Severe Thunderstorm Warning 130, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
927 PM EDT FRI OCT 21 2005

.SHORT TERM (REST OF TONIGHT)...

UPPER JET DYNAMICS ARE LARGELY RESPONSIBLE FOR THE ACTIVITY WHICH
MAINTAINED STRENGTH AS IT MOVED INTO THE COOLER...MORE STABLE
AIRMASS NORTH OF THE FRONT. NAM HAS PEGGED THE UPPER DIVERGENCE
AND ONGOING ACTIVITY WELL...AND SUGGESTS THAT ACTIVITY SHOULD
CONTINUE PAST MIDNIGHT...GRADUALLY SHIFTING EAST AS THE NIGHT
PROGRESSES. THIS IS IN LINE WITH CURRENT FORECAST...AND WILL TWEAK
THE POPS TO MATCH CURRENT TRENDS. TEMPS LOOK GOOD.

&&

PREVIOUS DISCUSSION...
(ISSUED 245 PM EDT FRI OCT 21 2005)

SHORT TERM (TONIGHT THROUGH TUESDAY)...

TONIGHT THROUGH SUNDAY: BAND OF CONVECTION OVER EASTERN KY/TN IS
ASSOCIATED WITH A WESTWARD MOVING MID LEVEL WAVE. MEANWHILE... THE
EDGES OF THE STABLE POOL OVER THE NC PIEDMONT AND NORTHERN COASTAL
PLAIN HAVE ERODED NICELY THIS AFTERNOON... ALTHOUGH LOCATIONS FROM
INT OVER TO RZZ REMAIN SOCKED IN. CONVECTIVE CUMULUS HAS BEGUN TO
DEVELOP SOUTH OF HIGHWAY 64 AND MSAS INDICATES THAT MUCH OF THIS
AREA HAS DESTABILIZED WITH LI VALUES DOWN TO ZERO TO -2 AND CAPES UP
TO 500-700 J/KG. DESPITE A SOMEWHAT WARM CAP AROUND 700 MB THE RUC
SHOWS CAPES GETTING UP TO 1000 J/KG IN THE SANDHILLS... AND WITH THE
NAM12 ALSO SHOWING CONVECTIVE PRECIP DEVELOPING INTO THE EVENING
HERE AND ACTIVITY ALREADY BLOSSOMING OVER CENTRAL SC... WILL INCLUDE
AN EARLIER AND SLIGHTLY HIGHER POP IN THE SOUTHEAST CWA THIS
EVENING. OTHERWISE... THE INCOMING WAVE DAMPENS CONSIDERABLY TONIGHT
WITH THE MORE FORMIDABLE TROUGH DIGGING IN TO ITS WEST OVER THE
PLAINS. DESPITE IMPROVING MOISTURE AND POSSIBLY SOME LINGERING
ELEVATED INSTABILITY OVERNIGHT... WITH THIS MARGINAL PVA AND JUST
WEAK LOW LEVEL THETA-E ADVECTION... WILL KEEP POPS IN THE CHANCE
CATEGORY EXCEPT FOR LIKELY POPS NEAR THE RESIDUAL WEDGE BOUNDARY
WHERE SURFACE CONVERGENCE SHOULD COME INTO PLAY. UPPER DIVERGENCE
WITHIN THE LEFT EXIT REGION OF THE JET DIVING TOWARDS THE STATE
INCREASES SATURDAY ALONG WITH IMPROVING PVA... AND EXPECT A GOOD
CHANCE OF CONVECTION WITH THE OCCLUDED FRONT MOVING THROUGH... BEST
DEPICTED BY THE NAM. THE NAM DOES KEEP A WEDGE REGIME OVER THE FAR
NORTHWEST PIEDMONT AND WILL KEEP NE WINDS THERE UNTIL FROPA SATURDAY
AFTERNOON. AT THIS TIME THE MID LEVEL WINDS GO WESTERLY AND DRY OUT
THE COLUMN ALOFT. THE NAM BRINGS CAPES UP TO 2000+ J/KG IN THE
SOUTHEAST CWA SATURDAY AFTERNOON... AND THETA-E LAPSE RATES IN
FORECAST SOUNDINGS EXCEED 20 DEGREES K. WITH BRN VALUES OF 15-25 AND
BULK SHEAR VALUES OF 40-50 KT... COULD SEE SOME STRONG STORMS & WILL
NEED TO KEEP AN EYE OUT FOR THIS. WILL KEEP HIGH CHANCE POPS THROUGH
SATURDAY EVERYWHERE THEN IN THE NORTHEAST FOR A FEW HOURS SATURDAY
EVENING BEFORE DRY AIR AND THE INCOMING HIGH PRESSURE AREA TAKE
OVER. GOOD MID LEVEL CAPPING ON SUNDAY SHOULD LIMIT ANY RAIN RISKS
BUT DO EXPECT SCATTERED TO BROKEN CLOUD DEVELOPMENT AT THE TOP OF
THE DRY ADIABATIC MIXED LAYER. TONIGHTS LOW TEMPS LOOK GOOD AND
WILL FOLLOW FAIRLY CLOSE TO CONSENSUS OF MOS GUIDANCE TEMPS SATURDAY
THROUGH SUNDAY.

SUNDAY NIGHT THROUGH TUESDAY: PLEASE SEE OFFICIAL BULLETINS FROM THE
NATIONAL HURRICANE CENTER CONCERNING HURRICANE WILMA. LATEST
FORECASTS KEEP WILMA FAR ENOUGH OFFSHORE TO BE OF LITTLE CONCERN TO
CENTRAL NC... ALTHOUGH NORTH TO NORTHEAST BOUNDARY LAYER WINDS COULD
GET BREEZY AT TIMES. OTHER THAN THAT... A LARGE CHILLY CANADIAN
SOURCE HIGH BUILDS INTO THE STATE IN EARNEST... BRINGING
TEMPERATURES SOME 5-10 DEGREES BELOW NORMAL. THE 12Z GFS HAS LOW
LEVEL THICKNESSES RUNNING 30-50 M BELOW NORMAL SO TEMPS COULD END UP
EVEN COLDER. LATEST MODEL RUNS DISAGREE ON THE POSITION AND
ORIENTATION OF THE LARGE UPPER VORTEX TO OUR NORTH AND ANY VORTICITY
MAXIMA ROTATING AROUND IT... SO HAVE KEPT SKIES PARTLY CLOUDY TO
ACCOUNT FOR THIS UNCERTAINTY. LOWS IN THE 40S SUNDAY NIGHT AND 37-45
MONDAY NIGHT. HIGHS 59-69 MONDAY AND 59-64 TUESDAY. -GIH

LONG TERM (TUESDAY NIGHT THROUGH FRIDAY)...

A SHORT WAVE WILL MOVE THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
.EXITING THE AREA THURSDAY. HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTH THURSDAY FURTHER ENHANCING THE COLDER AIR
ALREADY OVER THE REGION. LOWS MOSTLY IN THE 40S WITH HIGH IN THE
60S. -RHJ

AVIATION...

LOW CLOUDS AND FOG MAINLY ACROSS THE NORTHERN TAFS WILL CONTINUE TO
LIFT THROUGH THE AFTERNOON. CLOUDINESS HELD OVER THE AREA IN
ASSOCIATION WITH COLD FRONT THROUGH THE NORTHERN PORTION OF THE CWA.
ACROSS THE SOUTH MAINLY MID AND HIGH LEVEL SCATTERED CLOUDS. CLOUDS
WILL LOWER OVER THE CWA TONIGHT AS RAIN THREATENS THE REGION. MVFR
CONDITIONS AROUND SUNSET WILL BECOME IFR IN SCATTERED RAIN AND FOG
OVERNIGHT TO NEAR SUNRISE SATURDAY. IFR CONDITIONS CONTINUING
THROUGH THE DAY SATURDAY WITH CHANCE OF RAIN DURING THE AFTERNOON IN
RESPONSE TO A COLD FRONT MOVING THROUGH THE AREA. -RHJ

&&

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

SHORT TERM...MLM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
534 AM EDT FRI OCT 21 2005

NCZ007>011-021>028-038>043-073>078-083>086-088-089-220945-
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-
534 AM EDT FRI OCT 21 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL NORTH
CAROLINA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A STRONG COLD FRONTAL PASSAGE AND STRONG WINDS IN THE UPPER ATMOSPHERE
WILL COMBINE TO PRODUCE THUNDERSTORMS ON SATURDAY. SOME OF THE
STORMS COULD BECOME SEVERE...ESPECIALLY ACROSS NORTH PORTIONS OF
THE PIEDMONT AND COASTAL PLAIN. STAY TUNED TO ALL HAZARDS WEATHER RADIO
OR OTHER LOCAL MEDIA FOR THE LATEST UPDATES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT NEEDED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
745 PM EDT FRI OCT 21 2005

NCZ041-042-220045-
JOHNSTON-WAKE-
745 PM EDT FRI OCT 21 2005

...A STRONG THUNDERSTORM WILL MOVE ACROSS EASTERN WAKE AND WESTERN
JOHNSTON COUNTIES THROUGH 845 PM EDT...

AT 745 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 7
MILES NORTH OF LILLINGTON...OR ABOUT OVER ANGIER...MOVING NORTHEAST
AT 25 MPH.

SOME LOCATIONS AFFECTED BY THESE STORMS INCLUDE...EASTERN FUQUAY
VARINA...CLEVELAND...COATS CROSSROADS...AUBURN...AND CLAYTON.

GUSTY WINDS OF 35 TO 45 MPH... HAIL TO THE SIZE OF MARBLES... AND
DANGEROUS CLOUD-TO-GROUND LIGHTNING CAN BE EXPECTED WITH THESE
STORMS. LIGHT OBJECTS SUCH AS TRASH CANS...LAWN FURNITURE AND
AWNINGS COULD BE TOSSED AROUND.

MWS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
830 PM EDT FRI OCT 21 2005

NCZ026-027-041-220130-
FRANKLIN-NASH-WAKE-
830 PM EDT FRI OCT 21 2005

...STRONG THUNDERSTORMS WILL MOVE ACROSS FRANKLIN...NASH AND WAKE
COUNTIES THROUGH 900 PM EDT...

AT 830 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
ZEBULON...OR ABOUT 17 MILES EAST OF RALEIGH...MOVING NORTHEAST AT 25
MPH.

SOME LOCATIONS AFFECTED BY THESE STORMS INCLUDE...PILOT...AND...
RILEY...SAMARIA...AND...BUNN...LAKE ROYALE...SPRING HOPE...MOMEYER...
NASHVILLE...AND...CASTALIA.

VERY HEAVY RAIN AND DANGEROUS CLOUD-TO-GROUND LIGHTNING CAN BE
EXPECTED WITH THIS STORM. PEA TO MARBLE SIZED HAIL WILL ALSO OCCUR
IN THE PATH OF THIS STORM. THE STORM WILL MOVE INTO NASH AND
FRANKLIN COUNTIES BEFORE 845 PM.

14

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
836 PM EDT FRI OCT 21 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0822 PM     HAIL             4 SSE KNIGHTDALE        35.74N 78.46W
10/21/2005  0.75 INCH        WAKE               NC   TRAINED SPOTTER

            PENNY SIZED HAIL REPORTED AT INTERSECTION OF TURNIPSEED
            ROAD AND MAJOR FLADE ROAD.

&&

MWS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
857 PM EDT FRI OCT 21 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0828 PM     HAIL             ZEBULON                 35.82N 78.32W
10/21/2005  0.75 INCH        WAKE               NC   TRAINED SPOTTER

            PENNY SIZED HAIL REPORTED IN ZEBULON.

&&

MWS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
1234 AM EDT SAT OCT 22 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1204 AM     HAIL             THOMASVILLE             35.89N 80.08W
10/22/2005  1.25 INCH        DAVIDSON           NC   TRAINED SPOTTER

1204 AM     HAIL             2 N THOMASVILLE         35.92N 80.08W
10/22/2005  1.00 INCH        DAVIDSON           NC   TRAINED SPOTTER

1219 AM     HAIL             MONTICELLO              36.20N 79.68W
10/22/2005  1.00 INCH        GUILFORD           NC   TRAINED SPOTTER

&&

WSS