


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
066 FXUS61 KLWX 011807 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 207 PM EDT Fri Aug 1 2025 .SYNOPSIS... A strong area of high pressure over the northeast CONUS through this weekend will gradually shift offshore early next week. High pressure weakens into next week while the next front is expected to slowly approach from the south. && .NEAR TERM /THROUGH TONIGHT/... Strong 1030 mb high pressure center over northwest Wisconsin will gradually build eastward over the weekend bringing a significant change in air mass with temperatures more typical of September. For today, a low cloud overcast is expected to persist north of a frontal zone located south of the area with isolated to scattered showers are expected as an upper trough swings across the Northeast and Mid-Atlantic states. It will be refreshingly much cooler with highs in the mid 70s under a noticeable northerly breeze. Clearing will occur from north to south this evening as high pressure continues to build from the west and pushes drier air into the region. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... High pressure will set up over the northeast CONUS throughout the weekend. This will result in slightly below normal temperatures and a much less humid air mass. Expect highs in the low to mid 80s, with Sunday being the warmer of the two, along with dew points in the upper 50s to low 60s. Overnight lows will also be slightly below average, dropping into the 50s to low 60s (closer to mid 60s in the metros). && .LONG TERM /MONDAY THROUGH FRIDAY/... 1022-1024mb high pressure will remain wedged down the eastern side of the Appalachians from north-central PA through Monday. Meanwhile, quasi-zonal flow will continue aloft leading to a continuation seasonably cool temperatures, low humidity, and dry conditions at least for early August standards. Highs Monday will push into the mid to upper 80s east of the Alleghenies with mid to upper 70s and low 80s across the Shenandoah Valley/Blue Ridge/Catoctins/higher elevations above 2000 feet. Dewpoints will rise slightly into the upper 50s and low 60s as the wedge of high pressure weakens while shifting east into western New York and central New England. Lows Monday night will fall back into the low to mid 60s east of the Blue Ridge (Baltimore/Washington DC metros upper 60s) with mid to upper 50s over the mountains. Wedging high pressure over the interior Northeast and northern Mid- Atlantic will continue to weaken Tuesday while shifting offshore Tuesday into midweek. Meanwhile, a potent upper level trough will dig across the Great Lakes and through the southeastern U.S CONUS sending Gulf moisture northward into the region midweek. Showers and t-storm chances will increase as a result of this moisture being funneled northward between the western Atlantic ridge and incoming shortwave trough. Highest chances for storms Tuesday and Wednesday will be during the diurnal heating period over the mountains. This is due in part to the slow erosion of the wedge/residual dry air as high pressure kicks offshore. The wedge of high pressure will finally erode out Thursday as the trough swings through the region. In addition to the trough, will be an area of low pressure off the Carolinas. This may further inhibit the influx of moisture from Gulf as well as Atlantic later this week. With that said, have kept slightly higher shower and thunderstorm chances in Thursday and Friday as low and mid-levl moisture increases across the region. No real significant frontal boundaries look to cross the area during this time to flip over the airmass into the upcoming weekend ahead. Temperatures will remain at or just below average through at least Thursday. Highs each day will push into the upper 70s to mid 80s with overnight lows in the upper 50s and low to mid 60s. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... MVFR CIGs continue over the next few hours, but starting to see conditions improve from north to south. That trend will continue through around 21Z roughly. Clearing is expected from north to south later this evening as drier air filters in behind the cold front. Scattered to broken decks of stratocumulus clouds are expected during the day both Saturday and Sunday with clearing expected during the overnight hours. Predominantly VFR conditions are expected Monday through Thursday. Some temporary reductions are possible Tuesday through Thursday afternoons especially over the mountain terminals where showers and thunderstorms look to occur. Winds will remain out of the east and northeast MOnday and Tuesday at less than 10 kts. Winds change back to the west and southwest by the middle of next week. && .MARINE... Strong northerly winds will continue to strengthen through this afternoon, with Small Craft Advisories in effect for all waters at this time. Northerly winds will start to diminish late tonight into Saturday. Small Craft Advisories will gradually drop off through the day on Saturday as this occurs, with sub-SCA conditions expected thereafter. No marine hazards are expected Monday and Tuesday as high pressure sits nearby. Sub-SCA level winds are expected out of the east and northeast at less than 15 kts. Winds turn back to the west and southwest Wednesday and Thursday as high pressure pushes offshore. && .TIDES/COASTAL FLOODING... Winds turn onshore over the weekend as high pressure sets up over the northeast CONUS. This wind direction will result in increased tidal anomalies through Sunday, which could push the sensitive tidal sites into minor flood stage, particularly at Annapolis. This water will then also make a run up the Tidal Potomac Sunday into Monday, which could bring those sites close to minor by late Sunday into Monday. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Small Craft Advisory until midnight EDT tonight for MDZ008. VA...None. WV...None. MARINE...Small Craft Advisory until midnight EDT tonight for ANZ530-531- 535-538-539. Small Craft Advisory until noon EDT Saturday for ANZ532-533- 536-540>542. Small Craft Advisory until midnight EDT Saturday night for ANZ534-537-543. && $$ SYNOPSIS...CJL NEAR TERM...CJL SHORT TERM...CJL LONG TERM...EST AVIATION...CJL/EST MARINE...CJL/EST TIDES/COASTAL FLOODING...CJL