Area Forecast Discussion
Issued by NWS Sterling, VA

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191 FXUS61 KLWX 241142 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 742 AM EDT Sat Jun 24 2017 .SYNOPSIS... A cold front is crossing the region early this morning. High pressure will build back into the region later today. Additional weak cold fronts will cross the region Sunday through Tuesday, but with little if any precipitation. High pressure will cross the region Wednesday and then settle over the western Atlantic Ocean late in the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Initial boundary associated with the remnant circulation of Cindy is crossing the region with a squall line at this time. Not much depth to the line but a rumble of thunder can`t be ruled out, along with a brief wind gust to around 40 mph and brief blinding downpour. After the line and front clears the area, northwest flow will start bringing drier air into the region. All showers should clear the area before midday, with midday and afternoon turning out mostly sunny. Temperatures will still be quite warm with good mixing behind the front, so still expecting highs well into the 80s, with 90 possible in the warm spots. However, dew points will generally be sliding downward, so it won`t feel as oppressive. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... The remainder of the short term will feature an upper trough settling over the Great Lakes, and surface high pressure over the central US. Northwest surface flow and passing disturbances aloft will bring weak reinforcing cold fronts southwest across the area. With much drier air in place, little if any precip is expected with these fronts, though an isolated shower or t-storm can`t be completely ruled out, especially Monday and Monday night as a little more forcing is present aloft. Otherwise, temperatures will be sliding downward each day, with low-mid 80s Sunday and upper 70s to low 80s Monday. Lows will decline in a similar fashion, with low-mid 60s common tonight, upper 50s to low 60s more likely Sunday night, and mid-upper 50s more common Monday night. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Cool (for late June) weather to start the long term as an upper trough starts sliding east across the region and high pressure to our west keeps a cool northwest flow in place. The passing trough may result in enough instability to result in a stray shower or t-storm Tuesday, but most spots stay dry. The trough starts moving east away from us Wednesday, with ridging building in from the southwest late in the week as the surface high pushes east and sets up shop off the coast (i.e. a Bermuda high). This will result in temperatures starting to warm back above normal by the end of the week, and an increasing risk of diurnal terrain showers and storms in the mountains by Friday. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... Variable conditions this morning as cold front and squall line moves through. Occasional IFR with heavy rain and gusty winds to 35 knots possible as cold front passes. After it is through, generally expect VFR through remainder of forecast period, with winds diminishing, especially tonight. An isolated thunderstorm could occur Monday or Tuesday with a weak reinforcing cold front and following upper trough, but odds are low. && .MARINE... High pressure building in behind a cold front should continue to cause sporadic SCA gusts today, but odds of continued SCA winds beyond this afternoon, while not negligible, look low, and therefore have not extended headlines any further. Will need to watch for potential mixing and resulting SCA gusts Sunday and Monday with multiple weak reinforcing cold fronts moving through, however. Otherwise, mainly dry through the rest of the forecast period, with just an isolated thunderstorm possible Monday or Tuesday with a weak front and following trough. && .TIDES/COASTAL FLOODING... Coastal flood advisories up for several portions of our upper bay shore along with the DC waterfront right now thanks to persistent southerly flow and above normal astronomical tides. This should be a one-cycle event, however, since northwest winds are already enveloping the region behind the approaching cold front. Water levels should stay below minor flood thresholds for the foreseeable future after this morning`s high tide. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...Coastal Flood Advisory until 10 AM EDT this morning for DCZ001. MD...Coastal Flood Advisory until 8 AM EDT this morning for MDZ018. Coastal Flood Advisory until 10 AM EDT this morning for MDZ014. Coastal Flood Advisory until 11 AM EDT this morning for MDZ011. Coastal Flood Advisory until 1 PM EDT this afternoon for MDZ508. VA...Coastal Flood Advisory until 10 AM EDT this morning for VAZ054. WV...None. MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ530>543. && $$ SYNOPSIS...RCM NEAR TERM...RCM SHORT TERM...RCM LONG TERM...RCM AVIATION...RCM MARINE...MM/RCM TIDES/COASTAL FLOODING...RCM

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