000
FXUS62 KRAH 011102
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
700 AM EDT MON SEP 1 2014

.SYNOPSIS...THE REGION WILL REMAIN UNDER THE INFLUENCE OF HIGH
PRESSURE THROUGH MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 AM MONDAY...

BERMUDA HIGH PRESSURE WILL CONTINUE TO SUPPLY A WARM AND HUMID
SOUTHERLY FLOW TODAY...WITH WEAK SOUTHWESTERLY FLOW ALOFT.  THE H85
THERMAL RIDGE...WITH TEMPS AROUND 20C...SHIFTS OVER THE
PIEDMONT...AND LOW-LEVEL THICKNESSES ARE FORECAST TO START OUT
AROUND 1420M...ABOUT 10M HIGHER THAN SUNDAY MORNING.  STATISTICAL
AGREEMENT IS IN PRETTY GOOD AGREEMENT WITH MID 90S AROUND ALL OF
CENTRAL NC.  THE LEE/THERMAL TROUGH SHOULD SHARPEN AND DEWPOINTS
SHOULD MIX OUT MORE IN THE WEST WITH A LITTLE MORE WESTERLY
WIND...BUT TO THE EAST DEWPOINTS WILL BE IN THE UPPER 60S AND LOWER
70S...WHICH WILL PUSH HEAT INDICES UP AROUND 100F. A WEAK WAVE OVER
WEST VIRGINIA..NOTED IN WATER VAPOR IMAGERY THIS MORNING...SHOULD
PASS OFF TO THE NORTH OF THE AREA TODAY...LEAVING THE SEABREEZE
AND/OR DIFFERENTIAL HEATING AS THE MAIN TRIGGERS FOR CONVECTION THIS
AFTERNOON.  WILL INCLUDE A CHANCE POP ACROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN WHERE MODEST MLCAPE OF 1500 J/KG IS FORECAST
TO DEVELOP.  OTHERWISE JUST A SLIGHT CHANCE ACROSS THE WEST.

CONVECTION WILL BE DIURNALLY DRIVEN AND WILL COME TO AN END EARLY
THIS EVENING.  STRATUS WILL BE POSSIBLE AGAIN..WITH GUIDANCE AGAIN
POINTING TO THE COASTAL PLAIN.  LOWS IN THE UPPER 60S AND LOWER 70S.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM MONDAY...

HOT AND HUMID CONDITIONS CONTINUE ON TUESDAY...WITH H85 TEMPS AGAIN
AROUND 20C AND SOUTHERLY FLOW AROUND THE BERMUDA HIGH.  A SHORTWAVE
CROSSING THE GREAT LAKES WILL LEAD TO SOME VERY WEAK HEIGHT FALLS
OVER VIRGINIA AND NC...WHICH SHOULD INCREASE CONVECTIVE COVERAGE
AMIDST MLCAPE OF 1000-2000 J/KG AND PW OVER 1.75 INCHES.  SHEAR IS
FORECAST TO REMAIN RELATIVELY WEAK...HOWEVER...AND THE BETTER SEVERE
THREAT SHOULD ACCORDINGLY REMAIN TO OUR NORTH.  HIGHS IN THE MID 90S
AND HEAT INDICES AROUND 100F IN THE EAST.

THE WEAK HEIGH FALLS ALOFT AND LINGERING OUTFLOW BOUNDARIES MAY HELP
MAINTAIN SOME SHOWERS/STORMS INTO THE OVERNIGHT HOURS TUESDAY
NIGHT...WITH MOST ACTIVITY DWINDLING AFTER MIDNIGHT.  LOWS IN THE
UPPER 60S AND LOWER 70S.


&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 250 AM MONDAY...

A HOT SUB-TROPICAL RIDGE OVER THE SOUTHEAST WILL WAX AND WANE
THROUGHOUT THE FORECAST PERIOD. AFTER PEAKING OVER THE SE EARLY THIS
WEEK...THE RIDGE WILL BRIEFLY RETREAT WEST AND YIELD TO A GENERALLY
E-W ORIENTED MID LEVEL SHEAR AXIS FORECAST TO DRIFT SOUTH INTO THE
CAROLINAS WED-THU...BEFORE EXPANDING NORTHWARD ONCE AGAIN...INTO THE
OH VALLEY AND MIDDLE ATLANTIC...FRI-SAT. MEDIUM RANGE ENSEMBLE
GUIDANCE SUGGESTS THIS TREND WILL CONTINUE INTO NEXT WEEK...WITH
BRIEF WEAKENING OF THE SUB-TROPICAL RIDGE SUN-MON...AT THE BASE OF A
PROGRESSIVE NORTHERN STREAM TROUGH FORECAST TO CROSS SE CANADA...
ONLY TO RE-EXPAND THROUGH MID WEEK.

THE EBB AND FLOW OF THE PATTERN ALOFT...AND ASSOCIATED PERIODIC
RELAXATION OF THE SUB-TROPICAL RIDGE...WILL ALLOW A PAIR OF COLD
FRONTS TO SETTLE INTO NC - ONE WED INTO THU AND THE OTHER SAT NIGHT-
SUN. BOTH MODEST COOLING AND ABOVE AVG PRECIPITATION CHANCES WILL
OCCUR DURING THESE TIMES...IN CONTRAST TO OTHERWISE HOT CONDITIONS
IN THE LOWER TO MIDDLE 90S...WITH DIURNALLY; PIEDMONT, AND SEA-
BREEZE-DRIVEN CONVECTION.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 700 AM MONDAY...

SOUTHERLY FLOW CONTINUES AROUND THE BERMUDA HIGH...AND A FEW
LOCATIONS...INCLUDING KRWI...ARE REPORTING IFR CEILINGS THIS
MORNING. THE FEW PATCHES OF STRATUS WILL QUICKLY LIFT THIS MORNING
AND VFR CONDITIONS WILL PREVAIL TODAY. ISOLATED SHOWERS/STORMS ARE
POSSIBLE THIS AFTERNOON...MAINLY ALONG THE SEABREEZE...WITH THE BEST
CHANCE AT KFAY AFTER 18Z.  EARLY MORNING STRATUS AND/OR VSBYS
RESTRICTIONS WILL BE POSSIBLE TUESDAY MORNING.  MODELS AGAIN POINT
TOWARD THE COASTAL PLAIN...KFAY TO KRWI...AS THE MOST LIKELY AREA
FOR RESTRICTIONS IN THE 08-12Z TIME FRAME.

OUTLOOK... BRIEF RESTRICTIONS IN DIURNAL CONVECTION ARE POSSIBLE
EACH AFTERNOON...WITH RESTRICTIONS IN LOW CLOUDS AND FOG DURING THE
PRE-DAWN MORNING HOURS.

&&

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

&&

$$

SYNOPSIS...SEC
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...SEC/BLS

NWS RAH Office Area Forecast Discussion