Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 260759 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 359 AM EDT Tue Mar 26 2024 .SYNOPSIS...
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Surface ridging will keep fair and seasonable weather conditions today. Showers return to the area tonight as a weak cold front approaches and eventually crosses the area Thursday morning. A backdoor front will cross the area Saturday.
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&& .NEAR TERM /THROUGH TONIGHT/...
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High level cirrus has been streaming into the area from the west early this morning. Meanwhile, marine layer stratocu is moving in from the east with onshore flow. This trend continues through the day with increasing cloud cover and high pressure exiting. As a slow-moving cold front approaches from the west, rain chances increase generally west to east through the day, but most of the area east of the mountains is expected to remain dry through the afternoon. High temperatures cap out in the 50s for much of the area. Rain moves in tonight and low temperatures fall into the low to mid 40s.
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&& .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
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A slow-moving cold front will make its way through the area Wednesday into Thursday, bringing widespread showers. Shower activity may be more scattered to start early Wednesday with less favorable forcing as an upper trough moves off to the northeast before a secondary shortwave digs to our south. Rain chances gradually decrease west to east Thursday. Rainfall totals will be dependent on the track of the coastal low associated with the secondary shortwave, but for now anticipate 0.50" to 0.75". Locally higher amounts are possible over portions of central VA and southern MD based on the current forecast track of the low. Highs will be in the 50s both Wednesday and Thursday for most of the area, though a bit cooler in the 40s along the Alleghenies on Thursday behind the cold front. Lows on Wednesday night will also drop behind the cold front in the mountains by Thursday night (30s) but the rest of the area should remain in the 40s.
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&& .LONG TERM /FRIDAY THROUGH MONDAY/...
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Low pressure will be moving toward coastal New England Friday while high pressure builds across the southeastern states. A tight pressure gradient will result in gusty northwest winds. Gusts could come close to Wind Advisory criteria, especially in the higher elevations. Otherwise clearing skies are expected with seasonable temperatures. High pressure slides to the south Friday night as a warm front approaches from the west. The front will likely stall near the area over the weekend as the flow becomes more zonal. Shortwave troughs interacting with this boundary may bring some chances for showers, although timing is uncertain and rainfall amounts would likely be light. PoP/Sky forecasts are currently modest due to the timing differences, but there is some consensus of at least some scattered showers at some point over the weekend. Temperatures will likely trend above normal over the weekend. If the front remains close enough by on Monday, shower chances will remain. It may be a little cooler though since there is some agreement on the front slipping south of the area. More appreciable rain chances will eventually arrive as a stronger trough approaches from the Midwest, but this may not be until Monday night or Tuesday.
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&& .AVIATION /08Z TUESDAY THROUGH SATURDAY/...
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VFR conditions early this morning are expected to deteriorate to MVFR for the metro terminals as the marine stratocu moves in from the east. Some improvement is possible this afternoon before rain moves in tonight. IFR to LIFR cigs start late tonight and likely continue through Wednesday and into Thursday. VFR conditions are expected Friday but with northwesterly wind gusts of 25-35 kt. A weak front may approach Saturday and provide a chance of showers and perhaps some wind gusts to around 20 kt, but confidence in both is low as computer model spread increases.
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&& .MARINE...
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SCAs remain in effect early this morning before diminishing after sunrise. Winds over the waters will be east to southeast through Wednesday before increasing out of the northwest Thursday behind the cold front. SCAs will likely be needed Thursday afternoon into Friday. Strong northwest flow is expected Friday behind the departing low. SCAs are likely and marginal gales are possible. Winds diminish some Friday night, but SCAs may continue. Current NBM forecast indicates advisories are possible on Saturday as well as a weak front approaches, but model spread increases during this time.
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&& .TIDES/COASTAL FLOODING...
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Water level anomalies are around 1.5-2 feet above normal this morning. While they have recently leveled off, models indicate another half to three quarters foot rise is possible through early Wednesday as onshore flow continues. Previous forecasts were running a bit high, so have made a few headline adjustments through today. However, the primary message remains the same that fairly widespread minor to locally moderate flooding is expected through the middle of the week. Water levels will begin falling Thursday after a front pushes through.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...Coastal Flood Advisory until 5 PM EDT this afternoon for DCZ001. Coastal Flood Watch from this afternoon through Wednesday afternoon for DCZ001. MD...Coastal Flood Advisory until 3 PM EDT Wednesday for MDZ011-016. Coastal Flood Advisory until 1 PM EDT this afternoon for MDZ014. Coastal Flood Warning from 1 PM this afternoon to noon EDT Wednesday for MDZ014. Coastal Flood Advisory until 11 AM EDT this morning for MDZ017. Coastal Flood Warning from 11 AM this morning to 6 AM EDT Wednesday for MDZ017. Coastal Flood Advisory until 7 PM EDT Wednesday for MDZ018. Coastal Flood Advisory from 9 AM this morning to 3 PM EDT Wednesday for MDZ508. VA...Coastal Flood Advisory until 3 PM EDT Wednesday for VAZ054-057. Coastal Flood Advisory from 7 PM this evening to 3 PM EDT Wednesday for VAZ053-055-527. WV...None. MARINE...Small Craft Advisory until 5 AM EDT early this morning for ANZ534-537-543.
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&& $$ SYNOPSIS...ADM/CAS NEAR TERM...CAS SHORT TERM...CAS LONG TERM...ADS AVIATION...ADS/CAS MARINE...ADS/CAS TIDES/COASTAL FLOODING...ADS

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