Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 53, NWS Norman, OK

April 20, 1997Atoka County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 20, 1997, 8:20 PM CDT for Atoka County, Oklahoma. It was in force for 55 min. 4 reports 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: Apr 20, 1997, 8:20 PM CDT (01:20 UTC)
Expired: Apr 20, 1997, 9:15 PM CDT
In force: 55 min
Issued by: NWS Norman, OK
Area: Whole counties

County Atoka County, OK

The radar

The Norman radar (KTLX), 155 km from the middle of the area, began a volume at 01:19 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
Apr 20, 8:50 PM CDT	Hail 0.75	Atoka, OK
Apr 20, 8:55 PM CDT	Hail 0.88	Tushka, OK
Apr 20, 9:05 PM CDT	Hail 0.75	Tushka, OK
Apr 20, 9:15 PM CDT	Hail 0.75	Atoka, 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 watch it was issued in

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

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

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 1.3 hours before the alert went out and 156 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: 490 J/kg
Mixed-layer CIN: -106 J/kg
Mixed-layer LCL: 2384 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 14 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 Apr 20, 3:36 PM CDT, 4 hours 44 minutes earlier.

Area forecast discussion, Apr 20, 3:36 PM CDT, 4 hours 44 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
330 PM CDT SUN APR 20 1997

SFC LO MOVING THRU ERN KS THIS AFTN WITH CDFNT TRAILING SWWD THRU ABT
THE MIDDLE OFTHE FA. LO LVL FLO HAS VEERED AHD OF THE BNDRY LESSENING
THE CONVERGENCE. VEERED WINDS IN LOWER LVLS ON AREA PROFILERS ALSO
IMPLIES THAT LO LVL MOISTR IS SHALLOW. THUS WILL LIMIT POPS FOR TONIGHT
TO THE ERN ZONES WHERE LO LVL MOISTR MAY BE DEEPER. TSTM THRT FOR
TONIGHT SHUD END WITH THE PASSAGE OF THE FNT LATER TONIGHT. MODELS
DIFFER WITH SOLN IN LATTER PDS. NGM SEEMS TOO STG WITH S/W MOVING
THROUGH THE NWLY FLO ACRS THE CNTRL PLAINS ON MONDAY AND PREFER SOLN OF
ETA/AVN. WL LV IN LO POPS FOR MONDAY FROM PREV FCST WITH APCHG S/W AND
WK SFC BNDRY DVLPG. MORE SIG WV APCHS MONDAY NIGHT AND TUESDAY AND WL
GENLY GO ALG WITH HIER AVN GUIDANCE POPS FOR THOSE TWO PDS.

FCSTID = 12
OKC   53  76  52  67 /  10  20  30  50
HBR   51  78  50  68 /  10  20  40  50
SPS   54  83  53  72 /  10  20  30  50
GAG   48  77  46  64 /  10  20  40  40
PNC   53  76  51  66 /  10  20  30  40
DUA   82  56  82  55 /  30  20  30  50

.OKC...
OK...NONE.
TX...NONE.

In the hours before

Local storm report, Apr 20, 7:26 PM CDT, 54 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
727 PM CDT SUN APR 20 1997

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

700 PM     3 E HOLDENVILLE            OK  0.88 INCH HAIL
04/20/97   HUGHES

700 PM     RINGLING                   OK  0.88 INCH HAIL COVERED THE
04/20/97   JEFFERSON                      GROUND

700 PM     3 SE HEALDTON              OK  1.00 INCH HAIL
04/20/97   CARTER

708 PM     4 N CALVIN                 OK  1.00 INCH HAIL
04/20/97   HUGHES

712 PM     5 S DAVIS                  OK  1.00 INCH HAIL AT TURNER FALLS
04/20/97   MURRAY

BZ>

Local storm report, Apr 20, 7:27 PM CDT, 53 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
727 PM CDT SUN APR 20 1997

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

700 PM     3 E HOLDENVILLE            OK  0.88 INCH HAIL
04/20/97   HUGHES

700 PM     RINGLING                   OK  0.88 INCH HAIL COVERED THE
04/20/97   JEFFERSON                      GROUND

700 PM     3 SE HEALDTON              OK  1.00 INCH HAIL
04/20/97   CARTER

708 PM     4 N CALVIN                 OK  1.00 INCH HAIL
04/20/97   HUGHES

712 PM     5 S DAVIS                  OK  1.00 INCH HAIL AT TURNER FALLS
04/20/97   MURRAY

BZ

Special weather statement, Apr 20, 7:57 PM CDT, 23 minutes before

OKZ045-041-TXZ090-210145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
800 PM CDT SUN APR 20 1997

SEVERE THUNDERSTORM WATCH NUMBER 162 IS NO LONGER IN EFFECT FOR THE
FOLLOWING COUNTIES IN OKLAHOMA

JEFFERSON AND MURRAY

AND CLAY COUNTY IN TEXAS.

THE FRONT RESPONSIBLE FOR THE THUNDERSTORMS EARLIER THIS EVENING WILL
CONTINUE TO CAUSE SHOWERS AND THUDERSTORMS TO THE EAST OF THESE
COUNTIES.

THE SEVERE THUNDERSTORM WATCH REMAINS EFFECTIVE FOR MUCH OF THE
REMAINDER OF SOUTHEAST OKLAHOMA UNTIL 11 PM.

WR

Special weather statement, Apr 20, 8:00 PM CDT, 20 minutes before

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Local storm report, Apr 20, 8:11 PM CDT, 9 minutes before

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Local storm report, Apr 20, 8:12 PM CDT, 8 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 7:00 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson	45 min
Apr 20, 7:10 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Pontotoc	50 min
Apr 20, 7:35 PM CDT	Severe Thunderstorm Warning	OUN	Johnston	55 min
Apr 20, 7:40 PM CDT	Severe Thunderstorm Warning	OUN	Hughes	50 min
Apr 20, 7:43 PM CDT	Severe Thunderstorm Warning	OUN	Carter	47 min
Apr 20, 7:58 PM CDT	Severe Thunderstorm Warning	OUN	Coal	47 min
Apr 20, 8:27 PM CDT	Severe Thunderstorm Warning	OUN	Johnston	48 min
Apr 20, 9:12 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Pushmataha	63 min
Apr 20, 10:15 PM CDT	Severe Thunderstorm Warning	OUN	Choctaw	45 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1997 Every severe thunderstorm warning in 1997

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.