Area Forecast Discussion
Issued by NWS Sterling, VA

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493 FXUS61 KLWX 290050 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 850 PM EDT Tue May 28 2024 .SYNOPSIS... A cold front will move over the area Wednesday night, bringing unsettled conditions tomorrow afternoon and into the early evening. In the wake of the frontal passage, high pressure will build in from the northwest and will linger through the weekend. && .NEAR TERM /THROUGH WEDNESDAY/...
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As of shortly before 9 PM this evening, a broken line of showers and a couple thunderstorms was pivoting across I-95. The strongest activity was just southeast of DC with reports of 40-50 mph wind gusts and pea size hail. Activity should wane over the next hour with the loss of heating. Low temperatures will fall into the 50s for most with those at higher elevations dipping into the upper 40s. Metro areas will be slightly warmer tonight, with low temperatures staying in the low 60s.
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&& .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... An upper level trough will pivot overhead Wednesday as a reinforcing cold front moves through the area Wednesday evening. Shortwave energy moving overhead tomorrow afternoon will bring increased coverage for showers and thunderstorms. QPF totals generally remain below 0.25" so flooding threat remains low. The airmass will be relatively stable with limited instability, so the threat for severe weather remains low. Shower and thunderstorm chances will decrease Wednesday night with the loss of daytime heating. Dry conditions are expected on Thursday as dry air moves in aloft. Winds remain out of the northwest, gusting up to 15 knots in the wake of a frontal passage. There will be a temperature gradient across the forecast area on Wednesday with high temperatures ranging from the low 60s in the Alleghenies to nearing 80 along I-95 and in the southern portions of the area. Overnight low temperatures will be in the upper 40s at higher elevations with the rest of the area staying in the 50s. In the wake of the frontal passage Wednesday night, high temperatures on Thursday will be a few degrees cooler when compared to the previous day. Highs will be in the low 60s for those at higher elevations with the rest of the area in the mid 70s. Low temperatures on Thursday night dip into the low 40s with those further east staying in the mid to low 50s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... The trough axis will be to the east Friday, so there should be less cloud cover overall. Northwest flow will support another day with below normal temperatures and low humidity. The surface high will move nearly overhead by Saturday morning, so there should be favorable radiational cooling Friday night. Outlying areas should easily fall into the 40s again, while some of the deeper valleys could fall into the 30s. A narrow ridge will build aloft Saturday while the surface high continues to drift to the southeast. Temperatures will warm several degrees to around or above normal. The ridge axis will push to the east Sunday and a more zonal flow will develop across the eastern half of the country. Timing of individual waves in this regime is uncertain, rather there will just be a gradual return to more unsettled weather as we remain on the warm side of low pressure systems tracking well to the north. Ensemble precipitation probabilities and experimental convective machine learning guidance suggest potential for a more active day on Tuesday. Temperatures will continue to run above normal through early next week while humid air gradually makes a return. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
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Any convective activity should wane by 02Z. VFR conditions are expected overnight as westerly winds diminish this evening. Winds will shift to northwesterly tonight under clearing skies. Winds remain out of the northwest Wednesday blowing 5-10 knots. Shower and thunderstorm chances increase Wednesday afternoon, so introduced -SHRA to IAD, DCA, and BWI. Though winds remain out of the northwest Thursday, winds gust up to 15 knots in the wake of a cold front passage. VFR conditions are expected both days with the precipitation chance decreasing for Thursday. No significant weather expected Friday and Saturday with high pressure. Low chance of a thunderstorm Sunday depending on the timing of the next disturbance.
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&& .MARINE...
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Winds decrease to below SCA criteria tonight and shift to northwesterly. As a cold front moves over the area, showers and thunderstorms may impact the waters on Wednesday. SMWs may be needed as any storms move over the waters. In the wake of the frontal passage, northwesterly winds pick up to SCA criteria Wednesday night. Winds are expected to remain below SCA criteria on Thursday. Lingering marginal SCA conditions are possible Friday morning, but overall winds will be lessening through Saturday as high pressure builds into the area. Winds will become southerly by Sunday but may not increase appreciably. & .TIDES/COASTAL FLOODING... Winds will remain out of the west today before shifting to northwesterly tonight through Thursday. This will lead to decreasing tidal anomalies with no coastal flooding anticipated for the next few days.
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&& .TIDES/COASTAL FLOODING...
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Winds will shift to northwesterly tonight through Thursday. This will lead to decreasing tidal anomalies with no coastal flooding anticipated for the next few days.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...None.
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&& $$ SYNOPSIS...AVS NEAR TERM...AVS/DHOF SHORT TERM...AVS LONG TERM...ADS AVIATION...ADS/AVS/DHOF MARINE...ADS/AVS/DHOF TIDES/COASTAL FLOODING...LWX