079  
FXUS61 KRNK 160620  
AFDRNK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BLACKSBURG VA  
220 AM EDT MON JUL 16 2018  
   
SYNOPSIS
 
 
HIGH PRESSURE ALONG THE MID-ATLANTIC COAST WILL MOVE EAST OUT INTO  
THE ATLANTIC OCEAN TONIGHT INTO MONDAY. A COLD FRONT WILL APPROACH  
OUR REGION MONDAY AND MOVE THROUGH TUESDAY.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
AS OF 200 AM EDT MONDAY...  
 
AT 2AM... SEEING AN UPTICK IN CONVECTIVE ACTIVITY OVER THE  
WESTERN NRV. THIS HAS PROMPTED FLOOD ADVISORY FOR SOUTHEASTERN  
WYTHE CO. IN VA. INCREASE IN ACTIVITY IS THE RESULT OF ENHANCED  
MID-LEVEL LIFT AND STEEPENING OF MID-LEVEL LAPSE RATES THUS  
RESULTING IN ELEVATED CAPE AND NOCTURNAL DEEP DEEP CONVECTION.  
WITH PWATS AOA 1.5 AND WEAK MIDLEVEL STEERING WINDS (LESS THAN 5  
M/S), SHOWERS ARE VERY RAIN EFFICIENT WITH RADAR ESTIMATING  
LOCALIZED RATES OF 2-4 INCHES AN HOUR.  
 
PLENTY OF MID AND HIGH CLOUDS REMAIN ACROSS THE ENTIRE FORECAST  
AREA, THIS BLANKET OF CLOUD COVER RESULTING IN MILD  
TEMPERATURES. COMBINE THIS WITH DEWPOINTS IN THE U60S TO AROUND  
70 AND IT FEELS RATHER MUGGY. SOME FOG FORMATION IS POSSIBLE  
EARLY THIS MORNING WHERE RAIN HAS OCCURRED, BUT CLOUD COVER WILL  
MITIGATE FORMATION OF THE TYPICAL RIVER VALLEY FOG.  
 
THE UPPER LEVEL DISTURBANCE WILL SLOWLY TRAVERSE OUR AREA  
MONDAY. THE SOUTHWEST TO WEST FLOW WILL COMBINE WITH RICH  
MOISTURE AND INSTABILITY TO CREATE SCATTERED TO NUMEROUS SHOWERS  
AND THUNDERSTORMS ESPECIALLY DURING THE AFTERNOON AND EVENING  
HOURS. THE BEST OPPORTUNITY FOR THUNDERSTORMS WILL OCCUR IN THE  
MOUNTAINS. WITH PWATS CLIMBING TO AROUND 2 INCHES, SOME OF THE  
THUNDERSTORMS HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINS.  
HIGH TEMPERATURES ON MONDAY WILL VARY FROM THE MID 70S IN THE  
MOUNTAINS TO ROUND 90 DEGREES IN THE PIEDMONT.  
 

 
   
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/
 
 
AS OF 240 PM EDT SUNDAY...  
 
AN WEAK UPPER LEVEL TROUGH WILL PIVOT OVER THE REGION AHEAD OF A  
COLD FRONT MONDAY NIGHT. A SHORT WAVE ASSOCIATED WITH THIS TROUGH  
WILL KEEP CONVECTION ONGOING OVERNIGHT, BUT AREAL COVERAGE OF STORMS  
WILL WANE WITH LOSE OF HEATING. CONVECTION MONDAY AFTERNOON AND  
NIGHT WILL HELP REMOVE INSTABILITIES ACROSS THE MOUNTAINS AND  
THEREFORE LIMIT THE POTENTIAL FOR STRONG TO SEVERE STORMS TUESDAY AS  
A COLD FRONT TRACKS OVER THE REGION. TUESDAY MORNING, THE COLD FRONT  
WILL MOVE ACROSS THE MOUNTAINS, POSSIBLY MAKING IT TO THE BLUE RIDGE  
BY NOON. IN THE AFTERNOON, DIURNAL HEATING ALONG WITH A LEE TROUGH  
WILL GENERATE A LINE OF THUNDERSTORMS EAST OF THE BLUE RIDGE. THE  
SURFACE FRONT IS THEN EXPECTED TO JUMP TO THE LEE TROUGH THROUGH THE  
AFTERNOON, CONTINUING TO TRACK EAST DURING THE EVENING. MODELS HAVE  
THIS LEE TROUGH SOMEWHERE BETWEEN HWY 29 AND I-85. IT IS THIS AREA  
WHERE STRONG TO SEVERE STORMS ARE LIKELY TUESDAY AFTERNOON AND  
EVENING.  
 
EVEN THOUGH THE AREA HAS BEEN IN A DRY SPELL FOR A WEEK, SOME  
LONGER, WITH CREEKS AND STREAMS RUNNING WELL BELOW NORMAL, FLASH  
FLOODING IS STILL A POSSIBILITY. WITH A DEEP WARM LAYER AND PWAT  
VALUES WELL ABOVE NORMAL, SLOW MOVING STRONG THUNDERSTORMS COULD  
PRODUCE LOCALIZED FLASH FLOODING. THE MOUNTAINS ARE SUSCEPTIBLE TO  
FLOODING MONDAY AFTERNOON AND EVENING, WHILE THE FOOTHILLS AND  
PIEDMONT WILL SEE THE THREAT TUESDAY AFTERNOON AND EVENING.  
 
THE FRONT WILL BE EAST OF I-85 BY MIDNIGHT, HOWEVER THE  
DEWPOINT/THETA-E FRONT LAGS BEHIND. A FEW LIGHT SHOWERS MAY PERSIST  
ACROSS NORTHERN NORTH CAROLINA IN THE EVENING, BUT DRIER AIR AND  
CLEARING SKIES WILL WORKS IT WAY SOUTH BY SUNRISE WEDNESDAY. THERE  
WILL BE A NOTICABLE DROP IN HUMIDITIES WEDNESDAY, HOWEVER, DRY AIR  
AND ABUNDANT SUNSHINE WILL KEEP TEMPERATURES WARM AND NEAR NORMAL.  
THE COOLER AIR WILL ARRIVE WEDNESDAY NIGHT.  
 
MORNING CLOUDS AND SHOWERS WILL KEEP MOUNTAINS TEMPERATURES AT OR  
SLIGHTLY BELOW NORMAL ON TUESDAY. TEMPERATURES WILL RANGE FROM THE  
MID 70S TO MID 80S. TEMPERATURES WILL BE AT OR ABOVE NORMAL FOR THE  
FOOTHILLS AND PIEDMONT COUNTIES TUESDAY. TEMPERATURES WILL RUN FROM  
THE UPPER 80S TO LOWER 90S. FOLLOWING THE PASSING OF THE COLD FRONT,  
TEMPERATURES WEDNESDAY WILL FALL SHORT OF NORMAL BY 3F-6F. HIGHS  
WILL RANGE IN THE 70S WEST TO 80S EAST.  
 

 
   
LONG TERM /WEDNESDAY THROUGH SUNDAY/
 
 
AS OF 240 PM EDT SUNDAY...  
 
DRY HIGH PRESSURE WILL MOVE OVER NEW ENGLAND AND WEDGE SOUTH INTO  
GEORGIA THURSDAY INTO FRIDAY. A DISTURBANCE WILL TRACK ALONG THE  
EASTERN EDGE OF THE WEDGE (SOUTHEASTERN STATES) FRIDAY THEN OFF THE  
NORTH CAROLINA COAST FRIDAY NIGHT. AT THIS TIME, THIS DISTURBANCE IS  
FAR ENOUGH AWAY TO NOT BRING ANY RAIN TO THE AREA. OVER THE GREAT  
LAKES, A CLOSED LOW IS EXPECTED TO FORM. SHORT WAVES TRACKING AROUND  
THIS LOW MAY BRING SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS FRIDAY  
AND TO THE ENTIRE FORECAST AREA NEXT WEEKEND.  
 
FORECAST CONFIDENCE IS HIGH THROUGH SATURDAY AS BOTH THE GFS AND ECM  
ARE IN AGREEMENT. MODELS SEPARATE ON SUNDAY TO WHERE THE UPPER LOW  
WILL TRACK. THE GFS MOVES THE LOW EASTWARD TOWARDS TORONTO WHILE THE  
ECM TRACKS IT SOUTH INTO INDIANA. BOTH SCENARIOS WILL BRING SHOWERS  
AND THUNDERSTORMS INTO THE REGION.  
 
TEMPERATURES THROUGH THE PERIOD WILL BE NEAR NORMAL.  
 

 
   
AVIATION /06Z MONDAY THROUGH FRIDAY/
 
 
AS OF 200 AM EDT MONDAY...  
 
SHORTWAVE TROUGH WILL SLOWLY MOVE EAST ACROSS THE MID-ATLANTIC  
REGION. THIS WILL RESULT IN MULTI CLOUD-LAYERS, MOST OF WHICH  
WILL BE ABOVE 3KFT. SCATTERED SHOWERS AND A FEW STORMS WILL BE  
FOUND ACROSS THE AREA THIS MORNING, WITH ASSOCIATED WITH LOCALIZED  
SUB-VFR. DAYTIME HEATING WITH RESULT IN INCREASING COVERAGE THIS  
AFTERNOON AND EVENING.  
 
EXTENDED AVIATION...  
 
A CONTINUED THREAT FOR SHOWERS/STORMS WILL EXIST TONIGHT AND  
TUESDAY. THE FRONT WILL MOVE ACROSS THE AREA LATE TUESDAY WITH  
POST FRONTAL DRYING WEDNESDAY. RETURN FLOW WILL BRING MOISTURE  
BACK INTO THE AREA THURSDAY AND FRIDAY.  
 

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

 
 

 
SYNOPSIS...KK  
NEAR TERM...PM  
SHORT TERM...RCS  
LONG TERM...RCS  
AVIATION...PM  
 
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