Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 290108 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 908 PM EDT Thu Mar 28 2024 .SYNOPSIS... Low pressure will continue to slide by to our east today before pushing off to the northeast and strengthening on Friday. High pressure will build to our south on Friday, resulting in gusty winds over the region. Multiple upper level disturbances will pass overhead this weekend into early next week resulting in generally unsettled weather. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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Rain has ended across the area, with the cold front continuing to track through the area. Some gusty northwest winds are already filling in just behind the front. Clouds will continue over the next several hours across the far eastern areas before clearing out. Previous Discussion Follows: Another shortwave will dive through the larger trough late tonight, bringing a return of some clouds and a brief period of upslope snow showers. Snow amounts should generally be less than one inch. Overnight lows will be in the 30s for most of the area (upper 20s along the higher ridges of the Allegheny Front). Winds will sharply increase with the arrival of this next shortwave tonight. A Wind Advisory was issued for Grant, Highland, and Pendleton counties for gusts up to 50 mph. This should really pick up between 3-6 AM and likely continue through Friday.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... The aforementioned low pressure system will track toward the Canadian Maritimes on Friday as high pressure simultaneously builds to our south. A strong pressure gradient over the region will be the result, with gusty northwesterly winds expected across the area. Gusts will generally range from 30-45 mph, but could be even up to 50 mph in the mountains. As mentioned in the near term section above, Wind Advisories will continue through 8 PM Friday along the Allegheny Front. While there is some potential for Wind Advisories further east, the best certainty for now was out west. There is still a bit of uncertainty regarding the height of the inversion and how aligned the winds will be with height. Any slight deviations in either of those 2 variables could keep us just below advisory criteria. Will leave the final decision to a later forecast cycle at this time. Any lingering clouds will clear through the day, and high temperatures will range from the upper 40s in the mountains to the lower to middle 60s across Central Virginia. Relative humidity values are expected to crash tomorrow in strong northwest flow to around 20 to 25 percent. This paired with the strong winds could lead to an elevated fire danger Friday afternoon. More on that in the fire danger section below. Friday night should remain dry although with some increase in clouds. A thermal gradient will begin to develop across the area as warm advection begins ahead of a low pressure system in the Great Lakes. This will result in lows in the mid 30s across northeast Maryland to the lower to mid 40s across the central Shenandoah Valley and central Virginia. This warm front will remain draped across the area through Saturday as the low tracks toward the Mid Atlantic. The track of this low and the warm frontal position will have influence on high temperatures (50s north/60s to near 70 south) as well as where the most rain falls. The highest rain chances currently stretch across the eastern West Virginia panhandle and northern Maryland. Clouds may linger Saturday night along with some rain showers along the Alleghenies. Lows will be in the 40s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A warm front lingering around the Ohio Valley and Mid-Atlantic through the weekend will bring clouds and some shower activity. Currently the greatest chance for precipitation on Sunday is along the Alleghenies, expanding eastward from there with 20-30 PoPs but generally remaining west of I-95 during the day. Low pressure approaches from the west Monday into Tuesday, bringing greater chances of rain for the start of the week. Guidance has trended colder after the system exits Wed/Thurs, bringing possible upslope snow along the Alleghenies to finish off the extended. Temperatures will be well above normal Sunday with highs in the 60s to 70s outside of the mountains, and closer to normal for the start of the week (50s to 60s) as the next low pressure system moves through. Behind the system will be near to slightly below normal. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/...
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VFR conditions are expected for the remainder of the night as the majority of the clouds and moisture have shifted to the east. Gusty winds will pick up late tonight as a surge of northwest flow builds in. VFR conditions expected Friday, but northwest winds will gust 25-35 kt through the day. Sub-VFR conditions along with light rain are possible Saturday north of a warm front which will waver near MRB and the metro areas. Restrictions are possible Sunday into early next week with shower activity from a weak front lingering in the region followed by a low pressure system. Winds could be gusty on Sunday, up to around 20-25 kt out of the northwest. Monday will be less gusty with winds out of the east/northeast.
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&& .MARINE...
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Small Craft Advisories are in effect for all waters through tonight. Winds are expected to reach gale force late tonight near southern Maryland as low pressure passes off the coast, thus a Gale Warning has been issued starting at midnight and going through 6 AM. Winds will then increase across all waters Friday. A Gale Warning has been issued for the entire day Friday for much of the waters. Highest gusts are likely in the upper Potomac and northern/central Bay zones. At this time, sub-SCA conditions are most likely Friday night into Saturday night. Winds over portions of the waters may approach SCA criteria during the day Sunday and Monday as a weak front and low pressure system move through the area.
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&& .FIRE WEATHER...
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For Friday, winds will increase (25 to 35 knots) with localized higher gusts in the highest elevations. These winds will be coupled with RHs in the low to mid 20s in the eastern WV panhandle, north-central and western MD as well as portions of northern and central VA. An SPS for elevated fire danger is in effect Friday afternoon through early evening in the aforementioned area. While 10-hr fuel moistures may not necessarily be near threshold, local observations from fire behavior analysts today indicated the 1-hr fuels were sufficient enough to burn this afternoon. Lingering cloud cover may inhibit the RHs a bit for a period in the morning but should diminish late in the morning into the early afternoon. Further extensions of the SPS may be needed overnight as new guidance comes in.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...Wind Advisory from 4 AM to 8 PM EDT Friday for VAZ503-504. WV...Wind Advisory from 4 AM to 8 PM EDT Friday for WVZ501-502-505- 506. MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ530-531-535- 536-538>542. Gale Warning from 6 AM to 6 PM EDT Friday for ANZ530-531-535- 536-538>542. Small Craft Advisory until midnight EDT tonight for ANZ532>534- 537-543. Gale Warning from midnight tonight to 6 PM EDT Friday for ANZ532-533. Small Craft Advisory from 6 AM to 6 PM EDT Friday for ANZ534- 537-543. Gale Warning from midnight tonight to 6 AM EDT Friday for ANZ534-537-543. && $$ SYNOPSIS...CJL NEAR TERM...CJL/ADM SHORT TERM...CJL LONG TERM...CJL AVIATION...CJL/ADM MARINE...CJL FIRE WEATHER...CJL/ADM

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