Area Forecast Discussion
Issued by NWS Wakefield, VA

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811 FXUS61 KAKQ 291812 AFDAKQ Area Forecast Discussion National Weather Service WAKEFIELD VA 212 PM 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/... SCT to BKN SC/AC should thin out as the days progresses due to drier air filtering in from the north. Expect a pt to mstly aftn as high pressure builds in from the north. Highs 60-65F near the coast and in the upper 60s to lower 70s well inland. Previous Discussion: 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 /18Z WEDNESDAY THROUGH MONDAY/... High pressure ridge extending from a center over the James Bay south into the Mid Atlantic States will slip slowly to the east. Strong low pressure over the southern Great Plains will move northeast into the Ohio Valley by Thursday night. Stratocumulus over interior Virginia and North Carolina will continue to erode from north to south. Have RIC PHF and ECG with MVFR cigs for the first couple of hours of the 18Z TAF. The sky will be mostly SKC this evening and overnight. Layered cloudiness increases from the west on Thursday but will remain VFR through 18Z. No visibility issues are indicated through Thursday morning. Winds will be from the north and northeast at around 10 knots during the balance of the afternoon. Winds will be less than 5 knots from the northeast and east overnight and mainly easterly 5 to 10 knots on Thursday morning. OUTLOOK...The aforementioned low pressure system will move from the Ohio Valley across northern portions of the Mid Atlantic States to south of New England by Saturday morning. Widespread rain develops Friday morning which will combine with a chance for thunderstorms Friday afternoon and evening. Periods of MVFR/IFR will be likely. Conditions improve by Saturday morning. High pressure builds back into the area for the weekend. There will be a chance for showers western portions of the area by late Monday as the next system develops over the Mississippi Valley. && .MARINE... Winds have not increased as much as expected and are generally 10 kt across the Bay and lower VA coast. have lowered wind speeds for today some and may need to lower them even more with the early afternoon to update. Generally expect n to ne winds around 10 kt with slightly higher winds gusting to 15 kt from Wallops Island north to Ocean City. 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. Conditions just sub-SCA 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...MPR/MAM SHORT TERM...LKB/MAM LONG TERM...TMG AVIATION...LSA MARINE...TMG/JAO

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