Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 601, NWS Norman, OK

September 20, 2001Ellis County, Harper County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Sep 20, 2001, 8:13 PM CDT for Ellis County, Harper County, Oklahoma. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 20, 2001, 8:13 PM CDT (01:13 UTC)
Expired: Sep 20, 2001, 8:45 PM CDT
In force: 32 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Ellis County, OK, Harper County, OK

The radar

The Dodge City radar (KDDC), 142 km from the middle of the area, began a volume at 01:14 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Sep 20, 3:45 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Dodge City, (KDDC), launched 00:00Z, 1.2 hours before the alert went out and 142 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: 488 J/kg
Mixed-layer CIN: -205 J/kg
Mixed-layer LCL: 2154 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 67 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 20, 2:49 PM CDT, 5 hours 24 minutes earlier.

Area forecast discussion, Sep 20, 2:49 PM CDT, 5 hours 24 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
249 PM CDT THU SEP 20 2001

HIGH BASED CONVECTION CONTINUES TO FORM MAINLY OVER THE SOUTHEAST
HALF OF AREA...ABOVE COLD POOL AND IN REGION OF DPVA AND MID LEVEL
WARM AIR ADVECTION. LATEST MODEL GUIDANCE SUGGESTS THIS AREA OF
CONVECTION WILL EITHER PERSIST OVERNIGHT OR EXPAND WESTWARD.
PROBLEMS WITH HEAVY RAIN HAVE ALREADY OCCURRED AND WITH ADDITIONAL
HEAVY RAIN POSSIBLE...WILL ISSUE A FLASH FLOOD WATCH FOR TONIGHT FOR
THE SOUTHEAST CORNER OF OKLAHOMA.

FARTHER NORTHWEST...WEAKENING COLD FRONT ACROSS KANSAS SHOULD HELP
SCATTERED TSRA TO DEVELOP ALONG ITS LEADING EDGE AS IT MOVES INTO
THE AREA LATER TONIGHT. MAIN AREA OF LIFT WILL SLIDE TO OUR
NORTHEAST WHICH PRECLUDES THE NEED FOR HIGH POPS ACROSS FAR NORTHERN
OKLAHOMA. WILL GO WITH 30 TO 40 POPS AND MENTION THE POSSIBILITY FOR
SEVERE TSRA THIS EVENING DUE MAINLY TO STRONGER MID LEVEL FLOW.

TSRA MAY BE ONGOING FRIDAY AM ACROSS SOUTH CENTRAL/SOUTHEAST
OKLAHOMA...BUT WILL KEEP FFA THROUGH JUST TONIGHT TO PROVIDE
MIDNIGHT SHIFT WITH MAXIMUM FLEXIBILITY. FRONT WILL LIKELY WEAKEN
FURTHER DURING THE DAY FRIDAY BUT COULD STILL PROVIDE ENOUGH
BOUNDARY LAYER CONVERGENCE TO WARRANT A NEED FOR SMALL POPS MOST
AREAS.

MODELS ARE SLOWLY CONSOLIDATING TOWARD A MODERATE/STRONG COLD FRONT
ENTERING NORTHERN OKLAHOMA SATURDAY NIGHT/EARLY SUNDAY. WILL STEER
FORECAST IN THE DIRECTION OF COOLER TEMPS FOR SUNDAY THROUGH TUESDAY
BUT ATTEMPT TO KEEP SOME LEVEL OF PERSISTENCE AND CONSISTENCY WITH
THE PREVIOUS FORECAST IN CASE THIS SOLUTION DOES NOT OCCUR.

THANKS TSA AND FTW FOR COORDINATION...

GAG 65/85/65/88/60 42333
PNC 66/85/64/86/62 42333
HBR 66/85/66/88/65 53202
OKC 66/83/64/86/65 54202
SPS 66/85/66/88/66 74200
DUR 66/81/66/85/65 86200

.OUN...
OK...FLASH FLOOD WATCH OKZ 030>032-039>043-045>048-050>052
TX...NONE.
JAMES

In the hours before

Local storm report, Sep 20, 6:17 PM CDT, 1 hour 56 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
617 PM CDT THU SEP 20 2001

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

0545 PM    12 N CAMP HOUSTON         OK   1.75 INCH HAIL
09/20/01   WOODS                          PUBLIC REPORT

J

Local storm report, Sep 20, 6:21 PM CDT, 1 hour 52 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
621 PM CDT THU SEP 20 2001

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

0616 PM    THALIA                    TX   .75 INCH HAIL
09/20/01   FOARD                          AMATEUR RADIO REPORT

J

Local storm report, Sep 20, 7:25 PM CDT, 48 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
725 PM CDT THU SEP 20 2001

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

0645 PM    2 W PLAINVIEW             OK   3.00 INCH HAIL
09/20/01   WOODS                          SPOTTER REPORT

0710 PM    11 E BUFFALO              OK   2.00 INCH HAIL
09/20/01   HARPER                         PUBLIC REPORT

J

Local storm report, Sep 20, 7:50 PM CDT, 23 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
750 PM CDT THU SEP 20 2001

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

0705 PM    VERA                      TX   WIND DAMAGE. POWER POLES
09/20/01   KNOX                           DOWN. AMATEUR RADIO
                                          REPORT.

J

Local storm report, Sep 20, 8:00 PM CDT, 13 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
800 PM CDT THU SEP 20 2001

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

0748 PM    3 E BUFFALO               OK   .75 INCH HAIL
09/20/01   HARPER                         PUBLIC REPORT

0740 PM    10 E BUFFALO              OK   1.25 INCH HAIL
09/20/01   HARPER                         SPOTTER REPORT

J

Local storm report, Sep 20, 8:07 PM CDT, 6 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
807 PM CDT THU SEP 20 2001

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

0625 PM    4 NNW PLAINVIEW           OK   .75 INCH HAIL
09/20/01   WOODS                          PUBLIC REPORT

J

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 20, 7:30 PM CDT	Severe Thunderstorm Warning	OUN	Harper	45 min
Sep 20, 8:04 PM CDT	Severe Thunderstorm Warning	OUN	Woodward	41 min
Sep 20, 8:45 PM CDT	Severe Thunderstorm Warning	OUN	Woodward	45 min
Sep 20, 10:19 PM CDT	Severe Thunderstorm Warning	OUN	Blaine	41 min
Sep 20, 10:39 PM CDT	Severe Thunderstorm Warning	OUN	Kingfisher	51 min
Sep 20, 10:48 PM CDT	Severe Thunderstorm Warning	OUN	Garfield	27 min
Sep 20, 10:54 PM CDT	Severe Thunderstorm Warning	OUN	Blaine	51 min
Sep 20, 11:38 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Kingfisher	52 min
Sep 21, 1:05 AM CDT	Severe Thunderstorm Warning	OUN	Kay	25 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.