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 272326 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 726 PM EDT MON APR 27 2015 .SYNOPSIS... AN UPPER DISTURBANCE MOVES ACROSS THE AREA THIS EVENING KEEPING THE REGION IN A COOL AIR MASS. LOW PRESSURE OVER TEXAS WILL SHIFT EAST INTO THE GULF COAST STATES AND TN VALLEY TO BRING OUR NEXT ROUND OF RAIN BY MIDWEEK. SHOWERS MAY LINGER INTO FRIDAY BEFORE HIGH PRESSURE BUILDS BACK IN FROM THE WEST WITH IMPROVING CONDITIONS FOR THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... AS OF 400 PM EDT MONDAY... THINGS SHOULD BE RELATIVELY QUIET THROUGH THE NEAR TERM. SATELLITE PICS SHOW A GOOD AMOUNT OF CONVECTIVE CLOUDS OVER THE AREA LATE THIS AFTERNOON BUT SHOWERS ASSOCIATED WITH THE APPROACHING SHORT WAVE ROTATING AROUND THE UPPER LOW OVER THE NORTHEAST US REMAIN WELL TO THE NORTH. STILL BELIEVE THERE WILL BE A CHANCE FOR SOME SHOWERS ACROSS THE GREENBRIER VALLEY THROUGH THE ALLEGHANY HIGHLANDS FOR A BRIEF PERIOD EARLY THIS EVENING...BUT NOTHING SIGNIFICANT IS EXPECTED. THEN AS WE LOSE OUR DIURNAL HEATING...CLOUDS WILL BE ON THE DECREASE AND ALLOW FOR DECENT RADIATIONAL COOLING OVERNIGHT. THIS SHOULD MAKE AREAS OF FROST POSSIBLE WEST OF THE BLUE RIDGE SO A FROST ADVISORY HAS BEEN ISSUED. THERE WILL ALSO BE PATCHY FROST POSSIBLE EAST OF THE RIDGE BUT DO NOT EXPECT COVERAGE TO BE GREAT ENOUGH TO WARRANT AN ADVISORY SO HAVE ISSUED AN SPS TO COVER THIS. TOMORROW LOOKS LIKE A FAIR WEATHER DAY WITH HIGH PRESSURE RIDGING IN FROM THE NORTHWEST. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 400 PM EDT MONDAY... A LOW PRESSURE SYSTEM SHOULD EMERGE FROM THE GULF COAST DURING TUESDAY NIGHT. INCREASING HIGH CLOUDS OVER THE CWA COULD KEEP LOW TEMPERATURES NOT DIPPING QUITE AS MUCH BY WEDNESDAY MORNING AS REFLECTED IN THE 12Z MODEL GUIDANCE. OVERALL...THE GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT WITH A SLOWER ARRIVAL SOLUTION OF THE LOW PRESSURE SYSTEM ARRIVING BY WEDNESDAY AFTERNOON. POPS WERE CUT BACK A LITTLE DURING EARLY WEDNESDAY BUT INCREASED THEREAFTER TO REFLECT THIS CHANGE. UNSEASONABLY COOL TEMPERATURES FOR LATE APRIL SHOULD KEEP INSTABILITY TOO LOW TO MENTION ANY CHANCE OF THUNDER THROUGHOUT THIS PERIOD. QPF SOLUTIONS APPEAR TO BE IN THE ONE QUARTER TO HALF AN INCH RANGE FOR WEDNESDAY AND THURSDAY...WHICH SHOULD NOT POSE ANY FLOODING CONCERNS AT THIS TIME. HOWEVER...THE SOUTHEAST FLOW PRIOR TO THE CENTER OF LOW PRESSURE REACHING THE NORTH CAROLINA COAST ON THURSDAY...COULD AID IN SOME UPSLOPE ENHANCEMENT OF THE RAIN OVER THE SOUTHERN BLUE RIDGE...SO LOCALLY HIGHER AMOUNTS ARE CERTAINLY POSSIBLE IN THE NORTHWEST NORTH CAROLINA MOUNTAINS. AS THIS LOW PRESSURE SYSTEM INTENSIFIES JUST OFF THE COAST...A TRAILING UPPER LEVEL LOW WILL APPROACH FROM THE GREAT LAKES TO BRING A SECOND ROUND OF RAIN FOR THURSDAY NIGHT. CLOUD COVER SHOULD REMAIN PREVALENT ACROSS THE ENTIRE CWA...SO TEMPERATURES ONLY WILL VARY FROM 40S FOR LOWS...TO MID 50S AND LOWER 60S FOR HIGHS. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 PM EDT SUNDAY... THE UPPER LEVEL LOW SHOULD CROSS OVERHEAD EARLY ON FRIDAY...WHILE ANOTHER ROUND OF RAIN SHOWERS ARRIVES OVER THE MID ATLANTIC. NORTHWEST FLOW SHOULD PROVIDE A LITTLE UPSLOPE ENHANCEMENT ALONG THE WESTERN SLOPES. THE OVERALL FLOW PATTERN ALOFT SHOULD FLATTEN AND TURN MORE ZONAL BY THE UPCOMING WEEKEND...WITH STILL A HINT OF A TROUGH OVER THE EAST COAST. SURFACE HIGH PRESSURE SHOULD PROVIDE A DRIER AND MILDER SATURDAY...BUT CONFIDENCE WANES BY SUNDAY DUE TO DIFFERING SOLUTIONS ON HOW FAR A WARM FRONT WILL STRETCH EASTWARD DUE TO A DEVELOPING LOW PRESSURE SYSTEM OVER THE NORTHERN PLAINS. ONCE HIGH PRESSURE PUSHES WELL OFFSHORE ON MONDAY...EXPECT WARMER TEMPERATURES TO ARRIVE COURTESY OF WARM AIR ADVECTION BOTH AT THE SURFACE AND ALOFT. BUILDING 500 MB HEIGHTS OVER THE EAST COAST SHOULD ALLOW WARM AND MOIST SOUTHWEST FLOW FROM THE GULF OF MEXICO TO BEGIN MOVING OVER THE APPALACHIAN MOUNTAINS. THE GFS SHOWS A FEW SHOWERS POPPING UP WEST OF THE BLUE RIDGE FOR MONDAY...WITH MAYBE AN ISOLATED THUNDERSTORM POSSIBLE FOR THE NORTHWEST NORTH CAROLINA MOUNTAINS IN THE AFTERNOON. THE ECMWF IS SLOWER WITH THE LOW PRESSURE SYSTEM IN THE NORTHERN PLAINS...AND KEEPS A STRONGER CAP ALOFT TO PREVENT ANY CONVECTIVE ACTIVITY. IT IS TOO FAR OUT TO GIVE ANYTHING ELSE OTHER THAN A MENTION OF SLIGHT CHANCE POPS. && .AVIATION /23Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
AS OF 210 PM EDT MONDAY... HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD...ESPECIALLY EAST OF THE BLUE RIDGE. CLOUDS SHOULD LOWER TO POSSIBLY DIP BELOW VFR ALONG WESTERN SLOPES OVERNIGHT AS A SHORT WAVE TRACKS FROM THE OHIO VALLEY TO NORTH CAROLINA. BREEZY AND GUSTY CONDITIONS EARLY THEN SUBSIDENCE INVERSION DEVELOPS FOLLOW BY WEAK HIGH PRESSURE. BY MIDNIGHT...WINDS WILL WEAKEN TO LIGHT AND VARIABLE THROUGH LATE TUESDAY MORNING. AS HIGH PRESSURE DRIFTS OVER THE REGION TUESDAY...WINDS SPEEDS WILL REMAIN LIGHT WHILE BECOMING NORTH-NORTHERLY. EXTENDED AVIATION DISCUSSION... VFR CONDITIONS ARE EXPECTED BEFORE CONDITIONS WORSEN ON WEDNESDAY. MODELS WERE SPEEDING UP MOISTURE INTO THE AREA...ESPECIALLY SOUTH OF A BLF-DAN LINE BY WED MORNING. ATTM...THE GFS IS MOST AGGRESSIVE IN HANGING THE STORM BACK CLOSER TO THE COAST INTO FRIDAY WHICH COULD KEEP THE AREA SOCKED INTO SUB VFR WEATHER LONGER. THE ECMWF IS MORE PROGRESSIVE...AND ALL IN ALL LOOKS LIKE WED-THU ARE SUB VFR DAYS...WITH SOME IMPROVEMENT FRIDAY.
-- End Changed Discussion --
&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...FROST ADVISORY FROM 2 AM TO 9 AM EDT TUESDAY FOR VAZ007- 009>020-022>024. NC...FROST ADVISORY FROM 2 AM TO 9 AM EDT TUESDAY FOR NCZ001-002- 018. WV...FROST ADVISORY FROM 2 AM TO 9 AM EDT TUESDAY FOR WVZ042>044- 507-508. && $$ SYNOPSIS...MBS NEAR TERM...MBS SHORT TERM...PW LONG TERM...PW AVIATION...RCS

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