-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 190658
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
258 AM EDT SUN MAY 19 2013

.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL TRACK SLOWLY EAST ACROSS THE REGION
THROUGH MONDAY. WEAK HIGH PRESSURE WILL BUILD OVERHEAD TUESDAY INTO
WEDNESDAY.

&&

.NEAR TERM /TODAY AND TONIGHT/...
AS OF 200 AM SUNDAY...

...LOCALLY HEAVY RAIN THROUGH MONDAY...

A DECAYING MCV WAS LOCATED OVER THE NORTHERN PIEDMONT AROUND ROXBORO
AT 145 AM. THIS MCV PRODUCED SOME LOCALLY HEAVY RAIN AS IT TRACKED
NNE FROM THE NC/SC BORDER THROUGH THE EASTERN AND NORTHERN PIEDMONT
SATURDAY EVENING THROUGH EARLY THIS MORNING. THE LATEST SATELLITE
AND RADAR DATA INDICATED A GRADUAL WEAKENING TREND CONTINUED WITH
SOME MODERATE RAIN STILL LOCATED OVER PORTIONS OF PERSON...
ALAMANCE... ORANGE AND DURHAM COUNTIES. RAINFALL AMOUNTS THUS FAR
HAVE BEEN CONCENTRATED ACROSS THE PIEDMONT AND WESTERN SANDHILLS...
WITH PORTIONS OF THE COASTAL PLAIN SEEING ISOLATED TO SCATTERED
RAINFALL. THIS SHOULD CHANGE TODAY AS MOST OF THE AREA WILL HAVE A
SOLID SHOT AT 0.5 TO 1 INCH OF RAIN... WITH LOCALLY 2 INCHES.

THE LATEST WV SATELLITE DATA INDICATED ANOTHER VORTICITY MAXIMUM
ROTATING AROUND THE BACK SIDE OF THE SHORT WAVE TROUGH... OVER THE
VA/NC MOUNTAINS. SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEEN
DEVELOPING THIS LATE HOUR OVER THE EASTERN SLOPES OF THE NORTHERN
MOUNTAINS AND FOOTHILLS IN ASSOCIATION WITH THE INCREASING PVA
ASSOCIATED WITH THE APPROACHING VORT MAX. THESE SHOWERS ARE ALSO
AIDED IN THE ESE UPSLOPE FLOW INTO THE BLUE RIDGE. ALSO OF NOTE...
CONVECTION EXTENDED BACK INTO EASTERN TENNESSEE AND NORTHERN GEORGIA
FROM WESTERN NORTH CAROLINA. IT APPEARS THAT THIS CONVECTION WILL
DEVELOP/SPREAD EASTWARD WITH TIME THIS MORNING INTO THE WESTERN
PIEDMONT. THERE MAY BE A WEAKENING TREND FOR A FEW HOURS AROUND
DAYBREAK THROUGH LATE MORNING... THEN CONVECTION SHOULD BLOSSOM
AGAIN AS THE VORT MAX PUSHES OVER CENTRAL AND NORTHERN SECTIONS OF
OUR REGION THIS AFTERNOON... LASTING INTO THE EVENING. SEVERAL LOW
LEVEL BOUNDARIES EXIST FROM THE OVERNIGHT CONVECTION. IN ADDITION...
DIFFERENTIAL HEATING OVER THE SOUTHERN PIEDMONT INTO THE SANDHILLS
AND COASTAL PLAIN THROUGH BREAKS IN THE OVERCAST WILL SERVE TO
INCREASE INSTABILITY WITH SURFACE HEATING TODAY. PRECIPITABLE WATER
VALUES ARE FORECAST TO INCREASE FROM 1.25 TO 1.75 TO 2.0 INCHES THIS
AFTERNOON AND TONIGHT WITH ADDITIONAL INFLOW FROM THE WESTERN
ATLANTIC AND EASTERN GULF OF MEXICO INTO THE SYSTEM OVER CENTRAL NC.
MORE IN THE WAY OF LOCALLY HEAVY RAIN SHOULD RESULT. WE WILL
CONTINUE TO MENTION THE LOCALLY HEAVY RAIN AND POTENTIAL FOR MAINLY
URBAN AND SMALL STREAM FLOODING TODAY THROUGH TONIGHT.

THE HIGHEST POP SHOULD BE OVER THE WEST THIS MORNING... WITH MORE
ISOLATED TO SCATTERED SHOWERS IN THE EAST. THE HIGHEST POP SHOULD
SLOWLY SPREAD EAST INTO THE EASTERN PIEDMONT AND PORTIONS OF THE
SANDHILLS THIS AFTERNOON AND EVENING. THE COASTAL PLAIN SHOULD SEE
MORE SCATTERED CONVECTION AND WARMER TEMPERATURES THIS AFTERNOON AND
EVENING.

MODELS INDICATE MORE LOW CLOUDS/MOISTURE/SHOWERS LIMITING
INSTABILITY OVER THE WESTERN AND PARTS OF THE NORTHERN PIEDMONT THIS
AFTERNOON. MLCAPES SHOULD REACH OR EXCEED 1000-1500 J/KG IN THE
SOUTH AND EAST THIS AFTERNOON. WEAK SHEAR OF 15 KTS OF LESS WILL
CONTINUE TO LIMIT THUNDERSTORMS CAPABILITY TO BECOME SEVERE.
HOWEVER... CLUSTERS OF SLOW MOVING AND TRAINING SHOWERS AND
THUNDERSTORMS MAY RESULT IN SOME MINOR FLOODING. FLASH FLOOD
GUIDANCE HAS BEEN LOWERING OVER THE NORTHERN PIEDMONT... BUT NOT TO
THE POINT OF A THREAT OF A WIDESPREAD FLOODING THREAT. NO WATCH WILL
BE ISSUED AT THIS TIME. THE HEAVY RAIN/MINOR FLOODING THREAT WILL BE
MONITORED IN INSTANCES OF TRAINING CELLS OVER URBAN OR POOR DRAINAGE
AREAS.

HIGHS TODAY WILL AGAIN BE TEMPERED BY THE CLOUDS AND SHOWERS
ESPECIALLY IN THE WEST AND NORTH WHERE READINGS AROUND 75 SHOULD
AGAIN PREVAIL. HIGHS MAY REACH OR EXCEED 82-83 OVER FROM
FAYETTEVILLE TO GOLDSBORO BEFORE SHOWERS DEVELOP. LOWS TONIGHT
SHOULD AGAIN BE IN THE MID TO UPPER 60S.

OF ISSUE AGAIN TONIGHT SHOULD BE LOW STRATUS AND FOG... PARTICULARLY
OVER THE PIEDMONT.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 230 AM SUNDAY...

A GRADUAL SHIFT OF THE DEEP MOISTURE TO THE EASTERN ZONES IS
ANTICIPATED MONDAY. THE MID/UPPER TROUGH IS FORECAST TO WEAKEN BUT
STILL LINGER OVER THE REGION ON MONDAY. WE SHOULD SEE ANOTHER DAY OF
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS... MAINLY IN THE
CENTRAL AND EASTERN ZONES... AND MAINLY DURING THE AFTERNOON AND
EVENING HOURS.

DEEP LAYER MOISTURE ON THE ORDER OF 1.75 TO 2 INCHES WILL SHIFT TO
THE COASTAL PLAIN WITH NOTABLE DRYING IN THE MOUNTAINS. LOCALLY
HEAVY RAIN CAN AGAIN OCCUR... ESPECIALLY FROM THE EASTERN PIEDMONT
TO THE COAST. QPF OF 0.25 TO 0.50 WILL BE FORECAST WITH LOCALLY 1.5
INCHES IN THE COASTAL PLAIN. HIGHS WILL AGAIN BE TEMPERED BY THE
CLOUDS/MOISTURE WITH READINGS MOSTLY 78-84.

MORE LOW STRATUS AND FOG WILL BE LIKELY MONDAY NIGHT AFTER THE
SHOWERS MOSTLY DISSIPATE. LOWS IN THE MID TO UPPER 60S.
&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
AS OF 256 AM SUNDAY...

THE UPPER LEVEL WAVE WILL MOVE ACROSS THE AREA ON TUESDAY... WITH
PWATS 1.5" OR GREATER OVER THE AREA. SUFFICIENT INSTABILITY... WITH
WEAK SHEAR... WILL SUPPORT DEVELOPMENT OF GENERAL PULSE
THUNDERSTORMS... POTENTIALLY SEA BREEZE ENHANCED LATE IN THE DAY.
HIGHS IN THE MID 80S.

WHILE A WEAK UPPER LEVEL RIDGE BUILDS IN BRIEFLY ON WEDNESDAY...
MOISTURE STILL REMAINS HIGH OVER THE AREA... CONTINUING TO SUPPORT
THUNDERSTORM DEVELOPMENT MAINLY DURING THE AFTERNOON AND EVENING
HOURS WEDNESDAY AND THURSDAY... AND SOUTHERLY FLOW WILL KEEP HIGHS
NEAR TO SLIGHTLY ABOVE NORMAL IN THE LOW TO MID 80S... AND LOWS IN
THE MID 60S TO NEAR 70. A TROUGH OVER THE PLAINS STATES ON WEDNESDAY
WILL BEGIN TO MOVE EASTWARD... REACHING OUR AREA AT THE END OF THE
WEEK. THE ASSOCIATED COLD FRONT LOOKS TO DIP IN TO THE REGION LATE
WEEK. THE GFS HAS REMAINED SLOWER WITH THE FRONT THE LAST FEW
RUNS... DEVELOPING A LOW PRESSURE AREA AND MOVING IT ALONG THE
ATLANTIC COAST... AND DELAYING THE FRONTAL PASSAGE UNTIL SATURDAY.
AT THIS POINT... ENSEMBLE MEANS DO NOT SUPPORT THIS SOLUTION. THE
ECMWF IS FASTER AND BRINGS THE FRONT THROUGH FRIDAY. WILL CONTINUE
CHANCE POPS ON FRIDAY... TAPERING TO SLIGHT CHANCE SATURDAY.
-- End Changed Discussion --

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 210 AM SUNDAY...

IFR TO LIFR CIGS WILL DEVELOP THROUGH SUNRISE EXCEPT MVFR TO VFR
CIGS AROUND KFAY. SCATTERED SHOWERS WILL BECOME MORE WIDESPREAD WITH
ISOLATED THUNDERSTORMS IN THE WEST THIS MORNING... THEN AT ALL TAF
SITES THIS AFTERNOON AND EVENING. MOSTLY MVFR CIGS AND VSBYS
EXPECTED THIS AFTERNOON AND EVENING.. OCCASIONALLY REDUCED TO LIFR
IN HEAVY SHOWERS AND ISOLATED THUNDERSTORMS.

SIMILAR CONDITIONS EXPECTED MONDAY WITH LIFR TO IFR MORNING CIGS...
BECOMING MVFR DURING THE DAY. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS... ESPECIALLY DURING THE AFTERNOON AND EVENING.

DRIER CONDITIONS ARE FORECAST TUESDAY INTO WEDNESDAY WITH MORNING
STRATUS... FOG... IFR TO LIFR CIGS/VSBYS BECOMING VFR DURING THE
DAY. WIDELY SCATTERED SHOWERS/STORMS DURING THE AFTERNOON TUESDAY.
ONLY ISOLATED SHOWERS BY WEDNESDAY AFTERNOON.

&&

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

&&

$$

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