Severe Thunderstorm Warning 305, NWS Raleigh, NC

000 
WWUS52 KRAH 241349
SVSRAH

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
948 AM EDT WED OCT 24 2007

NCC069-077-183-241358-
/O.CAN.KRAH.SV.W.0305.000000T0000Z-071024T1400Z/
WAKE NC-FRANKLIN NC-GRANVILLE NC-
948 AM EDT WED OCT 24 2007

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN GRANVILLE...WEST
CENTRAL FRANKLIN AND NORTHERN WAKE COUNTIES IS CANCELLED...

THE STORM THAT PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE 
LIMITS. HOWEVER TORRENTIAL DOWNPOURS AND WIND GUSTS NEAR 35 MPH CAN 
BE EXPECTED AS THE STORM MOVES THROUGH
WAKE FOREST...ROLESVILLE AND FRANKLINTON. 

LAT...LON 3617 7855 3606 7831 3568 7867 3579 7884
TIME...MOT...LOC 1348Z 211DEG 32KT 3596 7856

$$

WSS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
725 AM EDT WED OCT 24 2007

.SYNOPSIS...HIGH PRESSURE OVER THE ATLANTIC AND LOW PRESSURE OVER
THE GULF STATES WILL CHANNEL A FLOW OF WARM MOIST AIR FROM THE SOUTH
INTO CENTRAL NORTH CAROLINA TODAY AND TONIGHT. A COLD FRONT WILL
PUSH SOUTH INTO THE AREA EARLY THURSDAY AND REMAIN NEARLY STATIONARY
THROUGH FRIDAY. ANOTHER COLD FRONT WILL DRIFT SLOWLY EASTWARD ACROSS
THE AREA ON SATURDAY.

&&

.NEAR TERM /THROUGH TODAY/...
ALTHOUGH SHOWERS ARE RATHER SPARSE UPSTREAM AT 06Z THIS MORNING
AND SOME RIDGING REMAINS EVIDENT IN THE STREAMLINES ALOFT...MODELS
SHOW THE AIRMASS DESTABILIZING AND UNDERGOING DEEP MOIST ADVECTION
FROM THE SOUTH AFTER 12Z. PRECIPITABLE WATER APPROACHES 2 INCHES
THIS AFTERNOON. THIS FAVORS THE DEVELOPMENT OF WIDESPREAD SHOWERS
AND SCATTERED THUNDERSTORMS OVER THE AREA WITH POPS INCREASING TO
CATEGORICAL LEVELS FOR THIS AFTERNOON. QPF WILL VARY AS WITH MOST
CASES WITH DEEP CONVECTION...BUT BASIN AVERAGES RANGING FROM
AROUND ONE-THIRD INCH IN THE COASTAL PLAIN TO NEARLY AN INCH IN
THE WEST ARE LIKELY. TEMPERATURES SHOULD REMAIN WELL ABOVE NORMAL
BUT CLOUDINESS WILL CAP HIGHS IN THE LOWER 80S EAST AND MID TO
UPPER 70S WEST. WIND GUSTS OF AROUND 25 MPH ARE LIKELY MAINLY
EAST DURING THE DAY. -RFG

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
WITH THE ARRIVAL OF A COLD FRONT FROM THE NORTH...THE SHALLOW
COOL AIRMASS OVER INTERIOR NC BY THU SHOULD SERVE AS A LAUNCHING
PAD FOR PERSISTENT MOIST AND CONDITIONALLY UNSTABLE AIR FROM THE
SOUTH AND SOUTHEAST FOR THE NEXT TWO DAYS. LARGE SCALE ISENTROPIC
LIFT AND SATURATION IS MOST EVIDENT AT THE 295K THETA LEVEL IN
ALL THE OPERATIONAL MODELS OVER CENTRAL NC DURING THE PERIOD.
MODEL EVENT TOTAL QPFS ARE IN THE 3 TO 4 INCH RANGE. WE WILL BE IN
THE MORE CONSERVATIVE 2 TO 3 INCH RANGE GIVEN UNCERTAINTY OF WHERE
THE GREATEST CONFLUENCE OF THE LOW LEVEL FLOW AND PLACEMENT OF THE
ELEVATED DEEP CONVECTION WILL OCCUR. POPS WILL REMAIN IN THE
LIKELY CATEGORY OR BETTER. TEMPERATURES WILL LOWER AND DIURNAL
EXTREMES NARROW WITH THE SHALLOW SURFACE BASED COOL AIR AND
WIDESPREAD CLOUDINESS AND PRECIPITATION. WE LOOK FOR HIGHS MAINLY
60S TO LOWER 70S AND LOWS MAINLY UPPER 5OS TO MID 60S. -RFG

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE MODELS FAVOR NE MOVEMENT OF THE CUTOFF LOW UP THE OHIO
VALLEY FRI NIGHT AND DAMPENING TO AN OPEN WAVE TO OUR NORTH SAT.
THIS BRINGS A COLD FRONT SLOWLY ACROSS OUR AREA AND OFF THE COAST
SAT EVENING. CHANCES OF RAIN FROM SCATTERED SHOWERS SHOULD REMAIN
HIGH THROUGH SAT THEN TAPER OFF SAT NIGHT AND EARLY SUN PENDING ANY
TRAILING SHORTWAVES IN THE BROAD LONG WAVE TROUGH OVER THE MIDDLE
EASTERN U.S. TEMPERATURES WILL SHOW A GRADUAL LOWERING DURING THE
WEEKEND.

A BROAD AREA OF SURFACE HIGH PRESSURE EXTENDS FROM NEW ENGLAND TO
THE SOUTHERN MS VALLEY FOR MON AND TUE WITH BROAD LOW PRESSURE
FLORIDA AND THE NW CARIBBEAN.  THIS KEEPS US IN A PERSISTENT NE FLOW
OVER CENTRAL NC WITH NEAR OR BELOW NORMAL TEMPERATURES.  CONDITIONS
ARE APT TO REMAIN DRY...BUT HINTS OF A SOUTHERN STREAM WAVE MAY
INDUCE CLOUDINESS AND POSSIBLY TROUGHING OR LOW PRESSURE DEVELOPMENT
ALONG THE COAST LATE OR BEYOND TUE.  -RFG

&&

.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
CONVECTION IS ALREADY BEGINNING TO SPREAD INTO THE SOUTHERN
PIEDMONT AND SANDHILLS THIS MORNING. COVERAGE WILL CONTINUE TO
INCREASE ACROSS CENTRAL NC THROUGHOUT THE DAY AS A COLD FRONT
APPROACHES FROM THE NORTH AND IT INTERACTS WITH A STRONG SOUTHERLY
WIND FLOW AND COPIOUS AMOUNTS OF MOISTURE. IFR CONDITIONS WILL
OCCUR WITH THE HEAVIER CONVECTION...BUT TIMING OF SUCH
CONDITIONS IS DIFFICULT TO PINPOINT. THEREFORE...THE TAF PACKAGE
REFLECTS PREDOMINATE MVFR CEILINGS WITH OCCASIONAL IFR CONDITIONS
IN ASSOCIATION WITH SHOWERS AND THUNDERSTORMS. KEEP IN MIND THAT
CEILINGS COULD VARY CONSIDERABLY AS THE DAY PROGRESSES. ANY MIXING
THAT CAN OCCUR TODAY...MOST LIKELY OVER THE COASTAL PLAIN...WILL
AID IN THE TRANSPORT OF HIGHER WINDS IN THE LOW LEVELS DOWN TO THE
SFC. THEREFORE...OCCASIONAL GUSTS OF UP TO 20 KT POSSIBLE...ESPECIALLY
AT FAY/RWI.

A BACKDOOR COLD FRONT WILL PUSH INTO THE REGION LATE TONIGHT. BEHIND
THIS FRONT...WIDESPREAD RAIN WILL BECOME LIKELY WITH CEILINGS
DROPPING TO IFR EVERYWHERE BY 12Z THU AS A COLD AIR DAMMING EVENT
BECOMES ESTABLISHED. IFR CEILINGS LOOK TO PERSIST INTO FRIDAY. BY
FRIDAY INTO SATURDAY...ANOTHER COLD FRONT WILL APPROACH FROM THE
WEST...BRINGING YET ANOTHER HIGH LIKELIHOOD FOR RAIN AND POTENTIAL
IFR CONDITIONS. -JFB

&&

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

&&

SYNOPSIS...RFG
NEAR TERM...RFG
SHORT TERM...RFG
LONG TERM...RFG
AVIATION...JFB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
357 AM EDT WED OCT 24 2007

NCZ007>011-021>028-038>043-073>078-083>086-088-089-250800-
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-
357 AM EDT WED OCT 24 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

GUSTY WINDS TO NEAR 30 MPH AND LOCALIZED HEAVY RAIN WITH THE
POTENTIAL FOR HIGHWAY AND URBAN DRAINAGE FLOODING ARE POSSIBLE
WITH BANDS OF SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NORTH
CAROLINA TODAY. OTHERWISE HAZARDOUS WEATHER IS NOT EXPECTED AT
THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

RFG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
556 AM EDT WED OCT 24 2007

NCZ007>011-021>028-038>043-073>078-083>086-088-089-241600-
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-
INCLUDING THE CITIES OF...ROXBORO...OXFORD...HENDERSON...
WARRENTON...ROANOKE RAPIDS...WINSTON-SALEM...GREENSBORO...
HIGH POINT...BURLINGTON...CHAPEL HILL...DURHAM...LOUISBURG...
NASHVILLE...ROCKY MOUNT...LEXINGTON...ASHEBORO...PITTSBORO...
RALEIGH...SMITHFIELD...WILSON...ALBEMARLE...TROY...
SOUTHERN PINES...SANFORD...LILLINGTON...GOLDSBORO...WADESBORO...
ROCKINGHAM...LAURINBURG...RAEFORD...FAYETTEVILLE...CLINTON
556 AM EDT WED OCT 24 2007

...SIGNIFICANT RAINFALL IS LIKELY ACROSS CENTRAL NORTH CAROLINA
THE NEXT FEW DAYS...

CENTRAL NORTH CAROLINA IS LIKELY TO RECEIVE ITS FIRST SIGNIFICANT
WIDESPREAD RAINFALL SINCE SEPTEMBER 14TH...AND QUITE POSSIBLY THE
GREATEST EVENT TOTAL AMOUNT OF RAINFALL IN SEVERAL MONTHS.

TODAY THROUGH SATURDAY...THE WEATHER IS EXPECTED TO REMAIN UNSETTLED
WITH CONSIDERABLE CLOUDINESS...NUMEROUS SHOWERS...SCATTERED
THUNDERSTORMS...AND PERIODS OF RAIN...POSSIBLY HEAVY AT TIMES. FOR
THE FOUR DAY PERIOD...AVERAGE RAINFALL AMOUNTS OF TWO INCHES ARE
LIKELY. LOCALIZED HEAVIER AMOUNTS ARE POSSIBLE.

THE CAUSE OF ALL THIS WET WEATHER IS A SURGE OF WARM MOIST AIR
FLOWING NORTH FROM THE EASTERN GULF OF MEXICO AND OFF THE
SUBTROPICAL ATLANTIC INTO THE CAROLINAS BETWEEN DEEP LOW PRESSURE
OVER THE GULF STATES AND HIGH PRESSURE OFF THE EAST COAST. THIS
CHANNEL OF MOIST AIR IS EXPECTED TO COLLIDE WITH A COLD FRONT
SLIPPING SOUTH FROM THE OHIO VALLEY BY THURSDAY AND REMAINING
STATIONARY OVER THE AREA THROUGH FRIDAY. ANOTHER COLD FRONT
IS EXPECTED TO PUSH INTO THE AREA FROM THE WEST ON SATURDAY.

BECAUSE MAIN STEM RIVERS AND MAJOR STREAM CHANNELS ARE
EXCEPTIONALLY LOW OR NEARLY DEPLETED BY THE DROUGHT...FLOODING IS
NOT EXPECTED AT THIS TIME. HOWEVER...WITH BANDS OF HEAVY SHOWERS
AND THUNDERSTORMS...RAINFALL RATES EXCEEDING ONE INCH PER HOUR ARE
POSSIBLE. THIS SUDDEN DELUGE MAY CAUSE LOCALIZED FLOODING OF
HIGHWAYS AND URBAN DRAINAGES. INITIAL RAINFALL AFTER THE
PROLONGED DRY SPELL MAY ALSO CAUSE SLICK PAVEMENT SURFACES AND
CAUTION IS ADVISED FOR MOTORISTS UPON FIRST ENCOUNTERING WET
HIGHWAYS TODAY.

RFG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
840 AM EDT WED OCT 24 2007

NCZ024-025-040-041-076-077-241345-
ORANGE-DURHAM-CHATHAM-WAKE-LEE-HARNETT-
INCLUDING THE CITIES OF...CHAPEL HILL...DURHAM...PITTSBORO...
RALEIGH...SANFORD...LILLINGTON
840 AM EDT WED OCT 24 2007

....THUNDERSTORMS WITH HEAVY RAIN WILL AFFECT THE WESTERN SECTIONS
OF THE TRIANGLE...

A CLUSTER OF SHOWERS AND THUNDERSTORMS WILL MOVE NORTH NORTHEAST
ACROSS THE WESTERN SECTIONS OF THE TRIANGLE THROUGH 930 AM. THE
HEAVIER SHOWERS AND STORMS WILL AFFECT SUCH PLACES AS
PITTSBORO...APEX...CARY...JORDAN LAKE...RESEARCH TRIANGLE
PARK...R D U AIRPORT...CHAPEL HILL...CARRBORO AND DURHAM.

THE SHOWERS AND STORMS WILL PRODUCE ABOUT AN INCH OF RAIN IN LESS
THAN HOUR. THE INITIAL ONSET OF THE RAIN WILL CAUSE SLICK SPOTS TO
DEVELOP ON ROADS AND HIGHWAYS. ALSO STORM DRAINS MAY BE CLOGGED
WITH TREE OR LEAF DEBRIS. THIS MAY CAUSE EXTENSIVE PONDING.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
921 AM EDT WED OCT 24 2007

NCZ008-009-026-041-241415-
FRANKLIN-GRANVILLE-VANCE-WAKE-
921 AM EDT WED OCT 24 2007

...STRONG THUNDERSTORMS WILL MOVE FROM NORTHERN WAKE COUNTY INTO
SOUTHERN GRANVILLE...VANCE... AND WESTERN FRANKLIN COUNTIES THROUGH
1015 AM EDT...

AT 921 AM EDT...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS 5 MILES
WEST OF FALLS LAKE...OR ABOUT 10 MILES NORTH OF RALEIGH...MOVING
NORTH NORTHEAST AT 35 MPH.

THE STRONG THUNDERSTORMS WILL BE NEAR PURNELL AROUND 930 AM EDT.

GUSTY WINDS OF 40 TO 50 MPH...VERY HEAVY RAIN... AND DANGEROUS
CLOUD-TO-GROUND LIGHTNING CAN BE EXPECTED WITH THESE STORMS. THESE
WINDS ARE CAPABLE OF BRINGING DOWN LARGE TREE LIMBS. LIGHT OBJECTS
SUCH AS TRASH CANS...POTTED PLANTS AND LAWN FURNITURE COULD BE
TOSSED AROUND. RAINFALL AMOUNTS MAY EXCEED ONE INCH DURING THE NEXT
HOUR IN THESE AREAS. MOTORISTS SHOULD DRIVE WITH CAUTION TO AVOID
HYDROPLANING.

GIH