121  
FXUS61 KRNK 220014  
AFDRNK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BLACKSBURG VA  
814 PM EDT MON MAY 21 2018  
   
SYNOPSIS
 
 
A SOUTHERLY FLOW WILL CONTINUE TO PUSH WARM AND HUMID AIR INTO  
OUR REGION EARLY THIS WEEK. THE NEARLY STATIONARY FRONT TO OUR  
NORTH WILL FINALLY PUSH SOUTH ACROSS OUR AREA WEDNESDAY. HIGH  
PRESSURE WILL FOLLOW THE FRONT WEDNESDAY NIGHT AND KEEP THE AREA  
MOSTLY DRY THROUGH FRIDAY.  
 

 
   
NEAR TERM /THROUGH TUESDAY/
 
 
AS OF 200 PM EDT MONDAY...  
 
A BLOCKING RIDGE CENTERED OVER BERMUDA STRETCHES WESTWARD TO COVER  
PORTIONS OF THE SOUTHEAST AND MID ATLANTIC STATES TONIGHT. THIS  
RIDGE IS EXPECTED TO SINK SOUTH TUESDAY, LOSING ITS INFLUENCE ON THE  
REGION AND ALLOWING AN UPPER LEVEL TROUGH AND A COLD FRONT TO  
APPROACH THE AREA FROM THE NORTHWEST. OVER THE GULF STATES NORTH  
INTO THE TENNESSEE VALLEY, A WEAK UPPER LEVEL TROUGH WILL CONTINUE  
TO DRAW GULF AND ATLANTIC MOISTURE NORTHWARD INTO THE AREA TONIGHT  
AND TOMORROW.  
 
FROM THIS AFTERNOON INTO THIS EVENING, STORMS WILL TRACK FROM THE  
SOUTHEAST TO THE NORTHWEST. TOMORROW THE STEERING FLOW SHIFTS WITH  
STORMS MOVING FROM THE SOUTHWEST TO THE NORTHEAST. ALL STORMS WILL  
BE SLOW MOVING AND WITH THE ADDITION OF TROPICAL MOISTURE, HEAVY  
DOWNPOURS ARE LIKELY THIS AFTERNOON AND EVENING AND AGAIN TOMORROW  
AFTERNOON AND NIGHT. SINCE THE GROUND REMAINS WET AND CREEKS,  
STREAMS AND RIVERS ARE ELEVATED, THERE IS A CHANCE FOR RENEWED  
FLOODING THIS EVENING AND TOMORROW.  
 
AS FAR AS SEVERE THREAT, MODEL SOUNDINGS SUGGEST VERY MOIST LAYER  
WITH SBCAPES AROUND 1000 J/KG THIS AFTERNOON. CANNOT RULE OUT SOME  
ISOLATED WET MICROBURSTS BUT MAIN THREAT IS LOCALIZED FLASH FLOODING.  
 
TEMPERATURES WILL REMAIN MUGGY OVERNIGHT WITH READINGS IN THE 60S.  
TEMPERATURES TUESDAY WILL RANGE IN THE 70S ACROSS THE MOUNTAINS TO  
LOW TO MID 80S EAST.  
 

 
   
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/
 
 
AS OF 300 PM EST MONDAY...  
 
SCATTERED TO WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED  
TUESDAY EVENING INTO EARLY WEDNESDAY AS AN UPPER LEVEL  
DISTURBANCE PUSHES ACROSS THE CENTRAL APPALACHIANS TOWARD THE  
COAST AHEAD OF AN APPROACHING COLD FRONT. RIGHT NOW, INSTABILITY  
APPEARS TO BE MODEST WITH THIS DISTURBANCE SUCH THAT IT WOULDN'T  
BE A SURPRISE TO SEE A FEW CELLS BECOME STRONG TO SEVERE BEFORE  
MIDNIGHT WEDNESDAY, MAINLY ACROSS THE PIEDMONT, BUT THE THREAT  
OF WIDESPREAD SEVERE STORMS OVERALL APPEARS LIMITED.  
 
THE COLD FRONT WILL SINK SOUTHWARD, ADVANCING TO THE INTERSTATE  
81 CORRIDOR AROUND DAWN BEFORE LOOSING SPEED SOMEWHAT AS IT  
CONTINUES A SOUTHWARD DRIFT. BELIEVE WE WILL SEE A  
REDEVELOPMENT OF SHOWERS ACROSS THE MOUNTAINS IN THE NORTHWEST  
FLOW UPSLOPE REGIONS, HOWEVER INSTABILITY WILL BE LIMITED.  
GREATER INSTABILITY WILL BE FOUND IN THE VICINITY OF THE FRONT  
ACROSS EXTREME SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA,  
WHERE SCATTERED STRONG STORMS MAY REDEVELOP WITH AFTERNOON  
HEATING WHERE CAPES MAY EXCEED 2000 J/KG. OUTFLOWS FROM ANY OF  
THESE STORMS WILL HELP TO PUSH THE FRONT FURTHER SOUTHWARD BY  
EVENING, CLEARING THE BOUNDARY THROUGH OUR AREA AFTER SUNSET  
WEDNESDAY.  
 
HIGH PRESSURE WILL SHIFT TOWARD NEW ENGLAND WEDNESDAY NIGHT,  
CAUSING WINDS ACROSS THE MID ATLANTIC TO SWING MORE EASTERLY BY  
THURSDAY MORNING. THOUGH INSTABILITY WILL BE VERY MODEST WITHIN  
THE WEAK HIGH PRESSURE WEDGING ACROSS THE REGION, MAY SEE A FEW  
SHOWERS/ISOLATED STORMS DEVELOP ALONG THE BLUE RIDGE WITH  
AFTERNOON HEATING AS MARINE AIR OFF THE ATLANTIC IS FORCED INTO  
THE MOUNTAINS.  
 

 
   
LONG TERM /FRIDAY THROUGH MONDAY/
 
 
AS OF 300 PM EST TUESDAY...  
 
WINDS WILL SHIFT MORE SOUTHERLY ON FRIDAY AS HIGH PRESSURE  
SLIDES OFF SHORE. THOUGH MOISTURE AND INSTABILITY WILL REMAIN  
LIMITED, EXPECT SLIGHTLY GREATER COVERAGE OF SPOTTY, DAYTIME  
HEATING-DRIVEN SHOWERS AND THUNDERSTORMS. COVERAGE OF SHOWERS  
AND THUNDERSTORMS WILL INCREASE DURING THE WEEKEND AS A WARM  
FRONT LIFTS NORTHWARD THROUGH THE MID ATLANTIC, BRINGING A  
RETURN OF DEEPER MOISTURE FROM THE GULF COAST REGION. AFTERNOON  
TEMPERATURES WILL RANGE FROM THE MID 70S TO THE MID 80S EACH  
DAY, WHILE OVERNIGHT LOWS WILL GENERALLY BE IN THE 60S AREAWIDE.  
 

 
   
AVIATION /00Z TUESDAY THROUGH SATURDAY/
 
 
AS OF 800 PM EDT MONDAY...  
 
NUMEROUS THUNDERSTORMS WILL CONTINUE EAST OF A KDAN TO KLYH LINE  
THIS EVENING WHERE THE AIR MASS IS STILL UNSTABLE. KLYH WILL BE  
STARTING THE TAF FORECAST PERIOD WITH MVFR CONDITIONS AND  
ERRATIC WINDS DUE TO A STRONG THUNDERSTORMS. HI-RES GUIDANCE AND  
HRRR INDICATED AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS WILL  
DIMINISH AFTER 06Z/2AM.  
 
HIGH CONFIDENCE OF MVFR FOG OVERNIGHT IN AREAS WHERE THERE HAS  
BEEN RAIN THIS AFTERNOON ACROSS MUCH OF SOUTHWEST VIRGINIA,  
NORTHERN NORTH CAROLINA AND SOUTHEAST WEST VIRGINIA. MEDIUM  
CONFIDENCE THAT KLWB WILL LOWER TO LIFR IN DENSE FOG AFTER  
08Z/4AM. CEILINGS ACROSS MUCH OF THE REGION WILL LOWER TO IFR  
LATE TONIGHT.  
 
THE FOG AND STRATUS THAT FORMS OVERNIGHT WILL BE GONE BY  
12-14Z/8-10AM TUESDAY. MORE THUNDERSTORMS ARE EXPECTED TUESDAY  
AFTERNOON AND EVENING. CONFIDENCE LOW AS TO THE LOCATION WHERE  
THE STORMS WILL FIRST DEVELOP. MVFR CONDITIONS ARE LIKELY WITH  
ANY OF THE STORMS, OTHERWISE HIGH CONFIDENCE OF A SCATTERED TO  
BROKEN VFR STRATOCUMULUS LAYER.  
 
   
EXTENDED AVIATION DISCUSSION
 
 
MVFR SHOWERS AND THUNDERSTORMS ARE LIKELY AGAIN WEDNESDAY.  
CONDITIONS ARE WILL BE DRIER AND ARE EXPECTED TO BE VFR THURSDAY  
AND FRIDAY.  
 

 
   
RNK WATCHES/WARNINGS/ADVISORIES
 
 
VA...NONE.  
NC...NONE.  
WV...NONE.  
 

 
 

 
SYNOPSIS...RCS  
NEAR TERM...RCS  
SHORT TERM...NF  
LONG TERM...NF  
AVIATION...AMS/RCS  
 
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