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 232147 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 547 PM EDT WED JUL 23 2014 .SYNOPSIS...
-- Changed Discussion --
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AND CROSS THE MID ATLANTIC REGION THURSDAY. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE FRONTAL PASSAGE. DRIER AIR WILL MOVE INTO THE AREA BEHIND THE FRONT FRIDAY WITH A DAY OR TWO OF DRY WEATHER...FRIDAY INTO SATURDAY. MOISTURE WILL QUICKLY RETURN OVER THE WEEKEND WITH HEAT AND HUMIDITY HELPING TO TRIGGER MORE THUNDERSTORM ACTIVITY. A STRONG FRONT IS EXPECTED TO CROSS THE AREA LATE SUNDAY INTO MONDAY.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH THURSDAY/... AS OF 445 PM EDT WEDNESDAY... SCATTERED THUNDERSTORMS DEVELOPING MAINLY ALONG THE BLUE RIDGE LATE THIS AFTERNOON IN THE WARM AND HUMID AIR MASS WITH SURFACE DEWPOINTS NEARING 70F AND PLENTY OF INSTABILITY. A FEW STORMS COULD BE SEVERE ALONG WITH BRIEF HEAVY RAINFALL WITH ATTENDANT LOCAL RUNOFF ISSUES. SHOULD SEE CONVECTION DIMINISH WITH LOSS OF HEATING LATER THIS EVENING. NEXT QUESTION WILL BE PRECIPITATION CHANCES LATER TONIGHT AND INTO TOMORROW IN ASSOCIATION WITH APPROACHING COLD FRONT AS UPPER TROUGH AMPLIFIES OVER THE GREAT LAKES. FRONTAL BOUNDARY WILL MAKE ITS WAY TOWARD THE WESTERN CWA BY THU MORNING...AND MODELS DEVELOP FAIRLY WIDESPREAD COVERAGE OF PRECIP ACROSS THE WEST EARLY TOMORROW AND SPREADING EAST ACROSS THE PIEDMONT AS THE DAY PROGRESSES. THUNDER MAY BE LIMITED BY CLOUD COVER AND LACK OF INSTABILITY ESPECIALLY ACROSS THE WESTERN HALF OF THE CWA BUT OVERALL CHANCES FOR CONVECTION WILL INCREASE OVER THE PIEDMONT LATER IN THE DAY WITH POSSIBLY SOME HEATING AND MORE INSTABILITY. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AS WELL WITH STILL VERY HIGH PWATS AHEAD OF THE FRONT. CLOUD COVER AND HIGH DEWPOINTS WILL KEEP LOWS TONIGHT WELL ABOVE NORMAL RANGING FROM MID 60S TO LOWER 70S...WITH DIURNAL RANGE LIMITED TOMORROW AS WELL. HIGHS SHOULD BE 5 TO 8F LOWER THAN TODAYS WARM VALUES. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
AS OF 500 PM EDT WEDNESDAY... SURFACE COLD FRONT IS EXPECTED TO SLIP SOUTHEAST OF OUR AREA THURSDAY NIGHT BEFORE STALLING ALONG THE CAROLINA COAST FRIDAY. MODELS MAINTAIN CONTINUITY WITH DRY HIGH PRESSURE BUILDING INTO THE FORECAST AREA FROM THE NORTH. IN SPITE OF THE DRY AIR...THICKNESSES DO NOT FALL THAT MUCH...SO DO NOT EXPECT MUCH IN THE WAY OF A TEMPERATURE CHANGE. IF ANYTHING...INCREASED SUNSHINE WILL HELP BOOST SURFACE TEMPERATURES TO AT LEAST OUR JULY NORMALS FRIDAY...THEN BEGIN WARMING BACK UP SATURDAY AS SOUTHERLY FLOW INCREASES BEHIND THE DEPARTING SURFACE HIGH. FOR SATURDAY...MOISTURE WILL BEGIN TO RETURN TO THE FORECAST AREA FROM THE SOUTH AND SOUTHWEST. CAN`T RULE OUT A LATE AFTERNOON POPUP SHOWER OVER THE MOUNTAINS...BUT THINK MOST AREAS WILL REMAIN DRY UNTIL THE ARRIVAL OF A FRONT LATE IN THE WEEKEND. WILL HAVE TO MONITOR THIS UPSTREAM FRONT CLOSELY AS IT MAY CAST SOME PREFRONTAL SHOWERS AND STORMS OUR WAY AS EARLY AS SATURDAY NIGHT.
-- End Changed Discussion --
&& .LONG TERM /SUNDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 515 PM EDT WEDNESDAY... STRONG COLD FRONT IS SLATED TO CROSS THE FORECAST AREA LATE SUNDAY INTO MONDAY...ASSOCIATED WITH A VIGOROUS SHORT WAVE TROUGH THAT WILL BE MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS PARTICULARLY STRONG DISTURBANCE...NOTED BY ALL THE MODELS...PROMISES TO AMPLIFY THE EASTERN LONG WAVE TROUGH...A PATTERN THAT WILL NET COOLER THAN NORMAL TEMPERATURES FOR SEVERAL DAYS NEXT WEEK. DURING THE TRANSITION SUNDAY INTO MONDAY...INCREASED INSTABILITY AHEAD OF THE FRONT ALONG WITH STRONG DYNAMIC FORCING WILL RESULT IN POTENTIAL FOR STRONG TO SEVERE STORMS. THE OPPORTUNITY WILL EXIST FOR ORGANIZED DEEP CONVECTION WITH POTENTIAL FOR A MESOSCALE CONVECTIVE SYSTEM (MCS) TO CROSS THE FORECAST AREA FROM THE WEST. ATTM WILL MAINTAIN THE BEST CHANCE FOR SHOWERS/STORMS SUNDAY...WITH THE THREAT LINGERING INTO MONDAY UNTIL THE SURFACE FRONT CAN COMPLETELY CLEAR THE FORECAST AREA. GENERALLY FOLLOWED HPC GUIDANCE THROUGH THE PERIOD TRENDING POPS DOWNWARD AFTER THE EARLY WEEK FROPA.
-- End Changed Discussion --
&& .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... AS OF 125 PM EDT WEDNESDAY... SCATTERED CONVECTION BEGINNING TO DEVELOP ACROSS HIGHER TERRAIN OF WESTERN CWA SO HAVE KEPT VCTS AT ROA/BCB/BLF/LWB WITHIN NEXT 1-2 HOURSRR. THE CONVECTION WILL WANE LATE AFTERNOON/EARLY EVENING BEFORE FRONTAL PRECIP ARRIVES AFTER MIDNIGHT IN THE BLF/LWB CORRIDOR. EXTENDED AVIATION DISCUSSION... NEXT NORTHERN STREAM UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL APPROACH WORK THROUGH THE REGION ON THURSDAY. THIS WILL BRING THE BEST CHANCES OF MORE WIDESPREAD SHOWERS TO THE MOUNTAINS AND PERHAPS SOME DEEPER CONVECTION EAST OF THE BLUE RIDGE PENDING TIMING OF THE BOUNDARY THURSDAY AFTERNOON. AIRMASS WILL DRY OUT BEHIND THE FRONT GOING INTO FRIDAY- SATURDAY. OVERALL EXPECT SUB VFR AT TIMES THURSDAY WITH SHRA/TSRA AND MAYBE SOME FOG THU NIGHT...FOLLOWED BY VFR FRI- SAT OUTSIDE OF ANY VALLEY FOG AT KLWB/KBCB EACH MORNING. && .EQUIPMENT...
-- Changed Discussion --
AS OF 500 PM EDT WEDNESDAY... KFCX RADAR IS DOWN...BUT MAY RETURN TO LIMITED SERVICE THIS EVENING. TECHNICIANS CONTINUE TO EVALUATE THE PROBLEMS...SO EVEN IF THE RADAR COMES BACK UP IT MAY BE SUSCEPTIBLE TO MORE DOWN. THERE IS A COMBINATION OF ISSUES THAT STEMMED FROM A POWER SURGE OR POWER SUPPLY FAILURE. THIS HAD A RIPPLE EFFECT TO OTHER SYSTEMS...ONE OF WHICH WAS A PRESSURE SWITCH ON AN OIL PUMP THAT HAD TO BE REPLACED TODAY. ADDITIONAL WORK MAY NEED TO BE COMPLETED THURSDAY.
-- End Changed Discussion --
&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PM NEAR TERM...PC/WP SHORT TERM...PM LONG TERM...PM AVIATION...PC/WP EQUIPMENT...PM

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