Area Forecast Discussion
Issued by NWS Sterling, VA

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960 FXUS61 KLWX 231551 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1051 AM EST Fri Feb 23 2018 .SYNOPSIS... A frontal boundary along southern Virginia this morning will begin to lift northward today as a warm front. This boundary will remain stretched across our area through Saturday. A stronger cold front will sweep through the region on Sunday, bringing drier and clearer conditions. High pressure builds in to the region from the west for the first half of next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Light rain showers have generally cleared the CWA, but cloudy skies blanket the region with temperatures generally holding in the upper 30s and low 40s. A stationary boundary residing along the VA/NC border this morning will gain some momentum and lift northward as a warm front today, moving into western portions of our area by this evening. Forcing aloft is now mostly north of the region, but with warm air overrunning cool, moist air, expect patchy mist and drizzle to linger. Expect temperatures today to remain seasonable in the upper 40s to near 50 degrees for much of the area, with northern and northeast MD holding on to the middle 40s. Portions of West Virginia and the Shenandoah Valley looked poised to break in to the warm sector as the aforementioned warm front lifts northward, which would result in temperatures well in to the 50s to near 60 degrees.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
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As the warm front lifts in to our area by this evening, rain chances will be favored over our far northern and western zones of western MD and portions of the WV highlands. Much of the area should remain fairly dry tonight, with areas of fog developing after midnight. Temperatures will remain mild for this time of year, in the mid- upper 40s to near 50 degrees. Low pressure will move northeastward along the stationary boundary across our area on Saturday, bringing increased rain chances once again. The first half of Saturday does look drier as rain should hold off for much of the area until Saturday afternoon/evening. Highs on Saturday will be in the 60s across the southern half of our area, with low to mid 50s likely towards the MD/PA border as the frontal boundary bisects the CWA. Lows Saturday night will not fall far, holding in the 50s area wide, with continued periods of rain showers. A stronger cold front will sweep through the area on Sunday, currently progged to move through Sunday afternoon. We will see showers and perhaps a thunderstorm or two with its passage. Highs on Sunday will be quite warm, approaching 70 degrees for much of the area, with upper 60s across northern MD. We will see dryer and clearer conditions Sunday night as the front moves south of our area. Lows will still be well above average Sunday night, ranging from the low 40s to near 50 degrees.
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&& .LONG TERM /MONDAY THROUGH THURSDAY/...
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High pressure will be the primary player in the extended forecast. However, there is some disagreement as to when it will take over (Mon vs Tue) and when it will relinquish control to the next wave of warm-frontal precipitation (Wed vs Thu). Due to these uncertainties, will need to take the more pessimistic route, which is closer to the ECMWF Mon but GFS Wed-Thu. Temperatures will be safely above freezing through the period when precip is a possibility, so no p-type concerns anticipated. Highs will generally range from the mid 50s to around 60. Aside from Monday night, when cold advection should be at its greatest, lows will range from the mid 30s-mid 40s.
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&& .AVIATION /16Z FRIDAY THROUGH TUESDAY/...
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Ample clouds and moisture across the terminals this morning is bringing MVFR/IFR conditions. Light easterly wind will veer out of the south and southwest today, with showers/drizzle this morning. Conditions may improve to MVFR this evening for a period, but IFR VIS/CIGs look to return overnight with areas of fog at the terminals. Low pressure will approach from the west with a frontal boundary over our area, thus continued rain chances and low CIGs/VIS will continue through Saturday night, bringing periods of IFR conditions. A cold front will move across the terminals Sunday afternoon, with periods of sub-VFR conditions ahead of it. High pressure will start to build in to the region Sunday night with improving flying conditions. Any lingering restrictions Monday will clear. VFR anticiapted for the duration of the period.
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&& .MARINE...
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A warm front will lift into the area today, with winds remaining light through Saturday. Thus no headlines expected during this time. A cold front will approach from the west on Sunday, increasing winds out of the south southwest, likely bringing wind gusts to near SCA thresholds. High pressure will build in behind the frontal passage Sunday night, resulting in lighter winds across the waters. Winds should remain below Small Craft Advisory thresholds Mon- Tue as high pressure builds over the waters.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...None.
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&& $$ SYNOPSIS...BKF NEAR TERM...BKF/RCM SHORT TERM...BKF/RCM LONG TERM...HTS AVIATION...BKF/HTS/RCM MARINE...BKF/HTS/RCM

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