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 171351 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 951 AM EDT THU APR 17 2014 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE WILL REMAIN OVER THE NORTHEASTERN U.S. THROUGH FRIDAY KEEPING A RELATIVELY COOL AIR MASS ACROSS THE REGION. AN AREA OF LOW PRESSURE WILL MOVE VERY SLOWLY THROUGH THE SOUTHEASTERN STATES INTO SATURDAY...WHICH WILL BRING CLOUDS TO THE ENTIRE AREA AND A CHANCE OF RAIN TO NORTH CAROLINA AND FAR SOUTHERN VIRGINIA. A STRONGER COLD FRONT WILL APPROACH THE REGION FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 940 AM EDT THURSDAY... ONLY MINOR CHANGES MADE TO THE FORECAST AS DRY HIGH PRESSURE OVER NEW ENGLAND CONTINUES TO DOMINATE OUR REGION. INCREASED CLOUD COVER SLIGHTLY AS HIGH CLOUDS SHOWN ON VISIBLE SATELLITE WERE DRIFTING OVER AREAS SOUTH OF HIGHWAY 460 THIS MORNING. CANADIAN MODEL FORECAST SHOWS THESE CLOUDS WILL THIN DURING THE AFTERNOON. OTHERWISE...FORECAST TEMPS RUNNING JUST A TAD COOLER THAN 13Z OBSERVATIONS...SO ADJUSTED READINGS UP A COUPLE OF DEGREES CLOSER TO THE ADJUSTED NAM MOS GUIDANCE. LOW PRESSURE DEVELOPING ACROSS THE SOUTHEAST STATES/EASTERN GULF LATE IN THE PERIOD WILL REMAIN SUFFICIENTLY FAR SOUTH THROUGH THIS TIME FRAME TO HAVE NO IMPACT ON THE REGION THROUGH THIS TIME FRAME. A NORTHERN STREAM UPPER SHORT WAVE APPROACHING FROM THE NORTHWEST WILL ALSO HAVE LITTLE IMPACT OTHER THAN ALSO SOME HIGH CLOUDS LATE IN THE PERIOD. MAIN CONCERN THROUGH THIS TIME FRAME WILL ONCE AGAIN BE FREEZING TEMPERATURES AND FROST POTENTIAL. FOR FRIDAY MORNING...ANY FREEZING TEMPERATURES LOOK VERY SPOTTY AS AIR MASS CONTINUES TO SLOWLY MODIFY. MORE IMPORTANTLY...HOWEVER...WILL BE STRENGTHENING EASTERLY FLOW IN RESPONSE TO DEVELOPING LOW PRESSURE IN THE SOUTHEAST. THE EXTENT OF THIS WIND FLOW IS NOT TOTALLY CLEAR AT THIS POINT...BUT ENOUGH CONFIDENCE THAT WEST OF THE BLUE RIDGE IN THE SOUTHERN SHENANDOAH VALLEY THAT ENOUGH DECOUPLING WILL EXIST FOR DEVELOPMENT OF WIDESPREAD FROST AS TEMPERATURES DROP INTO THE LOWER AND MID 30S AFTER LATE TONIGHT/EARLY FRIDAY. THUS...HAVE GONE AHEAD AND ISSUED A FROST ADVISORY FOR BOTETOURT...AMHERST...AND ROCKBRIDGE...THE MAIN AREA OF CONCERN AT THIS POINT. DAY SHIFT MAY NEED TO CONSIDER EXPANDING THIS FURTHER EAST AND SOUTH DEPENDING ON DEGREE OF CONFIDENCE IN DECOUPLING ALLOWING FOR FROST FORMATION. GROUND IS QUITE MOIST...SO IF WINDS REMAIN LIGHT...TEMPERATURES SHOULD BE COLD ENOUGH FOR FROST TO DEVELOP.
-- End Changed Discussion --
&& .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM EDT THURSDAY... FRIDAY INTO FRIDAY NIGHT...A COLD AIR DAMMING RIDGE WILL BE IN PLACE ACROSS THE LEE OF THE APPALACHIANS. PROGRESSIVELY INCREASING MOISTURE OFF THE ATLANTIC WILL PROGRESS INTO THE AREA ON SOUTHEAST WINDS...ROUNDING THE BASE OF THE RIDGE. ANTICIPATE AT LEAST A MOSTLY CLOUDY SKY ON FRIDAY WITH INCREASING CLOUD COVER FRIDAY NIGHT. ANOTHER FEATURE ALSO WILL BE CONTRIBUTING TO INCREASED CLOUD COVER TO AREA IN GENERAL...AND POTENTIALLY SOME PRECIPITATION TO THE SOUTHERN AND SOUTHEASTERN PORTION OF THE REGION. 00Z/8PM GUIDANCE AMONG THE GFS...ECMWF...AND CANADIAN SOLUTIONS BRING A CLOSED LOW SLOWLY NORTHEAST THROUGH THE GULF COAST STATES WITH THE NORTHERN EXTENT OF ITS PRECIPITATION SHIELD BRUSHING OUR SOUTHERN TIER COUNTIES BY FRIDAY EVENING...CONTINUING THROUGH THE NIGHT...AND CONCLUDING INTO SATURDAY MORNING. THE LOW ITSELF IS PROGGED TO CONTINUE A SLOW NORTHEAST TRACK AND EXIT THE U.S. OFF THE GA/SC COAST AROUND SATURDAY EVENING. WHILE THESE THREE SOLUTIONS ARE SIMILAR...THEY ARE A SHIFT NORTH AS COMPARED TO THEIR EARLIER COUNTERPARTS THAT HAD DRY SOLUTIONS...AND THE 00Z/8PM NAM SOLUTION HAS MAINTAINED A MORE SOUTHERLY...AND THUS DRIER AND WARMER SOLUTION FOR OUR REGION. GIVEN THIS...WILL OFFER NO MORE THAN A SLIGHT CHANCE OF LIGHT RAIN FROM THE NORTHERN MOUNTAINS OF NC EASTWARD ALONG THE NC/VA BORDER DURING THE FRIDAY EVENING/NIGHT TIME FRAME...AND GREATER CLOUD COVER...AND COOLER TEMPERATURES ACROSS THE FORECAST AREA AS A WHOLE. WILL REFRAIN FROM CONTINUING THE SLIGHT CHANCE INTO SATURDAY AT THIS POINT...AND ALLOW OUR FORECAST TO CONTINUE FORWARD NEARLY UNCHANGED THROUGH THE REMAINDER OF THE WEEKEND. THIS SOLUTION IS ONE THAT KEEPS THE REGION WITHIN A ZONE OF DRY...HIGH PRESSURE...WITH EVER SLOWLY RISING HEIGHTS THROUGH THE PERIOD...WHILE THE CLOSED LOW SPINS OFF THE COAST OF THE SOUTHEAST U.S. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 330 PM EDT WEDNESDAY... UPPER RIDGING BUILDING BEHIND A CLOSE UPPER LOW OFF THE SOUTHEAST COAST WILL PROVIDE A NICE BOOST IN TEMPS FOR MUCH OF THE LONG TERM. DESPITE CLOUDS AHEAD OF ANOTHER WEAK SYSTEM APPROACHING FROM THE GREAT LAKES...WARM SW FLOW SHOULD SHOVE +10C H85 AIR OUR WAY INTO TUESDAY. H8H TEMPS ARE ONLY SLIGHTLY COOLED BY THIS BOUNDARY WITH SHOWERS PROBABLY CONFINED TO TUESDAY NIGHT OR WEDNESDAY MORNING. HEIGHTS BUILD QUICKLY BEHIND THIS DISTURBANCE IN RESPONSE TO A CLOSED LOW AND DIGGING NEGATIVELY TILTED TROUGH THROUGH THE ROCKIES...WITH THE WARM PATTERN CONTINUING THROUGH THE END OF THE FORECAST. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... AS OF 730 AM EDT THURSDAY... VFR CIGS/VSBYS EXPECTED TO CONTINUE THROUGH THE PERIOD AS A LARGE COLD...DRY HIGH PRESSURE AREA ANCHORS ACROSS THE NORTHEASTERN U.S. THROUGH THE PERIOD. LOW PRESSURE ALOFT WILL BE DEEPENING ACROSS THE EASTERN GULF SE GA/SC/NORTHERN FL THROUGH THE PERIOD...WHICH WILL PROLONG THE E-NE SFC FLOW INTO THE REGION FOR SEVERAL DAYS. AS THE FLOW BECOMES MORE ESE-SE THU NIGHT INTO FRI AND INCREASED MARITIME FLOW...SOME LOW CLOUDS MAY BEGIN TO DEVELOP ACROSS THE PIEDMONT...ESPECIALLY IN UPSLOPE AREAS ALONG THE BLUE RIDGE...BUT THIS SHOULD REMAIN BEYOND THIS VALID TAF PERIOD. A FEW HIGH CLOUDS WILL SKIRT THE AREA FROM THE WEST TODAY...BUT HIGH CLOUDS WILL INCREASE CONSIDERABLY OVERNIGHT AND AFT 06Z COULD BECOME BKN-OVC IN MOST AREAS AT 250. WINDS ENE- ESE THROUGH THE PERIOD AT 6-9KTS...WITH LOW END GUSTS POSSIBLE LYH/ROA DURING THE DAYTIME. BLF CONTINUES TO EXHIBIT TYPICALLY GUSTY SE WINDS FOR SYNOPTIC PATTERN...AND THIS SHOULD CONTINUE THROUGH MUCH OF THE TAF VALID PERIOD WITH PERIODIC GUSTS TO 20KTS POSSIBLE. HIGH CONFIDENCE IN VFR CIGS/VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... THE NEXT COLD FRONT APPROACHES FROM THE WEST FRIDAY WHILE ANOTHER SYSTEM STAYS OFF THE SOUTHEAST COAST. THERE IS POTENTIAL FOR INCREASE CLOUDS FRIDAY-SATURDAY OVER THE SOUTHEAST BUT MOST PLACES SHOULD STAY VFR...POTENTIALLY MVFR EARLY FRI ACROSS THE PIEDMONT. VFR FOR SUNDAY WITH HIGH PRESSURE REMAINING ACROSS THE NORTHEAST AND MID ATLANTIC. THE NEXT SYSTEM TO BRING MVFR TO POTENTIALLY IFR CIGS AND -SHRA TO THE AREA DOES NOT ARRIVE UNTIL EARLY TO MID PART OF NEXT WEEK. && .CLIMATE... AS OF 1000 AM EDT WEDNESDAY... RECORD LOWS AT BLACKSBURG...BLUEFIELD AND LEWISBURG THIS MORNING BLACKSBURG TIED THEIRS AT 24...BLUEFIELD TIED THEIRS AT 23 AND LEWISBURG BROKE THEIRS AT 23. APRIL 17TH RECORD LOWS ROANOKE 27F 1980......FORECASTED LOW 31F. LYNCHBURG 27F 1904....FORECASTED LOW 30F. DANVILLE 28F 1962.....FORECASTED LOW 30F. BLUEFIELD 25F 2001....FORECASTED LOW 32F. BLACKSBURG 20F 1974...FORECASTED LOW 26F. LEWISBURG 25F 2001....FORECASTED LOW 20F. && .RNK WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
VA...FROST ADVISORY FROM 4 AM TO 9 AM EDT FRIDAY FOR VAZ023-024-035. NC...NONE. WV...NONE.
-- End Changed Discussion --
&& $$ SYNOPSIS...RAB NEAR TERM...PH/RAB SHORT TERM...DS LONG TERM...KM AVIATION...KK/RAB CLIMATE...JC/KM

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