


Area Forecast Discussion
Issued by NWS Sterling, VA
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Issued by NWS Sterling, VA
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-- Discussion containing changed information from previous version are highlighted. --640 FXUS61 KLWX 101933 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 333 PM EDT Thu Jul 10 2025 .SYNOPSIS...-- Changed Discussion --A weak front will remain north of the region through Friday. Weak high pressure will build over the area Saturday, then another front may drop southward toward the area Sunday. This cold front tracks through the region early next week before stalling off to the south.-- End Changed Discussion --&& .NEAR TERM /THROUGH TONIGHT/...-- Changed Discussion --Relative to the previous couple of days, the local radar imagery shows much less activity across the region. A stubborn area of low stratus continues to advect eastward in time, but still remains a fixture across areas east of I-64. Radar returns remain quite weak under this overcast deck which are likely yielding up to a couple hundredths of an inch of rain. Off to the west, an agitated cumulus field has developed along the Allegheny Front. However, radar trends are not terribly promising as most echoes have collapsed fairly quickly after genesis. Eventually expect these towers to utilize the 1,500 to 2,000 J/kg of surface-based CAPE to produce isolated afternoon to evening thunderstorms. Elsewhere, will continue to monitor a west-east axis of convection stretching from southern New Jersey back across northern Delaware. Current instability values are quite high over northeastern Maryland, but cloud cover remains abundant. Off to the south near the I-64 corridor, the Weather Prediction Center has maintained a Slight risk for excessive rainfall (i.e., flash flooding). The current radar/satellite trends suggest no imminent threats, but there is some loose high- resolution model signal of active convection later today. Will maintain higher probabilities for showers and thunderstorms this afternoon and evening. Given the robust cloud cover across the area, temperatures have been cooler than recent days. Most locations are confined to the low 80s, with a few spotty mid 80s. Despite this cool down, the local region remains squarely in the warm sector with the synoptic frontal boundary in southern New York. This warm/humid air mass continues into the overnight hours with forecast low temperatures in the upper 60s to low 70s, slightly cooler from the Blue Ridge westward. Given light winds and a moist low-level troposphere, patchy fog may become a bit more widespread overnight. Areas more vulnerable to dense fog could see some more significant visibility reductions at times.-- End Changed Discussion --&& .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...-- Changed Discussion --The synoptic pattern and its weak gradients remain a fixture in the forecast ahead. Behind a rather weak trough, mid/upper heights will slowly rise in time on Friday into Saturday. This results in an uptick in temperatures with daily highs pushing into the upper 80s to low 90s. For mid-July climatology, those are fairly typical for the time of year. With persistent dew points topping out in the upper 60s to mid 70s, ample instability will trigger diurnally-forced showers and thunderstorms. The latest suite of high-resolution models do not show too great of convective coverage. This is likely owing to a lack of meaningful forcing and rising heights aloft. In this case, convection may be more tied to the terrain and mesoscale boundaries (i.e., bay/river breezes). The current Storm Prediction Center outlook maintains a Marginal risk for severe thunderstorms, mainly along and west of the Blue Ridge. Heading into Friday night, little change is expected from the previous night. An active summertime pattern continues into the first half of the weekend. Convective chances do go up on Saturday with afternoon/evening probabilities around 40 to 60 percent. While diurnal heating and terrain circulations will likely work their magic in convective initiation, it remains to be seen where forcing aloft and previous convective complexes act on renewed development. Forecast high temperatures will again be in the upper 80s to low 90s. Seasonable conditions persist into the overnight hours with mild temperatures on tap.-- End Changed Discussion --&& .LONG TERM /SUNDAY THROUGH THURSDAY/...-- Changed Discussion --Summer pattern will continue for the foreeseable picture with no big fronts to scour out the low-level moisture. A sharp mid-level trough is fcst to traverse the area Monday afternoon and enhance the thunderstorm potential. This trough will likely bring a threat of more widespread t-storms and the risk of scattered severe t-storms Monday. After Monday, the trough axis will shift east with upper level ridging building to the NW, likely causing a sharp decrease in t-storm coverage. Temperatures will remain at or slightly above average, especially at night.-- End Changed Discussion --&& .AVIATION /19Z THURSDAY THROUGH TUESDAY/...-- Changed Discussion --Based on the latest radar/satellite trends, have pulled the PROB30 groups out of the D.C. terminals. However, despite a lackluster appearance on radar, will stay the course with the TEMPO group between 20-23Z at KCHO. Otherwise, the main story has been the gradual eastward progression of an MVFR stratus deck. This has largely curbed any convective chances thus far. Otherwise, expect VFR conditions with somewhat light and variable winds. For tonight, calm winds and moist conditions will favor patchy fog development across the area. MVFR conditions are shown for most terminals, but with IFR conditions at KCHO and KMRB. This should eventually burn off an hour or two after sunrise on Friday. For Friday into Saturday, while conditions will be mainly VFR, convective chances each afternoon/evening could certainly lead to some restrictions. Probabilities are a bit higher on Saturday regarding thunderstorm chances. Gradients remain rather weak, but winds should mainly have a south to southeasterly component to them. Numerous to widespread t-storms, some possibly severe Monday afternoon.-- End Changed Discussion --&& .MARINE...-- Changed Discussion --While synoptic winds remain weak through Saturday given a lack of meaningful gradients, hazardous marine conditions would come from any convective activity. The threat for showers and thunderstorms today have diminished and are more focused toward the southern waters. However, during the following couple of days, thunderstorm chances go up, particularly by Saturday. Thus, there is some threat for Special Marine Warnings, particularly for the stronger cells. Sub-SCA conditions likely through much of the CWF 5-day fcst period.-- End Changed Discussion --&& .TIDES/COASTAL FLOODING...-- Changed Discussion --Over the course of the next few days, water levels slowly become more elevated in time given persistent southerly winds. This carries some of the more sensitive locations into Action stage (i.e., Annapolis and Baltimore), particularly during the higher of the two astronomical high tide cycles. The Stevens Ensemble system supports this gradual uptick in anomalies into the weekend.-- End Changed Discussion --&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...BRO NEAR TERM...BRO SHORT TERM...BRO LONG TERM...LFR AVIATION...LFR/BRO MARINE...LFR/BRO TIDES/COASTAL FLOODING...BRO/LFR