Special Weather Statement, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
725 AM EDT MON JUL 21 2014

.SYNOPSIS...A LOW PRESSURE AREA WILL HOLD OVER THE DEEP SOUTH
THROUGH TUESDAY... RESULTING IN A MOIST ATLANTIC FLOW FROM THE
SOUTHEAST INTO NORTH CAROLINA... AND UNSETTLED WEATHER TO START THE
WORK WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 AM MONDAY...

TODAY THROUGH TONIGHT: A DAMP AND VOLATILE ATMOSPHERE WILL HOLD OVER
CENTRAL NC AT LEAST THROUGH TONIGHT. THE LATEST SURFACE ANALYSIS
SHOWS A FRONTAL ZONE STRETCHING ACROSS THE GULF COAST THROUGH
CENTRAL GA/SC AND ACROSS SE NC... ASSOCIATED WITH A MID LEVEL TROUGH
OVER THE INTERIOR SOUTHEAST STATES AND MIDSOUTH. THIS TROUGH ALOFT
DEEPENS TO A BAGGY CLOSED LOW OVER SRN AL/GA BY TONIGHT... WITH A
WEAK BUT DISTINCT SHEAR AXIS STRETCHING NE ACROSS NC. PW VALUES ARE
ALREADY ON THE HIGH SIDE (120-140% OF NORMAL) AND ARE PROJECTED TO
RISE FURTHER... SURPASSING 2 INCHES OVER NEARLY THE ENTIRE CWA AND
PERHAPS 2.25 INCHES IN THE SE CWA... AS LOW LEVEL FLOW REMAINS FROM
THE SSE AND DRAWS IN ATLANTIC MOISTURE WHILE PRONOUNCED MID LEVEL
MOISTURE AND CONVECTIVE DEBRIS CLOUDS PERSIST WITHIN A WEAK STEERING
REGIME. THE LATEST HIGH-RES AND CONVECTION-ALLOWING MODELS SUGGEST
THAT THE PIEDMONT/WRN SANDHILLS WILL SEE THE GREATEST COVERAGE OF
SHOWERS AND ISOLATED STORMS THROUGH EARLY AFTERNOON... WHICH WOULD
THEN DRIFT EASTWARD INTO THE ERN SANDHILLS/COASTAL PLAIN DURING THE
AFTERNOON AND EARLY EVENING... BEFORE DECREASING IN COVERAGE BY
MIDNIGHT. THE GENERAL AGREEMENT ON THIS EVOLUTION BOOSTS FORECAST
CONFIDENCE... AND WILL FOLLOW THIS TREND IN THE FORECAST WITH GOOD
CHANCE POPS EAST AND LIKELY WEST EARLY... TRENDING DOWN IN THE WEST
AND UP IN THE EAST THIS AFTERNOON. BUT GIVEN THAT THE FLOW IS SO
WEAK WITH AN INCREASINGLY MOIST COLUMN AND SUBTLE MESOSCALE
BOUNDARIES GENERATED BY OUTFLOWS AND DIFFERENTIAL HEATING... SHOWERS
AND STORMS COULD POP UP ANYWHERE TODAY AND SIMPLY MEANDER. SLOW
STORM MOTION AND A FAIRLY DEEP WARM LAYER (AROUND 3.5 KM) TO FOSTER
WARM RAIN PROCESSES WILL BRING A RISK OF LOCALLY HEAVY RAINFALL
TODAY... ALTHOUGH NOT OVER A LARGE ENOUGH AREA TO NECESSITATE A
FLASH FLOOD WATCH AT THIS TIME. RAINFALL COULD BE EXACERBATED OVER
THE FAR WRN PIEDMONT WHERE LOW LEVEL MOIST UPGLIDE ATOP THE
RETREATING SHALLOW SURFACE RIDGE MAY ENHANCE LIFT. WILL TREND POPS
DOWN TO LOWER CHANCE TONIGHT... LOWER IN THE NE AND BETTER IN THE SW
WHERE MODELS SHOW SLIGHTLY BETTER MOISTURE TRANSPORT. CONSIDERABLE
CLOUDINESS WILL CUT DOWN ON HEATING TODAY ESPECIALLY EAST AND SE...
AND EXPECT HIGHS FROM THE LOW 80S NW TO MID 80S IN THE COASTAL
PLAIN. LOWS 68-72... LARGELY FOLLOWING PERSISTENCE. -GIH

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 AM MONDAY...

THE BAGGY LOW OVER SRN AL IS EXPECTED TO DRIFT WESTWARD TUE/TUE
NIGHT TOWARD LA... NUDGING THE WEAK SHEAR AXIS ALOFT TO OUR WEST...
WHICH IN TURN BUMPS THE DIFFUSE SURFACE FRONTAL ZONE WESTWARD TOWARD
THE NC FOOTHILLS. PW IS EXPECTED TO HOLD AT OR ABOVE 2.0 INCHES...
WITH A SURGE IN LOW LEVEL MOISTURE TRANSPORT BY AFTERNOON. MODELS
GENERATE SPARSE PRECIP THROUGH MIDDAY MAINLY IN THE FAR SOUTH AND
FAR WRN PIEDMONT... THEN SPREAD NUMEROUS SHOWERS OVER THE WRN
PIEDMONT AND BACK TO THE FOOTHILLS IN THE AFTERNOON. MODELS DEPICT
MARGINAL TO MODERATE INSTABILITY BUT WITH WEAK DEEP LAYER SHEAR...
EXPECT ANOTHER ROUND OF MAINLY NON-SEVERE MULTICELL CLUSTERS
PRODUCING POCKETS OF HEAVY DOWNPOURS. WILL HAVE THE HIGHEST POPS IN
THE NW AND FAR WRN CWA AND LOWER POPS ELSEWHERE... AS OVERALL LIFT
IS TEMPERED BY MODEST HEIGHT RISES. SLIGHTLY GREATER SUNSHINE IS
ANTICIPATED WITH SLIGHTLY LOWER CONVECTION COVERAGE AND SIMILAR
THICKNESSES... SO EXPECT TUE TEMPS TO TOP OUT A BIT HIGHER THAN
TODAY... 85-89. LOWS TUE NIGHT 69-73 WITH POPS LOWERING TO SLIGHT
CHANCE. -GIH

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 230 AM MONDAY...

WEDNESDAY THROUGH FRIDAY: AN UPPER LEVEL TROUGH WILL APPROACH AND
MOVE INTO CENTRAL NC DURING THIS PERIOD. EXPECT THE USUAL SUMMERTIME
DIURNAL SHOWERS AND STORMS FOR WEDNESDAY AS A THE PIEDMONT TROUGH
SETS UP OVER THE AREA AND SURFACE WINDS SHIFT TO SOUTHWESTERLY. THE
INCREASING WARM MOIST SOUTHWEST FLOW WILL YIELD HIGHS AROUND 90
DEGREES AND LOWS IN THE LOW TO MID 70S. PWAT VALUES WILL BE BETWEEN
1.50 AND 2.00 INCHES...AND WITH CAPE AROUND 1500 J/KG AND RELATIVELY
WEAK SHEAR...EXPECT THE MAIN STORM THREATS TO BE HEAVY RAIN AND
STRONG GUSTY WINDS. THE UPPER LEVEL TROUGH WILL BE SLOW TO TRAVERSE
THE CAROLINAS AT THE END OF THE WORK WEEK. THE 00Z GFS INDICATES AN
INITIAL FRONT MOVING INTO CENTRAL NC THURSDAY NIGHT INTO FRIDAY
MORNING...WITH WINDS VEERING TO NORTHWESTERLY...AND STALLING OVER
THE AREA ON FRIDAY. A SECONDARY FRONT ASSOCIATED WITH THE MAIN PUSH
OF COOLER AIR IS EXPECTED TO MOVE INTO THE REGION LATE FRIDAY/FRIDAY
NIGHT...WITH HIGH PRESSURE OVER THE OH VALLEY. THE HIGHEST CHANCES
FOR SHOWERS AND STORMS IN THE NORTHWEST AND LOWEST CHANCES IN THE
SOUTHEAST ON THURSDAY...WITH THE REVERSE BEING THE CASE FOR FRIDAY.
HIGHS THURSDAY WILL BE MAINLY IN THE LOW TO MID 90S...AND OVERNIGHT
LOWS IN THE UPPER 60S TO LOW 70S. WITH THE NW WINDS ON FRIDAY...
EXPECT HIGHS 3-5 DEGREES COOLER THAN THURSDAY...MID TO UPPER 80S...
AND LOWS IN THE MID 60S TO AROUND 70 DEGREES.

SATURDAY AND SUNDAY: THE AFOREMENTIONED HIGH OVER THE OH VALLEY
WEAKENS AND THE BOUNDARY THAT LINGERED ACROSS THE AREA BECOMES
WASHED OUT OVER THE WEEKEND. GIVEN THE LACK OF A DOMINATING SURFACE
FEATURE AND THE GENERAL TROUGHINESS ALOFT...EXPECT A RETURN TO MORE
SEASONAL CONDITIONS FOR THE WEEKEND...WITH CHANCES FOR AFT/EVE
SHOWERS AND STORMS AND NEAR NORMAL TEMPERATURES...HIGHS IN THE UPPER
80S TO AROUND 90 DEGREES AND LOWS IN THE UPPER 60S TO LOW 70S.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 725 AM MONDAY...

SMALL CLUSTERS OF SHOWERS AND A COUPLE OF STORMS LINGER OVER CENTRAL
NC... MOST LIKELY TO AFFECT RDU IN THE VERY NEAR TERM. OTHERWISE...
IFR CIGS AT INT/GSO/RDU WILL SLOWLY LIFT TO MVFR THROUGH THE MORNING
AND EARLY AFTERNOON... WHILE MVFR VSBY AT FAY WILL DISPERSE BY 15Z.
A WEAK TROUGH ALOFT OVER THE DEEP SOUTH IS EXPECTED TO CLOSE OFF
INTO A LOW OVER AL/GA TODAY AND TONIGHT... WHICH WILL KEEP A VERY
MOIST AND UNSETTLED ATMOSPHERE OVER NC... WITH A LIGHT FLOW FROM THE
SE AND S DRAWING IN ATLANTIC MOISTURE. SCATTERED TO NUMEROUS SHOWERS
AND STORMS PRODUCING MVFR CONDITIONS ARE EXPECTED TO AFFECT ALL
CENTRAL NC TAF SITES AT SOME POINT TODAY... DRIFTING TO THE N OR
NW... HOWEVER DETERMINING PRECISELY WHEN EACH SITE WILL BE AFFECTED
IS DIFFICULT... RESULTING IN LOWER THAN USUAL CONFIDENCE. ONCE THE
ONGOING SHOWERS/STORMS NOW OVER CENTRAL NC MOVE ON... THE BEST
ESTIMATE ON TIMING OF LATER STORMS IS THAT THEY ARE MOST LIKELY TO
AFFECT INT/GSO 14Z-18Z... RDU FROM 16Z-20Z... AND RWI/FAY 18Z-22Z.
BUT AGAIN... CONFIDENCE IN THESE TIMES ARE VERY LOW... AS STORMS
WILL TEND TO FORM ON SUBTLE ILL-DEFINED BOUNDARIES WITH A MEANDERING
MOVEMENT AND ADDITIONAL DEVELOPMENT ON OUTFLOWS. THERE IS A GOOD
CHANCE OF IFR CIGS REDEVELOPING BY LATE EVENING OR SOON AFTER
MIDNIGHT TONIGHT... LASTING THROUGH THE NIGHT... AT ALL TAF SITES...
ACCOMPANIED BY MVFR FOG. ISOLATED SHOWERS AND STORMS REMAIN POSSIBLE
ALL THROUGH THE NIGHT.

LOOKING BEYOND 12Z TUE MORNING... CIGS SHOULD LIFT TO VFR BY LATE
TUE MORNING... WITH ANOTHER PERIOD OF SCATTERED SHOWERS AND STORMS
TU AFTERNOON AND EVENING. SUB-VFR CONDITIONS SHOULD RETURN ONCE
AGAIN TUE NIGHT-WED MORNING AS THE MOIST UNSETTLED PATTERN HOLDS.
SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED EACH DAY...
MAINLY AFTERNOON THROUGH EVENING... WITH CHANCES IMPROVING EACH DAY
THROUGH FRI. -GIH

&&

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

&&

SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...KCP
AVIATION...HARTFIELD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
455 AM EDT MON JUL 21 2014

NCZ007>011-021>028-038>043-073>078-083>086-088-089-220930-
PERSON-GRANVILLE-VANCE-WARREN-HALIFAX-FORSYTH-GUILFORD-ALAMANCE-
ORANGE-DURHAM-FRANKLIN-NASH-EDGECOMBE-DAVIDSON-RANDOLPH-CHATHAM-WAKE-
JOHNSTON-WILSON-STANLY-MONTGOMERY-MOORE-LEE-HARNETT-WAYNE-ANSON-
RICHMOND-SCOTLAND-HOKE-CUMBERLAND-SAMPSON-
455 AM EDT MON JUL 21 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED
TODAY. SOME OF THESE SHOWERS AND STORMS WILL BE SLOW MOVING AND
PRODUCE LOCALLY HEAVY DOWNPOURS... WHICH COULD RESULT IN MINOR
FLOODING IN URBAN AND POOR DRAINAGE AREAS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
821 AM EDT MON JUL 21 2014

NCZ040-075-076-211415-
LEE-CHATHAM-MOORE-
821 AM EDT MON JUL 21 2014

...SPECIAL WEATHER STATEMENT...

AT 815 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
AREA OF SLOW MOVING SHOWERS AND THUNDERSTORMS OVER NORTHERN MOORE
AND SOUTHERN CHATHAM COUNTY.

RAINFALL RANGING BETWEEN 1 AND 2 INCHES ARE LIKELY THROUGH 1000 AM
THIS MORNING. HEAVY RAIN FELL OVER NORTHWEST CHATHAM COUNTY
OVERNIGHT...ESPECIALLY NORTH OF SILER CITY AROUND STALEY. THIS
ADDITIONAL HEAVY RAIN COULD CAUSE MINOR FLOODING IN POORLY DRAINED
AREAS.

LOCATIONS IMPACTED INCLUDE... SANFORD...PITTSBORO...CARTHAGE...SILER
CITY...GOLDSTON...BROADWAY... ROBBINS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LOCALLY HEAVY RAIN WILL QUICKLY REDUCE VISIBILITY AND RESULT IN
PONDING OF WATER ON ROADWAYS. RAIN WILL BE WIDESPREAD ALONG HIGHWAY
64...AND DRIVERS ARE URGED TO SLOW DOWN AND USE EXTRA CAUTION TO
AVOID HYDROPLANING.

&&

LAT...LON 3552 7955 3584 7954 3585 7891 3561 7899
      3560 7896 3549 7900 3525 7970 3551 7977
TIME...MOT...LOC 1215Z 240DEG 49KT 3563 7925

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