Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 300624 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 224 AM EDT MON MAR 30 2015 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST OVERNIGHT BEFORE PASSING ACROSS THE AREA MONDAY MORNING. A SECOND COLD FRONT AND ASSOCIATED CLIPPER SYSTEM WILL PASS ACROSS THE REGION ON TUESDAY...FOLLOWED BY HIGH PRESSURE FOR THE MIDDLE OF THE WEEK. MOISTURE AHEAD OF ANOTHER STRONGER COLD FRONT WILL INCREASE BY THE END OF THE WEEK BRINGING THE NEXT CHANCE FOR SHOWERS AND POSSIBLE STORMS ON FRIDAY. && .NEAR TERM /THROUGH TODAY/...
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AS OF 200 AM EDT MONDAY... AREA OF FRONTAL PRECIPITATION REMAINS WEST OF THE REGION...BUT IS CONSISTENTLY PROGGED AMONG THE MODELS TO REACH THE WESTERN PART OF THE CWA IN THE 08Z-12Z TIME FRAME. AIR MASS ACROSS THE REGION IS VERY DRY WITH DEWPOINTS STILL IN THE SINGLE DIGITS TO AROUND 12F EAST OF THE ALLEGHANY FRONT...20S/30S TO THE WEST. HAVE LOW CONFIDENCE IN MUCH OF ANY OF THE RAIN REACHING AREAS EAST OF THE BLUE RIDGE...AT LEAST MEASURABLE...BUT A FEW SPRINKLES ARE CERTAINLY NOT OUT OF THE QUESTION. HAVE ADJUSTED POPS DOWN EAST OF THE BLUE RIDGE AND REMOVED LIKELY POPS FROM THE SOUTHEAST REGION. P-TYPE ALL RAIN SO FAR TO THE WEST. EXPECTING TEMPERATURES TO LEVEL OFF OR SLOWLY RISE AS MID-LOW CLOUDS INCREASE THROUGH THE MORNING. THE SLIGHT INCREASE IN TEMPERATURE SHOULD REDUCE THE THREAT OF ANY WINTER PRECIPITATION. ALBEIT...THE GROUND SURFACES ARE WARM ENOUGH THAT ANY WINTER PRECIPITATION AT THE HIGHER ELEVATIONS WILL NOT BE AN ISSUE. AS OF 845 PM EDT SUNDAY... MAIN AXIS OF DEEPER PRE-FRONTAL MOISTURE REMAINS JUST WEST OF THE OHIO RIVER THIS EVENING WITH LOTS OF VERY DRY AIR STILL OVER THE AREA IN ADVANCE OF THIS BOUNDARY. THIS SEEN VIA THE LINGERING LOW PWAT AND MID LEVEL DRYNESS SEEN OFF THE EVENING RNK SOUNDING AS WELL AS THE CONTINUED LOW DEWPOINTS AT THE SURFACE PER LATEST OBS. MOST SOLUTIONS INCLUDING THE LATEST HRRR AND HIRES-ARW DO BRING SOME PRECIP INTO THE FAR NW SHORTLY AFTER MIDNIGHT...THEN SOUTH AND EAST TO THE BLUE RIDGE WITH BEST LIFT/MOISTURE WORKING DOWN THE WESTERN SLOPES INTO THE NW NC RIDGES BEFORE DAYBREAK. SHOWER BAND MAY THEN TEND TO JUMP EAST OF THE MOUNTAINS LATE OR EARLY MONDAY BUT IFFY GIVEN DEEP WESTERLY FLOW ALOFT SEEN OFF EVENING RAOBS. SINCE GUIDANCE REMAINS TOO FAST WITH PRECIP INTO THE DRY AIR FROM EARLIER...SLOWED DOWN POPS AGAIN OVERNIGHT IN THE WEST WHILE INCREASING SOME OVER THE SW TOWARD DAYBREAK WHERE RUNNING WITH BRIEF CAT/LIKELY POPS FOR LOW QPF. LEFT IN SOME LOW POPS OUT EAST AS WELL BUT DOUBTFUL AS TO HOW FAR EAST OF THE BLUE RIDGE MUCH MORE THAN SPRINKLES MAKE IT OVERNIGHT. VERY DRY AIR AND TEMPS COOLING INTO THE 30S COULD SUPPORT A BIT OF SLEET WEST AT THE ONSET SO ADDED WHILE KEEPING THE SNOW MENTION AT ELEVATION ACROSS THE NW WHERE COULD SEE SOME LIGHT ACCUMULATION. OTRW LOWERED TEMPS EARLY OVER THE WEST FOR SOME WET BULB COOLING AT THE ONSET BEFORE READINGS RISE LATE AS MIXING PICKS UP JUST AHEAD OF THE FRONT BY DAWN. PREVIOUS DISCUSSION AS OF 329 PM EDT SUNDAY... 1030 MB SFC HIGH PRESSURE CENTERED OVER SOUTH CAROLINA THIS AFTERNOON WILL MOVE SOUTHEAST THIS EVENING INTO TONIGHT. LOW PRESSURE OVER THE GREAT LAKES WITH A TRAILING COLD FRONT WILL MOVE EAST TONIGHT INTO MONDAY. CLOUD COVER WILL SPREAD EAST ACROSS THE AREA THIS EVENING INTO TONIGHT IN ADVANCE OF AN APPROACHING COLD FRONT. MODELS CONTINUE TO TREND SLOWER WITH THE ARRIVAL OF THE PRECIPITATION IN THE REGION. WITH A DRY AIRMASS IN PLACE AS NOTED BY PWAT AT 0.05 ON THIS MORNING 12Z RNK SOUNDING...SLOWED OUR ARRIVAL TIME A LITTLE. DESPITE THE DRY AIR...MOISTURE AND LIFT WILL INCREASE LATE TONIGHT INTO MONDAY MORNING. MODELS ARE STILL SHOWING PRECIPITABLE WATER RISING ABOVE 0.50 INCH. FOR TONIGHT POPS USED A BLEND OF HIRESW-ARW EAST...RAP AND NAM...THEN LEANED TOWARDS THE NAM AND GFS BLEND MONDAY. BELIEVE THERE IS ENOUGH COLD AIR TO ALLOW RAIN SHOWERS TO BECOME MIXED WITH SNOW SHOWERS IN THE HIGHER ELEVATIONS. A LIGHT SNOW ACCUMULATION LESS THAN A INCH MAY BE POSSIBLE IN THE NORTHWEST HIGHEST ELEVATIONS. WPC HAS PAINTED A SMALL AREA OF SNOW IN THE WINTER WEATHER DAY 1 OUTLOOK JUST TO OUR NORTH. WINDS PICK UP AHEAD OF THE COLD FRONT BUT BUFKIT SHOWED STRONGEST WINDS AHEAD OF THE FRONT JUST ABOVE THE SURFACE AND REMAINING ABOVE THE INVERSION. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER 30S IN THE NORTHWEST MOUNTAINS TO AROUND 40 DEGREES IN THE PIEDMONT. A COLD FRONT PASSING ACROSS THE AREA EARLY MONDAY...WILL TRIGGER SHOWERS AS IT MOVES EAST ACROSS THE PIEDMONT. SHOWERS WILL DIMINISH QUICKLY BEHIND THE FRONT AS WINDS SHIFT WEST TO NORTHWEST AS HIGH PRESSURE BUILDS IN FROM THE CENTRAL PLAINS. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE UPPER 40S IN SOUTHEAST WEST VIRGINIA TO THE LOWER TO MID 60S ACROSS THE PIEDMONT.
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&& .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... AS OF 305 PM EDT SUNDAY... NEXT SHORTWAVE/CLIPPER SLIDES FROM NRN IL MONDAY EVENING INTO CENTRAL VA BY TUESDAY AFTERNOON. MODELS ARE SIMILAR IN KEEPING MAIN THREAT OF SHOWERS NORTH OF INTERSTATE 64...SO NOT GOING WITH POPS ANY HIGHER THAN 25. A LITTLE LEFTOVER COLD AIR TUESDAY MORNING COULD ALLOW FOR SOME WINTRY MIX NORTH OF LEWISBURG AND HOT SPRINGS...BUT OVERALL DRY. WE WILL SEE HIGH PRESSURE WORK EASTWARD ACROSS THE MID ATLANTIC WEDNESDAY WITH SE FLOW DEVELOPING LATE IN THE DAY. TEMPS WILL BE AT AND ABOVE SEASONAL NORMS. THE WEST FLOW TUESDAY AHEAD OF THE CLIPPER SHOULD ENHANCE TEMPS ACROSS THE PIEDMONT BARRING ANY EXTENSIVE CLOUD COVER...WITH NEAR 70 POSSIBLE FROM DANVILLE/MARTINSVILLE SOUTH. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 200 PM EDT SUNDAY... MODELS CONTINUE TO VARY ON SPEED/AMPLIFICATION OF NEXT SYSTEM AFFECTING OUR AREA THE END OF THE WEEK...THOUGH IN DECENT AGREEMENT THAT THERE WILL BE A THREAT OF SHOWERS THU-EARLY SATURDAY...WITH FRIDAY LOOKING THE MOST UNSETTLED. WARM ADVECTION PATTERN WILL KICK IN ONCE THE HIGH MOVES OFF THE COAST WEDNESDAY NIGHT...THOUGH AM THINKING ENOUGH SE FLOW AND IN SITU WEDGE MAY HOLD TEMPS DOWN BRIEFLY BEFORE STRONGER LLJ MOVES ACROSS THE MTNS. EXPECT A CHANCE OF RAIN/RAIN SHOWERS BY THURSDAY WITH BETTER CONVERGENCE WEST OF THE MTNS...WITH SOME OVERRUNNING INTO THE SRN CWA. THURSDAY NIGHT INTO FRIDAY FRONTAL BOUNDARY WORKS SLOWLY SE INTO PA- KY LINE WITH 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 /06Z MONDAY THROUGH FRIDAY/...
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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.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/JH/KK NEAR TERM...JH/KK/RAB SHORT TERM...WP LONG TERM...WP AVIATION...JH/KK/RAB

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