894  
FXUS61 KLWX 040117  
AFDLWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
917 PM EDT SUN AUG 3 2025  
   
SYNOPSIS  
 
DRY CONDITIONS, LOW HUMIDITY, AND SEASONABLY COOL TEMPERATURES ARE  
EXPECTED THROUGH MONDAY AS WEDGING HIGH PRESSURE DRIFTS TOWARD NEW  
ENGLAND. HIGH PRESSURE BEGINS TO WEAKEN AS IT PUSHES OFFSHORE  
TUESDAY INTO WEDNESDAY ALLOWING THE HUMIDITY AND SHOWER CHANCES TO  
RETURN. AN AREA OF LOW PRESSURE WILL MOVE ALONG THE COAST WITH A  
WEAK FRONTAL BOUNDARY APPROACHING FROM THE WEST THURSDAY AND  
FRIDAY.  
 
 
   
NEAR TERM /THROUGH MONDAY/  
 
ELONGATED HIGH PRESSURE IS LOCATED NORTH OF THE AREA THIS  
EVENING. ALOFT, THERE IS A SHORTWAVE TROUGH OVER THE CENTRAL  
APPALACHIANS. A JET STREAK AHEAD OF THIS FEATURE HAS RESULTED IN  
A CIRRUS SHIELD SPREADING OVER PARTS OF THE AREA, BUT THESE  
CLOUDS WILL DEPART OVERNIGHT. MOSTLY CLEAR SKIES AND LIGHT WINDS  
WILL LEAD TO ANOTHER COOL NIGHT WITH LOWS IN THE MID TO UPPER  
50S AND LOW 60S (MOUNTAINS MID TO UPPER 40S AND LOW 50S).  
LOCATIONS SUCH AT BITTINGER, MD, MILL GAP/MUSTOE, VA, THE  
GLADES, MD, AND BAYARD, WV COULD SEE LOWS IN THE UPPER 30S AND  
LOW 40S). PATCHY FOG IS POSSIBLE, ESPECIALLY IN THE WESTERN  
RIVER VALLEYS.  
 
 
   
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/  
 
SURFACE RIDGE OF 1022-1024MB REMAINS WEDGED DOWN THE EASTERN SIDE OF  
THE APPALACHIANS MONDAY. MEANWHILE, QUASI-ZONAL FLOW REMAINS ALOFT  
LEADING TO SLIGHTLY BELOW SEASONAL NORMAL TEMPERATURES FOR EARLY  
AUGUST, LOW HUMIDITY, AND DRY CONDITION. MORE SUNSHINE MONDAY WILL  
LEAD TO HIGHS IN 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 NORTH AND EAST TOWARD THE NORTHERN  
MID-ATALNTIC/INTERIOR NORTHEAST. 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 EARLY WEDNESDAY. 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.  
 
UNCERTAINTY IN THE FORECAST BEGINS TO SHOW UP AS EARLY AS TUESDAY  
AFTERNOON WHEN SOME EPS/GEFS MEMBERS SHOWING LIGHT RAIN/DRIZZLE  
ARRIVING ACROSS PORTIONS OF THE SHENANDOAH VALLEY, CENTRAL VA  
PIEDMONT, AND ALLEGHENY HIGHLANDS REGION. GIVEN THE SLOW NATURE OF  
THE CUTOFF UPPER LEVEL TROUGH TO THE WEST AND THE STRONG HIGH  
PRESSURE CENTER SETTLING OVER NORTHERN NEW ENGLAND/SOUTHEAST QUEBEC,  
THE SLOWER SOLUTIONS ARE MORE LIKELY TO VERIFY. WITH THAT SAID,  
CARRYING 15 TO 25 PERCENT POPS MAINLY WEST ALLEGHENIES AND OVER THE  
SOUTHERN SHENANDOAH VALLEY/CENTRAL BLUE RIDGE WHERE AMPLE MOISTURE  
WILL BUILD IN FIRST DUE TO UPSLOPE EASTERLY/SOUTHEASTERLY FLOW. ONCE  
AGAIN, CONFIDENCE IS LOW FOR PRECIP TUESDAY GIVEN THE RESIDUAL DRY  
AIR ALOFT FROM WEDGING HIGH PRESSURE FIGHTING OFF LIGHT/MOIST  
EASTERLY FLOW.  
 
 
   
LONG TERM /WEDNESDAY THROUGH SUNDAY/  
 
PLENTY OF UNCERTAINTY REMAINS IN THE EXTENDED PERIOD IN REGARDS TO  
THE PLACEMENT AND TIMING OF A SLOW MOVING (NEARLY CUTOFF) UPPER  
LEVEL TROUGH FROM THE WEST AND AN AREA OF LOW PRESSURE WORKING ALONG  
THE SOUTHEAST U.S COAST. THESE TWO FEATURES COMBINED WITH THE  
INTERACTION OF BROAD WEDGING HIGH PRESSURE OFF THE NORTHERN NEW  
ENGLAND COAST/SOUTHERN CANADIAN MARITIMES WILL INFLUENCE HOW MUCH  
DEEP TROPICAL MOISTURE IS FUNNELING INTO THE REGION.  
 
AS OF NOW, HAVE WENT AHEAD AND INCREASED SHOWER AND THUNDERSTORM  
CHANCES (POPS 30-50 PERCENT), ESPECIALLY DURING THE AFTERNOON AND  
EVENING HOURS WEDNESDAY THROUGH FRIDAY AS ONSHORE FLOW INCREASES  
WITH THE LOW PRESSURE SYSTEM JUST OFF THE NC COAST AND AN INVERTED  
TROUGH NEARBY. HAVE BACKED OFF THE RAIN CHANCES FOR THE UPCOMING  
WEEKEND TO AROUND 15 TO 30 PERCENT. THE 12Z GFS/GEFS FAVORS LOW  
PRESSURE COMING UP ALONG THE COASTAL CAROLINAS AND INTO EASTERN  
VA/DELMARVA FRIDAY INTO SATURDAY LEADING TO INCREASED SHOWER AND  
THUNDERSTORM CHANCES DURING THIS TIME. THE 12Z ECMWF/EPS FAVORS MORE  
OF THE THURSDAY THROUGH FRIDAY TIMEFRAME FOR TROPICAL MOISTURE AS A  
STRONG BAROCLINIC ZONE SETS UP OVER THE REGION. THE ECMWF/EPS IS  
ALSO MORE AGGRESSIVE WITH HIGH PRESSURE WEDGING ITSELF BACK INTO THE  
AREA FOR THE UPCOMING WEEKEND ALLOWING PRECIPITATION CHANCES TO  
DECREASE. THE 12Z CANADIAN IS A BLEND OF THE TWO AFOREMENTIONED  
SOLUTIONS ABOVE ALONG WITH CENTRAL GUIDANCE. IT STILL CARRIES HEAVY  
PROBABILITY OF PRECIPITATION THURSDAY INTO FRIDAY WHILE LINGERING IT  
INTO THE WEEKEND.  
 
WITH ALL SAID, SPECIFICS SURROUNDING RAIN CHANCES, AMOUNTS, AND WIND  
WILL CONTINUE TO REMAIN UNCERTAIN UNTIL MODELS CAN GET A BETTER GRIP  
ON THE FEATURES AT PLAY. INCREASED ONSHORE FLOW WILL REMAIN LEADING  
TO SEASONABLY NORMAL TO SLIGHTLY BELOW NORMAL TEMPERATURES AND  
INCREASED CLOUDINESS THROUGHOUT THE EXTENDED PERIOD. EXPECT HIGHS IN  
THE 70S AND 80S WITH LOWS IN THE 50S AND 60S.  
 
 
   
AVIATION /01Z MONDAY THROUGH FRIDAY/  
 
LIGHT WINDS AND MOSTLY CLEAR SKIES MAY RESULT IN SOME VALLEY FOG  
LATE TONIGHT. THIS COULD AFFECT MRB, SO HAVE ADDED AN MVFR  
MENTION FOR NOW. FEWER CUMULUS ARE EXPECTED MONDAY AS LOW LEVEL  
MOISTURE THINS, BUT MID AND HIGH LEVEL CLOUDS WILL INCREASE  
TOWARD EVENING. WINDS WILL REMAIN LIGHT AND SOMEWHAT VARIABLE,  
THOUGH GENERALLY BETWEEN A NORTHEAST AND SOUTHEAST DIRECTION.  
 
MOISTURE RETURNS TUESDAY ALONG WITH AN ISOLATED SHOWER WEST OF A  
LINE FROM MRB TO SHD. INCREASING EASTERLY FLOW TUESDAY NIGHT  
COULD BRING IN SUB-VFR CIGS AND PERHAPS A LITTLE FOG/DRIZZLE.  
 
HIGHER CHANCES FOR LOWER CIGS LOOK TO OCCUR WEDNESDAY THROUGH FRIDAY  
AS ONSHORE FLOW INCREASES FURTHER. IN ADDITION TO THE POTENTIAL FOR  
LOWER CIGS WILL BE SOME TEMPORARY REDUCTIONS DURING THE  
AFTERNOONS/EVENINGS WEDNESDAY THROUGH FRIDAY AS SHOWER AND  
THUNDERSTORM CHANCES RETURN. THIS IS IS DUE LARGELY IN PART TO AN  
UPPER LEVEL TROUGH APPROACHING FROM THE WEST AND AREA OF LOW  
PRESSURE THROWING TROPICAL MOISTURE INTO THE REGION FROM THE  
SOUTHEAST U.S COAST. HIGHEST CHANCES FOR RAIN APPEAR TO BE ALONG AND  
WEST OF THE BLUE RIDGE. WINDS CHANGE BACK TO THE WEST AND SOUTHWEST  
WEDNESDAY AND THURSDAY NEXT WEEK.  
 
 
   
MARINE  
 
NO MARINE HAZARDS ARE EXPECTED THROUGH TUESDAY AS HIGH PRESSURE SITS  
NEARBY. SUB-SCA LEVEL WINDS ARE EXPECTED OUT OF THE EAST AND  
NORTHEAST AT LESS THAN 15 KTS. SCA CONDITIONS LOOK TO RETURN  
WEDNESDAY THROUGH FRIDAY AS ONSHORE FLOW INCREASE WITH LOW PRESSURE  
MOVING NORTH FROM THE SOUTHEAST U.S COAST. SHOWER AND THUNDERSTORM  
CHANCES WILL ALSO RETURN TO THE WATERS DURING THIS TIME.  
 
 
   
TIDES/COASTAL FLOODING  
 
A COASTAL FLOOD ADVISORY REMAINS IN EFFECT FOR THE SHORELINE OF  
ANNE ARUNDEL CO. FOR THE OVERNIGHT HIGH TIDE CYCLE. HOWEVER,  
ANOMALIES HAVE TRENDED DOWN, AND IT'S POSSIBLE WATER LEVELS  
REMAIN JUST BELOW MINOR FLOOD STAGE.  
 
ONSHORE WINDS REMAIN THROUGH MIDWEEK AS HIGH PRESSURE SETS UP OVER  
THE NORTHEAST CONUS. THE EAST TO NORTHEAST WIND DIRECTION WILL  
RESULT IN ELEVATED TIDAL ANOMALIES WHICH COULD PUSH THE  
SENSITIVE TIDAL SITES NEAR MINOR FLOOD STAGE. HOWEVER, THE  
LATEST FORECASTS HAVE TRENDED DOWN A BIT, AT LEAST THROUGH  
WEDNESDAY.  
 
 
   
LWX WATCHES/WARNINGS/ADVISORIES  
 
DC...NONE.  
MD...COASTAL FLOOD ADVISORY UNTIL 6 AM EDT MONDAY FOR MDZ014.  
VA...NONE.  
WV...NONE.  
MARINE...NONE.  
 
 
 
 
 
SYNOPSIS...EST  
NEAR TERM...ADS/KRR  
SHORT TERM...KRR/EST  
LONG TERM...EST  
AVIATION...ADS/KRR/EST  
MARINE...KRR/EST  
TIDES/COASTAL FLOODING...LWX  
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