000
FXUS62 KRAH 200658
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
300 AM EDT THU JUN 20 2013

.SYNOPSIS...
DRIER AND COOLER HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
NORTHEAST THROUGH SATURDAY. A SOUTHERLY FLOW WILL DEVELOP LATE IN
THE WEEKEND AND EARLY NEXT WEEK RESULTING IN WARMER AND POTENTIALLY
MORE UNSETTLED WEATHER.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM THURSDAY...

HIGH PRESSURE OVER THE NORTHERN MID-ATLANTIC COAST AND NEW ENGLAND
WILL EXTEND INTO CENTRAL NC TODAY...WHILE A COLD FRONT STALLS JUST
OFFSHORE.  MEANWHILE...THE FLOW ALOFT WILL BE WEAK...WITH A SHALLOW
UPPER DISTURBANCE APPROACHING FROM THE MISSOURI VALLEY TONIGHT.  IN

THE VERY NEAR TERM...SKIES ARE CLEARING FROM WEST TO EAST THIS
MORNING AND WHERE CALM CONDITIONS DEVELOP...PATCHY FOG WILL BE
POSSIBLE ACROSS THE NORTHERN/WESTERN PORTIONS OF THE PIEDMONT.
STRATUS SHOULD BE MORE PREVALENT ACROSS THE COASTAL PLAIN WITH MORE
INFLUENCE FROM AN EAST-NORTHEASTERLY WIND.

TODAY...
A STABLE NORTHEASTERLY FLOW WILL PREVAIL TODAY AND WILL SUPPRESS ANY
APPRECIABLE INSTABILITY TO OUR SOUTH AS DEWPOINTS SLOWLY FALL INTO
THE LOW TO MID 60S. FORECAST LOW LEVEL THICKNESSES IN THE 1380-1385M
RANGE THIS MORNING SUPPORT HIGHS IN THE 80-84 RANGE THIS
AFTERNOON...SLIGHTLY WARMER THAN WEDNESDAY BUT STILL BELOW NORMAL.

TONIGHT..
A WEAK UPPER DISTURBANCE WILL DRIFT SOUTHEAST OVER THE CAROLINAS
TONIGHT AND WEAKEN/LINGER THROUGH FRIDAY.  OTHER THAN SOME EXTRA
THIN HIGH CLOUDS...NO IMPACT IS EXPECTED FROM THIS FEATURE.  STRATUS
WILL AGAIN BE POSSIBLE BY 12Z FRIDAY AS HIGH PRESSURE OFF THE NEW
ENGLAND COAST CONTINUES TO SUPPLY A NORTHEASTERLY WIND.  LOWS IN
THE UPPER 50S NORTHEAST TO LOWER 60S SOUTHWEST.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...

HIGH PRESSURE INFLUENCE OVER THE AREA WILL BEGIN TO WEAKEN
FRIDAY...ALLOWING MOISTURE TO SLOWLY STARTING CREEPING BACK INLAND
AS THE STALLED OUT FRONTAL ZONE ALSO WEAKENS.  VERY DRY MID-LEVEL
AIR WILL KEEP CENTRAL NC CAPPED ONCE AGAIN...THOUGH ECMWF MOISTURE
FIELDS SUGGEST SOME WEAK INSTABILITY MAY DEVELOP ACROSS THE SOUTHERN
COASTAL PLAIN AND AN ISOLATED SHOWER MAY BE POSSIBLE.  HIGHS FAIRLY
COMPARABLE TO TODAY ARE EXPECTED...WITH 81-85 ACROSS THE AREA.
BASED ON FORECAST SOUNDINGS...LOW CLOUDS MAY BE MORE EXPANSIVE
FRIDAY NIGHT...AND THUS LOWS SLIGHTLY MILDER IN THE LOW/MID 60S.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...

NWP GUIDANCE FOR THE EXTENDED RANGE DESCRIBES A PATTERN WITH A
SUBTROPICAL RIDGE LOCATED OFF THE SOUTHEAST COAST WITH THE MAIN
WESTERLIES REMAINING WELL NORTH OF CENTRAL NORTH CAROLINA THROUGH
MOST OF THE PERIOD. A NARROW SURFACE RIDGE WILL EXTEND SOUTHWEST
INTO THE CAROLINAS AND VIRGINIA ON SATURDAY AND WILL THEN SHIFT
OFFSHORE ON SUNDAY WHICH WILL QUICKLY VEER A NORTHEAST/EAST
SURFACE WIND TO SOUTHERLY BY SUNDAY AND MONDAY AND THEN PERSISTING
INTO THE MIDDLE OF THE WEEK. THE SOUTHERLY FLOW WILL RESULT IN AN
INCREASE IN LOW LEVEL MOISTURE AND A MODEST INCREASE IN
TEMPERATURES.

IN TERMS OF SENSIBLE WEATHER THE PATTERN SHOULD RESULT IN FAIR
WEATHER ACROSS THE NORTH ON SATURDAY WITH A LIMITED THREAT OF A
SHOWER OR THUNDERSTORM IN THE SOUTH. THE THREAT OF MAINLY AFTERNOON
AND EVENING SHOWERS OR THUNDERSTORMS GRADUALLY INCREASES DURING THE
PERIOD AS AMBIENT MOISTURE INCREASES AND THE WESTERLIES TRY TO SLIP
SOUTHWARD IN THE LOWER GREAT LAKES AND OHIO VALLEY ON TUESDAY AND
WEDNESDAY. SKIES WILL REMAIN UNSETTLED WITH A TENDENCY FOR EARLY
MORNING STRATUS...ESPECIALLY IN THE SOUTHEAST AND ENHANCED CUMULUS
DURING THE AFTERNOON CONVECTIVE PERIOD. HIGH TEMPERATURES IN THE MID
80S WILL WARM INTO THE MID 80S TO NEAR 90 FOR MONDAY THROUGH
WEDNESDAY. LOWS WILL RANGE IN THE MID 60S TO NEAR 70 DEGREES. -BLAES

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...

VFR CONDITIONS ARE CURRENTLY OBSERVED ACROSS CENTRAL NC.  HOWEVER...
AS SKIES CLEAR FROM WEST TO EAST AND NORTHEASTERLY WINDS BECOME VERY
LIGHT OR CALM...MVFR/IFR VSBYS AND PATCHY LOW CLOUDS SEEM PROBABLE
GIVEN THE AMOUNT OF LOW LEVEL MOISTURE AROUND THE AREA.  NEAR TERM
GUIDANCE DOES NOT FAVOR WIDESPREAD FOG OR STRATUS...AND SURFACE OBS
WOULD SUGGEST TERMINALS WEST OF KRDU MAY BE FAVORED.

EXPECT RAPID IMPROVEMENT AFTER SUNRISE...WITH VFR CONDITIONS TO
PREVAIL DURING THE DAY.

OUTLOOK...
GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE WEEKEND...THOUGH
MOISTURE WILL SLOWLY INCREASE ACROSS THE AREA AND MAY ULTIMATELY
LEAD TO PERIODS OF OVERNIGHT SUB-VFR CONDITIONS BY EARLY NEXT WEEK.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BLAES
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS

NWS RAH Office Area Forecast Discussion