Area Forecast Discussion
Issued by NWS Blacksburg, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRNK 010555 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 155 AM EDT WED JUL 1 2015 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION LATE TONIGHT INTO WEDNESDAY. THE FRONT WILL STALL ACROSS THE AREA BY WEDNESDAY NIGHT. A SERIES OF LOWS WILL TRACK ALONG THE FRONT THURSDAY THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... AS OF 900 PM EDT TUESDAY... CONVECTION HAS BEEN ON OPPOSITE ENDS OF THE CWA THIS EVENING WITH ONE MAIN AREA OVER THE NW DRIVEN BY AN OUTFLOW BOUNDARY DIVING SE FROM THE LOWER OHIO VALLEY...AND THE OTHER OVER THE SE WITH A IMPULSE ALOFT PASSING TO THE SOUTH. THESE BANDS TO THE NW REMAIN THE MAIN CONCERN OVER THE NEXT FEW HOURS GIVEN LINGERING INSTABILITY OF OVER 1K J/KG ESPCLY IN AREAS CLOSER TO THE BLUE RIDGE WHERE THINGS HAVE NOT BEEN WORKED OVER YET. ALSO EVENING RNK SOUNDING QUITE UNSTABLE WITHOUT ANY CAPPING SO STILL SOME OPPORTUNITY FOR STORMS TO DEVELOP OUT INTO THE NEW/ROA VALLEYS IN THE NEXT FEW HOURS BEFORE LOSS OF HEATING CAUSES THINGS TO FINALLY FADE. HOWEVER GIVEN TRENDS OF MOST CELLS STAYING BELOW SEVERE CRITERIA...WENT AHEAD AND LET SEVERE WATCH 377 EXPIRE WITH MOSTLY ONLY ISOLATED STRONGER STORMS EXPECTED THROUGH MIDNIGHT OR SO ESPCLY NORTH AND WEST. DID BUMP UP POPS TO GO WITH MORE COVERAGE UNTIL SHORTLY AFTER MIDNIGHT WHEN THE LATEST HRRR SHOWS THE MAJORITY FADING. OTRW FEW ADDED CHANGES WITH LOWS MOSTLY IN THE 60S AND SOME PATCHY FOG AROUND WHERE RAIN HAS OCCURRED AND MORE CLEARING TAKES SHAPE LATE. UPPER FLOW WILL TURN MORE WESTERLY WEDNESDAY WITH FOCUS FOR STORMS SWINGING FURTHER SOUTHWEST...AND WEST FROM WESTERN KY INTO THE SMOKYS. HIGHEST POPS WILL BE IN THE SW VA/NW NC MTNS GIVEN THIS. MARGINAL RISK OF SVR REMAINS AROUND AND SOUTHWEST OF THIS AREA TOMORROW. WE SHOULD SEE MORE SUNSHINE AND RISING TEMPS ESPECIALLY IN THE PIEDMONT WITH HIGHS IN THE UPPER 80S/LOWER 90S. THE MOUNTAINS WILL BE WARM WITH INCREASING CLOUDS THEN SCATTERED STORMS...WITH LOWER 80S EXPECTED. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... AS OF 300 PM EDT TUESDAY A BROAD UPPER LEVEL TROF WILL REMAIN OVER THE EASTERN HALF OF THE U.S. THROUGH THE SHORT TERM PERIOD KEEPING AN UNSETTLED WEATHER PATTERN IN PLACE. MODELS DIFFER ON THE TIMING OF SHORTWAVES MOVING THROUGH THE UPPER TROF...BUT THERE IS CONSENSUS THAT ONE OF THE STRONGER WAVES MOVES OVER OUR AREA ON THURSDAY PROVIDING THE BEST CHANCE FOR WIDESPREAD AND ORGANIZED PRECIPITATION. OUR AREA ALSO FALLS UNDER THE RIGHT REAR QUAD OF A DEPARTING UPPER LEVEL JET IN NEW ENGLAND. WIDESPREAD CLOUDINESS ON THURSDAY MAY KEEP INSTABILITY DOWN...WITH MODELS SHOWING HIGHEST CAPES IN THE SOUTHEAST PORTION OF THE CWA WHERE MORE SUN IS EXPECTED. MODELS HAVE BEEN TRENDING SLOWER WITH THIS SYSTEM...AND AS A RESULT...LOWERED POPS IN THE EAST. HOWEVER...THIS MAY ALLOW FOR MORE HEATING IN THE SOUTH AND EAST RESULTING IN A BETTER CHANCE FOR SEVERE WEATHER. HEAVY RAIN IS ALSO POSSIBLE...AS PWATS SOAR TO 1.5 TO 2.0" BY THURSDAY AFTERNOON. WILL CONTINUE TO MENTION THE THREAT OF HEAVY RAIN AND ISOLATED SEVERE WEATHER IN THE HWO. IN THE WAKE OF THIS SYSTEM...THE SFC BOUNDARY IS PUSHED SOUTH INTO NC ON FRIDAY LEAVING US WITH A EAST/SOUTHEAST LOW LEVEL FLOW. AS A RESULT...DROPPED HIGHS ON FRIDAY AND KEPT HIGHEST POPS IN THE FAR WEST AND FAR SOUTH CLOSEST TO THE PROJECTED LOCATION OF THE LOW LEVEL BOUNDARY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 300 PM EDT TUESDAY THROUGH THE LONG TERM PERIOD...THE GFS AND ECMWF KEEP THE EASTERN U.S. UNDER AN UPPER TROF THAT FLATTENS BY EARLY NEXT WEEK. A SERIES OF SHORTWAVES WILL MOVE THROUGH THIS TROF THROUGH THE WEEKEND...KEEPING A CHANCE FOR SHOWERS AND STORMS THROUGH THE PERIOD...WITH THE HIGHEST POPS IN THE WEST CLOSEST TO THE BEST UPPER LEVEL SUPPORT. THE GFS AND TO A LESSER EXTENT THE CANADIAN MODELS ARE STRONGER AND DEEPER WITH AN UPPER LEVEL SYSTEM EARLY NEXT WEEK...WHILE THE ECMWF IS MORE OPEN AND PROGRESSIVE. WHAT ACTUALLY HAPPENS WILL LIKELY BE SOMEWHERE BETWEEN THESE SOLUTIONS....BUT THE BOTTOM LINE IS THAT OUR REGION WILL REMAIN ON THE EAST SIDE OF THE UPPER TROF AXIS...KEEPING UNSETTLED WEATHER IN PLACE THROUGH THE LONG TERM PERIOD. TEMPS ARE EXPECTED TO BE NEAR NORMAL THROUGH THE PERIOD. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
AS OF 155 AM EDT WEDNESDAY... CONVECTIVE ACTIVITY HAS EXITED THE REGION...LEAVING GENERALLY VFR CONDITIONS AT TAF SITES. HOWEVER...EXPECT LOW LEVEL MOISTURE TO BE RUNNING UP THE WESTERN SLOPES ON NW FLOW AS LOW PRESSURE PULLS THROUGH THE GREAT LAKES REGION. THIS WILL LIKELY BRING SOME MVFR CIGS TO KBCB AND KBLF. KLWB SEEMS TO FIND A WAY TO FOG IN AND WITH LIGHT FOG ALREADY AT THE STATION AFTER SOME PRECIPITATION THIS EVENING...WILL FORECAST LIFR CONDITIONS TOWARD DAYBREAK THOUGH IF CLOUD COVER DEVELOPS EARLY AND SHUTS OFF THE COOLING THIS MAY BE OVERDONE. WILL GO WITH MFVR FOG AT KLYH SINCE THEY HAD A GOOD DOSE OF RAIN BUT WILL STAY WITH UNRESTRICTED VSBYS AT KROA AND KDAN. ANY FOG/STRATUS WILL BE BURNING OFF AFTER DAYBREAK. A FRONTAL BOUNDARY WILL THEN REMAIN DRAPED OVER THE AREA AND HELP GENERATE SOME VFR CIGS AND ANOTHER ROUND OF SHRA/TSRA WEDNESDAY AFTERNOON. DO NOT HAVE A LOT OF CONFIDENCE IN TIMING OR LOCATION OF ANY CONVECTIVE DEVELOPMENT SO WILL KEEP TAFS DRY AND SEE IF LATER MESO MODEL RUNS CAN COME TO A CONSENSUS. WINDS WILL BE ON THE LIGHT SIDE WITH SOME LOW END GUSTS WEDNESDAY AFTERNOON. EXTENDED AVIATION DISCUSSION... THE REGION WILL BE IN A GENERAL NORTHWEST FLOW PATTERN THROUGH SATURDAY. WHILE ISOLATED TO SCATTERED SHOWERS AND STORMS CANNOT BE RULE OUT ANY OF THESE DAYS...THE BEST POTENTIAL WILL BE ON THURSDAY...THEN AGAIN LATER FRIDAY...FOLLOWED BY A THIRD POTENTIAL INCREASE IN COVERAGE ON SATURDAY AS SEPARATE SHORTWAVE TROUGHS PROGRESS TROUGH THE NORTHWEST FLOW. VFR CONDITIONS ARE EXPECTED FOR MOST OF THE AREA MUCH OF THE TIME. THE EXCEPTIONS WILL COME AS TEMPORARY DECREASES WITHIN ANY HEAVIER RAIN SHOWERS OR THUNDERSTORMS...AND THEN LATE AT NIGHT AND EARLY MORNING DUE TO RIVER OR MOUNTAIN VALLEY FOG...ESPECIALLY IN AREAS THAT RECEIVED PRECIPITATION THE DAY BEFORE.
-- End Changed Discussion --
&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...JH/WP SHORT TERM...PH LONG TERM...PH AVIATION...MBS/JH

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.