Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 280844 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 344 AM EST Wed Feb 28 2024 .SYNOPSIS...
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A strong cold front will approach the area later today bringing widespread showers, gusty winds, and even a few thunderstorms. Dry high pressure returns to the area Thursday with breezy conditions and much cooler temperatures. High pressure slides offshore Friday with increasing precipitation chances heading into the weekend as an area of low pressure passes to the south. Additional precipitation chances are likely with another front early next week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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More widespread precipitation arrives today as a strong cold front moves into the region. 00z hi-res/deterministic/ensemble guidance shows good agreement with the front arriving this afternoon before quickly racing east tonight into early Thursday morning. Before the front arrives, a few breaks in the clouds can be expected in the wake of the warm front exiting later this morning. This will push high temperatures quickly into the mid to upper 60s to perhaps 70 degrees. Winds will also increase out of the south/southwest at 10 to 15 mph with gusts 25-35 mph this morning into midday. The heaviest precipitation looks arrive later this afternoon and into this evening (3-8pm) before things quickly ending from west to east before midnight. Thunderstorm probabilities are low, but are not zero, for this front, given the increasing dewpoints and strong forcing. A marginal risk for severe weather has been issued from north-central MD and northern VA west into the MD/WV mountains. Forecast instability values are generally less than 500 J/kg with 0- 6 km shear values over 50-60 kts. With that said, a narrow line of shallow convection may develop along and ahead of the front later this afternoon and evening. Lightning will be limited with wind as the main concern as this linear convective line pushes through. Gusts of 45-55 mph can be expected with this convective line of showers as it pushes from west to east across the region. Rainfall amounts 0.5 to 1 inch can be expected areawide outside of the Alleghenies where 1 to 2 inches of rain is expected. Flood Watches remain in effect for western Grant, western Mineral, and Garrett counties to encompass this heavier rain threat combined with already saturated soils and elevated from melted snowpack in this area. Southerly winds will quickly switch to the northwest in the wake of the front this evening into tonight. This will lead to residual precipitation switching from rain showers to brief snow showers over the mountains. With precipitation quickly exiting any snow accumulation will be fairly light (coating to perhaps an inch) and confined to elevations above 2500 feet (i.e western upslope zones of the Allegheny Front). Winds will continue to increase Wednesday night into Thursday due in part to a strong 850 mb low level jet in excess of 50-60 kts+ and strong pressure rises as high pressure builds in. Gusts of 45 to 50 mph can be expected areawide with gusts of nearly 60 mph possible at the highest elevations and through the mountain gaps in Grant County where a High Wind Warning has been issued. Wind advisories have been issued to encompass this threat starting later this evening and continuing into early Thursday AM. Lows tonight will fall into the upper 20s and low to mid 30s. Mountain locations west of I-81 will crash into the teens and low 20s. Wind chill factors will quickly fall into the teens and 20s Thursday morning with single digit values over the mountains.
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&& .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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Winds will diminish rapidly by midday Thursday as high pressure gradually builds into the area. The high pressure center will settle overhead by Fri morning leading to a cold night in the 20s. Rain arrives Fri night associated with a weak sfc low developing along a coastal front. .LONG TERM /SATURDAY THROUGH TUESDAY/... March will start out dry with high pressure shifting off the east coast Friday morning. Cloud cover and southerly winds will increase throughout the day in return flow of high pressure. High temperatures on Friday will be in the 50s for most with those at higher elevations staying in the upper 40s. Precipitation chances will gradually increase southwest to northeast Friday evening and into the overnight as an area of low pressure tracks just south of the forecast area. Overnight low temperatures will be in the upper 30s to low 40s for most. For the weekend, precipitation is likely Saturday morning before decreasing to a chance of precipitation in the afternoon as shortwave energy pivots to our north. The highest chances for precipitation are along and east of the Blue Ridge Saturday morning as an area of surface low pressure tracks off the east coast. Temperatures will moderate throughout the weekend and into Monday as weak upper level ridging builds overhead. High temperatures on Saturday and Sunday rise to the upper 50s to mid 60s each day. Overnight low temperatures dip into the mid 40s to low 50s each night. Precipitation chances linger Sunday and into the workweek as a front stalls to our south and a low pressure system approach from the west. High temperatures Monday will continue to be in the 60s areawide with overnight low temperatures dipping into the 40s.
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&& .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
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MVFR showers and intermittent pockets of IFR will accompany a warm front this morning followed by a cold front later this afternoon and evening (20-02z/3-9pm). The strong cold front will bring multiple rounds of rain showers and perhaps a few thunderstorms to the terminals along with gusty winds. MVFR ceilings will be possible with precipitation activity. There could be a few breaks of VFR conditions midday between batches of rain with each of the fronts. Early Thursday could start as MVFR before becoming VFR with a gusty NW wind. Winds increasing through this morning from the south 15 to 25 knots gusts 35-40 knots this afternoon into tonight. Locally higher gusts are possible along the immediate front where shallow convection may develop. NW gusts Thursday up to 25 to 30 knots are possible, particularly during the late morning to afternoon hours. Winds decrease considerably into the night as a strong high pressure moves in from the west. VFR conditions are expected Friday as high pressure pushes offshore. Winds will switch back to the southerly direction with gusts up to 20 kts. Sub-VFR conditions return at times Saturday and Sunday as an inverted trough sits just off the coast and area of low pressure passes south of the region. Rain chances will increase at terminals, especially east of the Blue Ridge mountains (IAD, DCA, BWI, & CHO). Highest precipitation chances will be late Friday night through Saturday midday. Coverage becomes a bit more isolated for the remainder of Saturday into Sunday. Winds will switch to the east and northeast yielding increased low/mid level clouds and the potential for low cigs during this period. VFR conditions return briefly Monday before additional sub-VFR conditions Tuesday into Wednesday as another series of fronts push through the region.
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&& .MARINE...
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SCAs remain in effect for all waters this morning with Gale Warnings this afternoon into early Thursday morning. Winds will continue to increase this morning with gusts between 25 to 30 kts. Southerly winds of 15 to 25 kts sustained can be expected this afternoon and into tonight with gusts up to 40 kts as the pressure gradient tightens across the region. Winds will switch to the west/northwest later this evening into early Thursday morning with quick pressure rises as dry high pressure builds in. Sustained speeds of 20 to 30 kts can be expected with gusts up to 40 kts at times. This is the most likely period of the highest gusts with a slow tapering of the winds back to SCA levels late Thursday afternoon. Winds fall below SCA levels late Thursday night as a strong ridge of high pressure settles over the waters. High pressure shifts offshore Friday leading to southerly return flow. This could lead to a period of SCA level gusts up to 20 kts due to southerly channeling Friday afternoon and evening. Winds decrease back below SCA levels Friday night into Saturday. Sub-SCA east to northeast winds are expected throughout the weekend ahead.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...Wind Advisory from 6 PM this evening to 4 AM EST Thursday for DCZ001. MD...Wind Advisory from 6 PM this evening to 4 AM EST Thursday for MDZ003>006-008-011-013-014-503>508. Flood Watch through this afternoon for MDZ001. Wind Advisory from 1 PM this afternoon to 5 AM EST Thursday for MDZ001-501-502. VA...Wind Advisory from 6 PM this evening to 4 AM EST Thursday for VAZ025>031-040-053-054-501-505-506-508-526. Wind Advisory from 1 PM this afternoon to 5 AM EST Thursday for VAZ503-504-507. WV...Wind Advisory from 6 PM this evening to 4 AM EST Thursday for WVZ050>053-055. Flood Watch through this afternoon for WVZ501-503. Wind Advisory from 1 PM this afternoon to 5 AM EST Thursday for WVZ503-504-506. High Wind Warning from 1 PM this afternoon to 5 AM EST Thursday for WVZ501-502-505. MARINE...Small Craft Advisory until noon EST today for ANZ530>543. Gale Warning from noon today to 4 AM EST Thursday for ANZ530>543.
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&& $$ SYNOPSIS...EST NEAR TERM...LFR/EST SHORT TERM...LFR/EST LONG TERM...EST AVIATION...LFR/EST MARINE...LFR/EST

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