Area Forecast Discussion
Issued by NWS Sterling, VA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 251859 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 259 PM EDT Sat Mar 25 2017 .SYNOPSIS...
-- Changed Discussion --
A backdoor cold front will move into the local area this evening and stall just south of the area overnight and Sunday before returning north as a warm front on Monday. Another cold front will cross the area late Tuesday.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
Backdoor cold front is across south central Pennsylvania and will push south rest of today crossing the local area this evening. Some low topped showers are possible in the vcnty of the frontal zone and across the higher elevs due to some weak instability and sfc convergence. Clouds thicken rapidly this evening with fropa with low clouds/cigs and some light rain especially northern areas and along the western shore of the Chesapeake due to onshore flow. Cloudy and much cooler Sun due to cold air damming effects and onshore flow. Light rain or drizzle in the morning then tapering off as low level moisture erodes and cigs lift. Much better chance for showers Sun night in area of strong surface and moisture convergence and warm air overrunning cool surface air.
-- End Changed Discussion --
&& .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
-- Changed Discussion --
Front lifts north as a warm front Mon afternoon with temperatures rising back into the 70s. Area will be in a light westerly downslope flow leading to some clearing. Risk of showers increases again late Mon night and Tue as low pressure and associated cdfnt crosses the area. Enough instability is also present on Tue for a risk of t-storms. Drying expected late Tue night behind fropa.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Front approaches from the west on Tuesday with showers and thunderstorms possible. Conditions should start drying out early on Wednesday as high pressure builds over our region. Dry conditions continue into Thursday before a wave of low pressure moves through the Mid- Atlantic increasing PoPs Thursday night and into Friday. Another low pressure moves east towards the Mid- Atlantic Friday night into Saturday keeping rainy conditions over our region.
-- End Changed Discussion --
&& .AVIATION /19Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
Cigs will drop this evening to IFR everywhere except at KCHO and remain low through 18Z Sun then lift to MVFR. Showers expected Sun night everywhere. Cold front approaches on Tuesday, then dry conditions return Wednesday into Thursday. Sub-VFR periods possible Tuesday into Tuesday night, then VFR Wednesday into Thursday.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
Winds will strengthen across the upper Chesapeake Bay late this evening behind backdoor front. Winds remain gusty across the nrn waters and upper Potomac river through Sun. Winds then increase again Sun night across the southern waters with SCA Mon and Mon night. Cold front approaches on Tuesday, then dry conditions return Wednesday into Thursday. Winds are expected to remain below the small craft advisory threshold.
-- End Changed Discussion --
&& .LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 11 PM this evening to 9 PM EDT Sunday for ANZ530>532-535-538>540.
-- End Changed Discussion --
&& $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...IMR AVIATION...IMR/LFR MARINE...IMR/LFR

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.