Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 140759 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 359 AM EDT Sat Oct 14 2017 .SYNOPSIS...
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High pressure over the area will weaken rapidly through Sunday. A cold front will push into the Mid Atlantic Sunday night followed by a return to high pressure early next week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Widespread low clouds cover much of the fcst area except over Pendleton county with areas of drizzle along and east of I-95 and patchy dense fog where skies have cleared east of the Blue Ridge. These will gradually mix out through the day with a pleasant Sat with temps rising into the mid 70s. Areas of dense fog may form again late tonight under clear skies and light winds and dewpoints remain high.
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&& .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
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Warm day on Sun under strengthening southwest flow ahead of a cold front especially east of the Blue Ridge where clouds will be less and showers take longer to arrive. Showers appear likely everywhere during the evening Sun as cold front moves through the area. Gusty winds up to 30 mph will accompany the front as models show decent pressure rises. Showers will linger over southern MD into Mon morning before pushing south by midday. Rapid clearing expected Mon as drier air moves in behind fropa and as high pressure builds in. Taste of fall Tue morning with lows dropping into the 40s and even 30s west.
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&& .LONG TERM /TUESDAY THROUGH FRIDAY/...
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A shortwave trough will be moving off the coast Tuesday morning while surface high pressure builds eastward from the Ohio Valley. That high pressure system will be the story of the extended forecast period as it more or less remains parked over the region. The ensemble suite of guidance is in good agreement with the overall pattern. Aloft, flow will be progressive and wavy through midweek, with east coast ridging becoming amplified by the end of the week as a deep trough moves onto the west coast. Looking at the BUFKIT overview cross-section, there is a stark lack of moisture in the atmosphere for much of the week. It will remain cool through mid-week, but near normal. We`ll have to keep an eye on frost/freeze potential (mostly western valleys at this point) Tuesday and Wednesday mornings. Highs will remain in the 60s again on Tuesday despite sunshine. The airmass will modify as the week progresses with temperatures rising back above normal, although 80s look unlikely at this point.
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&& .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
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Widespread IFR even LIFR conditions this morning with cigs improving later today. Patchy dense fog possible again tonight. Cdfnt will be crossing the area early Sun evening with showers likely. Gusty NW winds behind fropa up to 25 kt Sun night. No significant weather expected Tuesday and Wednesday with high pressure.
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&& .MARINE...
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Light winds today, but winds strengthen Sun and especially Sun night with fropa. Gusts up to 25 kt expected on the waters. SCA will be raised later this morning. Small Craft Advisory conditions in northwest flow may linger through Tuesday morning on portions of waters. Winds will then subside through mid-week as high pressure builds over the area.
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&& .TIDES/COASTAL FLOODING...
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Tidal anomalies have come down significantly since yesterday, but water levels remain elevated on the Potomac River. Made significant changes to headlines to drop them at most places except along the Potomac River.
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&& .CLIMATE...
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A surge of warm air is expected Sunday ahead of the cold front. We are not currently forecasting records, but we are expecting temps to be close. Warm Temperature Records for October 15 (Sunday)... High Warm Low DCA 87 (1975) 67 (2008) BWI 86 (1989, 1975) 66 (1941) IAD 88 (1989) 64 (1985)
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&& .EQUIPMENT... The NWS 88D Sterling radar (KLWX) will be down during the day from 7 AM through at least 5 PM through Saturday. This is for nationally scheduled maintenance on the radome. Surrounding 88D radars as well as FAA terminal radars will be operational during this downtime. && .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...Coastal Flood Advisory until 7 AM EDT this morning for DCZ001. MD...Coastal Flood Advisory until 5 AM EDT early this morning for MDZ014. Coastal Flood Advisory from 9 AM this morning to midnight EDT tonight for MDZ017. VA...Coastal Flood Advisory until 7 AM EDT this morning for VAZ054. WV...None. MARINE...None.
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&& $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...ADS AVIATION...ADS/LFR MARINE...ADS/LFR TIDES/COASTAL FLOODING...LFR CLIMATE...LWX EQUIPMENT...LWX

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