Alert archive / North Carolina / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 320

May 20, 200012 counties in North Carolina; 10 counties in Virginia

The Storm Prediction Center issued this severe thunderstorm watch at May 20, 2000, 7:00 PM EDT for 12 counties in North Carolina; 10 counties in Virginia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: May 20, 2000, 7:00 PM EDT (23:00 UTC)
Expired: May 21, 2000, 12:00 AM EDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 22 counties

Bertie County, NC, Camden County, NC, Chowan County, NC, Gates County, NC, Hertford County, NC, Hyde County, NC, Martin County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, Washington County, NC, Chesterfield County, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Petersburg, VA, City of Suffolk, VA, Greensville County, VA, Prince George County, VA, Southampton County, VA, Sussex County, VA

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 20, 9:48 PM EDT	Severe Thunderstorm Warning	AKQ	Northampton	32 min
May 20, 10:30 PM EDT	Severe Thunderstorm Warning	MHX	Martin, Washington	45 min

The nearest sounding before it

Newport, NC (KMHX), launched 12:00Z, 11.0 hours before the alert went out and 178 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 101 J/kg
Mixed-layer CIN: -263 J/kg
Mixed-layer LCL: 1515 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WWUS9 KMKC 202245
MKC WW 202245
NCZ000-VAZ000-CWZ000-210400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 320
STORM PREDICTION CENTER NORMAN OK
645 PM EDT SAT MAY 20 2000

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

   NORTHEAST NORTH CAROLINA                     
   SOUTHEAST VIRGINIA                           
   COASTAL WATERS                     

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 700 PM UNTIL
MIDNIGHT 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 50 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 85 MILES WEST NORTHWEST OF ELIZABETH
CITY NORTH CAROLINA TO 60 MILES SOUTH SOUTHEAST OF ELIZABETH CITY
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.

OTHER WATCH INFORMATION...  CONTINUE...WW 318...WW 319...

DISCUSSION...THUNDERSTORMS EXPECTED TO CONTINUE FORMING INVOF SLOW-
MOVING BACKDOOR FRONT...WHERE CONVERGENCE WILL BE MAXIMIZED BY
PREVAILING WSW FLOW OVER NRN NC/SRN VA.  DEEP-LAYER SHEAR
SUFFICIENT FOR SUPERCELLS.  IN ADDITION...CONVECTIVE SYSTEM NOW
NEARING GSO SHOULD CONTINUE EWD THIS EVENING...EVENTUALLY MOVING
INTO WRN PART OF WATCH.  

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 28030.

...CORFIDI

;372,0773 361,0754 344,0754 360,0773;

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 4:30 PM EDT	Severe Thunderstorm Watch	SPC	Alexander, Alleghany, Avery, Buncombe, Burke, Caldwell and 25 more	6 hr
May 20, 5:30 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Caswell, Chatham, Davidson, Durham, Forsyth and 14 more	6 hr

Nearby

Severe Thunderstorm Watches in North Carolina, 2000 Severe Thunderstorm Watches in Virginia, 2000 Every severe thunderstorm watch in 2000

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.