Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 233, NWS Norman, OK

May 26, 2002Comanche County, Stephens County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 26, 2002, 2:47 AM CDT for Comanche County, Stephens County, Oklahoma. It was in force for 43 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 26, 2002, 2:47 AM CDT (07:47 UTC)
Expired: May 26, 2002, 3:30 AM CDT
In force: 43 min
Issued by: NWS Norman, OK
Area: Counties, with a storm outline in the text

Counties Comanche County, OK, Stephens County, OK

The radar

The Altus AFB radar (KFDR), 91 km from the middle of the area, began a volume at 07:49 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 26, 2:48 AM CDT	Hail 0.75	Duncan, OK	Hail was reported on the south side of Duncan.

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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 7.8 hours before the alert went out and 91 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: 2 J/kg
Mixed-layer CIN: -607 J/kg
Mixed-layer LCL: 906 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 59 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 
WUUS54 KOUN 260747
SVROKC
OKC031-137-260830-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
246 AM CDT SUN MAY 26 2002

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  STEPHENS COUNTY IN SOUTHERN OKLAHOMA
  EASTERN COMANCHE COUNTY IN SOUTHWEST OKLAHOMA

* UNTIL 330 AM CDT

* AT 246 AM CDT...DOPPLER RADAR DETECTED A SEVERE THUNDERSTORM OVER
  DUNCAN. ANOTHER SEVERE THUNDERSTORM WAS LOCATED JUST NORTH OF
  PUMPKIN CENTER... OR 15 MILES WEST OF MARLOW. THE STORMS WERE  
  MOVING EAST AT 25 MPH.

* LOCATIONS IN THE WARNING INCLUDE BRAY...DUNCAN AND MARLOW

HAIL UP TO THE SIZE OF QUARTERS IS LIKELY WITH THESE SEVERE 
THUNDERSTORMS. DIME SIZE HAIL IS BEING REPORTED IN DUNCAN AT 245 AM.

LAT...LON 3468 9840 3454 9826 3446 9795 3447 9756
          3469 9757

...SPEG.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Norman, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at May 26, 2:14 AM CDT, 33 minutes earlier.

Area forecast discussion, May 26, 2:14 AM CDT, 33 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
212 AM SUN MAY 26 2002

RATHER IMPRESSIVE MID/UPPER LEVEL S/W TROF AXIS CURRENTLY SLIDING
INTO THE FORECAST AREA. CONVECTION CONTINUES TO DEVELOP AHEAD OF
THIS FEATURE EARLY THIS MORNING OVER ROUGHLY THE SOUTHEAST HALF OF
THE FA..FEEDING OFF CAPES OF AROUND 1000 J/KG IN THE 800-700 MB
LAYER. EXPECT THIS TO CONTINUE FOR A GOOD PART OF THE DAY AS LIFT
CONTINUES TO ACT ON UNSTABLE LAYER ABOVE THE SURFACE..BUT COVERAGE
OF CONVECTION SHUD DECREASE BY AFTERNOON.  ATTENTION THEN TURNS TO
DEVELOPING BOUNDARY LAYER INSTABILITY AXIS FROM CENT/WRN TX NWD INTO
WRN KS. INTENSE CONVECTIVE DEVELOPMENT WILL PROBABLY OCCUR SOMEWHERE
ALONG THIS AXIS THIS AFTERNOON AND THEN MOVE EWD TONITE.  THUS..WE
WILL BUMP POPS UPWARD FOR THE FIRST 2 PDS.

FORECAST FOR PERIODS BEYOND BECOMES INCREASINGLY DEPENDENT UPON
CUMULATIVE EFFECTS OF CONVECTION AND RESIDUAL BOUNDARIES.  IT IS
LATE MAY..AND WE WILL LIKELY HAVE PRETTY HEALTHY INSTABILITY IN
PLACE EACH DAY. SO..CHANCES FOR STORMS WILL CONTINUE..WITH BEST
CHANCE RIGHT NOW LOOKING LIKE TUES INTO WED.  SEVERAL OF THE MEDIUM
RANGE MODELS WANT TO BUILD A RATHER SUBSTANTIAL UPPER RIDGE INTO THE
SRN PLAINS MID/LATE WEEK..BUT AM NOT NECESSARILY INCLINED TO BELIEVE
THIS SINCE THE SAME MODELS 6 DAYS AGO WERE FORECASTING A SIMLIAR
PATTERN FOR RIGHT NOW..WHICH IS HARDLY THE CASE.  WITH ALL THIS IN
MIND..WE REALLY DO NOT HAVE ANY COMPELLING REASONS TO MAKE MANY
CHANGES TO THE EXTENDED PERIODS..SO WE WONT ATTM.
 MILLER

PRELIM NUMBERS..
OKC   79  65  81  66 /  40  20  40  40
HBR   82  66  83  66 /  20  40  40  40
SPS   83  67  84  68 /  20  30  30  40
GAG   80  63  82  62 /  40  50  30  50
PNC   77  65  80  66 /  20  40  40  40
DUA   79  66  82  67 /  70  20  30  30

.OUN...
OK...NONE.
TX...NONE.

In the hours before

Special weather statement, May 25, 10:30 PM CDT, 4 hours 17 minutes before

OKZ004>048-050>052-TXZ083>090-260600-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1030 PM CDT SAT MAY 25 2002

THUNDERSTORM OUTLOOK...
SEVERE THUNDERSTORMS ARE NOT EXPECTED IN OKLAHOMA OR WESTERN NORTH
TEXAS THROUGH EARLY SUNDAY MORNING. ISOLATED TO SCATTERED
THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT...BUT NO ORGANIZED SEVERE
ACTIVITY IS EXPECTED.

DISCUSSION...
THERE IS SUFFICIENT INSTABILITY IN THE MID LEVELS OF THE ATMOSPHERE
TO ALLOW FOR A FEW ELEVATED THUNDERSTORMS TO FORM OVERNIGHT AS A
WEAK UPPER AIR DISTURBANCE MOVES ACROSS THE AREA. SMALL HAIL WILL BE
POSSIBLE WITH THE STRONGER THUNDERSTORMS...BUT THE THREAT OF
ORGANIZED SEVERE WEATHER IS LOW.

THREAT TABLE...
VALID THROUGH 700 AM CDT SUN MAY 26.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...40 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...10 PERCENT.

OTHER HAZARDOUS WEATHER...
NO OTHER HAZARDOUS WEATHER IS EXPECTED.

11

The office that day

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

Issued	Product	Office	Counties	Lasted
May 26, 4:18 AM CDT	Severe Thunderstorm Warning	OUN	Garvin, Murray	42 min
May 26, 5:01 AM CDT	Severe Thunderstorm Warning	OUN	Garvin, Murray, Pontotoc	44 min
May 26, 5:04 AM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal	41 min
May 26, 5:46 AM CDT	Severe Thunderstorm Warning	OUN	Coal, Pontotoc	44 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2002 Every severe thunderstorm warning 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.