Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 101409 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1009 AM EDT THU JUL 10 2014 .SYNOPSIS... A SLOW MOVING COOL FRONT WILL SLIDE SOUTHEAST ACROSS THE REGION TODAY BEFORE STALLING ACROSS NORTHERN NORTH CAROLINA THIS EVENING. WEAK AREAS OF LOW PRESSURE RIDING ALONG THE FRONT WILL KEEP UNSETTLED WEATHER GOING INTO TONIGHT BEFORE WEAK HIGH PRESSURE SPILLS SOUTH INTO THE REGION FOR FRIDAY AND SATURDAY. DEEPER MOISTURE WILL RETURN LATER IN THE WEEKEND AND EARLY NEXT WEEK AHEAD OF A MUCH STRONGER COLD FRONT THAT WILL BE PASSING THROUGH THE REGION BY NEXT TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM EDT THURSDAY UPDATED GRIDS TO RAISE POPS IN THE EAST WITH CONTINUING BANDS OF SHOWERS PUSHING NORTHEAST FROM NC PIEDMONT. HIGH-RES NMM MODEL SEEMS TO BE DOING BEST ON THE INITIALIZATION OF THE PRECIP PATTERN CURRENTLY OCCURRING AND DOES SHOW SCT CONVECTION DEVELOPING IN THE WEST THIS AFTERNOON WITH SOME REDEVELOPMENT OVER THE PIEDMONT THIS AFTERNOON...ALTHOUGH EXTENSIVE CLOUD COVER OVER THE EAST MAY INHIBIT THAT FROM OCCURRING. LOWERED MAX TEMPS A BIT IN THE EAST WHERE CLOUDS SHOULD HOLD ON THE LONGEST TODAY. PERVIOUS VALID DISCUSSION... AS OF 235 AM EDT THURSDAY... PASSING UPPER TROF AND SURFACE WAVE SHOULD FINALLY GIVE JUST ENOUGH OF A PUSH TO SLIDE THE DEEPER MOISTURE TO THE SE OVERNIGHT ALTHOUGH GUIDANCE LIKELY REMAINS A BIT FAST. APPEARS STILL A NEED FOR LIKELY POPS SE AND CHANCES BACK TO THE BLUE RIDGE THIS EVENING...THEN A GRADUAL SE SHIFT OF DIMINISHING POPS TO ONLY A SLIGHT CHANCE PIEDMONT BY DAYBREAK FOR NOW. ALSO EXPECT A DECREASE IN CLOUDS FROM THE NW AS THE FRONT SHIFTS SE...WHICH SHOULD HELP TEMPS COOL A BIT MORE WITH 60S MOST SPOTS...EXCEPT PERHAPS A FEW 50S NW AND VALLEYS IF DEWPOINTS DO INDEED DROP A LITTLE DESPITE FOG FORMATION. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 310 AM EDT THURSDAY... AN UPPER LEVEL TROUGH WILL MOVE EAST TO THE COAST WHILE AN INVERTED SURFACE TROUGH STRETCHES NORTH FROM THE CAROLINAS THROUGH THE MID ATLANTIC ON FRIDAY. EASTERLY FLOW WILL PRODUCE ABUNDANT CLOUD COVER IN THE MORNING...THEN BREAKS THROUGH THE AFTERNOON. UPSLOPE COMPONENT AND DIURNAL HEATING WILL THEN ALLOW PULSE STORMS TO DEVELOP OVER THE MOUNTAINS FRIDAY AFTERNOON...IF THEY CAN BREAK THROUGH THE CAP. ANY STORMS DEVELOPING FRIDAY AFTERNOON WILL FADING WITH SUNSET. EASTERLY FLOW WILL KEEP AREAS ALONG AND EAST OF THE BLUE RIDGE COOLER THAN NORMAL...WHILE NEAR NORMAL TEMPERATURES ARE EXPECTED ACROSS THE MOUNTAINS. A STRONG AND HOT UPPER LEVEL RIDGE OVER THE SOUTHERN PLAINS WILL STRETCH TO THE EAST ON SATURDAY. OUTER RINGS OF THIS RIDGE WILL BE OVER THE FORECAST AREA BY THE AFTERNOON. SO WE WILL NEED TO KEEP AN EYE ON THE OHIO VALLEY FOR ANY COMPLEXES THAT COULD TRACK IN OUR DIRECTION. FOR NOW...MODELS ARE PAINTING A SCATTERED PULSE STORM ENVIRONMENT OVER THE FORECAST AREA WITH STORMS FIRING OVER THE MOUNTAINS IN THE AFTERNOON...THEN OVER THE FOOTHILLS AND POSSIBLY THE PIEDMONT LATE IN THE AFTERNOON THROUGH THE EVENING. THESE SHOWERS WILL LIKELY WANE BY MIDNIGHT. TEMPERATURES SATURDAY WILL EDGE WARMER THAN NORMAL AS THE UPPER LEVEL RIDGE BUILDS EAST. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 245 PM EDT WEDNESDAY... BY SUNDAY AND MONDAY...A LOW LEVEL THETA-E AXIS SURGES INTO OUR AREA WHICH WILL INCREASE COVERAGE OF DIURNALLY DRIVEN SHOWERS AND STORMS. BUT SIMILAR TO WHAT WE HAVE EXPERIENCED RECENTLY...A DEEP WEST/SOUTHWEST FLOW SHOULD KEEP THE CONVECTION SCATTERED. TOWARD THE END OF THE LONG TERM PERIOD THE MEDIUM RANGE MODELS CONTINUE TO FORECAST A BROAD UPPER TROF AND AN ASSOCIATED CUT OFF LOW OVER THE NORTHERN GREAT LAKES BY TUESDAY. THIS FEATURE HELPS DRIVE A COLD FRONT THROUGH OUR AREA ON TUESDAY. THERE ARE STILL DIFFERENCES WITH REGARD TO THE TIMING OF THIS FRONT...WITH THE 06Z GFS FASTER THAN THE 00Z ECMWF. USING A BLEND OF THESE SOLUTIONS...WILL CONTINUE TO CARRY A CHANCE OF SHOWERS/STORMS ON TUESDAY. TEMPERATURES SHOULD CLIMB IN ADVANCE OF THE FRONT TO NEAR OR SLIGHTLY ABOVE NORMAL...BEFORE FALLING BELOW NORMAL TUESDAY NIGHT INTO WEDNESDAY WHEN DRIER AIR ARRIVES. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... AS OF 700 AM EDT THURSDAY... COMMS ISSUES REMAIN AT KDAN DESPITE AN INTERMITTENT RETURN OF OBSERVATION DATA. AMD NOT SKED CONTINUED IN THE TAF. CLUSTERS OF LIGHTER SHOWERS...PRIMARILY FROM MID DECK WILL CONTINUE TO AFFECT THE KLYH-KDAN CORRIDOR EARLY THIS MORNING WITH ADDED -SHRA LIKELY TO PASS NEAR KBCB/KROA THROUGH MID MORNING. OTRW PATCHY DENSE FOG THE MAIN CONCERN IN THE NEXT HOUR OR TWO ESPCLY WITH A PERIOD OF LIFR AT KLWB/KBCB AND IFR/MVFR AT KLYH AND KDAN. THIS FOG WILL FADE BY MID MORNING EXCEPT IN AREAS OVER THE EAST THAT MIGHT STILL BE SEEING SOME SHOWERS LINGER. APPEARS CIGS WILL ALSO BE SLOWER TO LIFT GIVEN SO MUCH MOISTURE AROUND SO INCLUDED MORE LOW END VFR BASES AT MOST SPOTS DURING THE MORNING BEFORE BREAKING OUT ESPCLY WESTERN LOCATIONS TO A 4-5K CU FIELD AFTER MIDDAY. KDAN MAY BE THE EXCEPTION WHERE LOWER CIGS LINGER BEFORE MORE SHRA/TSRA DEVELOPS. MODELS KEEPING THE THREAT OF SHRA/TSRA AROUND OVER THE SOUTHEAST CWA THIS AFTERNOON AND ALONG PARTS OF THE BLUE RIDGE AS WELL...SO KEPT VCTS AT ROA/LYH/DAN...AND KBCB. ALSO INCLUDED A VCSH AT KBLF/KLWB PER SLOWNESS OF THE FRONT TO PUSH SE AS EXPECT LINGERING LOW LEVEL MOISTURE TO COMBO WITH HEATING TO PRODUCE AT LEAST ISOLATED -SHRA WHICH SHOULD BE BETTER OVER THE WEST/NW. OTRW EXPECT VFR OUTSIDE OF ANY STORMS FOR THE MOST PART AFTER EARLY FOG FADES. WAVE SHOULD FINALLY TAKE THE NEXT ROUND OF SHRA/TSRA TO THE SE LATER THIS EVENING WITH PERHAPS ENOUGH DRYING TO END CONVECTION AT ALL LOCATIONS AFTER MIDNIGHT. EXTENDED AVIATION... A LOWER PROBABILITY OF PRECIPITATION IS EXPECTED ACROSS THE AREA ON FRIDAY AND SATURDAY AS WEAK HIGH PRESSURE SLIDES IN FROM THE NORTH. MOISTURE AND MORE WIDESPREAD SHRA/TSRA LIKELY TO RETURN FOR THE END OF THE WEEKEND AS THE FRONT RETURNS NORTH RESULTING IN PERIODS OF MVFR CONDITIONS. OTRW PATCHY FOG RESULTING IN LOCAL MVFR TO IFR CONDITIONS LIKELY DURING THE LATE NIGHTS AND EARLY MORNINGS ESPCLY VALLEY LOCATIONS AND WHERE EARLIER AFTERNOON RAINFALL OCCURRED. && .HYDROLOGY... AS OF 1000 AM EDT THURSDAY... US DROUGHT MONITOR ISSUED THIS MORNING...JULY 10 2014...SHOWS EXPANSION OF D0...ABNORMALLY DRY CATEGORY...ACROSS MUCH OF NEW RIVER VALLEY AND OVER PARTS OF THE VA AND NC PIEDMONT...CENTERED AROUND DANVILLE. PULASKI COUNTY VA APPEARS TO BE NEAR THE EPICENTER OF THE DEVELOPING CONDITIONS OVER THE NEW RIVER VALLEY WITH MUCH OF THAT COUNTY RECEIVING LESS THAN 50 PERCENT OF NORMAL RAINFALL SINCE EARLY MAY. && .EQUIPMENT... AS OF 100 AM EDT THURSDAY... COMMUNICATIONS OUTAGE CONTINUES WITH KDAN ASOS NOT TRANSMITTING. THE FAA IS AWARE OF THE OUTAGE AND WILL BE WORKING ON IT...BUT NO ESTIMATED TIME OF WHEN IT WILL BE WORKING AGAIN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH NEAR TERM...JH/PC SHORT TERM...RCS LONG TERM...AMS/PH/RCS/WERT AVIATION...AMS/JH/WP HYDROLOGY...PC EQUIPMENT...WP

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