR conditions across area terminals, with only localized Visibility/Ceiling restrictions in light N-NE flow. This will result in some ceilings localized LIFR/IFR cigs for a brief time early this morning in low stratus, with some patchy fog in areas that picked up ~1" of rain late Tuesday. Skies will scatter out and lift from north to south this morning as high pressure slowly nudges into the region from the north. Outlook: Dry w/ VFR conditions tonight through Thursday. However, clouds will increase on Thursday as another front approaches the region. Clouds then thicken and lower Thursday night as the next low pressure system approaches the area w/some patchy drizzle and IFR as early as Thursday evening. This system should bring widespread showers and thunderstorms to the area Friday/Friday night as it crosses the Mid-Atlantic region.
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&& .MARINE... Latest sfc analysis shows a cold front sliding off the Carolina coast with high pres over the Great Lakes region. The front will push farther offshore today as the high builds north of the region. Resulting north winds will increase this morning in association with weak CAA/pres rises. Currently expecting sustained winds up to ~15 kt with a few gusts up to 20 kt psbl over the Bay...but no SCA hazards issued attm. Also, seas will build close to 5 ft out 20 nm this aftn but confidence is not high enough to issue a SCA there also as seas should mainly cap out around 4 ft there. Conditions just sub-SCA again tonight with NE flow of 10-15 ft over the Bay/rivers/Sound and 15-20 kt over coastal waters. Similar conditions into Thu morning with seas near 5 ft out 20 nm over the coastal waters. Next cold front then approaches from the west Fri, with marginal SCA S/SE flow expected ahead of the front. This front crosses the waters late Fri night/Sat morning. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...LKB NEAR TERM...MAM SHORT TERM...LKB/MAM LONG TERM...TMG AVIATION...BMD/MAM/JEF MARINE...TMG is the U.S. government's official web portal to all federal, state and local government web resources and services.