Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 455, NWS Norman, OK

June 20, 2001Alfalfa County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jun 20, 2001, 9:59 PM CDT for Alfalfa County, Oklahoma. It was in force for 31 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: Jun 20, 2001, 9:59 PM CDT (02:59 UTC)
Expired: Jun 20, 2001, 10:30 PM CDT
In force: 31 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Alfalfa County, OK

The radar

The Vance AFB radar (KVNX), 18 km from the middle of the area, began a volume at 03:03 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
Jun 20, 10:33 PM CDT	Hail 0.88	Cherokee, 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
Jun 20, 9:00 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Dodge City, (KDDC), launched 00:00Z, 3.0 hours before the alert went out and 181 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: 1362 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 956 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 164 m²/s²
0-3 km storm-relative helicity: 395 m²/s²
Significant tornado parameter: 2.2
Supercell composite: 18.3

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 Jun 20, 9:45 PM CDT, 14 minutes earlier.

Area forecast discussion, Jun 20, 9:45 PM CDT, 14 minutes before

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In the hours before

Local storm report, Jun 20, 9:21 PM CDT, 38 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
Jun 20, 9:12 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Woods	48 min
Jun 20, 9:47 PM CDT	Severe Thunderstorm Warning	OUN	Harper	43 min
Jun 20, 10:28 PM CDT	Severe Thunderstorm Warning	OUN	Ellis, Harper, Woodward	47 min
Jun 20, 10:30 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa	45 min
Jun 21, 2:03 PM CDT	Severe Thunderstorm Warning	OUN	Love	42 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.