Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 150737 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 337 AM EDT Fri Sep 15 2017 .SYNOPSIS...
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An area of high pressure will build into the region today through Sunday. Tropical Storm Jose is forecast to move north as a hurricane along...but well offshore of...the Atlantic coast Monday into Tuesday. See the National Hurricane Center bulletins for the latest information on Jose.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Low and mid-level clouds will continue to break apart overnight through daybreak. With these clearing skies and low-level moisture in place, areas of fog will develop in parts of our region. As of 3am, places like Cumberland, Maryland and Winchester, Virginia are showing signs of reduced visibility. Other places should follow during the next few hours. Visibility, for the most part, will be about 1 to 2 miles, but there could be isolated spots that see less than one half mile by daybreak. Reduce speed and use low beam headlights to use caution in patchy or areas of fog. Low temperatures will reach the lower to middle 60s. Although the main upper level low, affiliated with the remnants of Irma, will be over eastern portions of New England and high pressure will be building into the region today, some leftover energy from Irma could stay back over the area. We have just a slight chance of a shower or two in parts of the region. Not everyone will get a shower. Computer models are very diverse of the locations that have this slight chance of showers. Highs today will be in the lower 80s. As any showers in the area dissipate this evening, skies will begin to clear once again. These clearing skies and residual moisture could play a role in introducing some patchy dense fog over much of our region overnight tonight. Lows will bottom out only in the middle 60s.
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&& .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
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High pressure will rebuild across the region Saturday through Sunday night. Once again, despite high pressure over much of the region, some weak upper level energy could stretch across the region and bring a slight chance of a shower to parts of the region. For the most part, high pressure will provide a dry and comfortable afternoon and evening, both Saturday and Sunday. Highs in the lower to middle 80s Saturday with lows in the middle 60s Saturday night. Highs lower 80s Sunday with lows middle 60s Sunday night.
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&& .LONG TERM /MONDAY THROUGH THURSDAY/...
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Model guidance consistent in forecasting a storm track for Jose that is northbound off the east coast of the United States. The official NHC forecast maintains this multi-model consensus. (Consult the NHC website for updates.) That said, it is important to note that track forecast errors on days 4-5 average 150-200 NM respectively. So, it would be premature to jump to any conclusions at this stage, but it would be prudent to monitor the progress of this system. Forecast will have low-end PoPs along the Bay along with 10-20 mph winds Monday into Tuesday, representing the potential gradient that may exist. On top of that, convergence and orographic lift may yield scattered showers in the mountains each afternoon. Wednesday into Thursday likely to be quieter as broad high pressure regains control. This timing is subject to change though, based on what pans out leading up to midweek. Stay tuned.
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&& .AVIATION /08Z FRIDAY THROUGH TUESDAY/...
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VFR conditions through daybreak. We can`t rule out MVFR or IFR conditions based on visibility for any fog that develops near the MRB and CHO terminals. Winds light and variable to perhaps calm. VFR conditions at all terminals today. We can`t rule out a shower in spots, but locations are uncertain. Nonetheless, the showers shouldn`t affect ceilings or visibility to a restriction. Winds northwest to north around 5 knots. VFR conditions tonight. Some patchy or areas of fog could reduce visibility, mainly near CHO and MRB. Winds northwest around 5 knots or less. VFR conditions Saturday and Saturday night at all terminals. Winds becoming northeast around 5 knots Saturday, then light and variable Saturday night. The most likely scenario at this time yields VFR conditions across the terminals Monday into Tuesday. The best bet for flight restrictions will be early each morning due to predawn low clouds and fog. All interests should monitor products from NHC for the latest on Jose.
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&& .MARINE...
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No marine hazards expected today through Saturday night. Winds northwest 5 to 10 knots Friday and Friday night. Winds becoming north to northeast around 10 knots Saturday, then easterly 5 to 10 knots Saturday night. The pressure gradient will be increasing Monday into Tuesday as Jose nears the Mid Atlantic coast. The potential for Small Craft Advisory caliber winds exists, with a minimal but non-zero probability of Tropical-Storm-Force winds. All interests should monitor products from NHC for the latest on Jose.
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&& .TIDES/COASTAL FLOODING...
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Water levels continue at one-half to three-quarters of a foot above astronomical predictions. Many action stages are being reached, with a couple mighty close to minor flood (eg: Annapolis). Will be dropping the aforementioned Advisory, with no other Advisories anticipated today. These trends likely to continue into the weekend...ie: reaching action stage with the night time tide cycle, which is the higher of the two astronomically. By Sunday night-Monday morning, water levels may increase due to increased onshore flow. These trends will be monitored.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...Coastal Flood Advisory until 5 AM EDT early this morning for MDZ014. VA...None. WV...None. MARINE...None.
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&& $$ SYNOPSIS...KLW/HTS NEAR TERM...KLW SHORT TERM...KLW LONG TERM...HTS AVIATION...KLW/HTS MARINE...KLW/HTS TIDES/COASTAL FLOODING...HTS

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