Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 280601 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 101 AM EST WED JAN 28 2015 .SYNOPSIS...STRONG LOW PRESSURE OFF NEW ENGLAND WILL PULL FURTHER AWAY OVERNIGHT AS COLD HIGH PRESSURE WILL BUILD EAST INTO NORTH CAROLINA. A CLIPPER LOW PRESSURE SYSTEM WILL SWING BY JUST TO OUR NORTH LATE THURSDAY THROUGH THURSDAY NIGHT. HIGH PRESSURE WILL AGAIN BUILD INTO OUR AREA FROM THE NORTHWEST ON FRIDAY. && .NEAR TERM /OVERNIGHT/... AS OF 912 PM TUESDAY... STRONG NW FLOW IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM WILL FUNNEL DRY CHILLY AIR INTO CENTRAL NC OVERNIGHT. A PERTURBATION ROTATING AROUND THE DEEP CYCLONE WILL CROSS OUR REGION OVERNIGHT. THIS SYSTEM MAY CAUSE A STRATUS DECK TO PERSIST OVER SECTIONS OF HALIFAX AND EDGECOMBE COUNTIES WHILE PATCHY CIRRUS MAY AFFECT THE REST OF THE REGION. CLEAR SKIES SHOULD RETURN BY 3-4 AM. THE COLD AIR ADVECTION WILL YIELD LOW LEVEL THICKNESSES IN THE 1265- 1270M RANGE BY EARLY WEDNESDAY. HISTORICALLY, THESE THICKNESSES HAVE PRODUCED MIN TEMPS AROUND 20-LOWER 20S. UPSTREAM...MIN TEMPS EARLY TUESDAY MORNING WERE IN THE MID TENS-LOWER 20S IN THE COAL FIELDS OF EASTERN KY (WHERE OUR AIR PARCELS ARE ORIGINATING). HOWEVER ATMOSPHERE OVER CENTRAL NC EXPECTED TO REMAIN WELL-MIXED THROUGH MOST OF THE NIGHT (AS EVIDENT OF THE GUST 20-25MPH BEING REPORTED AT A FEW SITES ACROSS THE NORTHERN PIEDMONT), POSSIBLY DECOUPLING BY 4- 5 AM. THUS...THE WINDS MAY AID TO KEEP TEMPS UP A BIT BUT WHEN/IF THE WINDS DECOUPLE...TEMPS SHOULD PLUMMET IN THE BONE DRY ATMOSPHERE. HAVE TWEAKED MIN TEMPS A BIT...YIELDING LOWS MOSTLY IN THE LOW-MID 20S AND NEAR 20 IN THE NORMALLY COLDER LOCATIONS. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 230 PM TUESDAY... HIGH PRESSURE IS FORECAST TO MOVE OVERHEAD WEDNESDAY INTO WEDNESDAY NIGHT. SUNNY SKIES AND LIGHT WINDS WILL TEMPER THE CHILLY AIR MASS. HIGHS ARE EXPECTED TO REACH THE MID TO UPPER 40S (WARMEST SOUTHERN PIEDMONT). IT APPEARS THAT THE HIGH LEVEL MOISTURE WILL HOLD OFF UNTIL THURSDAY. THEREFORE... CLEAR SKIES AND LIGHT WINDS SHOULD LEAD TO LOWS IN THE UPPER TEENS TO LOWER 20S. OPTIMAL RADIATIONAL COOLING SHOULD LEAD TO LOWS BELOW MOS GUIDANCE... ESPECIALLY OVER THE CENTRAL PIEDMONT. HIGH PRESSURE MOVES OFFSHORE AS A SHORT WAVE AND ASSOCIATED SURFACE FRONT MOVES INTO AND ACROSS THE OHIO VALLEY THURSDAY INTO THURSDAY NIGHT. WESTERLY FLOW ACROSS THE SOUTHERN STATES WILL QUASH LOW LEVEL MOISTURE ADVECTION...SO WILL KEEP ONLY A SLIGHT CHANCE POP WITH VERY LIGHT PRECIP AMOUNTS...A FEW HUNDREDTHS AT MOST...LIMITED TO A NARROW WINDOW FROM THURSDAY EVENING THROUGH PERHAPS MIDNIGHT. SOUTHWEST FLOW AHEAD OF THE FRONT WILL ALLOW FOR WEAK WARM AIR ADVECTION AND HIGHS WILL REACH THE UPPER 40S ACROSS THE NORTH TO LOWER 50S IN THE FAR SOUTHERN COUNTIES. EXPECT RAPID CLEARING AFTER MIDNIGHT...BUT MIXING AND LIMITED TIME FOR RADIATIONAL COOLING WILL MODERATE MINS FROM AROUND FREEZING IN THE NORTHWEST TO THE MID 30S ELSEWHERE OVERNIGHT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 230 PM TUESDAY... AS THE UPPER SHORT WAVE TROF MOVES OFFSHORE...ENSUING NORTHWEST FLOW WILL MAINTAIN A FLOW OF COOL AIR INTO THE WEEKEND. SURFACE HIGH PRESSURE WILL MIGRATE OUT OF THE UPPER MIDWEST OVER THE AREA...SO SKIES WILL BE MOSTLY CLEAR WITH HIGHS IN THE MID AND UPPER 40S ON FRIDAY COOLING TO THE LOW AND MID 40S SATURDAY AS THE HIGH PRESSURE NUDGES ARCTIC AIR DOWN THE ATLANTIC COAST. MINS SATURDAY MORNING WILL BE ON THE COOL SIDE...MOSTLY IN THE LOWER 20S DUE TO EXCELLENT RADIATIONAL CONDITIONS. THE HIGH EDGES OFFSHORE SATURDAY NIGHT...WITH A LIGHT SOUTHERLY FLOW AND INCREASING CLOUD COVERAGE TO KEEP MINS FROM CRASHING AS DEEPLY SUNDAY MORNING...LOWS SHOULD BE WITHIN A DEGREE OR TWO OF 30. THINGS ARE MORE INTERESTING/ACTIVE HEADING INTO EARLY NEXT WEEK...WITH PHASING OF A NORTHERN STREAM SHORT WAVE DIGGING DEEPLY INTO THE MIDWEST AND THE SOUTHERN STREAM JETSTREAM. THIS WILL INDUCE CYCLOGENESIS OVER THE OHIO VALLEY SUNDAY NIGHT...RESULTING IN A STRONG COASTAL LOW IN THE VICINITY OF CAPE COD ON MONDAY. STRONG WARM AIR AND MOISTURE ADVECTION AHEAD OF THE SYSTEM WILL SPREAD RAIN INTO WESTERN NORTH CAROLINA BY SUNDAY AFTERNOON...WITH WIDESPREAD RAIN OVER THE AREA SUNDAY NIGHT. HEAVY SHOWERS...MAYBE A ROGUE STORM OR TWO...LOOK TO BE A POSSIBILITY AS WELL WITH AN H85 JET OF 50+ KNOTS AND STRONG UPPER DIFFLUENCE IN PHASE MOVING ACROSS THE AREA OVERNIGHT. HIGHS SUNDAY WILL SHOW A WIDE RANGE...FROM AROUND 40 NORTH TO LOWER 50S IN THE SOUTH IN WARM AIR ADVECTION AHEAD OF THE FRONT. TEMPERATURES WILL BE SLOWER TO FALL SUNDAY NIGHT WITH A LATE FRONTAL PASSAGE...AND TEMPS WILL BE ABOVE FREEZING AS THE RAIN ENDS MONDAY MORNING. HIGHS MONDAY WILL RANGE FROM MID 40S WEST TO AROUND 50 EAST...WITH MINS CRASHING IN COLD AIR ADVECTION MONDAY NIGHT INTO THE MID 20S WITH SUNNY SKIES AND COOL HIGHS IN THE LOWER 40S ON TUESDAY. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
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AS OF 100 AM WEDNESDAY... 24 HOUR TAF PERIOD: VERY HIGH CONFIDENCE OF VFR CONDITIONS THROUGH THE TAF PERIOD AS VERY DRY AIR HAS COME INTO THE REGION WITH DEWPOINTS IN THE TEENS AND SINGLE DIGITS IN SOME SPOTS. WINDS ARE OUT OF THE NORTHWEST WITH SOME GUSTS STILL PREVAILING UP TO 20 KTS. OTHERWISE EXPECT 5-10 KT WINDS OVERNIGHT OUT OF THE NORTHWEST. OTHER THAN SOME SCATTERED CLOUDS AROUND THE 3500 FOOT LEVEL AND POSSIBLY SOME OROGRAPHIC CLOUDS AT THE 5-6 KFT LEVEL DRIFTING OUT OF VA AND INTO OUR NORTHEASTERN AREAS. OTHERWISE AN ALL AROUND PLEASANT AVIATION DAY. LONG TERM: THE NEXT THREAT TO AVIATION CONDITIONS WILL BE THURSDAY NIGHT INTO FRIDAY MORNING AS A FRONTAL SYSTEM CROSSES THE AREA AND THEN ANOTHER SYSTEM SUNDAY INTO MONDAY.
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&& .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...WSS SHORT TERM...BADGETT LONG TERM...MLM AVIATION...ELLIS

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