Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 240802 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 402 AM EDT Fri May 24 2019 .SYNOPSIS... A cold front will drift southward into the area this morning, settling near southern Virginia this evening. High pressure will crest over the area tonight, migrating off the Mid-Atlantic coast on Saturday. A weak cold front will approach from the north and linger nearby Sunday and Monday. Bermuda high pressure sets up toward the middle portion of next week, resulting in hot and humid conditions over much of the eastern United States. && .NEAR TERM /THROUGH TONIGHT/... Radar activity has waned significantly over the last 12 hours, with just a few weak showers heading toward central Virginia. A cold currently situated near the Mason Dixon Line will continue its track southward into our CWA this morning, settling across southern Virginia by this evening. As a result, drier air will filter into the area today, as dewpoints currently well into the 60s fall back into 50s by this afternoon. The drier air will be transported on increasing northwesterly flow in the wake of the front, which will be breezy at times today. Mostly clear skies early this morning will persist today, allowing for ample sunshine and temperatures rising into the low to middle 80s. While temperatures will be above normal for late May, the drier air will definitely take away the preview of summer we experienced yesterday. High pressure centered over the Great Lakes this morning will transit overhead tonight, turning winds light and northerly, while delivering dry conditions and temperatures ranging in the middle 50s to lower 60s. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Increasing clouds expected Saturday morning as the high shifts off the Mid Atlantic coast and the frontal boundary starts to lift northward as a warm front, settling near the Potomac Highlands by days end. The shifting high will also veer winds southerly, helping pump back into the area increasing humidity late in the day. As a result, afternoon showers and a few thunderstorms will be possible mainly along and west of the I-81 corridor. Only carrying chance POPs for now, so definitely not a washout for our mountain zones. Temperatures will actually be a touch cooler on Saturday compared to today as the warm front doesn`t actually lift through the area until Saturday night. Highs will top out in the lower 80s for most. A few showers will be possible across our northern tier Saturday night as the warm front does lift through the area, but a majority of locations will remain dry. Lows Saturday night holding in the middle 60s. Much warmer and humid conditions forecast on Sunday as the warm front races northward into New England and winds taking on a downsloping westerly flow. Temperatures will rise well into the 80s, with some low 90 degree readings quite possible across central Virginia. A weak cold front will be approaching from the north on Sunday, residing just to our north by Sunday evening. The warm and humid conditions combined with the approaching front will allow for afternoon showers and storms to spark, favoring northern/western MD and eastern WV with the highest POPs. Models are hinting at convection earlier in the day across IL/IN tracking eastward along the frontal boundary and nearing our area Sunday evening and night. Given the likely nocturnal arrival of this activity, which will be weakening as it travels eastward, and a meager shortwave trough tracking overhead, will advertise showers and isolated thunderstorms during the evening, with a chance of showers continuing overnight. That being said, there will be enough instability/shear, as well as the frontal forcing to bring a potential for at least some strong thunderstorms across western MD and eastern WV. Will have to monitor this threat over the next couple of days. && .LONG TERM /MONDAY THROUGH THURSDAY/... A cold front will drop into the area from the north for Memorial Day, resulting in a modest cool-down along with more clouds and the risk of a shower or t-storm. This trend reverses by Tuesday, as a wave of low pressure passing to the north helps nudge the front back to our north and allows warm humid air to overspread the region once again. Bermuda high pressure will thus regain control, and its strength should increase by Wednesday, with latest guidance hinting at widespread low-mid 90s for afternoon highs mid-week. By Thursday, a cold front will be approaching from the northwest, resulting in a modest drop in temps and an increased risk of showers and t-storms. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... A cold front will sink southward across the terminals this morning, settling to the south by this evening. As such, drier air will filter into the region on breezy northwest winds, gusting upwards of 25 knots through this afternoon. High pressure will transit the terminals overnight and early Saturday, with continued VFR conditions. Afternoon showers/storms may yield an episode of sub VFR conditions at MRB, but restrictions at all other terminals not expected with a developing light southerly wind. Better chance of showers and storms Sunday afternoon and overnight as a cold front nears the terminals from the north, thus the chance for brief sub VFR conditions exists. Low clouds could impact the terminals Monday or Tuesday on the cool side of a slow moving frontal boundary. By afternoon both days, the risk of sub-VFR conditions should generally lessen, particularly Tuesday as the front lifts back north. A stray shower or t-storm is also possible, especially Monday. && .MARINE... As a cold front pushes southward through the waters today, gusty northwest winds will take hold. As such, SCA conditions are expected until early this evening across all waters. High pressure will transit the waters overnight, with lighter winds prevailing. Increasing southerly flow is expected on Saturday as the high shifts offshore. Marginal SCA gusts will be possible Saturday afternoon and night, but confidence in occurrence and coverage is too low at this time for any SCA. Showers/storms could cross the waters late Sunday and Sunday night, delivering gusty winds. Outside of this activity, winds are expected to remain westerly and sub SCA. A shower or thunderstorm is possible Monday, though the risk of special marine warnings appears to be low. Conditions should be more tranquil Tuesday as a slow moving frontal boundary lifts back north of the waters. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 7 AM this morning to 8 PM EDT this evening for ANZ530>543. && $$ SYNOPSIS...BKF NEAR TERM...BKF SHORT TERM...BKF LONG TERM...RCM AVIATION...BKF/RCM MARINE...BKF/RCM

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