079  
FXUS61 KRNK 262310  
AFDRNK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BLACKSBURG VA  
710 PM EDT SUN MAR 26 2017  
   
SYNOPSIS
 
 
LOW PRESSURE NEAR CHICAGO WILL MOVE NORTHEAST THROUGH THE GREAT  
LAKES AND WEAKEN AS IT PASSES INTO ONTARIO TONIGHT AND MONDAY.  
A SECOND AREA OF LOW PRESSURE WILL MOVE NORTHEAST OUT OF THE  
SOUTHERN PLAINS CROSSING THE MID-MS VALLEY MONDAY, AND ACROSS  
THE OHIO VALLEY INTO THE NORTHERN MID-ATLANTIC MONDAY NIGHT AND  
TUESDAY. THESE WEATHER FEATURES WILL RESULT IN UNSETTLED WEATHER  
ACROSS THE CENTRAL AND NORTHERN APPALACHIANS THROUGH TUESDAY.  
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH MID WEEK.  
 

 
   
NEAR TERM /THROUGH MONDAY/
 
 
AS OF 659 PM EDT SUNDAY...RADAR AND METARS CONTINUE TO INDICATE  
ONGOING, THOUGH WEAKENING RAIN SHOWERS FROM ROANOKE TO  
REIDSVILLE NC EASTWARD INTO WESTERN PORTIONS OF APPOMATTOX  
COUNTY. THESE SHOWERS STAND TO DISSIPATE PER RECENT HRRR/NAMNEST  
OUTPUT. ALSO WATCHING STRONGER CONVECTIVE DEVELOPMENT TO THE  
THE WEST AND SOUTH OF OUR FORECAST AREA, PRIMARILY IN CENTRAL  
WEST VIRGINIA, ASSOCIATED WITH VORT MAX PINWHEELING NORTHEAST  
INTO SOUTHERN OHIO AROUND PARENT UPPER TROUGH EXTENDING  
SOUTHEASTWARD FROM THE UPPER MIDWEST. PAST COUPLE HRRR RUNS,  
WHICH HAVE GENERALLY HANDLED THE SPATIAL COVERAGE OF CONVECTION  
TO OUR WEST THE BEST SINCE IT PARTLY INITIALIZES OFF RADAR,  
CONTINUES TO SUGGEST THAT SOME POSSIBLE SCATTERED  
SHOWERS/POSSIBLE RUMBLE OF THUNDER MAY SLIP INTO MERCER, SUMMERS  
AND WESTERN GREENBRIER COUNTIES IN WV AS WELL AS OUR SOUTHWEST  
VIRGINIA TENNESSEE VALLEY COUNTIES NEXT COUPLE HOURS. AS WE  
PROGRESS TOWARD MIDNIGHT, UPPER TROUGH LIFTS TO OUR NORTHEAST,  
LEAVING US IN SHORTWAVE RIDGING OVERNIGHT. AS FORCING BECOMES  
NEBULOUS AT BEST, EXCEPT FOR SOME ADDITIONAL UPSLOPE CONVERGENCE  
ALONG THE SOUTHERN BLUE RIDGE, POPS SHOULD BE AT THEIR LOWEST  
OVERNIGHT WITH SHOWER COVERAGE BEING EVEN MORE ISOLATED THAN  
THEY PRESENTLY ARE. GIVEN RATHER SATURATED AIR MASS WOULD EXPECT  
SKIES TO STAY AT LEAST MOSTLY CLOUDY. LOWS ONLY FALL INTO THE  
50S TONIGHT.  
 
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 300 PM FOLLOWS...  
 
RADAR INDICATED A 30 MILE WIDE BAND OF RAIN SHOWERS PROPAGATING  
EAST ACROSS THE CENTRAL CWA. AS OF 3PM THE LEADING EDGE WAS  
ALONG THE 220 CORRIDOR FROM CLIFTON FORGE TO MARTINSVILLE.  
MOVEMENT WAS TO THE EAST AT 20 MPH.  
 
LEADING RAIN BAND WAS ASSOCIATED WITH A FRONT ALOFT, ARCING FROM  
NW TO SE FROM LOW PRESSURE MOVING THROUGH THE GREAT LAKES.  
THE ACTUAL SURFACE FRONT WAS OVER WESTERN KY/TN, WITH ADDITIONAL  
BANDS/CLUSTERS OF SHOWERS AND THUNDERSTORMS SCATTERED ACROSS THE  
OHIO VALLEY. THE INITIAL RAIN BAND OVER OUR CWA HAS OUTRUN ANY  
SURFACE INSTABILITY AND HAS BEEN WEAKENING WITH TIME. RAINFALL  
AMOUNTS HAVE BEEN AVERAGING BETWEEN A TENTH TO A QUARTER OF AN  
INCH, BUT AS THIS BAND OF SHOWERS CONTINUES TO MOVE EAST, THE  
OVERALL QPF WILL DIMINISH WITH AMOUNTS OF A TENTH OF AN INCH OR  
LESS. TIMING SUGGESTS THESE SHOWERS WILL REACH HIGHWAY 29  
CORRIDOR...CHARLOTTESVILLE, LYNCHBURG, DANVILLE, BETWEEN 5-6PM.  
 
BEHIND THE FRONT ALOFT, SOME PARTIAL CLEARING WAS TAKING PLACE,  
THE RAIN ONLY LASTING A COUPLE HOURS IN DURATION. ONCE THIS  
INITIAL RAIN AREA MOVES EAST, WILL HAVE TO WAIT FOR THE  
INSTABILITY DRIVEN SHOWERS OVER KY/TN AHEAD OF THE ACTUAL  
SURFACE FRONT TO MOVE EAST. MODELS SUGGEST MOST OF THIS ACTIVITY  
WILL DISSIPATE DURING THE OVERNIGHT, BUT UNTIL THEN WILL  
THREATEN OUR WESTERN CWA (PRIMARILY WEST OF I-77 IN VA/NC AND  
WEST OF LEWISBURG OR HIGHWAY 219 IN WV) THIS EVENING WITH  
POTENTIAL FOR BOTH SHOWERS AND THUNDERSTORMS AND AN ADDITIONAL  
TENTH OR TWO OF RAINFALL BEFORE MIDNIGHT.  
 
AS THE MAIN UPPER LEVEL LOW SLIDES BY TO OUR NORTHWEST OVERNIGHT,  
DYNAMIC SUPPORT WILL DECREASE. THE ACTUAL SURFACE FRONT IS  
FORECAST TO WASH OUT BEFORE CROSSING THE MOUNTAINS SO THIS WILL  
MAINTAIN A PERSISTENT MILD SOUTHERLY FLOW ACROSS THE FORECAST  
AREA OVERNIGHT. AS SUCH, THERE WILL BE A CONTINUED CHANCE OF  
SHOWERS MAINLY ALONG AND WEST OF THE BLUE RIDGE OVERNIGHT,  
ALTHOUGH NOTHING SEVERE PER WANING INSTABILITY. SOME PATCHY FOG  
IS ALSO POSSIBLE, BUT CLOUD COVER SHOULD PREVENT IT FROM  
BECOMING WIDESPREAD.  
 
ON MONDAY, A SECOND STORM SYSTEM WILL BE MOVING NORTHEAST OUT  
OF THE SOUTHERN PLAINS, CROSSING THE MID MS VALLEY DURING THE  
DAY AND INTO THE OH VALLEY MONDAY EVENING. RESPONSE WILL BE THE  
DEVELOPMENT OF MORE SHOWERS AND THUNDERSTORMS WITH FOCUS  
PRIMARILY TO OUR WEST ACROSS THE OH/TN VALLEYS. MODEL SOUNDINGS  
SUGGEST SOME INSTABILITY DRIVEN ACTIVITY MAY DEVELOP OVER OUR  
CWA DURING THE AFTERNOON ASSOCIATED WITH WEAK CONVERGENCE NEAR  
THE BLUE RIDGE. ATTM WILL ADVERTISE CHANCE THREAT FOR  
SHOWERS/STORMS MONDAY, BUT COVERAGE GENERALLY LESS THAN 50  
PERCENT AND NO MENTION OF SEVERE ATTM. CERTAINLY CAN'T RULE OUT  
A STRONGER STORM OR TWO IF TEMPERATURES RISE INTO THE 70S PERMITTING  
SURFACE BASED CAPE IN THE 1000-1500 RANGE.  
 
TEMPERATURES THROUGH MONDAY WILL REMAIN MILD WITH READINGS 10  
TO 15 DEGREES ABOVE NORMAL, AND REMAINING WELL ABOVE FREEZING.  
 

 
   
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/
 
 
AS OF 300 PM EDT SUNDAY...  
 
DURING THIS PORTION OF THE FORECAST, A PACIFIC BASED SYSTEM IS  
EXPECTED TO IMPACT THE REGION. GUIDANCE AMONG THE MODELS IS IN GOOD  
AGREEMENT OF BRINGING A SHORTWAVE TROUGH EASTWARD ALONG THE OHIO  
VALLEY AND THEN INTO THE NEW YORK CITY REGION MONDAY NIGHT INTO, AND  
THROUGH TUESDAY. THIS TRACK WILL KEEP THE REGION ON THE MILD SIDE OF  
THE SYSTEM UNTIL THE PASSAGE OF ITS ASSOCIATED COLD FRONT TUESDAY  
MORNING INTO THE AFTERNOON HOURS.  
 
SCATTERED SHOWERS AND ISOLATED STORMS ACROSS THE AREA MONDAY  
AFTERNOON, WILL LINGERING INTO MONDAY EVENING. THE SCATTERED SHOWERS  
WILL CONTINUE THROUGH THE OVERNIGHT, WITH COVERAGE INCREASING  
TOWARDS DAYBREAK IN THE WEST. THERE MAY BE AN INITIAL INCREASE IN  
COVERAGE ACROSS EASTERN PARTS OF THE AREA THROUGH THE EVENING HOURS,  
BUT DECREASE TO ISOLATED COVERAGE EARLY TUESDAY MORNING.  
 
AS THE FRONT CROSSES THE REGION ON TUESDAY, SHOWERS WILL BE IN  
GREATEST CONCENTRATION COINCIDENT AND JUST IN ADVANCE OF THE COLD  
FRONT. INSTABILITY IS PROGGED TO INCREASE ENOUGH TO WARRANT ISOLATED  
TO SCATTERED THUNDERSTORMS IN THIS SAME GENERAL AREA, WITH THE BEST  
POTENTIAL SHIFTING EASTWARD DURING THE COURSE OF THE DAY.  
 
COVERAGE WILL QUICKLY DECREASE TUESDAY EVENING WITH THE DEPARTURE OF  
THE COLD FRONT TO THE EAST. SOME LINGERING NORTHWEST FLOW UPSLOPE  
ISOLATED SHOWERS ARE POSSIBLE ACROSS PORTIONS OF SOUTHEAST WEST  
VIRGINIA, NEIGHBORING COUNTIES OF SOUTHWEST VIRGINIA, AND SOUTH INTO  
THE NORTHERN MOUNTAINS OF NORTH CAROLINA. COVERAGE WILL BE GREATEST  
DURING THE EVENING HOURS WITH DECREASING COVERAGE AS THE NIGH  
PROGRESSES.  
 
WEDNESDAY INTO WEDNESDAY NIGHT, AN UPPER LEVEL SHORTWAVE RIDGE IS  
PROGGED TO BUILD OVER THE AREA, ALL WHILE SURFACE HIGH PRESSURE  
NOSES SOUTH ALONG THE LEE OF THE APPALACHIANS. LOOK FOR ANY  
LINGERING ISOLATED SHOWERS IN THE WEST TO END BY NOON. LIMITED CLOUD  
COVER IS FORECAST FOR ALL OF THE REGION BY WEDNESDAY AFTERNOON. AS  
WEDNESDAY NIGHT PROGRESSES, LOW LEVEL FLOW ON THE WEST SIDE OF THE  
SURFACE RIDGE WILL ALLOW FOR MOISTURE LEVELS TO INCREASE. ANTICIPATE  
INCREASING CLOUD COVER, AND EVENTUALLY SOME PATCHY LIGHT RAIN ACROSS  
AREAS MAINLY NEAR THE CREST OF THE BLUE RIDGE FROM ROUGHLY ROANOKE,  
VA SOUTHWEST INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.  
 
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND FROM  
ROUGHLY FIFTEEN DEGREES ABOVE NORMAL MONDAY NIGHT INTO TUESDAY TO  
AROUND FIVE TO TEN DEGREES ABOVE NORMAL WEDNESDAY INTO WEDNESDAY NIGHT.  
 

 
   
LONG TERM /THURSDAY THROUGH SUNDAY/
 
 
AS OF 300 PM EDT SUNDAY...  
 
THE LEE SIDE RIDGE OF SURFACE HIGH PRESSURE WILL CONTINUE TO PREVAIL  
ON THURSDAY, ALTHOUGH LOW LEVEL FLOW NOT TOO FAR ABOVE THE SURFACE  
WILL START TO INCREASE AS A CLOSED UPPER LOW HEADS EASTWARD THROUGH  
THE CENTRAL U.S. LOOK FOR LIGHT RAIN TO INCREASE ACROSS THE AREA ON  
THURSDAY, ESPECIALLY WESTERN AND CENTRAL PARTS OF THE REGION. THE  
ACTIVITY WILL TAKE ON MORE OF A SHOWERY NATURE THURSDAY NIGHT AS THE  
UPPER SYSTEM DRAWS CLOSER.  
 
ON FRIDAY, SHOWERS WILL BE LIKELY ACROSS MOST OF THE REGION WITH  
ISOLATED THUNDERSTORM POSSIBLE ACROSS THE WESTERN AND SOUTHERN PARTS  
OF THE AREA. THE MAIN SYSTEM WILL TRACK NORTH OF THE AREA FRIDAY  
NIGHT INTO SATURDAY, WITH ITS ASSOCIATED COLD FRONT ACROSS OUR  
REGION EARLY FRIDAY NIGHT. LOOK FOR AN END OF THE SHOWER ACTIVITY  
FOR MUCH OF THE AREA BY SATURDAY MORNING. LINGERING UPSLOPE SHOWERS  
ON THE BACKSIDE OF THE SYSTEM WILL BE POSSIBLE ACROSS SOUTHEAST WEST  
VIRGINIA AND NEIGHBORING COUNTIES OF SOUTHWEST VIRGINIA.  
 
SATURDAY NIGHT INTO SUNDAY, AN UPPER LEVEL RIDGE WILL BUILD OVER THE  
AREA, ALLOWING FOR A GRADUAL DECREASE IN THE UPSLOPE SHOWERS IN THE  
WEST, AND LIMITED CLOUD COVER IN THE EAST.  
 
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL BE AROUND OR  
SLIGHTLY ABOVE NORMAL THURSDAY AND FRIDAY, BUT TREND TO READINGS  
ABOUT TEN DEGREES ABOVE NORMAL FOR SATURDAY AND SUNDAY.  
 

 
   
AVIATION /00Z MONDAY THROUGH FRIDAY/
 
 
AS OF 710 PM EDT SUNDAY...  
 
VFR TO VFR/MVFR PRESENTLY ACROSS MOST OF THE TERMINALS, AND  
THOSE CONDITIONS SHOULD CONTINUE THROUGH THE NEXT COUPLE OF  
HOURS. OF NOTE IS LOWER, MORE WIDESPREAD MVFR CEILINGS ALONG THE  
SOUTHERN BLUE RIDGE AND INTO THE NC MOUNTAINS THAT WILL  
CONTRIBUTE TO OBSCURED MOUNTAINS THROUGH MUCH OF THE TAF PERIOD.  
ONGOING UNRESTRICTED SHOWERS FROM ROANOKE AND LYNCHBURG SOUTH TO  
DANVILLE AND REIDSVILLE SHOULD PERSIST NEXT COUPLE OF HOURS AS  
WELL. LIMITED POTENTIAL FOR IN-CLOUD LIGHTNING IN SOUTHEAST WV  
NEXT COUPLE HOURS, BUT NOT EXPECTED TO AFFECT ANY TAF.  
 
CONFIDENCE IN CEILINGS IS LOW FOR THE REST OF THE OVERNIGHT, BUT  
EXPECT OVC VFR TO MVFR TO BE THE PRIMARY CEILING CONDITIONS FOR  
THE TERMINALS. GENERALLY REFLECTED THIS UNCERTAINTY WITH A  
SECOND SCT MVFR CLOUD GROUP. LIGHT SOUTH TO SOUTHEAST WINDS  
OVERNIGHT.  
 
FOR MONDAY...CEILINGS SHOULD BEGIN TO BECOME SCATTERED TO BROKEN  
AGAIN. POTENTIAL FOR SHOWERS AND THUNDERSTORMS AGAIN FOR  
TOMORROW, THOUGH WOULD TEND TO BE SPORADIC/INTERMITTENT. WINDS  
STAY SOUTHERLY AROUND 6-10 KTS.  
 
EXTENDED AVIATION DISCUSSION...  
 
AN ACTIVE WEATHER PERIOD WITH A SERIES OF VIGOROUS UPPER-LEVEL  
LOW PRESSURE AREAS TRACKING FROM WEST TO EAST ACROSS THE U.S.  
DURING THE WEEK. AREAS OF SUB-VFR CIGS/VSBYS ARE POSSIBLE,  
ESPECIALLY DURING THE MORNING HOURS, IN LOW CLOUDS AND FOG.  
COVERAGE OF SHOWERS AND THUNDERSTORMS WILL BE THE GREATEST  
DURING THE AFTERNOON AND EVENING COINCIDING WITH THE PEAK  
HEATING OF THE DAY.  
 

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

 
 

 
SYNOPSIS...PM  
NEAR TERM...AL/PM  
SHORT TERM...DS  
LONG TERM...DS  
AVIATION...AL/PM  
 
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