Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 252, NWS Norman, OK

May 21, 2001Atoka County, Coal County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 21, 2001, 12:28 AM CDT for Atoka County, Coal County, Oklahoma. It was in force for 47 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: May 21, 2001, 12:28 AM CDT (05:28 UTC)
Expired: May 21, 2001, 1:15 AM CDT
In force: 47 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Atoka County, OK, Coal County, OK

The radar

The Norman radar (KTLX), 129 km from the middle of the area, began a volume at 05:29 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.

What was reported inside it

Time	Report	Where	Remark
May 21, 12:30 AM CDT	Hail 1.5	Tupelo, OK

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 5.5 hours before the alert went out and 132 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: 2068 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 1431 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 13.3

Open this sounding in Storm Lab

The text

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

000 
WUUS54 KOUN 210530
SVROKC

OKC005-029-210615-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
1228 AM CDT MON MAY 21 2001

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN ATOKA COUNTY IN SOUTHEAST OKLAHOMA
  COAL COUNTY IN SOUTHEAST OKLAHOMA

* UNTIL 115 AM CDT

* AT 1228 AM CDT...DOPPLER RADAR DETECTED A SEVERE THUNDERSTORM 3   
MILES NORTHEAST OF CENTRAHOMA. OTHER SEVERE THUNDERSTORMS WERE 
DEVELOPING SOUTHWEST OF TUPELO... AND SOUTHEAST OF WARDVILLE. 
MOVEMENT WAS EAST AT 15 TO 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE CENTRAHOMA...CHOCKIE...COALGATE...
  DAISY...PHILLIPS...TUPELO AND WARDVILLE

HAIL UP TO 2 INCHES IN DIAMETER IS LIKELY WITH THESE SEVERE 
THUNDERSTORMS.

HEAVY RAINS MAY QUICKLY FLOOD LOW LYING AREAS SUCH AS CREEKS...
DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED
ROADS AS AUTOMOBILES CAN QUICKLY STALL.

LAT...LON 3467 9650 3448 9652 3451 9567 3460 9567
          3477 9609

The office that day

Everything else NWS Norman, OK issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 7:17 PM CDT	Tornado Warning	OUN	Coal	43 min
May 20, 7:43 PM CDT	Tornado Warning	OUN	Atoka	32 min
May 20, 11:38 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Hughes	52 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2001 Every severe thunderstorm warning in 2001

Sources

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