National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 190608
AFDRAH

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

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

&&

.NEAR TERM /TODAY AND TONIGHT/...
-- Changed Discussion --
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 70 SHOULD
AGAIN PREVAIL. HIGHS MAY REACH OR EXCEED 80 OVER FROM FAYETTEVILLE
TO GOLDSBORO BEFORE SHOWERS DEVELOP. LOWS TONIGHT SHOULD AGAIN BE IN
THE MID TO UPPER 60S.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 245 PM SATURDAY...

WITH THE MID/UPPER TROUGH STILL LINGERING OVER THE REGION ON
MONDAY...THE INCREASED SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED
TO PERSIST FOR AT LEAST ONE MORE DAY. THE TROUGH AXIS WILL SLOWLY
SHIFT EASTWARD DURING THE DAY AND INTO THE OVERNIGHT HOURS...WHICH
SHOULD GRADUALLY SHIFT THE BEST PRECIP CHANCES EASTWARD.
THEREFORE...THE HIGHEST POPS WILL BE FOCUSED ACROSS THE CENTRAL AND
EASTERN PORTIONS OF THE FORECAST AREA. GOOD DEEP LAYER MOISTURE WILL
STILL BE IN PLACE ACROSS THE REGION...ESPECIALLY ACROSS THE
EAST...WHERE PWAT VALUES ARE PROGGED TO BE NEAR 1.75 INCHES. AS A
RESULT...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE ONCE AGAIN AND WITH
THE EXPECTED AMOUNT OF PRECIP EXPECTED TO PRECEDE THE RAINFALL ON
MONDAY...SOME MINOR FLOODING...MAINLY IN POOR DRAINAGE AND URBAN
AREA WILL BE POSSIBLE. WITH ALL OF THE CLOUDS AND PRECIP ACROSS THE
AREA...HIGHS SHOULD BE HELD DOWN SOMEWHAT...WITH GENERALLY LOWER 80S
EXPECTED.

PRECIP CHANCES SHOULD GRADUALLY DECREASE MONDAY NIGHT AS THE
MID/UPPER LEVEL TROUGH AXIS SHIFTS EAST OF THE AREA. REGARDLESS...
CLOUD COVER SHOULD REMAIN FAIRLY EXTENSIVE THROUGHOUT THE OVERNIGHT
HOURS...KEEPING OVERNIGHT LOWS MOSTLY IN THE MID/UPPER 60S.


.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 245 PM SATURDAY...

SOME WEAK SHORTWAVE RIDGING WILL START TO BUILD OVER THE AREA
TUESDAY AND WEDNESDAY...WHILE AT THE SURFACE...THE BERMUDA HIGH WILL
START TO RIDGE WESTWARD INTO THE CAROLINAS. ALL OF THIS WILL
TRANSLATE TO A DECREASE IN PRECIP COVERAGE FOR THE MIDDLE OF THE
WEEK. ALSO CONTRIBUTING TO THIS WILL BE SOME SLIGHT MID LEVEL
DRYING...ALTHOUGH SUFFICIENT MOISTURE SHOULD REMAIN IN PLACE OVER
THE REGION...WITH PWAT VALUES HOVERING NEAR 1.5 INCHES OR SO.
THEREFORE...AM EXPECTING SCATTERED DIURNALLY DRIVEN PRECIP EACH DAY.
WITH MORE IN THE WAY OF BREAKS IN THE CLOUD COVER AND LESS PRECIP
COVERAGE...TEMPS SHOULD BE ABLE TO REBOUND NICELY INTO THE MID/UPPER
80S.

SHOWER AND THUNDERSTORM COVERAGE SHOULD BEGIN TO INCREASE ONCE AGAIN
BY THE END OF THE WEEK WITH THE APPROACH OF OUR NEXT MID/UPPER LEVEL
TROUGH AND ASSOCIATED COLD FRONT. THERE IS STILL SOME DISAGREEMENT
WITH THE TIMING OF THE COLD FRONTAL PASSAGE...BUT FOR NOW WILL GO
WITH AN LATE FRIDAY NIGHT/EARLY SATURDAY MORNING PASSAGE.
THEREFORE...WILL SHOW HIGHEST POPS THURSDAY AND FRIDAY/FRIDAY NIGHT
(BUT WILL STILL GO NO HIGHER THAN CHANCE UNTIL BETTER AGREEMENT IS
REACHED)...WITH POPS DECREASING FROM WEST TO EAST ON SATURDAY. WITH
INCREASED PRECIP CHANCES/CLOUDS ON THURSDAY AND FRIDAY...TEMPS WILL
MOSTLY BE IN THE LOW/MID 80S...WITH SLIGHTLY COOLER TEMPS EXPECTED
ON SATURDAY.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

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

&&

$$

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