Alert archive / North Carolina / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 201

May 1, 200218 counties in North Carolina; Grayson County, Virginia

The Storm Prediction Center issued this severe thunderstorm watch at May 1, 2002, 11:30 PM EDT for 18 counties in North Carolina; Grayson County, Virginia. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
May 1, 2002, 11:30 PM EDT (03:30 UTC)
Expired
May 2, 2002, 3:00 AM EDT
In force
4 hr
Issued by
the Storm Prediction Center

Counties Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Guilford County, NC, Iredell County, NC, Rowan County, NC, Stanly County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Grayson County, VA

The radar

The Roanoke radar (KFCX), 110 km from the middle of the area, began a volume at 03:32 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Warnings issued inside it

1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 1, 11:49 PM EDTSevere Thunderstorm WarningRNKWilkes41 min

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 3.5 hours before the alert went out and 95 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 00:00Z on 2002-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 292 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 00:00Z on 2002-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
292 J/kg
Mixed-layer CIN
-148 J/kg
Mixed-layer LCL
1208 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS20 KWNS 020330
SEL1  
SPC WW 020324
NCZ000-TNZ000-020700-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 201
STORM PREDICTION CENTER NORMAN OK
1124 PM EDT WED MAY 1 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   NORTHWEST NORTH CAROLINA                     
   EXTREME EAST TENNESSEE                          

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1130 PM
UNTIL 300 AM EDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 35 STATUTE MILES
EITHER SIDE OF A LINE FROM 50 MILES NORTH NORTHWEST OF HICKORY
NORTH CAROLINA TO 30 MILES SOUTH OF GREENSBORO NORTH CAROLINA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...  CONTINUE...WW 197...WW 198...WW
199...WW 200...

DISCUSSION...LARGE COMPLEX OF SEVERE STORMS IS NOW CROSSING THE
MOUNTAINS INTO WESTERN NORTH CAROLINA.  AIRMASS EAST OF MOUNTAINS
REMAINS MOIST/UNSTABLE WITH DEWPOINTS IN THE MID/UPPER 60S AND CAPE
VALUES OF 500-1500 J/KG.  IF CONVECTION CAN PERSIST...THREAT OF
LARGE HAIL AND DAMAGING WINDS WILL REMAIN FOR A FEW MORE HOURS.  

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM
MOTION VECTOR 29045.

...HART

365,0813 360,0794 351,0800 355,0815

WWUS20 KWNS 020330
SEL1  
SPC WW 020324
NCZ000-TNZ000-020700-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 201
STORM PREDICTION CENTER NORMAN OK
1124 PM EDT WED MAY 1 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   NORTHWEST NORTH CAROLINA                     
   EXTREME EAST TENNESSEE                          

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1130 PM
UNTIL 300 AM EDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 35 STATUTE MILES
EITHER SIDE OF A LINE FROM 50 MILES NORTH NORTHWEST OF HICKORY
NORTH CAROLINA TO 30 MILES SOUTH OF GREENSBORO NORTH CAROLINA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...  CONTINUE...WW 197...WW 198...WW
199...WW 200...

DISCUSSION...LARGE COMPLEX OF SEVERE STORMS IS NOW CROSSING THE
MOUNTAINS INTO WESTERN NORTH CAROLINA.  AIRMASS EAST OF MOUNTAINS
REMAINS MOIST/UNSTABLE WITH DEWPOINTS IN THE MID/UPPER 60S AND CAPE
VALUES OF 500-1500 J/KG.  IF CONVECTION CAN PERSIST...THREAT OF
LARGE HAIL AND DAMAGING WINDS WILL REMAIN FOR A FEW MORE HOURS.  

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM
MOTION VECTOR 29045.

...HART

365,0813 360,0794 351,0800 355,0815

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 1, 9:00 PM EDTTornado WatchSPCMitchell4 hr
May 2, 1:30 PM EDTSevere Thunderstorm WatchSPCAshe, Avery, Buncombe, Burke, Caldwell, Haywood and 6 more7 hr
May 2, 4:00 PM EDTTornado WatchSPCBertie, Camden, Chowan, Currituck, Edgecombe, Franklin and 12 more5 hr
May 2, 4:30 PM EDTSevere Thunderstorm WatchSPCAlamance, Alleghany, Caswell, Durham, Forsyth, Granville and 8 more6 hr
May 2, 5:00 PM EDTSevere Thunderstorm WatchSPCAlamance, Alleghany, Caswell, Durham, Forsyth, Granville and 8 more5 hr
May 2, 9:45 AM EDTTornado WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Wise and 2 more4 hr
May 2, 12:30 PM EDTSevere Thunderstorm WatchSPCAlbemarle, Alleghany, Amherst, Appomattox, Augusta, Bath and 45 more5 hr
May 2, 2:30 PM EDTTornado WatchSPCArlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 16 more7 hr
May 2, 2:45 PM EDTTornado WatchSPCAccomack, Amelia, Brunswick, Caroline, Charles City, Chesterfield and 50 more6 hr

Nearby

Severe Thunderstorm Watches in North Carolina, 2002Severe Thunderstorm Watches in Virginia, 2002Every severe thunderstorm watch in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.