428  
FXUS61 KLWX 151857  
AFDLWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
257 PM EDT MON JUL 15 2019  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL BUILD OVERHEAD THIS AFTERNOON. A WARM FRONT  
IS EXPECTED TO LIFT NORTH ACROSS THE AREA TUESDAY. THE REMNANTS  
OF BARRY WILL THEN AFFECT THE REGION WEDNESDAY INTO THURSDAY.  
HIGH PRESSURE WILL RETURN FOR SATURDAY.  
 

 
   
NEAR TERM /UNTIL 6 AM TUESDAY MORNING/
 
 
SCATTERED SHOWERS AND A FEW STRONG TO SEVERE THUNDERSTORMS ARE  
DEVELOPING FROM PENDLETON COUNTY TO AUGUSTA COUNTY TO PORTIONS  
OF ALBEMARLE COUNTY. ADDITIONAL SHOWERS AND THUNDERSTORMS COULD  
DEVELOP THE REMAINDER OF THIS AFTERNOON INTO EARLY THIS EVENING  
NEAR THE SAME ZONES AND PERHAPS FARTHER TO THE EAST TOWARD THE  
VIRGINIA NORTHERN NECK. THE MAIN THREATS WILL BE HEAVY RAIN AND  
DAMAGING WINDS AND HAIL.  
 
SBCAPE IS BETWEEN 2000 TO 3000 J/KG OVER WESTERN VIRGINIA.  
HIGH TEMPERATURES WILL CLIMB TO THE UPPER 80S TO NEAR 90.  
DEWPOINT TEMPERATURES WILL BE IN THE UPPER 60S TO LOWER 70S.  
AS THE CONVECTION DISSIPATES THROUGHOUT THE LATE EVENING AND  
OVERNIGHT, SOME CLOUD DEBRIS WILL LINGER.  
 

 
   
SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/
 
 
THE REMNANTS OF BARRY WILL MOVE SLOWLY NORTHWARD TUESDAY, THEN  
NORTHEASTWARD TUESDAY NIGHT, FINALLY EASTWARD WEDNESDAY AND  
WEDNESDAY NIGHT. ADDITIONAL WARMTH AND MOISTURE WILL FILL INTO  
THE REGION. SHOWERS AND THUNDERSTORMS WILL BE MORE IN COVERAGE  
ACROSS OUR REGION TUESDAY INTO TUESDAY EVENING, BUT NOT TOO  
WIDESPREAD. A FEW OF THE THUNDERSTORMS COULD BE STRONG TO SEVERE  
AS WE WILL HAVE MOISTURE IN PLACE AT THE LOW LEVELS, WARMTH OR  
HEAT IN PLACE AS WELL AHEAD OF THE REMNANTS OF BARRY, AND SOME  
WEAK ENERGY PRECEDING BARRY'S CENTER. NOT EVERYONE WILL GET A  
STRONG TO SEVERE THUNDERSTORM. HIGH TEMPERATURES WILL RISE INTO  
THE LOWER 90S PRETTY MUCH AREAWIDE TUESDAY WITH DEW POINTS  
RISING BACK INTO THE UPPER 60S AND LOW 70S. THEREFORE, THE HEAT  
INDEX VALUES WILL RANGE FROM THE MID 90S TO AROUND 100F. THIS  
RETURN OF MOISTURE WILL ALSO BRING MORE WIDESPREAD INSTABILITY.  
LOWS TUESDAY NIGHT ONLY DROP INTO THE 70S.  
 
THE REMNANT TROUGH THAT WAS ONCE BARRY WILL THEN MOVE INTO THE OHIO  
VALLEY ON WEDNESDAY, WITH PLENTY OF HEAT AND HUMIDITY OUT AHEAD OF  
IT. EXPECTING HIGHS IN THE LOW TO MID 90S WITH DEW POINTS IN THE LOW  
70S. HEAT INDEX VALUES BY THE AFTERNOON LIKELY REACH INTO THE 100-  
105F AND HEAT ADVISORIES MAY BE NECESSARY FOR PORTIONS OF THE  
REGION. ADDITIONALLY, AS THE TROUGH APPROACHES,  
SHOWER/THUNDERSTORM CHANCES WILL INCREASE DURING THE AFTERNOON  
AND EVENING, AND LIKELY LINGER OVERNIGHT. LOWS FROM 70-80F  
WEDNESDAY NIGHT.  
 

 
   
LONG TERM /THURSDAY THROUGH MONDAY/
 
 
TROUGHING ASSOCIATED WITH THE REMNANTS OF BARRY WILL BE CROSSING THE  
AREA THURSDAY. TIMING OF THE TROUGH WITH RESPECT TO THE DIURNAL  
CYCLE MAY PLAY A ROLE IN THE COVERAGE/INTENSITY OF ANY CONVECTION.  
LOCALLY HEAVY RAIN WOULD PROBABLY BE THE BIGGEST RISK GIVEN THE  
TROPICAL MOISTURE SOURCE. IT DOES LOOK LIKE CLOUD COVER WILL HELP  
HOLD TEMPERATURES DOWN A BIT SUCH THAT HEAT HEADLINES WOULD BE  
UNLIKELY.  
 
IN THE WAKE OF THIS TROUGHING, RIDGING WILL BUILD FRIDAY AND  
SATURDAY. THE HEAT WILL LIKELY BE MOST INTENSE DURING THESE TWO  
DAYS, WITH HIGH TEMPERATURES WELL INTO THE 90S, AND DEW POINTS NEAR  
OR ABOVE 70. WPC PROBABILISTIC HEAT INDEX GUIDANCE INDICATES A  
LIKELIHOOD OF HEAT ADVISORY CRITERIA (100 WEST/105 EAST) BEING MET  
ACROSS MUCH OF THE AREA. SATURDAY MAY HAVE THE HIGHEST HEAT INDICES,  
WITH THE SAME GUIDANCE SHOWING A RISK OF EXCESSIVE HEAT WARNING  
CRITERIA (105 WEST/110 EAST). CONVECTIVE CHANCES WILL BE LOWER BOTH  
DAYS DUE TO SUBSIDENCE, AND WILL LIKELY BE TIED TO THE COMBINATION  
OF TERRAIN CIRCULATIONS AND DIURNAL INSTABILITY.  
 
THE RIDGE MAY BEGIN TO FLATTEN A BIT SUNDAY INTO MONDAY, WHICH COULD  
OFFER A BETTER OPPORTUNITY FOR PERTURBATIONS IN THE FLOW REACHING  
THE AREA AND HELPING CONVECTIVE DEVELOPMENT. HOWEVER, ANY SORT OF  
FRONT DOESN'T ARRIVE UNTIL TUESDAY AT THE EARLIEST, SO EXPECT  
CONTINUED HOT AND HUMID CONDITIONS.  
 

 
   
AVIATION /19Z MONDAY THROUGH SATURDAY/
 
 
VFR IS EXPECTED AT ALL TERMINALS. BRIEF MVFR CONDITIONS ARE  
POSSIBLE WITH ANY SHOWERS AND THUNDERSTORMS NEAR CHO DURING THE  
AFTERNOON INTO EARLY EVENING. BRIEF GUSTY WINDS ARE POSSIBLE.  
ELSEWHERE, DRY WEATHER IS FORECAST.  
 
PREDOMINANTLY VFR WILL CONTINUE TONIGHT THROUGH WEDNESDAY NIGHT.  
EACH AFTERNOON AND EVENING WILL SEE CHANCES FOR SCATTERED SHOWERS  
AND THUNDERSTORMS, AND THEREFORE BRIEF REDUCTIONS TO  
VISIBILITIES/CEILINGS AND SOME LOCALIZED GUSTY WINDS. ANY LOCATIONS  
THAT SEE RAIN DURING THE DAY/EVENING MAY ALSO SEE SOME PATCHY FOG  
THE FOLLOWING NIGHT.  
 
A CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH  
THURSDAY. VFR CONDITIONS ARE LIKELY FRIDAY AND SATURDAY AS HIGH  
PRESSURE BUILDS.  
 

 
   
MARINE
 
 
SUB-SCA CONDITIONS ARE EXPECTED THROUGH TUESDAY NIGHT. LIGHT  
NORTHEAST WINDS THIS AFTERNOON WILL TURN LIGHT SOUTHERLY  
TONIGHT THROUGH TUESDAY NIGHT. SOME SCATTERED  
SHOWERS/THUNDERSTORMS WITH LOCALIZED GUSTY WINDS THEN BECOME  
POSSIBLE LATE TUESDAY AND TUESDAY EVENING.  
 
SOUTHERLY WINDS WILL THEN INCREASE WEDNESDAY AND WEDNESDAY NIGHT AND  
SCA CONDITIONS ARE POSSIBLE. IN ADDITION, CHANCES WILL INCREASE FOR  
SCATTERED SHOWERS AND THUNDERSTORMS.  
 
WINDS GENERALLY WILL BE BETWEEN SOUTH AND WEST THROUGH THE END OF  
THE WEEK WITH LOW CHANCES FOR ANY ADVISORIES. THE CHANCE OF  
THUNDERSTORMS WILL BE HIGHEST ON THURSDAY (AS REMNANTS OF BARRY  
PASS) THEN DECREASE FRIDAY AND SATURDAY.  
 

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

 
 

 
SYNOPSIS...KLW  
NEAR TERM...KLW  
SHORT TERM...KLW  
LONG TERM...ADS  
AVIATION...ADS/KLW  
MARINE...ADS/KLW  
 
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