Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 321, NWS Norman, OK

May 17, 1999Cleveland County, McClain County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at May 17, 1999, 2:15 AM CDT for Cleveland County, McClain County, Oklahoma. It was in force for 45 min. 3 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: May 17, 1999, 2:15 AM CDT (07:15 UTC)
Expired: May 17, 1999, 3:00 AM CDT
In force: 45 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Cleveland County, OK, McClain County, OK

The radar

The Norman radar (KTLX), 27 km from the middle of the area, began a volume at 07:19 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	Remark
May 17, 2:29 AM CDT	Hail 1.75	Norman, OK	Hail was reported on the University of Oklahoma campus.
May 17, 2:30 AM CDT	Hail 1.75	Goldsby, OK
May 17, 2:30 AM CDT	Thunderstorm Wind 56	Goldsby, 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
May 16, 10:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 7.3 hours before the alert went out and 13 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: 3513 J/kg
Mixed-layer CIN: -76 J/kg
Mixed-layer LCL: 880 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 8.9

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 May 16, 4:00 PM CDT, 10 hours 15 minutes earlier.

Area forecast discussion, May 16, 4:00 PM CDT, 10 hours 15 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
400 PM CDT SUN MAY 16 1999

WEAK SHORT WAVE MOVING THROUGH SOUTHWEST TEXAS THIS AFTERNOON
COMBINED WITH STRONG HEATING MAY LEAD TO A FEW THUNDERSTORMS
DEVELOPING ALONG THE DRYLINE IN WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS DURING THE LATE AFTERNOON AND EVENING HOURS... AS PER WW 274.
SURFACE MOISTURE CONVERGENCE HAS MAINTAINED A LOCAL MAX IN THIS
AREA. SOUTHWEST WINDS AHEAD OF THE DRYLINE IN NORTHWEST OKLAHOMA HAS
RESULTED IN WEAKER SURFACE CONVERGENCE IN THIS AREA. MEANWHILE... A
COLD FRONT IN THE OKLAHOMA PANHANDLE IS EXPECTED TO MOVE INTO
NORTHWEST OKLAHOMA LATER TONIGHT. THUNDERSTORMS ARE ALSO EXPECTED TO
DEVELOP ALONG THE FRONT AND SPREAD SOUTHEAST. ETA IS INDICATING A
FAVORABLE JUXTAPOSITION OF UPPER LEVEL JET STREAKS ACROSS THE CWA
LATE TONIGHT... LEADING TO UPPER LEVEL DIVERGENCE. MODELS SEEM TO
USE RESULTING LIFT TO WEAKEN THE CAP A BIT OVER THE AREA. THUS COULD
ALSO SEE A FEW THUNDERSTORMS DEVELOP LATE AHEAD OF THE COLD FRONT.
MOST OF THE THUNDERSTORMS EXPECTED TO BE IN THE SOUTHEAST BY MONDAY
AFTERNOON WITH DRY WEATHER IN THE AREA BY TUESDAY. WILL MAINTAIN A
CHANCE FOR MORE THUNDERSTORMS ON THURSDAY WITH ANOTHER WAVE MOVING
ACROSS THE AREA.

FCSTID = 32
OKC   68  78  56  80 /  50  60  10   0
HBR   66  81  55  83 /  50  50  10   0
SPS   69  81  57  83 /  50  60  20   0
GAG   61  71  50  79 /  40  20  10   0
PNC   68  76  55  78 /  50  50  10   0
DUA   71  80  59  82 /  40  60  30  10

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

In the hours before

Local storm report, May 16, 11:50 PM CDT, 2 hours 25 minutes before

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Local storm report, May 16, 11:50 PM CDT, 2 hours 25 minutes before

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Local storm report, May 17, 12:45 AM CDT, 1 hour 30 minutes before

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Local storm report, May 17, 12:45 AM CDT, 1 hour 30 minutes before

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Special weather statement, May 17, 2:05 AM CDT, 10 minutes before

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Special weather statement, May 17, 2:05 AM CDT, 10 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
May 16, 7:03 PM CDT	Severe Thunderstorm Warning	OUN	Harmon	42 min
May 16, 7:03 PM CDT	Severe Thunderstorm Warning	OUN	Greer	42 min
May 16, 7:15 PM CDT	Severe Thunderstorm Warning	OUN	Dewey, Major, Woods, Woodward	45 min
May 16, 7:20 PM CDT	Severe Thunderstorm Warning	OUN	Beckham	55 min
May 16, 7:38 PM CDT	Severe Thunderstorm Warning	OUN	Roger Mills	52 min
May 16, 8:15 PM CDT	Severe Thunderstorm Warning	OUN	Beckham	45 min
May 16, 8:25 PM CDT	Severe Thunderstorm Warning	OUN	Woods, Woodward	50 min
May 16, 8:30 PM CDT	Severe Thunderstorm Warning	OUN	Custer, Dewey, Roger Mills	45 min
May 16, 8:41 PM CDT	Severe Thunderstorm Warning	OUN	Washita	49 min
May 16, 9:01 PM CDT	Severe Thunderstorm Warning	OUN	Tillman	59 min
May 16, 9:10 PM CDT	Severe Thunderstorm Warning	OUN	Custer	50 min
May 16, 9:14 PM CDT	Tornado Warning	OUN	Woods	31 min
May 16, 9:21 PM CDT	Severe Thunderstorm Warning	OUN	Blaine	39 min
May 16, 9:22 PM CDT	Severe Thunderstorm Warning	OUN	Woodward	68 min
May 16, 9:35 PM CDT	Severe Thunderstorm Warning	OUN	Woods	40 min
May 16, 10:02 PM CDT	Severe Thunderstorm Warning	OUN	Tillman	43 min
May 16, 10:07 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Caddo, Canadian, Grady	53 min
May 16, 10:07 PM CDT	Severe Thunderstorm Warning	OUN	Garfield, Kingfisher, Major	53 min
May 16, 10:13 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton	47 min
May 16, 10:22 PM CDT	Severe Thunderstorm Warning	OUN	Tillman	53 min
May 16, 10:45 PM CDT	Severe Thunderstorm Warning	OUN	Stephens	60 min
May 16, 10:54 PM CDT	Severe Thunderstorm Warning	OUN	Oklahoma	66 min
May 16, 11:00 PM CDT	Severe Thunderstorm Warning	OUN	Grady	45 min
May 16, 11:09 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton	51 min
May 16, 11:15 PM CDT	Severe Thunderstorm Warning	OUN	Kay, Noble	45 min
May 16, 11:43 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson, Stephens	47 min
May 16, 11:56 PM CDT	Severe Thunderstorm Warning	OUN	Cotton	34 min
May 17, 12:17 AM CDT	Severe Thunderstorm Warning	OUN	Pontotoc, Pottawatomie, Seminole	28 min
May 17, 12:17 AM CDT	Severe Thunderstorm Warning	OUN	Murray	28 min
May 17, 12:26 AM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray	34 min
May 17, 12:40 AM CDT	Severe Thunderstorm Warning	OUN	Murray, Pontotoc	50 min
May 17, 12:40 AM CDT	Severe Thunderstorm Warning	OUN	Hughes, Seminole	50 min
May 17, 1:06 AM CDT	Severe Thunderstorm Warning	OUN	Blaine, Caddo	39 min
May 17, 1:42 AM CDT	Severe Thunderstorm Warning	OUN	Blaine, Canadian	48 min
May 17, 2:27 AM CDT	Severe Thunderstorm Warning	OUN	Canadian	48 min
May 17, 2:41 AM CDT	Severe Thunderstorm Warning	OUN	Blaine, Kingfisher	49 min
May 17, 3:21 AM CDT	Severe Thunderstorm Warning	OUN	Lincoln	39 min
May 17, 3:27 AM CDT	Severe Thunderstorm Warning	OUN	Kingfisher, Logan, Oklahoma	33 min
May 17, 3:27 AM CDT	Severe Thunderstorm Warning	OUN	Garfield	33 min
May 17, 3:56 AM CDT	Severe Thunderstorm Warning	OUN	Garfield	49 min
May 17, 12:34 PM CDT	Severe Thunderstorm Warning	OUN	Bryan	56 min
May 17, 2:12 PM CDT	Severe Thunderstorm Warning	OUN	Bryan	48 min
May 17, 2:31 PM CDT	Severe Thunderstorm Warning	OUN	Atoka	44 min
May 16, 7:54 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Hardeman	51 min
May 16, 8:37 PM CDT	Tornado Warning	OUN	Foard, Hardeman, Wilbarger	38 min
May 16, 9:18 PM CDT	Severe Thunderstorm Warning	OUN	Wilbarger	42 min
May 16, 9:25 PM CDT	Severe Thunderstorm Warning	OUN	Foard	50 min
May 16, 9:43 PM CDT	Severe Thunderstorm Warning	OUN	Wilbarger	47 min
May 16, 10:16 PM CDT	Severe Thunderstorm Warning	OUN	Foard	44 min
May 16, 10:29 PM CDT	Severe Thunderstorm Warning	OUN	Wilbarger	46 min
May 16, 10:36 PM CDT	Flash Flood Warning	OUN	Foard, Wilbarger	3 hr
May 16, 11:12 PM CDT	Severe Thunderstorm Warning	OUN	Wichita, Wilbarger	48 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1999 Every severe thunderstorm warning in 1999

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.