Area Forecast Discussion
Issued by NWS Sterling, VA

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471 FXUS61 KLWX 281905 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 305 PM EDT Sun Aug 28 2016 .SYNOPSIS...
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High pressure will remain over the Mid Atlantic through Monday before moving offshore. A cold front will move through the area Wednesday night. High pressure returns for late in the week.
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&& .NEAR TERM /THROUGH MONDAY/...
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Ridge of high pressure sfc and aloft will hold strong for another 24-30 hrs before it starts weakening more rapidly on Tue. Sct convection occurring over the Appalachians is expected to remain nearly stationary then dissipate later this evening. Convection tomorrow develops farther east to the Blue Ridge mtns, but is not expected to reach the metro areas. Becoming warmer with temps in the low 90s.
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&& .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
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Ridge weakens further on Tue allowing for better chances of convection especially west of the Blue Ridge, but still not likely to reach the metros.
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&& .LONG TERM /WEDNESDAY THROUGH SUNDAY/...
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A cold front will drop into the area from the northwest Wednesday into Wednesday night. The operational GFS runs the last day or so have wanted to push the surface front south ahead of the 850 mb front, which means northerly low-level flow by the time any forcing gets here. This is not totally out of the question given the anomalously strong surface high building in behind the front, but a few showers and thunderstorms will still be possible in the frontal zone late Wednesday afternoon and Wednesday evening. GFS/ECMWF have 850 mb temperatures dropping into the 12-15 C range behind the front for the latter portion of the week indicating a potential for temperatures several degrees below normal. The airmass will be much drier on a northerly flow as well. A few ensemble members of the GEFS/EC indicate a potential for some shower activity moving north associated with Gulf of Mexico moisture late in the upcoming weekend. Temperatures and humidity will begin to rebound during this time as well.
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&& .AVIATION /19Z SUNDAY THROUGH FRIDAY/...
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A shower or thunderstorm is possible late Wednesday afternoon or evening along a cold front. Southerly flow less than 10 knots Wednesday will become northerly Wednesday night and increase to 10 to 15 knots Thursday with a few gusts possible.
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&& .MARINE...
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Winds expected to remain below SCA through Tue. Southerly flow ahead of a cold front Wednesday should be light enough to stay below Small Craft Advisory criteria. Northerly flow behind the front could result in SCA level gusts Thursday.
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&& .TIDES/COASTAL FLOODING...
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Water levels expected to rise next 24 hrs with minor coastal flooding likely at Annapolis late tonight.
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&& .CLIMATE... Ranking of summer 2016 in terms of average temperature (JUN 1 - AUG 27) Site Rank Average Temperature DC 3 80.5 Balt 18 77.3 IAD 3 77.3 && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...DFH AVIATION...LFR/DFH MARINE...LFR/DFH TIDES/COASTAL FLOODING...LFR CLIMATE...RCM/ABW

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