895  
FXUS61 KLWX 130118  
AFDLWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
918 PM EDT SAT JUL 12 2025  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL REMAIN IN PLACE OFFSHORE THROUGH THE UPCOMING  
WEEK. A WEAKENING COLD FRONT WILL MOVE THROUGH ON MONDAY, BEFORE  
STALLING OUT AND DISSIPATING. A STRONGER COLD FRONT WILL  
APPROACH FROM THE NORTHWEST BY NEXT WEEKEND.  
 

 
   
NEAR TERM /THROUGH SUNDAY/
 
 
A BROAD LINEAR ORIENTATION OF SHOWERS AND STRONG TO SEVERE  
THUNDERSTORMS ARE ALIGNED FROM ALLEGANY COUNTY MARYLAND TO  
AUGUSTA COUNTY VIRGINIA. THIS LINEAR CONVECTION WILL MOVE EAST  
AT 20 TO 30 MPH OVER THE NEXT COUPLE OF HOURS. THE MAIN THREAT  
WILL BE TORRENTIAL RAINFALL THAT COULD LEAD TO FLASH FLOODING,  
LIGHTNING, AND DAMAGING WINDS. AS MIDNIGHT ARRIVES, MOST OF THIS  
CONVECTION SHOULD WEAKEN AND/OR DISSIPATE. A FEW SHOWERS OR A  
THUNDERSTORM COULD STILL LINGER ACROSS THE VIRGINIA PIEDMONT OR  
ALONG THE MASON-DIXON REGION. OTHERWISE, TOWARD THE LATTER HALF  
OF THE NIGHT, SOME PATCHY FOG OR LOW CLOUDS COULD FORM IN SOME  
PLACES. LOWS WILL DROP INTO THE UPPER 60S TO MIDDLE 70S.  
 
A POTENT SHORTWAVE AND ASSOCIATED AREA OF LOW PRESSURE AT THE  
SURFACE WILL TRACK NORTHEASTWARD TOWARD HUDSON BAY SUNDAY.  
WE'LL ACTUALLY EXPERIENCE SLIGHT HEIGHT RISES ALOFT AS THIS  
OCCURS, BUT THE LOW-LEVEL MASS RESPONSE ASSOCIATED WITH THE  
SURFACE LOW WILL LEAD TO INCREASED MOISTURE (PWATS INCREASING TO  
NEAR OR ABOVE 2 INCHES) AND LOW-LEVEL CONVERGENCE. MODEL  
GUIDANCE IS IN GOOD AGREEMENT THAT STORMS WILL DEVELOP ALONG A  
WELL-DEFINED SURFACE TROUGH OVER THE POTOMAC HIGHLANDS AND  
SHENANDOAH VALLEY DURING THE EARLY TO MID AFTERNOON HOURS. THOSE  
STORMS WILL THEN SLOWLY TRACK EASTWARD, REACHING THE US-15  
CORRIDOR BY AROUND 5 OR 6 PM, AND THEN START TO WEAKEN AS THEY  
APPROACH THE I-95 CORRIDOR AROUND SUNSET.  
 
MODEL SOUNDINGS SHOW AROUND 2000-3000 J/KG OF MLCAPE, AROUND  
600-800 J/KG OF DCAPE, 10-15 KNOTS OF EFFECTIVE BULK SHEAR, AND  
PWAT VALUES INCREASING TO NEAR 2 INCHES. THE LOWER DCAPE VALUES  
MAY TEMPER THE POTENTIAL FOR DOWNBURSTS IN STORMS TOMORROW, BUT  
THE OVERALL HIGHER COVERAGE OF STORMS AND HIGHER PWAT VALUES MAY  
STILL MAKE WATER LOADED DOWNBURSTS POSSIBLE. SPC CURRENTLY HAS  
MUCH OF THE AREA OUTLOOKED IN A MARGINAL RISK FOR SEVERE STORMS.  
WITH PWAT VALUES APPROACHING 2 INCHES AND SIGNIFICANT  
INSTABILITY PRESENT, STORMS SHOULD BE CAPABLE OF PRODUCING VERY  
HEAVY RAINFALL. THAT COUPLED WITH SLOW STORM MOTIONS MAY MAKE  
FLASH FLOODING POSSIBLE TOMORROW AS WELL. WPC HAS MUCH OF THE  
AREA OUTLOOKED IN A SLIGHT RISK FOR EXCESSIVE RAINFALL TOMORROW.  
 

 
   
SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/
 
 
A DECAYING COLD FRONT ASSOCIATED WITH SUNDAY'S SYSTEM WILL DROP  
SOUTHWARD INTO THE AREA ON MONDAY, BEFORE EVENTUALLY STALLING  
OUT. VARIOUS SOURCES OF GUIDANCE DIFFER WITH RESPECT TO WHERE  
THIS BOUNDARY WILL SET UP, BUT ADDITIONAL SHOWERS AND  
THUNDERSTORMS APPEAR LIKELY ALONG AND SOUTHEAST OF THE BOUNDARY  
WITHIN THE DEEPEST MOISTURE. CONTINUED HEAT AND HUMIDITY WILL  
PERSIST SUNDAY INTO MONDAY, WITH HIGH TEMPERATURES AROUND 90,  
LOW TEMPERATURES AROUND 70, AND DEWPOINTS IN THE LOW TO MID 70S.  
 

 
   
LONG TERM /TUESDAY THROUGH SATURDAY/
 
 
AN ACTIVE WEATHER PATTERN LOOKS TO CONTINUE THROUGH THE END OF NEXT  
WEEK, WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. MID-LEVEL  
RIDGING CENTERS OVER THE CAROLINAS BY MID TO LATE WEEK AS THE AXIS  
OF THE BERMUDA HIGH BUILDS TOWARD THE SOUTHWEST ATLANTIC. THE  
STALLED FRONTAL BOUNDARY OVER THE AREA TUESDAY LIFTS NORTH AS A WARM  
FRONT. THE REGION THEN REMAINS IN A HOT AND HUMID AIRMASS THE REST  
OF THE WEEK AS NUMEROUS SHORTWAVE TROUGHS TRAVERSE OVERHEAD. THE  
MOIST AIRMASS COULD FAVOR THUNDERSTORMS CAPABLE OF PRODUCING HEAVY  
DOWNPOURS AND LOCALIZED FLOODING. DEPENDING ON THE LOCATION OR  
DEVELOPMENT OF LOCAL MESOSCALE FEATURES, THERE COULD BE SOME  
POSSIBLE STRONG TO SEVERE STORMS. WHILE UNCERTAIN AT THIS TIME,  
TUESDAY AND WEDNESDAY LOOK TO HAVE THE BEST CHANCE FOR THAT. HIGHS  
WILL BE IN THE UPPER 80S TO LOW 90S, WITH HEAT INDICES IN THE  
LOW 100S.  
 

 
   
AVIATION /01Z SUNDAY THROUGH THURSDAY/
 
 
SHOWERS AND THUNDERSTORMS SHOULD WEAKEN AND/OR DISSIPATE LATE  
THIS EVENING INTO THE OVERNIGHT. LOW CLOUDS WILL MOVE IN DURING  
THE SECOND HALF OF THE NIGHT TONIGHT, WITH IFR CONDITIONS  
POSSIBLE LATE TONIGHT THROUGH THE FIRST HALF OF TOMORROW  
MORNING. CONDITIONS SHOULD GRADUALLY IMPROVE BACK TO VFR BY THE  
LATE MORNING/EARLY AFTERNOON HOURS. COVERAGE OF THUNDERSTORMS IS  
EXPECTED TO BE MUCH HIGHER TOMORROW, WITH MRB, CHO, IAD, AND  
DCA BEING THE MOST LIKELY TO EXPERIENCE IMPACTS. STORMS COULD  
POTENTIALLY WEAKEN OR DISSIPATE ALTOGETHER BEFORE REACHING BWI  
AND MTN. SHOWERS AND THUNDERSTORMS MAY ALSO BE POSSIBLE ON  
MONDAY, WITH CHO STANDING THE GREATEST CHANCE.  
 
WINDS WILL BE OUT OF THE SOUTHEAST THROUGH THE DAY TOMORROW,  
BEFORE BECOMING LIGHT AND SOMEWHAT VARIABLE IN THE VICINITY OF  
A DECAYING COLD FRONT ON MONDAY.  
 
DAILY AFTERNOON TO EVENING SHOWERS AND THUNDERSTORMS ARE IN THE  
FORECAST THROUGH THE MIDDLE OF NEXT WEEK. THESE STORMS COULD PRODUCE  
BRIEF PERIODS OF SUB-VFR CONDITIONS IF THEY MOVE OVER A TERMINAL.  
OUTSIDE OF SHOWER/THUNDERSTORM ACTIVITY, VFR CONDITIONS PREVAIL.  
 

 
   
MARINE
 
 
SUB-SCA LEVEL SOUTHEASTERLY WINDS ARE EXPECTED THROUGH SUNDAY,  
BEFORE WINDS BECOME LIGHT AND VARIABLE ON MONDAY. SMWS IN  
ASSOCIATION WITH THUNDERSTORMS MAY BE POSSIBLE AGAIN SUNDAY  
AFTERNOON AND EVENING AND AGAIN ON MONDAY. THERE IS A GOOD  
CHANCE THAT STORMS MAY DECAY TOMORROW EVENING BEFORE REACHING  
THE BAY.  
 
SOUTHERLY WINDS AROUND 10 KNOTS PREVAIL TUESDAY INTO WEDNESDAY.  
DAILY AFTERNOON TO EVENING THUNDERSTORMS COULD BE A HAZARD TO  
MARINERS WITH GUSTY WINDS AND LIGHTING STRIKES LIKELY. SOUTHERLY  
CHANNELING WEDNESDAY NIGHT COULD BRING WINDS NEAR SCA LEVELS OVER  
THE OPEN WATERS OF THE CHESAPEAKE BAY.  
 

 
   
TIDES/COASTAL FLOODING
 
 
A PROLONGED PERIOD OF SOUTHEASTERLY WINDS WILL LEAD TO ELEVATED  
TIDAL ANOMALIES OVER THE WEEKEND AND INTO EARLY NEXT WEEK. THIS  
CARRIES MOST OF THE TIDAL LOCATIONS INTO ACTION STAGE,  
PARTICULARLY DURING THE HIGHER OF THE TWO ASTRONOMICAL HIGH TIDE  
CYCLES. SENSITIVE LOCATIONS, SUCH AS ANNAPOLIS, ARE FORECAST TO  
HIT MINOR STAGE DURING THE HIGH TIDE CYCLE SUNDAY AND MONDAY  
MORNINGS.  
 

 
   
LWX WATCHES/WARNINGS/ADVISORIES
 
 
DC...NONE.  
MD...NONE.  
VA...NONE.  
WV...NONE.  
MARINE...NONE.  
 

 
 

 
 
SYNOPSIS...KJP  
NEAR TERM...KLW/KJP  
SHORT TERM...KJP  
LONG TERM...KRR  
AVIATION...KLW/KJP/KRR  
MARINE...KLW/KJP/KRR  
TIDES/COASTAL FLOODING...KLW  
 
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