Tornado and Flash Flooding in Oklahoma, September 20, 2001

Name: Tornado and Flash Flooding in Oklahoma, September 20, 2001
Start: 2001-09-20T04:00
End: 2001-09-20T22:25
Location: Oklahoma

September 20, 2001 · NWS OUN · 23 events in 13 counties and zones

15 hail, 4 lightning, 2 flash flood, 1 thunderstorm wind, 1 tornado, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $185,000
Crop damage: None recorded
Events: 23

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What forecasters said that day

The local office's own words before the first event, 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 the first event at Sep 20, 3:10 AM CST, 50 minutes earlier.

Area forecast discussion, Sep 20, 3:10 AM CST, 50 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
410 AM CDT THU SEP 20 2001

A FEW SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED OVERNIGHT IN A
MODEST WARM-AIR ADVECTION ZONE.  SIMILAR DEVELOPMENT SEEMS LIKELY
THROUGHOUT THE DAY IN THE CENTRAL AND SOUTHERN PART OF OUR FORECAST
AREA.  COVERAGE SHOULD BE LOW ENOUGH SO THAT CHANCE POPS WILL BE
SUFFICIENT.

BY LATE AFTERNOON... ALL INDICATIONS POINT TO A STRONG LINE OF
STORMS FORMING ALONG A COLD FRONT THAT WILL JUST BE APPROACHING THE
NORTHWEST TIP OF OUR FORECAST AREA.  WILL MENTION THE POSSIBILITY OF
SEVERE STORMS LATE THIS AFTERNOON AND/OR THIS EVENING ACROSS THE
NORTHWEST THIRD OF THE AREA.  THE STORMS ARE EXPECTED TO TRACK
EAST-SOUTHEAST AND SHOULD AFFECT MUCH OF THE NORTHERN PART OF THE
AREA... WHERE LIKELY POPS WILL BE USED.

THERE IS A BIT OF A RESPITE IN THE NORTH AND EAST SECTIONS FRIDAY
NIGHT INTO SATURDAY BEFORE SOMETHING HAPPENS ON SUNDAY.  EXACTLY
WHAT THAT MAY BE IS NOT CLEAR AT THIS POINT.  ABOUT HALF THE
MEDIUM-RANGE MODELS PORTRAY A MILDLY COOL AIRMASS RIDGING INTO THE
AREA FROM THE UPPER MIDWEST.  THE OTHER HALF... ONCE AGAIN INCLUDING
THE AVN/MRF... CRANK UP A HORRIFIC 500 MB LOW OVER ILLINOIS AND
INDIANA... AND PLUNGE MUCH-COLDER-THAN-NORMAL AIR DOWN THE PLAINS.
AT THIS POINT... THE EXISTING FORECAST LOOKS LIKE IT SIDES SOMEWHAT
WITH THE MILDER SOLUTION... WHICH IS THE COURSE THAT SEEMS MOST
REASONABLE AT THIS TIME.  IF THE MRF TURNS OUT TO BE RIGHT...
TEMPERATURES EARLY NEXT WEEK WILL BE ABOUT 15 DEGREES BELOW NORMAL.

WHETHER THE FRONT ON SUNDAY IS A MINOR COOL-DOWN OR A VIRTUAL
BLUE-NORTHER... IT APPEARS THAT IT SHOULD SEND UP ANOTHER ROUND OF
THUNDERSTORMS... SO THAT HAS BEEN RETAINED/EXPANDED FOR SATURDAY
NIGHT THROUGH SUNDAY NIGHT.

FCSTID = 23 = CMS

OKC   84  63  80  62 /  30  40  30  10
HBR   85  62  83  61 /  30  40  30  20
SPS   86  66  84  63 /  30  20  40  30
GAG   87  58  83  56 /  40  60  20  10
PNC   85  61  80  60 /  20  60  20   0
DUA   84  65  81  64 /  30  30  40  10

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

The radar

The Norman radar (KTLX), 27 km away, was scanning. The volume nearest the first event began at 10:10 UTC.

Open the radar archive at this moment

Event by event

15 hail, 4 lightning, 2 flash flood, 1 thunderstorm wind, 1 tornado. Local standard time, as filed.

Lightning, Oklahoma

When: September 20, 4:00 AM CST
Where: Oklahoma County, Oklahoma City
Property damage: $5,000
Reported by: NEWSPAPER
Coordinates: 35.552, -97.407 (the zone’s center; the record gives no point)

Lightning struck an oil pump tank battery on South High, damaging the saltwater container.

Lightning, Oklahoma

When: September 20, 4:00 AM CST
Where: Oklahoma County, Oklahoma City
Reported by: NEWSPAPER
Coordinates: 35.552, -97.407 (the zone’s center; the record gives no point)

Lightning struck a house chimney in the 1100 block of Southwest 1st, but no damage was reported.

Hail, Oklahoma

When: September 20, 4:10 AM CST
Where: Oklahoma County, Oklahoma City
Measured: 1 in hail
Reported by: EMERGENCY MANAGER
Coordinates: 35.483, -97.533

Hail was reported near the intersection of Northwest Expressway and Portland.

Thunderstorm Wind, Canadian

When: September 20, 4:15 AM CST
Where: Canadian County, 7 mi NE of El Reno
Property damage: $10
Reported by: GENERAL PUBLIC
Coordinates: 35.600, -97.883

Six-inch diameter limbs from a sycamore tree were downed.

Lightning, Oklahoma

When: September 20, 5:45 AM CST
Where: Oklahoma County, Oklahoma City
Reported by: NEWSPAPER
Coordinates: 35.552, -97.407 (the zone’s center; the record gives no point)

Lightning struck a ventilation tube on top of an oil tank battery on Crossroads Boulevard.

Lightning, Cleveland

When: September 20, 6:00 AM CST
Where: Cleveland County, Norman
Property damage: $180,000
Reported by: NEWSPAPER
Coordinates: 35.203, -97.326 (the zone’s center; the record gives no point)

A house on Tarkington Drive was struck by lightning and completely burned.

Flash Flood, Carter

When: September 20, 8:10 AM CST
Where: Carter County, Ardmore
Reported by: LAW ENFORCEMENT
Coordinates: 34.251, -97.286 (the zone’s center; the record gives no point)

Water, to a depth of 1.5 feet, was reported in a residential area.

Flash Flood, Johnston

When: September 20, 8:19 AM CST
Where: Johnston County, Tishomingo
Reported by: LAW ENFORCEMENT
Coordinates: 34.317, -96.661 (the zone’s center; the record gives no point)

A residential street was closed due to high water.

Hail, Noble

When: September 20, 9:53 AM CST
Where: Noble County, 8 mi E of Marland
Measured: 0.75 in hail
Reported by: GENERAL PUBLIC
Coordinates: 36.567, -97.000

Hail, Grady

When: September 20, 1:50 PM CST
Where: Grady County, Ninnekah
Measured: 0.75 in hail
Reported by: LAW ENFORCEMENT
Coordinates: 34.950, -97.917

Hail, Woods

When: September 20, 4:17 PM CST
Where: Woods County, 13 mi NNE of Camp Houston
Measured: 0.88 in hail
Reported by: GENERAL PUBLIC
Coordinates: 36.983, -99.033

Hail, Woods

When: September 20, 4:45 PM CST
Where: Woods County, 12 mi N of Camp Houston
Measured: 1.75 in hail
Reported by: GENERAL PUBLIC
Coordinates: 36.983, -99.117

Tornado, Woods

When: September 20, 5:20 PM CST to 5:23 PM CST
Where: Woods County, 7 mi N of Camp Houston
Rating: F0
Path length: 0.1 mi
Path width: 25 yd
Reported by: STORM CHASER
Coordinates: 36.917, -99.117

This tornado caused no damage as it remained nearly stationary, north of Camp Houston.

Hail, Woods

When: September 20, 5:25 PM CST
Where: Woods County, 4 mi NNW of Plainview
Measured: 0.75 in hail
Reported by: GENERAL PUBLIC
Coordinates: 36.883, -99.267

Hail, Woods

When: September 20, 5:45 PM CST
Where: Woods County, 2 mi W of Plainview
Measured: 3 in hail
Reported by: STORM CHASER
Coordinates: 36.833, -99.267

Hail, Harper

When: September 20, 6:10 PM CST
Where: Harper County, 11 mi E of Buffalo
Measured: 2 in hail
Reported by: STORM CHASER
Coordinates: 36.833, -99.417

Hail, Harper

When: September 20, 6:40 PM CST
Where: Harper County, 10 mi E of Buffalo
Measured: 1.25 in hail
Reported by: STORM CHASER
Coordinates: 36.833, -99.433

Hail, Harper

When: September 20, 6:48 PM CST
Where: Harper County, 3 mi E of Buffalo
Measured: 0.75 in hail
Reported by: GENERAL PUBLIC
Coordinates: 36.833, -99.567

Hail, Woodward

When: September 20, 7:15 PM CST
Where: Woodward County, 5 mi N of Woodward
Measured: 1 in hail
Reported by: STORM CHASER
Coordinates: 36.500, -99.400

Hail, Woodward

When: September 20, 8:00 PM CST
Where: Woodward County, 9 mi SSW of Woodward
Measured: 0.75 in hail
Reported by: GENERAL PUBLIC
Coordinates: 36.317, -99.467

Hail, Blaine

When: September 20, 9:35 PM CST
Where: Blaine County, 4 mi W of Watonga
Measured: 0.88 in hail
Reported by: LAW ENFORCEMENT
Coordinates: 35.850, -98.483

Hail, Garfield

When: September 20, 9:45 PM CST
Where: Garfield County, Garber
Measured: 1 in hail
Reported by: EMERGENCY MANAGER
Coordinates: 36.433, -97.583

Hail, Kingfisher

When: September 20, 10:25 PM CST
Where: Kingfisher County, Dover
Measured: 0.88 in hail
Reported by: EMERGENCY MANAGER
Coordinates: 35.983, -97.917

What these are

Lightning: A lightning strike that killed, injured or caused damage.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Oklahoma in 2001 Every state in 2001 This day in weather history The tornado archive for Oklahoma, 2001 Warnings in Oklahoma, September 2001

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5263564, 5263566, 5263452, 5263453, 5263565, 5263567, 5263454, 5263455, 5263456, 5263457, 5263458, 5263552, 5263553, 5263554, 5263555, 5263556, 5263558, 5263557, 5263559, 5263560, 5263561, 5263562, 5263563.