819  
FXUS61 KLWX 220801  
AFDLWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
401 AM EDT THU AUG 22 2019  
   
SYNOPSIS
 
A COLD FRONT WILL CROSS THE AREA LATE TONIGHT OR  
EARLY FRIDAY, THEN MOVE INTO THE CAROLINAS OVER THE WEEKEND.  
CANADIAN HIGH PRESSURE WILL BUILD NORTH OF THE REGION OVER THE  
WEEKEND AND HOLD THROUGH EARLY NEXT WEEK.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
ONE LAST HOT HUMID DAY IN STORE BEFORE SIGNIFICANT COOL DOWN  
TAKES PLACE FOR THE WEEKEND. A SFC TROF WILL BE IN PLACE THIS  
AFTERNOON TO HELP FOCUS SCATTERED SHOWERS AND THUNDERSTORMS  
WHILE ACTUAL CDFNT LAGS BEHIND OVER PA. HI-RES CONVECTIVE MODELS  
SHOW SCATTERED CONVECTION DEVELOPING LATE IN THE DAY (AFTER 20Z)  
SOUTH OF US-50 DOWN INTO CENTRAL VA WITH THE STRONGEST  
CONVECTION OVER CENTRAL AND EASTERN VA. A FEW SEVERE STORMS WILL  
BE POSSIBLE GIVEN AMPLE CAPE AND MARGINAL SHEAR VALUES.  
CONVECTION SHOULD EXIT THE AREA BY 03Z TONIGHT, BUT A FEW  
SHOWERS WILL REMAIN POSSIBLE AS CDFNT WILL BE CROSSING THE AREA  
LATE TONIGHT INTO EARLY FRI MORNING.  
 

 
   
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
 
 
SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL REMAIN POSSIBLE  
FRIDAY ESPECIALLY IN THE MORNING AS CDFNT SAGS SOUTHWARD. SEVERE  
WX, IF ANY, WOULD BE CONFINED TO EASTERN VA AND FAR SOUTHERN MD  
CHESAPEAKE BAY WATERS. MOST OF THE SHOWERS SHOULD BE GONE BY  
MIDNIGHT FRI NIGHT IF NOR EARLIER. DRY AND MUCH COOLER WEATHER  
WILL ESTABLISH FOR THE WEEKEND AS HIGH PRESSURE BUILDS FROM THE  
NORTH.  
 

 
   
LONG TERM /SUNDAY THROUGH WEDNESDAY/
 
 
HIGH PRESSURE WILL BUILD INTO THE REGION SUNDAY AND LINGER  
THROUGH TUESDAY. DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES  
ARE EXPECTED EACH DAY FOR MOST OF OUR REGION. AN ONSHORE FLOW FROM  
THE WESTERN ATLANTIC COULD SPAWN A FEW SHOWERS OR A THUNDERSTORM  
MONDAY AFTERNOON AND AGAIN TUESDAY AFTERNOON, MAINLY IN THE UPSLOPE  
AREAS AND ALONG THE CHESAPEAKE BAY.  
 
THE HIGH PRESSURE WILL MOVE TO THE NORTHEAST TUESDAY NIGHT AND  
WEDNESDAY. A COLD FRONT WILL APPROACH THE REGION FROM THE WEST. THE  
APPROACHING FRONT WILL ALLOW FOR A SOUTHERLY RETURN FLOW TO DEVELOP  
AND BRING IN MORE HUMID CONDITIONS AND WARMER TEMPERATURES.  
SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD, OR AT  
LEAST THE CHANCES WILL INCREASE GOING INTO WEDNESDAY.  
 
ONE CAVEAT TO THE EXTENDED FORECAST THAT COULD MAKE OR BREAK OUR  
REGION WITH A LOT OF SHOWERS AND THUNDERSTORMS OR DRY THROUGH A  
LONG STRETCH WILL BE THE POSSIBLE COASTAL LOW, SUB-TROPICAL LOW,  
OR PERHAPS TROPICAL LOW ALONG THE EAST COAST MONDAY NIGHT THROUGH  
WEDNESDAY. PLACEMENT AND INTENSITY AND TIMING ARE LOW CONFIDENCE  
FACTORS SO FAR WITH THE POSSIBLE LOW PRESSURE SYSTEM. BOTH THE  
EUROPEAN AND GFS MODELS HINT OF THIS LOW ALONG THE EAST COAST AND  
MID-ATLANTIC COAST, BUT NEITHER MODEL HAS A DIRECT IMPACT ON OUR  
CWA. WE WILL HAVE TO SEE WHAT, IF ANY, LOW DEVELOPS AND WHERE IT  
MOVES OVER THE NEXT TWO TO THREE DAYS.  
 

 
   
AVIATION /08Z THURSDAY THROUGH MONDAY/
 
 
SCATTERED AFTERNOON AND EARLY EVENING T-STORMS EXPECTED. CDFNT  
CROSSES THE AREA LATE TONIGHT OR EARLY FRI. HIGH PRESSURE BUILDS  
FOR THE WEEKEND.  
 
VFR CONDITIONS FOR ALL TERMINALS SUNDAY THROUGH MONDAY NIGHT. WE  
CAN'T RULE OUT A SHOWER OR THUNDERSTORM NEAR CHO LATE SUNDAY  
INTO SUNDAY NIGHT, OR A SHOWER OR THUNDERSTORM AT ANY TERMINAL  
MONDAY AFTERNOON. WINDS NORTHEAST TO EAST 5 TO 10 KNOTS  
SUNDAY THROUGH MONDAY, BECOMING SOUTHEAST 5 TO 10 KNOTS  
MONDAY NIGHT.  
 

 
   
MARINE
 
 
GUSTY T-STORMS POSSIBLE LATE TODAY OR THIS EVENING MAY REQUIRE  
SMWS. SHOWERS MAY LINGER ACROSS THE SOUTHERN WATERS ALL DAY FRI.  
 
NO MARINE HAZARDS EXPECTED SUNDAY THROUGH MONDAY NIGHT. WINDS  
NORTHEAST 10 KNOTS SUNDAY THROUGH MONDAY, BECOMING EAST 10  
KNOTS MONDAY NIGHT.  
 

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

 
 

 
SYNOPSIS...LFR  
NEAR TERM...LFR  
SHORT TERM...LFR  
LONG TERM...KLW  
AVIATION...LFR/KLW  
MARINE...LFR/KLW  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab VA Page
The Nexlab MD Page
The Nexlab WV Page Main Text Page