Damaging Wind in North Carolina, April 17, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1217 PM EDT MON APR 17 2006

.SHORT TERM /REST OF TODAY/...
UPDATE HAS BEEN ISSUED TO REFLECT ISSUANCE OF SEVERE THUNDERSTORM
WATCH 196...IN EFFECT UNTIL 21Z. LINE OF CONVECTION ORGANIZING IN
EAST TENNESSEE MARCHING STEADILY TOWARD OUR WESTERN ZONES.

THERE WAS INITIAL CONFUSION OVER THE COUNTIES ORIGINALLY SLATED TO
BE IN THE WATCH. WE RECENTLY ISSUED A CORRECTED WATCH COORDINATION
MESSAGE...UNDER THE PRODUCT INVENTORY LIST HEADER CAEWCNGSP...WITH
THE PROPER COUNTIES AND REMOVING COUNTIES INADVERTENTLY INCLUDED
THE FIRST TIME.

&&

.PREV DISCUSSION...
 /ISSUED 1100 AM EDT MON APR 17 2006/

SHORT TERM /REST OF TODAY/...
LATEST MESOSCALE ANALYSIS THIS MORNING INDICATES A WAVY-TYPE
FRONTAL FEATURE STRETCHING FROM A SURFACE WAVE OVER EASTERN NORTH
CAROLINA...WEST TO THE NORTH CAROLINA PIEDMONT...THEN BACK TO THE
NORTHWEST TO SURFACE LOW PRESSURE OVER THE KENTUCKY COAL FIELDS.
THE PART OF THIS COMPLEX FRONTAL ALIGNMENT OVER NORTHEAST PART OF
THE TAR HEEL STATE IS SINKING TO THE SOUTH. THE SURFACE LOW OVER
KENTUCKY...IN CONJUNCTION WITH A RATHER POTENT SHORTWAVE
ALOFT...IS PROJECTED TO SWING SOUTHEAST AND WEAKEN THROUGH THE AFTERNOON.
ISODROSOTHERM ANALYSIS INDICATES DEWPOINTS ALREADY BEGINNNING TO
MIX OUT OVER THE NORTHWEST PIEDMONT...ALTHOUGH THIS HAS MORE TO DO
WITH A DRY POCKET OR INITIAL DIURNAL MIXING THAN WITH DRYING
ASSOCIATED WITH THE FRONT ITSELF.

UPSTREAM RADAR MOSAIC SHOWS CONVECTION ALREADY ORGANIZING AHEAD OF
THE KENTUCKY SURFACE WAVE AND ASSOCIATED SHORTWAVE. THIS CLUSTER
HAS BEEN FOLLOWING THE SOUTHERN END OF THE DEEPER SURFACE DEWPOINT
AXIS. IT WILL BE INTERESTING TO SEE WHAT HAPPENS AS THIS ONGOING
CONVECTION MOVES OFF THE HIGHER TERRAIN AND ENCOUNTERS THE MUCH
DRIER AIR INVADING OUR NORTHERN AREAS FROM THE NORTHEAST.

OBSERVED SOUNDINGS THIS MORNING WERE ALREADY UNSTABLE. PROJECTED
SOUNDINGS SHOW SURFACE TO MID LEVEL THETA-E 25 TO 30. MOISTURE HAS
CREPT WELL NORTHWARD INTO THE MOUNTAINS. THE STORM PREDICTION
CENTER MOVED THE SLIGHT RISK OUTLOOK FOR TODAY A TAD TO THE WEST
ACROSS THE NORTH CAROLINA PORTION OF THE FORECAST AREA. THE KEY
WILL BE TO FOLLOW THE EVENTUAL PATH OF THE VORT AND ASSOCIATED
STEEPER LAPSE RATES THERE IS A POINT...SOMEWHERE IN THE MOUNTAINS
OR THE UPSTATE...WHERE THE ATMOPSHERE WILL BE TOO CAPPED TO
SUPPORT CONVECTION TODAY. THAT LOCATION APPEARS TO BE...THIS
MORNING ANYWAY...ACROSS THE SOUTHERN NORTH CAROLINA MOUNTAINS.

OBSERVED SOUNDINGS CONFIRM THE STRONGER WINDS PROJECTED ON
FORECAST SOUNDINGS. WITH DEEP MIXING...ESPECIALLY SOUTH WHERE
SATELLITE IMAGERY SHOWS SKIES STILL PRETTY MUCH CLEAR...IT WOULD
NOT BE MUCH OF A STRETCH TO TAP THOSE HIGHER WINDS ALOFT.
CERTAINLY...THE AFTERNOON LOOKS WINDY...AT HIGHER TERRAIN
LOCATIONS AND ACROSS MOST OF THE UPSTATE...NORTHEAST GEORGIA AND
THE NORTH CAROLINA PIEDMONT. WE DECIDED TO HOIST A LAKE WIND
ADVISORY FOR ALL LOCATIONS TIL 7 PM THIS EVENING.

FINALLY...WE RAISED MAXES TO UPPER 80S/AROUND 90 SOUTHERN
AREAS...AND KEPT COOLER MAXES ACROSS THE NORTHERN TIER TODAY. WE
TOOK CHANCE OF RAIN DOWN TO 40% FOR THE REST OF THE DAY...HIGHEST
IN AN ARC FRM NORTHERN MOUNTAINS TO THE NORTHWEST PIEDMONT...DOWN
TO 30% OR SO FOR THE SOUTHERN PIEDMONT AND THE EASTERN UPSTATE. WE
TOOK CHANCE OF RAIN TO ISOLATED FROM SCATTERED FOR THE GREENVILLE
SPARTANBURG METRO AREA.

FIRE WEATHER...
MIXING HEIGHTS COULD END UP A TAD HIGHER THAN EARLIER PROJECTED
FOR THE SOUTHERN AREAS...INCHING TOWARD 9000 FEET IN A FEW SPOTS.

PREV DISCUSSION...
 /ISSUED 251 AM EDT MON APR 17 2006/

SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
THE NAM...GFS AND RUC ARE ALL CONSISTENT IN BRINGING THE VORT MAX
ACROSS KENTUCKY DURING THE MORNING.  THE NAM AND GFS BOTH BRING IT
ACROSS SOUTHWEST VIRGINIA AND BRUSHING OUR NORTHEAST COUNTIES IN THE
MID DAY AND EARLY AFTERNOON.  THE COLD FRONT WILL MOVE SOUTH DURING
THE DAY WITH DEW POINTS GENERALLY IN THE 55 TO 60 RANGE SOUTH OF THE
ADVANCING FRONT AND CAPES ABOVE 1000 OVER LOCATIONS ALONG AND SOUTH
OF INTERSTATE 85.  SPC HAS POSTED A SLIGHT RISK OF SEVERE FOR OUR
FAR EASTERN ZONES...GENERALLY NEAR AND EAST OF INTERSTATE 77 FOR
STORM COMPLEX THAT IS EXPECTED TO CROSS THE AREA.  WITH WET BULB
ZERO BEING IN THE 8500 TO 9500 RANGE...HAIL IS A CONCERN AS WELL AS
DELTA THETA-E SHOWING DOWNBURST POTENTIAL WITH EXPECTED ORGANIZED
CONVECTION.  AS THE FRONT CROSSES FROM NORTH TO SOUTH...THE
ATMOSPHERE WILL STABILIZE AND MOST THUNDERSTORM ACTIVITY SHOULD BE
MOVING OFF THE COAST AT THE DAY.  THE FRONT SHOULD STALL OUT OVER
FAR SOUTHERN GEORGIA ON TUESDAY MORNING.  DRY WEATHER EXPECTED
TUESDAY AND INTO AT LEAST MOST OF TUESDAY NIGHT.

MADE SMALL ADJUSTMENTS UPWARD ON POPS AND WEATHER FOR WEDNESDAY
AND EARLY WEDNESDAY NIGHT AS IT APPEARS A GREATER CHANCE IS
WARRENTED AT LEAST FOR THE WESTERN AREAS.

LONG TERM /THURSDAY THROUGH SUNDAY/...
DEEP UPPER LOW PRESSURE WILL MOVE SLOWLY FROM THE GREAT LAKES REGION
TO NEW ENGLAND THU THROUGH SUN. ENERGY ROTATING AROUND THIS LARGER
SCALE VORTEX WILL BE DIFFICULT TO TIME THROUGH THE PERIOD. A LEAD
FRONTAL SYSTEM APPROACHING THE REGION ON THU SHOULD WASH OUT WITH
LIMITED MOISTURE ALONG THE DECAYING BOUNDARY. THE MOST PROMINENT
SHORTWAVE SHOULD CROSS THE REGION DAYTIME SATURDAY...ASSOCIATED WITH
THE DEEPEST MOISTURE AXIS...AND CONVERGENCE NEAR THE SURFACE
REFLECTION. A STRONG 850 MB JETLET COULD TRAVERSE THE REGION ON
SATURDAY AHEAD OF THIS SHORTWAVE...AND STRONG THUNDERSTORMS COULD
RESULT IN THE WARM SECTOR. THE MAIN UPPER TROUGH AXIS WILL LIKELY
SWEEP THROUGH THE REGION ON SUNDAY...BUT WITH DEEPER LAYER DRYING
ALREADY IN PLACE.

AVIATION...
LOW LEVEL JET WILL CONTINUE TO AFFECT THE REGION THROUGH SUNRISE.
WINDS ARE ABOUT 30 KTS FROM 240 DEGREES 1000 FEET OFF THE GROUND
AND 40 KTS FROM 260 DEGREES AT 2000 FEET. HOWEVER...MOST SITES
REMAIN MIXED AT THE SURFACE...SO THE ABSOLUTE WIND CHANGE IS NOT
ENOUGH TO WARRANT A LOW LEVEL WIND SHEAR GROUP.

WINDS WILL GRADUALLY VEER OF OF THE WEST TODAY...THEN QUICKLY TURN OUT
OF THE NORTHEAST THIS EVENING AS A POTENT BACK-DOOR COLD FRONT WORKS
ITS WAY ACROSS THE REGION. SO WE CAN EXPECT A PERIOD OF CROSS WINDS
BY MID AFTERNOON AT MANY TAF SITES. THERE WILL ALSO BE VERY DEEP
MIXING LATER IN THE DAY...SO WE WILL NEED TO BE ON THE LOOKOUT FOR A
FEW CROSSWIND GUSTS AS HIGH AS 30 KTS...ESPECIALLY AT THE UPSTATE
TAF SITES DURING THE MID TO LATE AFTERNOON HOURS. LOOKS AS IF KCLT
WL SEE A SHARP WIND SHIFT FROM NORTHWEST TO NORTHEAST BETWEEN 20 AND 22
UTC WITH THE COLD FRONT PASSAGE.

AS FOR THE THREAT OF CONVECTION...THE NAM DEVELOPS A NARROW RIBBON
OF HIGH INSTABILITY RIGHT ACROSS THE CHARLOTTE METRO AREA DURING THE
AFTERNOON. HAVE A CB GROUP IN THE TAF TO ACCOUNT FOR THIS...BUT THE
POTENTIAL EXITS FOR STRONG THUNDERSTORMS TO BE IN THE VCNTY OF KCLT
FOR SEVERAL HOURS...BEGINNING AROUND 17 UTC. FARTHER TO THE SOUTH
AIRMASS LOOKS TOO DRY FOR CONVECTION OVER THE UPSTATE...BUT KAVL MAY
ALSO HAVE TO CONTEND WITH SOME THUNDERSTORMS BY LATE MORNING.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...LAKE WIND ADVISORY FOR GAZ010-017-018-026-028-029 UNTIL 7 PM
     MONDAY.
NC...LAKE WIND ADVISORY FOR NCZ033>037-048>059-062>072-082 UNTIL 7
     PM MONDAY.
SC...LAKE WIND ADVISORY FOR SCZ001>014-019 UNTIL 7 PM MONDAY.
&&

SHORT TERM...

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
529 AM EDT MON APR 17 2006

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-
SCZ001>014-019-181000-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-CALDWELL-
ALEXANDER-IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-
BUNCOMBE-MCDOWELL-BURKE-CATAWBA-ROWAN-GRAHAM-NORTHERN JACKSON-
MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-POLK-RUTHERFORD-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
OCONEE MOUNTAINS-PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-
GREATER OCONEE-GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-
CHEROKEE-YORK-ANDERSON-ABBEVILLE-LAURENS-UNION SC-CHESTER-
GREENWOOD-
529 AM EDT MON APR 17 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
GEORGIA...PIEDMONT NORTH CAROLINA...WESTERN NORTH CAROLINA AND
UPSTATE SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS WILL CROSS THE NORTHERN MOUNTAINS OF NORTH CAROLINA
AND THEN CROSS THE FOOTHILLS AND PIEDMONT OF THE CAROLINAS TODAY.
A FEW OF THE STORMS OVER THE PIEDMONT IN THE MID DAY AND EARLY
AFTERNOON MAY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

MORE THUNDERSTORMS COULD AFFECT THE AREA IN THE MID TO LATE WEEK.
AT THE CURRENT TIME...THE BEST CHANCE OF ANY SEVERE WOULD BE OVER
THE FAR WESTERN AREAS OF THE FORECAST AREA...THE WESTERN TIP OF
NORTH CAROLINA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY IN THE CAROLINA
PIEDMONT...GENERALLY ALONG AND EAST OF INTERSTATE 77.

OUTLAW