Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 441, NWS Norman, OK

September 14, 2002Coal County, Hughes County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Sep 14, 2002, 9:14 PM CDT for Coal County, Hughes County, Oklahoma. It was in force for 46 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Sep 14, 2002, 9:14 PM CDT (02:14 UTC)
Expired: Sep 14, 2002, 10:00 PM CDT
In force: 46 min
Issued by: NWS Norman, OK
Area: Counties, with a storm outline in the text

Counties Coal County, OK, Hughes County, OK

The radar

The Norman radar (KTLX), 108 km from the middle of the area, began a volume at 02:17 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
Sep 14, 9:30 PM CDT	Thunderstorm Wind	Centrahoma, OK	Six inch diameter tree limbs were downed.

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, 2.2 hours before the alert went out and 112 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: 1380 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 1169 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.1

Open this sounding in Storm Lab

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 Sep 14, 3:14 PM CDT, 6 hours earlier.

Area forecast discussion, Sep 14, 3:14 PM CDT, 6 hours before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
310 PM CDT SAT 14 2002

FIRST PERIOD POPS WILL BE HEAVILY DEPENDENT ON SATELLITE AND RADAR
TRENDS TOWARD ISSUANCE TIME. THERE WILL BE TWO MAIN AREAS/FEATURES
TO WATCH. ONE IS ACROSS NORTH CENTRAL ZONES NEAR VORTEX CENTER.
MOSTLY INDUCED BY COLD CORE TEMPS...THIS COULD POSE A PROBLEM FOR
FLOODING...AS A FAIRLY LARGE AREA OF NORTH CENTRAL OKLAHOMA RECEIVED
BETWEEN 2 AND 4+ INCHES OF RAIN EARLY THIS MORNING. A FLASH FLOOD
WATCH MAY BE NEEDED IF ACTIVITY BECOMES ORGANIZED...BUT HEAVIEST
RAIN STILL EXPECTED FURTHER SOUTH.

SECOND IS WEAK SURFACE BOUNDARY...WHICH IS BECOMING BETTER DEFINED
ACROSS WEST CENTRAL OKLAHOMA. GIVEN DECENT WARM-UP AHEAD OF
BOUNDARY...ALONG WITH WEAKLY CAPPED ENVIRONMENT...THIS FEATURE
EXPECTED TO LIGHT UP AND PROVIDE MUCH OF CENTRAL/SOUTHERN OKLAHOMA
AND WESTERN NORTH TEXAS TEXAS WITH SHOWERS AND THUNDERSTORMS. IF
LINE CAN DEVELOP AND FILL IN...TO WOULD LIKELY MOVE INTO CENTRAL
PARTS OF OKLAHOMA LATE THIS AFTERNOON THROUGH EARLY EVENING...THEN
SHIFT SOUTH AND EAST. MAIN CONCERN WITH ANY ACTIVITY WILL BE
LIGHTNING AND HEAVY RAINFALL. LINGERING (LIGHT) SHOWERS WILL LIKELY
BE SEEN ACROSS CENTRAL AND SOUTHERN AREAS AFTER THIS LINE MOVES
THROUGH.

LOW POPS WILL NEED TO BE KEPT ACROSS EASTERN/SOUTHERN PORTIONS OF
FORECAST AREA ON SUNDAY AS UPPER VORT CENTR IS SLOW TO MOVE OUT AND
SURFACE FRONT BEGINS TO STALL. THEN...IT APPEARS THAT THERE WILL BE
A COUPLE OF DRY SEASONABLE DAYS UNTIL MID WEEK...WHEN MEDIUM RANGE
MODELS WANT TO BRING IN ANOTHER SUBSTANTIAL FRONT. DYNAMIC SUPPORT
WILL BE THERE FOR POPS TO BE CONTINUED. WILL LEAVE POPS IN THE
WEDNESDAY NIGHT AND THURSDAY TIME FRAME FOR NOW. ANOTHER FRONT IS
PROGD AGAIN FOR THE WEEKEND.

FCSTID =  11

PRELIMINARY CCF NUMBERS...
OKC   63  78  57  81 /  80  20   0   0
HBR   62  78  56  83 /  80  10   0   0
SPS   65  81  60  84 /  60  20   0   0
GAG   55  76  49  81 /  60   0   0   0
PNC   59  77  55  80 /  80  20   0   0
DUA   66  81  59  83 /  80  40   0   0

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

In the hours before

Local storm report, Sep 14, 8:02 PM CDT, 1 hour 12 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
802 PM CDT SAT SEP 14 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0640 PM    OKLAHOMA CITY             OK   60 MPH WIND GUST
09/14/02   OKLAHOMA                       OKC FIRE DEPT

FM

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 14, 8:48 PM CDT	Severe Thunderstorm Warning	OUN	Carter	27 min
Sep 14, 8:52 PM CDT	Severe Thunderstorm Warning	OUN	Pontotoc	28 min
Sep 14, 8:59 PM CDT	Severe Thunderstorm Warning	OUN	Johnston	46 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.