Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 241952 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 252 PM EST Fri Nov 24 2017 .SYNOPSIS...
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High pressure will remain just offshore of the mid-Atlantic through tonight. A cold front will cross the region Saturday and move east of the Chesapeake Bay Saturday night. High pressure moves back into the area Sunday and remains in control through the middle part of the upcoming work week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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High pressure has shifted a bit to our east this afternoon, residing just off the Delmarva coast. This has allowed winds to turn southerly, albeit light, which has brought temperatures to near normal levels, hovering in the low to mid 50s. Skies are clear thanks to the proximity of the high and ample dry air aloft. As a result, no precipitation echos have been detected by the local radar. High pressure will continue to reside to our south and east tonight, continuing the southerly flow across the region. Temperatures will bottom out near normal, with low to mid 30s north and west of the metro area, and mid to upper 30s near the city centers. Clear skies this evening will transition with some high level clouds starting to stream overhead throughout the night, especially across our western zones as a cold front progresses eastward from the Great Lakes region.
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&& .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
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The aforementioned cold front will cross our CWA during the day Saturday, exiting the region by Saturday evening. This front will bring with it an increase in cloud cover Saturday morning, but carry limited moisture. Model guidance indicates possible spotty rain showers moving east of the mountains, but any accumulations are expected to be light as downsloping will act to deter shower progression. Temperatures on Saturday will average above normal in the mid to upper 50s. Behind the frontal passage, west to northwest winds will increase appreciably Saturday night, resulting in upslope rain showers transitioning to snow showers during the evening in the favored locations, with minor accumulations of an inch or less possible thru sunrise Sunday. Temperatures will settle down in the 30s for most, near 40 degrees in the cities, and lower 30s further west. Breezy conditions Sunday morning will start to subside during the afternoon has high pressure builds in from the west southwest. Expect dry conditions to finish out the weekend with highs in the mid to upper 40s, to near 50 in the metro area. Low temperatures Sunday night will fall down in the mid to upper 30s for most.
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&& .LONG TERM /MONDAY THROUGH FRIDAY/...
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The last week of November is shaping up to be dominated by high pressure dry weather and above normal temperatures...with a cold front expected toward the end of the week. Monday starts out with seasonal temperatures as the departing upper level low lifts into the Canadian maritimes. High pressure builds in early in the week. A warm front will cross the region Tuesday allowing mid-week daytime max temperatures to be close to 10 degrees (F) above normal...both Wednesday and Thursday under mostly sunny skies. By Friday, a cold front will cross the region. The airmass associated with this front originates more from the Pacific region...so only a drop in temperatures back to near seasonal levels along with more cloud cover. Any precipitation associated with the front will be limited.
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&& .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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VFR conditions expected across the terminals for the next 24 hours. Light and southerly winds this afternoon will continue in to Saturday morning ahead of an approaching cold front. Clouds will be on the increase early Saturday but predominate VFR VIS/CIGs are expected as any shower activity will remain limited. The cold front will pass through the terminals during the afternoon and exit to the east Saturday evening. Winds will turn gusty out of the west northwest in its wake, averaging 10 to 15 knots with gusts up to 20 knots. Winds will subside during the day Sunday with clearing skies and dry conditions forecast, thus no flight restrictions expected. VFR conditions are expected to prevail through Wednesday as high pressure controls our weather pattern.
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&& .MARINE...
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Light southerly winds today will continue overnight and in to Saturday morning ahead of an approaching cold front. Small Craft Advisory conditions expected to begin Saturday evening and continue through Sunday as gusty northwesterly winds increase behind the front. As a result, an SCA has been issued for the overnight period Saturday. Conditions on the waters should remain below SCA levels on Monday. On Tuesday there could be near SCA levels on the Bay due to southerly channeling on the back side of the surface high as it moves just off the eastern seaboard. However water temperatures are cooler than the airmass above the waters...so that should limit mixing down of higher wind speeds to the water`s surface.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...Lee/BKF NEAR TERM...BKF SHORT TERM...BKF LONG TERM...SMZ AVIATION...BKF/SMZ MARINE...BKF/SMZ

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