823  
FXUS61 KRLX 071838  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
238 PM EDT TUE JUL 7 2020  
   
SYNOPSIS
 
 
HEAT PERSISTS WITH MAINLY DIURNALLY DRIVEN CONVECTION. A COLD  
FRONT BREAKS THE HEAT THIS WEEKEND.  
 

 
   
NEAR TERM /THROUGH WEDNESDAY/
 
 
AS OF 225 PM TUESDAY...  
 
THE HEAT WAVE CONTINUES. AN UPPER LEVEL SHORT WAVE TROUGH, OR  
WEAKNESS, WAS HELPING TO FOCUS CONVECTION OVER THE MIDDLE OHIO  
VALLEY THIS AFTERNOON. WHILE THAT CONVECTION WILL NOT MAKE IT  
EAST OF THE OHIO RIVER, INSTABILITY BUILDING TO 2-3 KJ/KG AND  
LIGHT AND VARIABLE FLOW THROUGH THE COLUMN SPELL PULSE POP-UP  
SLOW MOVERS WITH HIGH RAINFALL RATES GIVEN PW VALUES OF 1.7-1.8  
IN, A LITTLE LESS OVER CENTRAL WV. CONVECTION WAS ALSO BEGINNING  
TO FIRE OVER THE HIGHER MOUNTAINOUS TERRAIN ON THE ELEVATED  
HEAT SOURCE EFFECT THERE.  
 
RIVER VALLEY FOG IS MOST LIKELY TO FORM OVERNIGHT TONIGHT WHERE  
RAIN OCCURS THIS AFTERNOON OR EVENING.  
 
RIDGING MAY BUILD A BIT TO THE NORTH WEDNESDAY AS A REX BLOCK  
DEVELOPS, WITH UPPER LEVEL LOW PRESSURE TO THE SOUTH. THIS MAY  
HOLD DOWN CONVECTION A BIT, AND THE FORECAST IS FOR SCATTERED  
CONVECTION OVER THE HIGHER TERRAIN AND ISOLATED CONVECTION  
ELSEWHERE.  
 
CENTRAL GUIDANCE REFLECTS A PERSISTENCE FORECAST FOR  
TEMPERATURES AND DEW POINTS, WHICH SPELLS APPARENT TEMPERATURES  
IN THE MID AND UPPER 90S THIS AND WEDNESDAY AFTERNOON, WITH 100  
NOT OUT OF REACH FOR HOTTER URBAN AREAS.  
 

 
   
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/
 
 
AS OF 239 PM TUESDAY...  
 
THE UPPER LEVEL PATTERN BEGINS TO TRANSITION INTO A REX BLOCK  
ORIENTATION WEDNESDAY NIGHT INTO THURSDAY WITH A MID LEVEL RIDGE  
ACROSS THE NORTHEAST US AND A COASTAL LOW MOVING NORTHWARD ALONG THE  
MID-ATLANTIC COASTAL AREAS. THIS PATTERN SHOULD SUPPORT A  
CONTINUATION OF THE WARM AND HUMID CONDITIONS ACROSS OUR AREA WITH  
TEMPERATURES AROUND TEN DEGREES ABOVE NORMAL. IN ADDITION, SCATTERED  
CONVECTION WILL BE POSSIBLE ACROSS THE AREA DURING PEAK HEATING IN  
THE AFTERNOON AND EVENING HOURS ON THURSDAY GIVEN THE WARM AND HUMID  
AIRMASS IN PLACE. WITH LITTLE TO NO SHEAR AND A LACK OF UPPER  
SUPPORT, ANY ACTIVITY IS EXPECTED TO BE PULSE CONVECTION WITH A MAIN  
THREAT FOR LOCALLY HEAVY DOWNPOURS AS PWATS ARE EXPECTED TO EXCEED  
1.75 INCHES. WHILE CONVECTIVE COVERAGE SHOULD BE SOMEWHAT LIMITED ON  
THURSDAY DUE TO LACK OF FORCING, PRECIPITATION COVERAGE IS EXPECTED  
TO INCREASE ON FRIDAY AS AN UPPER LEVEL TROUGH AND ASSOCIATED  
FRONTAL BOUNDARY APPROACHES THE REGION. THUS, WILL LEAVE WIDESPREAD  
HIGH CHANCE POPS IN THE FORECAST FOR NOW, BUT WOULDN'T BE SURPRISED  
IF LIKELY POPS GETS INTRODUCED INTO SUBSEQUENT FORECASTS.  
 

 
   
LONG TERM /SATURDAY THROUGH TUESDAY/
 
 
AS OF 239 PM TUESDAY...  
 
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE ONGOING ACROSS THE AREA  
AT THE START OF THE LONG TERM PERIOD AS THE AFOREMENTIONED FRONTAL  
BOUNDARY PUSHES THROUGH. PRECIPITATION COVERAGE SHOULD DECREASE BY  
SATURDAY NIGHT AS THE UPPER TROUGH AND FRONTAL BOUNDARY PUSH EAST OF  
THE AREA, BUT SHOWERS AND STORMS STILL APPEAR TO BE POSSIBLE ON  
SUNDAY AS ADDITIONAL SHORTWAVE ENERGY MOVES INTO THE REGION. BY  
EARLY NEXT WEEK, CONDITIONS ARE EXPECTED TO REMAIN UNSETTLED AS  
MODELS SUGGEST THAT A CLOSED UPPER LOW MAY DEVELOP NEAR OR OVER THE  
REGION MONDAY INTO TUESDAY. OTHERWISE, TEMPERATURES WILL BE  
SLIGHTLY COOLER THIS WEEKEND FOLLOWING THE FRONTAL PASSAGE, BUT  
STILL WILL REMAIN JUST ABOVE NORMAL THROUGH THE END OF THE LONG  
TERM PERIOD.  
 

 
   
AVIATION /19Z TUESDAY THROUGH SUNDAY/
 
 
AS OF 225 PM TUESDAY...  
 
HEAT WAVE PATTERN CONTINUES, WITH DIURNALLY DRIVEN CONVECTION  
AGAIN THIS AFTERNOON. CONVECTION WAS ALREADY FIRING IN SOUTHEAST  
OHIO, AND SHOULD FIRE OVER THE HIGHER MOUNTAINOUS TERRAIN AS  
WELL.  
 
VALLEY FOG TONIGHT IS MOST LIKELY TO FORM IN AREAS THAT GET  
RAIN THIS AFTERNOON OR EVENING. ANY FOG THAT DOES FORM IS  
LIKELY TO BURN OFF BY OR SHORTLY AFTER 12Z WEDNESDAY, WITH  
DIURNALLY DRIVEN CONVECTION ONCE AGAIN WEDNESDAY AFTERNOON.  
 
SURFACE FLOW WILL REMAIN LIGHT AND VARIABLE. LIGHT SOUTHERLY  
FLOW ALOFT BECOMES LIGHT AND VARIABLE AS WELL THIS AFTERNOON,  
AND THEN LIGHT NORTHEAST ON WEDNESDAY.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...  
 
FORECAST CONFIDENCE: MEDIUM TO HIGH.  
 
ALTERNATE SCENARIOS: AMENDMENTS MAY BE NEEDED FOR DIRECT  
THUNDERSTORM IMPACTS THIS AFTERNOON OR EVENING. FOG FORMATION  
MAY VARY OVERNIGHT, ESPECIALLY WHERE RAIN OCCURS.  
 
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY  
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:  
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.  
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.  
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.  
 
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05  
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01  
CRW CONSISTENCY H H H H H H H H H H H H  
HTS CONSISTENCY H H H H H H H H H H H H  
BKW CONSISTENCY H H H H H H H H H H H H  
EKN CONSISTENCY H H H H H H H H H H H H  
PKB CONSISTENCY H H H H H H H H H H H H  
CKB CONSISTENCY H H H H H H H H H H H H  
 
AFTER 18Z WEDNESDAY...  
IFR POSSIBLE WITH VALLEY FOG IN THE LATE NIGHT/EARLY MORNING  
HOURS EACH DAY EXCEPT AT BKW, ESPECIALLY IF RAIN FALLS AT THE  
TERMINAL IN DAYTIME SHOWERS/STORMS. BRIEF IFR POSSIBLE IN  
THUNDERSTORMS DURING THE AFTERNOON AND EVENING HOURS EACH DAY.  
 
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON  
INTO SATURDAY NIGHT, AND IN FOG OR STRATUS OVERNIGHT SATURDAY  
NIGHT INTO SUNDAY MORNING.  
 

 
   
RLX WATCHES/WARNINGS/ADVISORIES
 
 
WV...NONE.  
OH...NONE.  
KY...NONE.  
VA...NONE.  
 

 
 

 
SYNOPSIS...TRM/RG  
NEAR TERM...TRM  
SHORT TERM...RG  
LONG TERM...RG  
AVIATION...TRM  
 
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