Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 171322 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 922 AM EDT Tue Oct 17 2017 .SYNOPSIS... High pressure will remain across the Mid Atlantic through the rest of the week and this weekend. A low pressure system may affect the region early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Sprawling area of high pressure will continue moving overhead through the day today bringing sunny skies and relatively light winds. After a chilly start, temperatures will remain on the cool side today, with highs generally from 60-65F. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... The center of high pressure will remain over the Mid-Atlantic through the middle of the week, and then pushed back to the southwest a little by late Thursday as a shortwave trough swings across the area. Some cirrus could be associated with this feature as well but otherwise skies will be clear. Tonight will offer another opportunity for frost, with perhaps a better chance for most outlying areas across the CWA given calm winds and dew points in the mid 30s. Think the freeze potential is fairly low, but it could be close in the colder valleys. With deeper low level ridging, temperatures will moderate Wednesday and Thursday, with highs edging into the 70s. Some of the typical colder locales could be close to frost potential Wednesday night, but lows will be back into the 40s for most (50s for the cities) by Thursday night. && .LONG TERM /FRIDAY THROUGH MONDAY/... High pressure will cross the region Friday and pass off the Atlantic coast Saturday. It will remain in control off the coast Sunday, but then an approaching cold front and low pressure wave will begin to increase clouds Sunday night, with an increasing chance of rain on Monday. Southerly flow will allow temperatures to remain mild even Monday despite the increased cloud cover and increasing risk of rain... with highs in the 70s through the long term. Lows will be moderating, with 40s to start and 50s likely by Sunday night. In fact, if clouds and southerly flow dominate enough, its not impossible that it stays in the 60s in many locales Sunday night. Guidance is pretty impressive with the wave of low pressure Monday night into Tuesday, with a signal for heavy rain and possibly thunderstorms, but given that it is still a week out, a lot can still change. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... High pressure will provide mostly clear skies and light winds through Saturday. && .MARINE... There`s still enough gradient to allow Small Craft Advisory conditions on the wider waterways this morning. Based on forecast winds aloft, don`t think winds will really start calming until later this morning from north to south. Therefore Small Craft Advisory will remain in effect until Noon. High pressure moves in from the west later today and will remain nearby through Saturday. Winds will be 10 kt or less through the period. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until noon EDT today for ANZ531>534-536- 537-539>543. && $$ SYNOPSIS...RCM NEAR TERM...ADS/MM SHORT TERM...ADS LONG TERM...RCM AVIATION...ADS/MM/RCM MARINE...ADS/MM/RCM is the U.S. government's official web portal to all federal, state and local government web resources and services.