558  
FXUS61 KLWX 171954  
AFDLWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
354 PM EDT THU JUL 17 2025  
   
SYNOPSIS
 
 
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. THE FRONT WILL  
BECOME STATIONARY OVER THE AREA TOMORROW, BEFORE RETURNING  
NORTHWARD ACROSS THE AREA ON SATURDAY. A STRONGER COLD FRONT  
WILL MOVE THROUGH ON SUNDAY NIGHT.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
CURRENT SATELLITE IMAGERY SHOWS MOSTLY SUNNY SKIES, WITH SOME  
CUMULUS SCATTERED ABOUT THE AREA. CONDITIONS ARE HOT AND HUMID,  
WITH HEAT ADVISORIES IN EFFECT FOR ROUGHLY THE EASTERN HALF OF  
THE FORECAST AREA. TEMPERATURES ARE NEARING THEIR HIGHS FOR THE  
DAY IN THE LOW TO MID 90S, WHILE DEWPOINTS ARE HOLDING IN THE  
LOW TO MID 70S. THIS IS RESULTING IN HEAT INDICES NEAR OR IN  
EXCESS OF 100 DEGREES ACROSS MUCH OF THE AREA. A SOUTHWESTERLY  
BREEZE AT AROUND 10-20 MPH MAY BE PROVIDING SOME SLIGHT RELIEF  
FROM THE HEAT.  
 
SURFACE OBSERVATIONS SUGGEST THAT THERE IS A WEAK SURFACE TROUGH  
EXTENDING ROUGHLY FROM PETERSBURG, WV NORTHEASTWARD TO JUST WEST  
OF HAGERSTOWN, WHERE WESTERLY WINDS FURTHER WEST ARE MEETING  
SOUTHWESTERLY WINDS FURTHER TO THE EAST. THE CUMULUS FIELD IS  
STARTING TO DEEPEN SLIGHTLY IN THE VICINITY OF THIS SURFACE  
TROUGH, AND SOME SHOWERS AND A FEW THUNDERSTORMS ARE STARTING TO  
FORM ACROSS THE HIGHER TERRAIN IN THE ALLEGHENIES. THE MAIN  
FORECAST QUESTION TODAY IS JUST HOW MUCH THUNDERSTORM ACTIVITY  
WILL GET GOING ALONG THIS SURFACE TROUGH LATER THIS AFTERNOON  
INTO THIS EVENING AS IT SLOWLY SAGS TOWARD THE SOUTH. MOST  
GUIDANCE SUGGESTS THAT COVERAGE OF STORMS SHOULD REMAIN LOW, AND  
AS A RESULT, WE'RE FORECASTING JUST ISOLATED THUNDERSTORMS THIS  
AFTERNOON. WHILE MOST LOCATIONS SHOULD REMAIN DRY, THE  
BACKGROUND ENVIRONMENT DOES APPEAR TO BE FAVORABLE FOR  
PRODUCING STRONG WINDS IF A MORE ROBUST STORM WERE TO BECOME  
ESTABLISHED. SPC MESOANALYSIS AND MODEL SOUNDINGS SHOW AROUND  
1500-3000 J/KG OF MLCAPE, 800-1200 J/KG OF DCAPE, STEEP LOW-  
LEVEL LAPSE RATES, AND AROUND 20-30 KNOTS OF BACKGROUND FLOW IN  
THE LOW TO MID LEVELS, WHICH ARE ALL FAVORABLE FOR PRODUCING  
STRONG WINDS. WITH PROGRESSIVE STORM MOTIONS AND LOWER  
PRECIPITABLE WATER VALUES THAN PRECEDING DAYS, STORMS TODAY  
AREN'T EXPECTED TO POSE A RISK FOR FLASH FLOODING.  
 
ANY THUNDERSTORM ACTIVITY SHOULD WIND DOWN THIS EVENING,  
RESULTING IN DRY CONDITIONS DURING THE SECOND HALF OF THE  
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH LATE TONIGHT, CAUSING  
WINDS TO TURN LIGHT OUT OF THE NORTH. OVERNIGHT LOWS ARE  
FORECAST TO BE IN THE UPPER 60S TO LOW 70S.  
 

 
   
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
 
 
THE AFOREMENTIONED FRONT WILL STALL OUT OVER THE AREA TOMORROW.  
THIS WILL ALLOW SLIGHTLY COOLER AND LESS HUMID AIR TO WORK INTO  
NORTHERN MD, WITH DEWPOINTS DROPPING INTO THE 60S, AND  
TEMPERATURES ONLY MAKING IT INTO THE LOW TO MID 80S. FURTHER  
SOUTH, THE CENTRAL SHENANDOAH VALLEY AND CENTRAL VIRGINIA WILL  
REMAIN ON THE WARM SIDE OF THE BOUNDARY, WITH DEWPOINTS HOLDING  
IN THE 70S AND TEMPERATURES MAKING IT INTO THE UPPER 80S. DRY  
CONDITIONS ARE EXPECTED TO START THE DAY, BUT MODEL GUIDANCE IS  
IN GOOD AGREEMENT THAT SHOWERS AND THUNDERSTORMS WILL FORM AGAIN  
TOMORROW AFTERNOON AS A CONVECTIVELY GENERATED DISTURBANCE  
APPROACHES FROM THE WEST. COVERAGE OF THESE SHOWERS AND STORMS  
SHOULD BE GREATEST ALONG/ON THE WARM SIDE OF THE BOUNDARY  
(CENTRAL SHENANDOAH VALLEY/CENTRAL VIRGINIA), WHERE MORE  
INSTABILITY WILL BE PRESENT, WITH LITTLE TO NO COVERAGE EXPECTED  
AS YOU MOVE TOWARD MORE STABLE AIR IN PLACE OVER NORTHEAST  
MARYLAND. LIKE MANY DAYS OVER THE LAST WEEK, THE AIRMASS IN  
PLACE ON THE WARM SIDE OF THE BOUNDARY WILL BE VERY MOISTURE  
RICH, UNSTABLE, AND SATURATED IN THE VERTICAL. MODEL SOUNDINGS  
SHOW MLCAPE VALUES AROUND 1500-3000 J/KG AND PWAT VALUES IN  
EXCESS OF 2 INCHES ON THE WARM SIDE OF THE BOUNDARY, WHICH  
SHOULD MAKE STORMS CAPABLE OF PRODUCING VERY HEAVY RAINFALL.  
THIS RAISES CONCERNS FOR FLOODING ONCE AGAIN, PRIMARILY FROM  
THE CENTRAL SHENANDOAH VALLEY INTO CENTRAL VIRGINIA, WHERE WPC  
HAS A SLIGHT RISK FOR EXCESSIVE RAINFALL. NUMEROUS CAMS SHOW  
LOCALIZED MAXES OF 2-5 INCHES IN THIS REGION TOMORROW. A FLOOD  
WATCH FOR FLASH FLOODING MAY NEED TO BE CONSIDERED FOR THIS AREA  
DURING SUBSEQUENT SHIFTS. A THREAT FOR ISOLATED DAMAGING WINDS  
MAY ALSO BE POSSIBLE ON THE WARM SIDE OF THE BOUNDARY. SPC  
CURRENTLY HAS A SIMILAR AREA OUTLOOKED IN A MARGINAL RISK,  
DRIVEN BY DAMAGING WINDS.  
 
ADDITIONAL SHOWERS AND THUNDERSTORMS MAY BE POSSIBLE AGAIN ON  
SATURDAY AS ANOTHER WEAK DISTURBANCE APPROACHES FROM THE OHIO  
VALLEY. THE PRIMARY FOCUS SHOULD AGAIN BE IN SOUTHWESTERN  
PORTIONS OF THE FORECAST AREA, WHERE THE GREATEST INSTABILITY  
AND MOISTURE CONTENT WILL RESIDE, BUT AN AFTERNOON STORM CAN'T  
BE RULED OUT ANYWHERE ACROSS THE AREA. HIGH TEMPERATURES WILL BE  
IN THE 80S (MID-UPPER 80S SOUTH, LOWER 80S NORTH), WITH  
DEWPOINTS IN THE 70S.  
 

 
   
LONG TERM /SUNDAY THROUGH THURSDAY/
 
 
A COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY EVENING. AHEAD OF THE  
COLD FRONT, THERE WILL BE DEEP NW FLOW WITH LACK OF SFC CONVERGENCE.  
IF ANYTHING MANAGES TO DEVELOP, IT WILL LIKELY BECOME SEVERE, BUT  
ANY STORMS WILL LIKELY BE ISOLATED IN COVERAGE. LOOKS LIKE AN SMW  
DAY. COLD FRONT WILL PUSH SOUTH OF THE AREA BY MONDAY MORNING ENDING  
ANY T-STORM RISK.  
 
BEHIND THE FRONT MONDAY, SFC DEWPOINTS WILL DROP INTO THE 50S, WHICH  
WILL BE A WELCOME RELIEF TO THE OPPRESSIVE HUMIDITY OF THE PAST  
SEVERAL WEEKS. HEIGHT RISES WILL PREVAIL DURING THE MIDDLE PART OF  
THE WEEK LEADING TO A SUBSTANTIAL WARMING TREND AND INHIBITING  
CONVECTION. HEIGHT RISES PEAK ON THU AS SUBTROPICAL RIDGE OVER THE  
MID-SOUTH INCHES CLOSER TO THE AREA. SUBTROPICAL RIDGE WILL START  
BREAKING DOWN AS NORTHEASTERN U.S. TROUGH DEEPENS AND PROMOTES  
HEIGHT FALLS ACROSS THE REGION. EXPECT THUNDERSTORM CHANCES TO  
INCREASE AS A RESULT.  
 

 
   
AVIATION /19Z THURSDAY THROUGH TUESDAY/
 
 
PREVAILING VFR CONDITIONS, WITH AFTERNOON CHANCES FOR SHOWERS  
AND THUNDERSTORMS ARE EXPECTED EACH OF THE NEXT THREE DAYS.  
THERE IS ALSO SOME HINT IN GUIDANCE THAT SUB-VFR CEILINGS MAY  
TRY TO WORK INTO THE AREA FRIDAY NIGHT. COVERAGE OF  
THUNDERSTORMS IS EXPECTED TO REMAIN LOW TODAY, SO HAVE  
MAINTAINED PROB30S IN THE TAFS. COVERAGE OF STORMS IS LARGELY  
EXPECTED TO REMAIN LOW TOMORROW AS WELL, EXCEPT IN THE VICINITY  
OF CHO, WHERE A HIGHER COVERAGE OF STORMS IS EXPECTED. SATURDAY  
MAY ALSO FEATURE A SIMILAR PATTERN, WHERE COVERAGE OF STORMS IS  
HIGHER IN THE VICINITY OF CHO AND LOWER FURTHER NORTHEAST.  
 
WINDS TODAY MAY GUST TO AROUND 20 KNOTS OUT OF THE SOUTHWEST THIS  
AFTERNOON, BEFORE DECREASING THIS EVENING. WINDS SHOULD STAY  
LIGHT AND GRADUALLY VEER AROUND FROM SOUTHWEST TO NORTHWEST TO  
NORTHEAST LATER TONIGHT INTO TOMORROW MORNING. WINDS WILL REMAIN  
LIGHT TOMORROW, AND MAY BE OUT OF THE EAST FOR A GOOD PORTION  
OF THE DAY. WINDS SHOULD BECOME SOUTH TO SOUTHEASTERLY ON  
SATURDAY.  
 
ISOLATED T-STORMS EXPECTED SUNDAY. DRY MONDAY BEHIND A COLD  
FRONT.  
 

 
   
MARINE
 
 
SPORADIC GUSTS TO LOW-END SCA LEVELS WITHIN SOUTHWESTERLY FLOW WILL  
REMAIN POSSIBLE THROUGH THE REMAINDER OF THE AFTERNOON. SMWS MAY  
POTENTIALLY BE NEEDED LATE THIS AFTERNOON INTO THIS EVENING IF  
ANY THUNDERSTORMS MOVE OVER THE WATERS. A COLD FRONT WILL MOVE  
OVER THE WATERS LATER TONIGHT, CAUSING THE WINDS TO SHIFT TO OUT  
OF THE NORTH LATE TONIGHT, AND THEN EAST TO NORTHEAST TOMORROW.  
WINDS WILL THEN TURN OUT OF THE SOUTH ON SATURDAY. AN SMW FOR  
THUNDERSTORM WINDS CAN'T BE RULED OUT FRIDAY OR SATURDAY  
AFTERNOON.  
 
ISOLD T-STORMS SUN MAY PRODUCE STRONG WIND GUSTS AND REQUIRE SMWS.  
SCA CONDITIONS POSSIBLE SUN NIGHT INTO MONDAY BEHIND A COLD  
FRONT.  
 

 
   
TIDES/COASTAL FLOODING
 
 
ANOMALIES HAVE STARTED TO DECREASE WITHIN WEST TO SOUTHWESTERLY  
FLOW. ANNAPOLIS IS FORECAST TO NEAR ACTION STAGE DURING HIGH  
TIDE CYCLE TOMORROW MORNING. OTHERWISE, THE THREAT FOR TIDAL  
FLOODING APPEARS LOW.  
 

 
   
LWX WATCHES/WARNINGS/ADVISORIES
 
 
DC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR DCZ001.  
MD...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MDZ008.  
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MDZ003>006-008-  
011-013-014-016>018-503>508.  
VA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR VAZ028-030-031-  
053>055-057-501-502-505-506-526-527.  
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ051>053.  
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR  
ANZ530>543.  
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ530.  
 

 
 

 
 
SYNOPSIS...KJP  
NEAR TERM...KJP  
SHORT TERM...KJP  
LONG TERM...LFR  
AVIATION...LFR/KJP  
MARINE...LFR/KJP  
TIDES/COASTAL FLOODING...LWX  
 
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