Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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. --
338 FXUS62 KRAH 110832 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 329 AM EST THU FEB 11 2016 .SYNOPSIS...A NARROW AREA OF HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NC THIS MORNING THEN DRIFT SOUTHWARD. AN UPPER LEVEL DISTURBANCE WILL CROSS OUR REGION FRIDAY. AN ARCTIC HIGH PRESSURE SYSTEM WILL SEND SOME OF THE COLDEST AIR THIS WINTER SEASON INTO CENTRAL NC FOR THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 3 AM THURSDAY... UPPER LEVEL TROUGH COVERING THE EASTERN THIRD OF THE U.S. LOSES A BIT OF ITS AMPLITUDE TODAY. AN AREA OF HIGH PRESSURE AT THE SURFACE WILL COVER THE CAROLINAS...PROVIDING MOSTLY CLEAR SKIES. LOW LEVEL CAA WILL BEGIN TO ABATE AFTER 18Z THOUGH THE 850MB THERMAL TROUGH WILL LIE OVERHEAD THROUGH 00Z. AFTERNOON TEMPS WILL REMAIN WELL BELOW NORMAL FOR MID FEBRUARY RANGING FROM THE MID-UPPER 30S NORTH TO NEAR 40-LOWER 40S SOUTH. TONIGHT...MAINLY CLEAR SKIES FOR THE FIRST HALF OF THE PERIOD WILL ALLOW TEMPS TO FALL APPRECIABLY. BY OR SHORTLY AFTER MIDNIGHT...CLOUDS WILL INCREASE FROM THE WEST-SW...LIMITING NOCTURNAL COOLING FOR THE REMAINDER OF THE NIGHT. MIN TEMPS SHOULD VARY FROM NEAR 20 NORTH TO THE MID 20S FAR SOUTH-SW.
-- End Changed Discussion --
&& .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... AS OF 230 PM WEDNESDAY... WITH THE LONGWAVE TROUGH HOLDING OVER ERN NOAM... A PERTURBATION NOW COMING INTO THE PACIFIC NORTHWEST WILL RIDE ATOP THE WESTERN RIDGE AND SHEAR OUT AS IT DIVES INTO THE TROUGH BASE AND EVENTUALLY CROSSES THE CAROLINAS FRI GENERATING WEAK DPVA. THE FORCING FOR ASCENT WITH THIS FEATURE WILL BE AUGMENTED BY UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE JET DIVING INTO THE CENTRAL CONUS TOWARD THE SOUTHEAST STATES... AND THIS WILL SUPPORT SURFACE LOW PRESSURE DEVELOPMENT... TRACKING ACROSS AR AND THE GULF STATES/SRN GA/SRN SC THU/THU NIGHT BEFORE SHIFTING OFF THE SC COAST FRI MORNING. THE OVERALL LIFT IS NOT TERRIBLY IMPRESSIVE HOWEVER... AND THE LATEST MODEL RUNS DO NOT SUBSTANTIALLY DEEPEN THE SURFACE LOW UNTIL IT IS ALREADY WELL OFF THE COAST AND MOVING ENE AWAY FROM NC... KEEPING IT RATHER WEAK AND FLAT WITHOUT A STRONG THERMAL ADVECTION PATTERN. MOISTURE IS ALSO UNIMPRESSIVE... WITH FORECAST SOUNDINGS INDICATING MULTIPLE UNSATURATED LAYERS AND INCONSISTENT MOISTENING ABOVE -10C THAT BRINGS DOUBT AS TO THE PRESENCE OF ICE ALOFT. WITH MODELS CONTINUING TO DEPICT VERY LIGHT TO NO QPF EXCEPT AS ONE GETS CLOSER TO THE CENTRAL COASTAL AREA... WILL TAKE POPS AND AMOUNTS DOWNWARD OVER MUCH OF THE CWA. THICKNESSES AND THE VERTICAL THERMAL STRUCTURES NOTED ON FORECAST SOUNDINGS SUPPORT A MOSTLY RAIN/SNOW MIX OVER THE FAR SE CWA... AND WHILE THIS IS THE AREA THAT IS MOST LIKELY TO SEE SOME SLIGHTLY HEAVIER BANDED PRECIP ON THE NW SIDE OF THE DEPARTING LOW... THE HIGH PROBABILITY OF A MIXTURE WILL KEEP ANY ACCUMULATIONS VERY LOW... WITH ONLY A SLUSHY COATING AT MOST. FURTHER INLAND... WITHIN THE COLDER THICKNESSES... ANY PRECIP SHOULD BE LIGHT FLURRIES... YIELDING LITTLE MORE THAN A LIGHT DUSTING WITH NO TRAVEL IMPACTS. EXPECT CONSIDERABLE CLOUD COVER FRI... WITH CLEARING FRI NIGHT AS THE POLAR FRONT DROPS SOUTHEAST THROUGH THE AREA... MOST LIKELY OCCURRING AFTER MIDNIGHT. HIGHS 36-42 FRI AND LOWS 21-28. -GIH && .LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 325 AM THURSDAY... ...BITTERLY COLD AIR THIS WEEKEND WITH A WINTRY WEATHER THREAT EARLY NEXT WEEK... SATURDAY THROUGH SUNDAY: ARCTIC HIGH PRESSURE WILL BUILD INTO THE REGION ON SATURDAY AS THE DEPARTING SYSTEM LIFTS WELL OFF TO THE NORTH AND EAST OF THE AREA... WHILE A MID/UPPER LOW OVER THE NORTHEAST U.S. TO START THE PERIOD SHIFTS EASTWARD AND OFFSHORE BY SATURDAY NIGHT. THIS SHOULD RESULT IN A DRY... BUT COLD WEEKEND ACROSS CENTRAL NC... WITH BREEZY CONDITIONS EXPECTED ON SATURDAY. THE SURFACE HIGH SHOULD SETTLE OVER THE REGION ON SUNDAY... AT LEAST TAKING AWAY THE ADDED CHILLY BREEZE. WITH LOW LEVEL THICKNESS VALUES EXPECTED TO BE WELL BELOW NORMAL FOR THIS WEEKEND (BOTTOMING OUT NEAR 1230 METERS ON SUNDAY MORNING) THINK TEMPS WILL BE NEAR 20 DEGREES BELOW NORMAL. HIGHS ON SATURDAY MAY STRUGGLE TO REACH FREEZING ACROSS THE NORTHERN HALF OF THE CWA... WITH HIGH TEMPS SUNDAY GENERALLY FREEZING OR BELOW FOR MOST... IF NOT ALL... OF THE CWA. EXPECT HIGH ON SATURDAY WILL RANGE FROM THE LOWER 30S NORTH TO NEAR 40 ACROSS THE FAR SOUTH. HIGHS SUNDAY ARE EXPECTED TO RANGE FROM THE UPPER 20S TO GENERALLY THE LOWER 30S. LOW SUNDAY MORNING WITH SURFACE HIGH PRESSURE JUST TO THE NORTHWEST OF THE AREA ARE EXPECTED TO RANGE FROM AROUND 10 TO 15 DEGREES. SUNDAY NIGHT THROUGH WEDNESDAY: THE NEXT SYSTEM WITH A THREAT OF WINTER WEATHER IS EXPECTED TO AFFECT THE AREA EARLY MONDAY INTO TUESDAY. MEDIUM RANGE MODELS CONTINUE TO SHOW S/W ENERGY TRACKING FROM THE PLAINS INTO THE EASTERN U.S EARLY NEXT WEEK... WHILE AMPLIFYING. THIS SHOULD HELP A SURFACE LOW DEVELOP ACROSS THE SOUTHEAST U.S... WITH PRECIP SPREADING INTO CENTRAL NC IN ADVANCE OF THE APPROACHING SYSTEM ON SUNDAY NIGHT/MONDAY MORNING. MEANWHILE... THE ARCTIC SURFACE HIGH (WHICH WILL BE OVERHEAD ON SUNDAY) WILL SHIFT OFFSHORE SUNDAY NIGHT INTO MONDAY. HOWEVER... THERE SHOULD BE AMPLE COLD DRY AIR IN PLACE TO SUPPORT EITHER SNOW OR SLEET EARLY MONDAY MORNING... FOR LOCATIONS THAT DO INDEED SEE PRECIP (BEST CHANCE ACROSS THE WESTERN/NORTHWESTERN PIEDMONT). HOWEVER... WE ARE TALKING ABOUT S/W ENERGY THAT HAS NOT MOVED ONSHORE YET ACROSS THE WESTERN U.S... WHICH HAS LED TIMING/TRACK/STRENGTH DIFFERENCES WITH THIS SYSTEM FROM RUN TO RUN ALONG WITH A LARGE SPREAD IN THE MODELS AND THE ENSEMBLES... THOUGH IT APPEARS WE SHOULD SEE SOME TYPE OF DAMMING DEVELOP ON MONDAY (IN-SITU POSSIBLY). HOW AMPLIFIED THE TROUGH IS AND THE TRACK AND CONFIGURATION OF THE SURFACE LOW/LOWS WILL GREATLY AFFECT WHAT TYPE OF PRECIP WE SEE ON MONDAY INTO TUESDAY (OUTSIDE OF THE INITIAL LEAD PRECIP WHICH WILL LIKELY BE IN THE FORM OF SNOW OR SLEET). WILL CONTINUE TO TREND THE FORECAST TO THE CLIMATOLOGICAL FAVORED AREAS FOR WINTER PRECIP... WITH MOST LOCATIONS TURNING TO ALL RAIN BY MONDAY EVENING. GIVEN THE TIMING ISSUES THERE IS SOME UNCERTAINTY WITH REGARD TO HOW FAST THE PRECIP WILL EXIT... AND IF WE COULD SEE ANY WRAP AROUND WINTER PRECIP. FOR NOW WILL CONTINUE TO SHOW TEMPS MODERATING ON TUESDAY... WITH ONLY ONE P-TYPE... RAIN. DRY WEATHER IS EXPECTED TO RETURN ON TUESDAY NIGHT AND CONTINUE FOR WEDNESDAY. HIGH AND LOW TEMPS EARLY NEXT WEEK WILL GREATLY DEPEND ON THE TIMING AND TRACK OF THE SYSTEM... THOUGH WE SHOULD SEE LOWS GENERALLY IN THE 20S FOR MONDAY MORNING. TEMPS SHOULD MODERATE BACK TO NEAR NORMAL BY MID NEXT WEEK... WITH HIGHS BACK INTO THE 50S... LOWS IN THE 30S.
-- End Changed Discussion --
&& .AVIATION /06Z THROUGH MONDAY/... AS OF 1240 AM THURSDAY... HIGH CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL ACROSS CENTRAL NC THROUGH TONIGHT. SFC WINDS WILL GENERALLY BE 10 KTS OR LESS EXPECT IN THE VICINITY OF KRWI WHERE EARLY MORNING GUSTS 14-18KTS MAY OCCUR. AN UPPER LEVEL DISTURBANCE WILL CROSS THE MID ATLANTIC FRIDAY. THIS SYSTEM MAY BRING LOW END VFR/MVFR CEILINGS TO CENTRAL NC...ESPECIALLY KRWI AND KFAY ALONG WITH A THREAT FOR LIGHT WINTRY PRECIPITATION...MAINLY IN VICINITY OF KRDU...KRWI...AND KFAY. ARCTIC24 HOUR TAF PERIOD: HIGH CONFIDENCE OF VFR CONDITIONS THROUGH THE TAF PERIOD. WIND GUSTS WILL BE THE ISSUE THAT LINGERS THIS EVENING. WEST NORTHWESTERLY WINDS AT 10 KTS GUSTING 15-20 KTS WILL BE POSSIBLE AT ALL TAF SITES BUT ESPECIALLY AT KGSO/KINT THROUGH THE EVENING. VFR CONDITIONS ARE EXPECTED THROUGH THURSDAY. LONG TERM: A COASTAL SYSTEM ON FRIDAY WITH A SHORTWAVE MOVING ACROSS THE NORTH WILL BRING A CHANCE FOR SUB-VFR CONDITIONS PARTICULARLY AT EASTERN TAF SITES. THE NEXT MORE SIGNIFICANT SYSTEM IS PROGGED TO ENTER THE REGION MONDAY NIGHT INTO TUESDAY. AIR WILL SPILL INTO CENTRAL NC BEHIND THE DEPARTING DISTURBANCE SATURDAY AND SUNDAY. THE NEXT THREAT FOR ADVERSE AVIATION CONDITIONS SHOULD OCCUR MONDAY AS AN AREA OF LOW PRESSURE LIFTS NORTHEASTWARD ACROSS THE SE U.S.24 HOUR TAF PERIOD: HIGH CONFIDENCE OF VFR CONDITIONS THROUGH THE TAF PERIOD. WIND GUSTS WILL BE THE ISSUE THAT LINGERS THIS EVENING. WEST NORTHWESTERLY WINDS AT 10 KTS GUSTING 15-20 KTS WILL BE POSSIBLE AT ALL TAF SITES BUT ESPECIALLY AT KGSO/KINT THROUGH THE EVENING. VFR CONDITIONS ARE EXPECTED THROUGH THURSDAY. LONG TERM: A COASTAL SYSTEM ON FRIDAY WITH A SHORTWAVE MOVING ACROSS THE NORTH WILL BRING A CHANCE FOR SUB-VFR CONDITIONS PARTICULARLY AT EASTERN TAF SITES. THE NEXT MORE SIGNIFICANT SYSTEM IS PROGGED TO ENTER THE REGION MONDAY NIGHT INTO TUESDAY. && .CLIMATE... HERE ARE THE RECORD LOWS AND RECORD LOW MAXIMUM TEMPERATURES FOR SAT FEB 13TH AND SUN FEB 14TH AT GSO... RDU... AND FAY: REC YR REC YR LOW LOW MAX ---------------------------------------------- GSO: 02/13 11 1955 31 1986 02/14 6 1905 22 1914 RDU: 02/13 4 1899 10 1899 02/14 -2 1899 27 1916 FAY: 02/13 14 1973 32 1955 02/14 12 1968 33 1916 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...26/ELLIS SHORT TERM...HARTFIELD LONG TERM...BSD AVIATION...WSS CLIMATE...WFO RAH

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