Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 300818 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 418 AM EDT MON MAR 30 2015 .SYNOPSIS... A COLD FRONT WILL SWEEP THROUGH THE REGION TODAY FOLLOWED BY WEAK HIGH PRESSURE TONIGHT. A DRY COLD FRONT WILL THEN MOVE THROUGH THE REGION TUESDAY FOLLOWED BY ANOTHER AREA OF WEAK HIGH PRESSURE FOR WEDNESDAY. ANOTHER COLD FRONT WILL MOVE INTO THE REGION AND STALL THURSDAY THROUGH FRIDAY...BRINGING AN EXTENDED PERIOD OF RAIN AND MILD TEMPERATURES TO THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 345 AM EDT MONDAY... FOCUS TODAY WILL BE ON A STRONG COLD SLATED TO SWEEP THROUGH THE REGION FROM NORTHWEST TO SOUTHEAST THIS MORNING. THIS FRONT WILL BRING A BRIEF PERIOD OF RAIN SHOWERS TO THE REGION FOLLOWED BY GUSTY W-NW WINDS FROM MID-MORNING THROUGH THE AFTERNOON. WEAK HIGH PRESSURE WILL BUILD INTO THE REGION AFTER SUNSET ALLOWING WINDS TO DIMINISH. DEWPOINTS REMAIN VERY LOW ACROSS THE REGION IN THE WAKE OF THE ANTECEDENT ARCTIC HIGH PRESSURE SYSTEM NOW LOCATED JUST SOUTHEAST OF THE CWA. ALTHOUGH THE UPPER SHORT WAVE IS STRONG...THE LACK OF SFC-BASED MOISTURE WILL INHIBIT MUCH PRECIPITATION. LATEST MODELS HAVE TRENDED DOWNWARD WITH FRONTAL ASSOCIATED PRECIPITATION TODAY...AND THIS SEEMS PRUDENT GIVEN THE DRY AIR MASS IN PLACE. THE BEST COMBINATION OF MOISTURE/DYNAMICS WILL TRACK TO THE SOUTHWEST OF THE REGION...HENCE ROBBING THE AREAS TO THE NORTH OF THE DEEPER MOISTURE AS WELL. DOWNSLOPE WINDS WILL ALSO NOT HELP. FOLLOWED CLOSELY THE HRRR/GFS WITH RESPECT TO PRECIPITATION POTENTIAL AND AMOUNTS TODAY...FOCUSING MAINLY ON THE MOUNTAINS FROM EASTERN WV DOWN TO NORTHWEST NC...WITH A TREND TOWARD ZERO POPS ALL AREAS BY MID-DAY AS THE SHORT WAVE/FRONT EXIT QUICKLY TO THE EAST. A SECONDARY AREA OF BETTER POPS MAY BE EXPECTED ACROSS THE NC PIEDMONT...BUT THIS SHOULD REMAIN MOSTLY SOUTHEAST OF THE CWA. SERIOUSLY DOUBT THAT MUCH...IF ANY...MEASURABLE PRECIPITATION WILL MAKE IT EAST OF THE BLUE RIDGE INTO THE VA PIEDMONT. WITH SFC TEMPS REMAINING ABOVE FREEZING AND 850MB TEMPS ABOVE FREEZING...THE LIKLIHOOD OF FROZEN PRECIPITATION HAS TRENDED DOWNWARD. BUFKIT SOUNDINGS FROM BOTH THE NAM AND GFS SUPPORT THE TREND TOWARD WHATEVER PRECIPITATION FALLS...FALLING AS LIQUID. HOWEVER...WE ARE SEEING SNOW PELLETS HERE AT BCB/RNK SUGGEST THAT THE VERY DRY SFC AIR ALLOWED FOR STRONG EVAPORATIVE COOLING TO SUPPORT -SN/IP AS EARLIER EXPECTED. HOWEVER...BY THE TIME 850MB TEMPS DROP BELOW 0C...THE PRECIPITATION HAS EXITED THE REGION. UPSLOPE -SHSN/-SHRA IS EXPECTED TO LIMITED AT BEST WITH SFC WINDS BEHIND THE FRONT WNW-W...AS OPPOSED TO A BETTER NW DIRECTION...ALONG WITH INTRUSION OF MORE VERY DRY AIR. WINDS WILL BE THE MAIN ISSUE TODAY...STOPPING JUST SHORT OF WIND ADVISORY CRITERIA ALONG AND JUST EAST OF THE CREST OF THE BLUE RIDGE. A FEW GUSTS FROM LATE MORNING THROUGH THE AFTERNOON OF 30-35KTS CANNOT BE RULED OUT. WILL MENTION IN THE HWO. WITH DOWNSLOPE WINDS AND INCREASING SUNSHINE...TEMPERATURES EAST OF THE BLUE RIDGE WILL LIKELY BE EVEN MILDER TODAY THAN THEY WERE SUNDAY...REACHING THE LOW TO MID 60S. HIGHS IN THE 50S TO THE WEST...WITH 40S IN THE MOUNTAINS OF WV. THE AIR MASS BEHIND THE FRONT IS CONSIDERABLY WARMER THAN WHAT WE SAW OVER THE WEEKEND AND HAS A HIGH PERCENTAGE OF PACIFIC-BASED AIR GIVEN THE INCREASING ZONAL FLOW ALOFT. THUS...FEW...IF ANY AREAS WILL DROP BELOW FREEZING TUE MORNING. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 345 AM EDT MONDAY... LOOKING TO START TUESDAY OFF WITH SOUTHWESTERLY FLOW ESTABLISHED ALONG THE CENTRAL APPALACHIAN CHAIN AS HIGH PRESSURE RESIDES OVER THE SOUTHEAST STATES...WHILE A DEEP LOW PRESSURE SYSTEM PASSES RAPIDLY EASTWARD ACROSS THE SOUTHERN GREAT LAKES. THE PRESSURE GRADIENT ACROSS OUR AREA WILL CONTINUE TO TIGHTEN DURING THE MORNING AND AFTERNOON AS THE LOW SHIFTS TOWARDS LOWER NEW ENGLAND... RESULTING IN GUSTY WINDS THROUGH THE DAY...WHERE GUSTS WILL LIKELY REACH 30 MPH...POSSIBLY AS HIGH AS 40 MPH AT TIMES IN A FEW AREAS. WITH ABUNDANT SUNSHINE INTO THE EARLY AFTERNOON TO AID IN HEATING... EXPECT AFTERNOON HIGHS TO REACH INTO THE 60S MOST LOCATIONS... POSSIBLY 70 OVER THE SOUTHSIDE...JUST BEFORE THE LOW DRAGS A COLD FRONT ACROSS OUR AREA DURING THE EVENING. WILL SEE A FEW UPSLOPE RAIN SHOWERS DEVELOP ALONG THE WESTERN RIDGES DURING TUESDAY EVENING AS THE COLD FRONT ENTERS OUR AREA...BRINGING A NORTHWESTERLY WIND SHIFT. HIGH PRESSURE MOVING IN BEHIND THE COLD FRONT WILL CAUSE WINDS TO VEER NORTH TUESDAY NIGHT...BRINGING AN END TO ANY RESIDUAL SHOWER ACTIVITY AFTER ONLY A FEW HOURS. HIGH PRESSURE WILL CONTINUE TO PUSH EAST ON WEDNESDAY...BECOMING CENTERED OVER THE MID ATLANTIC COAST TO BUTT UP AGAINST THE EASTERN FACE OF THE APPALACHIANS. WITH LITTLE COLD AIR INTRUSION ASSOCIATED WITH THIS HIGH PRESSURE SYSTEM AND ABUNDANT SUNSHINE IN PLACE...AFTERNOON HIGHS WILL RANGE FROM THE UPPER 50S ALONG INTERSTATE 64...TO THE LOW/MID 60S ACROSS NORTHERN NORTH CAROLINA. HIGH PRESSURE WILL PUSH OFF THE COAST ON THURSDAY...ALLOWING SOUTHERLY FLOW TO BECOME MORE FIRMLY ESTABLISHED ALONG THE APPALACHIAN CHAIN AS A STRONG COLD FRONT PASSES ACROSS THE PLAINS. WILL NOT BE SURPRISED TO SEE A FEW SHOWERS DEVELOP IN THE STRONG AFTERNOON HEATING ON THURSDAY AS WEAK DISTURBANCES PASS ACROSS THE AREA. WEATHER MODELS ARE INDICATING MODEST INSTABILITY WHICH COULD SUPPORT AN ISOLATED THUNDERSTORM OR TWO...BUT NOT ENOUGH CONFIDENCE IN THAT RIGHT NOW TO PUT IT IN THE FORECAST. EXPECT THURSDAY AFTERNOON HIGHS TO RANGE FROM THE MID 60S TO THE LOW 70S. RAIN CHANCES WILL INCREASE THURSDAY NIGHT AS THE COLD FRONT PUSHES SOUTH OF THE OHIO RIVER TOWARD DAWN ON FRIDAY. OVERNIGHT TEMPERATURES WILL HOLD IN THE 50S. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 400 AM EDT MONDAY... ON FRIDAY...A COLD FRONT WORKS SLOWLY SE INTO PA-KY LINE WITH THE MAIN SFC LOW WELL INTO CANADA. ANOTHER WAVE OR TWO OF LOW PRESSURE IS EXPECTED TO FORM ALONG THE FRONT FRIDAY AFTERNOON/EVENING. MODELS SHOW INSTABILITY IN THE WARM SECTOR AND ADDED SOME THUNDER IN MOST PLACES FRIDAY. STILL NOT GOING TO HAVE LIKELY POPS YET...AS MODELS ARE NOT CONSISTENT WITH POTENTIAL FOR SEEING A BREAK IN THE ACTION IN BETWEEN WAVES. AS WE HEAD INTO FRIDAY NIGHT-SATURDAY...THE ECMWF KICKS THE FRONT EAST FAST BY ABOUT 5-8 HOURS...WITH GFS SLOWLY EDGING IT SOUTHWARD WITH WEAKER LOW. WILL MAINTAIN SHOWER CHANCES WITH HIGHER POPS FRIDAY NIGHT BEFORE WE START TO SEE DRYING BY SAT AFTERNOON. A BRIEF SHOT OF COOLER/DRIER AIR...THOUGH CLOSER TO NORMAL FOLLOWS THIS FRONT SAT NIGHT-SUNDAY. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... AS OF 200 AM EDT MONDAY... FRONT STILL WEST OF THE ALLEGHANYS. AIR MASS ACROSS THE REGION REMAINS VERY DRY...ESPECIALLY EAST OF THE BLUE RIDGE. SOME MID- LEVEL CLOUDS HAVE SPREAD INTO EASTERN WV...BUT MAJORITY OF THE CWA STILL SEEING CLOUDS AOA 120. TIMING OF FRONT AND ASSOCIATED PRECIPITATION IN THE 08Z-12Z TIME FRAME LWB-BLF...NEAR BCB 12Z- 14Z...THEN LYH-DAN 13Z-15Z. WITH THE DRY AIR MASS ONLY RECOVERING MARGINALLY EAST OF THE BLUE RIDGE AND DOWNSLOPE WEST WINDS DEVELOPING THROUGH THE MORNING...EXPECT MOST OF ANY MEASURABLE RAINFALL TO REMAIN WEST OF THE ALLEGHANYS...MOSTLY SPRINKLES TO THE EAST. CIGS WILL DROP INTO THE MVFR RANGE IN UPSLOPE AREAS OF EASTERN WV/FAR SW VA...BUT SHOULD BE LOW-END VFR AT WORST EAST OF THE BLUE RIDGE...WITH A MIXTURE IN BETWEEN...I.E. BCB. UPSLOPE MVFR CIGS WILL CONTINUE UPSLOPE AREAS OF EASTERN WV/SW VA THROUGH EARLY AFTERNOON...THEN IT SHOULD BECOME VFR WITH JUST SCT SC IN THE 020-035 RANGE. SKIES WILL BECOME SKC/SCT250 EAST OF THE BLUE RIDGE BY EARLY AFTERNOON. A BRIEF REDUCTION IN VISIBILITY DURING -SHRA TO MVFR POSSIBLE UPSLOPE AREAS...LWB-BLF-MKJ-TNB...THROUGH 15Z...OTHERWISE CIGS ARE EXPECTED TO REMAIN VFR THROUGH THE TAF VALID PERIOD. WINDS SW-WSW 5-10KTS THROUGH 12Z...THEN W-WNW 10-15KTS WITH GUSTS 20-27KTS THROUGH LATE AFTERNOON...BECOMING 5KTS OR LESS AFT 00Z. STRONGEST WINDS WILL BE ALONG AND JUST EAST OF THE CREST OF THE BLUE RIDGE THROUGHOUT THE DAY...E.G. ROA. MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION FORECAST... ANOTHER CLIPPER LIKE SYSTEM WILL TRACK ACROSS THE REGION TUE INTO WED. STRONG/GUSTY WINDS WILL BE POSSIBLE WITH THIS SYSTEM...BUT LITTLE CLOUD COVER/PRECIPITATION IS EXPECTED AS ASSOCIATED LOW PRESSURE PASSES BY WELL TO THE NORTH OF THE REGION. A QUASI-STATIONARY FRONTAL BOUNDARY WILL SET UP ACROSS THE REGION FOR THE LATER HALF OF THE WEEK...LEAVING AN UNSETTLED PATTERN IN PLACE UNTIL THE FRONT IS PUSHED SOUTH BY HIGH PRESSURE MOVING EAST FROM THE MIDWEST. AN EXTENDED PERIOD OF MVFR TO LOCALLY IFR CIGS AND LOCALLY/BRIEF MVFR VSBYS APPEAR POSSIBLE IN -SHRA DURING THE THU-FRI TIME FRAME. IMPROVED AVIATION CONDITIONS ARE EXPECTED BY SAT/SUN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB NEAR TERM...RAB SHORT TERM...NF LONG TERM...WP AVIATION...JH/KK/RAB

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