Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 240039 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 839 PM EDT Wed May 23 2018 .SYNOPSIS... High pressure over the Great Lakes will build over the Mid-Atlantic through the end of the week, then move offshore this weekend. Low pressure may approach the area from the south early next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Surface cool front has continued to push south into North Carolina. Dry weather is anticipated overnight. Except for a few high cirrus, a mainly clear night is expected. Winds will be light to calm but with lower dew points any fog should be limited to river valleys. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... The center of high pressure will move overhead later in the day Thursday into Thursday night before moving offshore Friday. In the meantime, we can enjoy dry conditions Thursday into Friday. As we get into late Friday and Friday night and looking out west into the Potomac Highlands, we could encounter a shower or two; otherwise, dry conditions for all. Dewpoint temperatures will be in the lower 50s Thursday versus the lower 60s that we experienced this afternoon. This should make conditions a little more comfortable. Temperatures both Thursday and Friday will reach the lower to middle 80s with increasing humidity expected Friday around the back side of the area of high pressure. Low temperatures Thursday night expected to be in the middle 50s to upper 50s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Saturday into Sunday, a high pressure system will be located off the Atlantic coast near Bermuda. This will lead to a south to southwesterly flow which will work to funnel tropical moisture into the region. Temperatures rising up into the mid to upper 80s on Saturday and Sunday coupled with tropical moisture could lead to the formation of convective showers and thunderstorms which may produce heavy showers. Monday through Tuesday, a weak boundary will approach from the west. A south to southwesterly flow will continue the flow of tropical moisture into the region. High temperatures will be in the low to mid 80s on Monday. The approaching frontal boundary on Monday will act as a convergence zone which may allow for some forcing to cause the formation of storms and showers. The combination of tropical moisture and the boundary will lead to a chance for thunderstorms and showers on Monday. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... VFR expected through Friday night. A little patchy fog is possible mainly in river valleys tonight but should stay VFR at TAF sites. Otherwise just a few high cirrus as high pressure builds in from the Great Lakes. Winds light/variable tonight become N then NE Thu generally less than 10 kts, then light variable Fri night as high pressure continues its trek over the Mid-Atlantic. The combination of tropical moisture and rising temperatures up into the mid 80s will lead to an environment that could be conducive for the formation of scattered showers and thunderstorms over the weekend. Some restrictions are possible. && .MARINE... SCA dropped at 6 PM. Light winds tonight, then northerly to northeasterly around 10 knots Thursday but below SCA criteria as high pressure moves overhead. Some of the wider waters of the Bay may come close to SCA criteria Friday night as southerly flow increases on the back side of the high as it moves offshore. Over the weekend, winds will be out of the south which may lead to the need for a Small Craft Advisory. Chances for showers will increase as high pressure shifts into the western Atlantic. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...DHOF NEAR TERM...KLW/DHOF SHORT TERM...KLW LONG TERM...JMG AVIATION...KLW/DHOF/JMG MARINE...KLW/DHOF/JMG is the U.S. government's official web portal to all federal, state and local government web resources and services.