Alert archive / Arkansas / Tornado Warnings in 2009

Tornado Warning 33, NWS Tulsa, OK

August 20, 2009Benton County, Arkansas

NWS Tulsa, OK issued this tornado warning at Aug 20, 2009, 3:31 AM CDT for Benton County, Arkansas. It was in force for 29 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 20, 2009, 3:31 AM CDT (08:31 UTC)
Expired: Aug 20, 2009, 4:00 AM CDT
In force: 29 min
Issued by: NWS Tulsa, OK
Area: Storm-based polygon

County Benton County, AR

The radar

The Springfield radar (KSGF), 120 km from the middle of the area, began a volume at 08:31 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
Aug 20, 3:45 AM CDT	HAIL 0.88	Bentonville, AR

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Aug 19, 8:48 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 8.5 hours before the alert went out and 69 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: 14 J/kg
Mixed-layer CIN: -250 J/kg
Mixed-layer LCL: 1306 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 154 m²/s²
0-3 km storm-relative helicity: 363 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WFUS54 KTSA 200831
TORTSA
ARC007-200900-
/O.NEW.KTSA.TO.W.0033.090820T0831Z-090820T0900Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TULSA OK
331 AM CDT THU AUG 20 2009

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN BENTON COUNTY IN NORTHWEST ARKANSAS

* UNTIL 400 AM CDT

* AT 331 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 2 MILES
  SOUTHEAST OF GRAVETTE...MOVING EAST AT 35 MPH.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...HIWASSE...
  HIGHFILL...BELLA VISTA AND BENTONVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE NEAR THE PATH OF THIS STORM...TAKE COVER NOW IF NO
UNDERGROUND SHELTER IS AVAILABLE MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR. MOBILE HOMES AND VEHICLES SHOULD BE ABANDONED FOR MORE
SUBSTANTIAL SHELTER. AVOID WINDOWS

&&

LAT...LON 3639 9396 3625 9435 3637 9456 3650 9445
      3650 9423
TIME...MOT...LOC 0831Z 290DEG 29KT 3641 9441

$$

2 follow-up statements

000 
WWUS54 KTSA 200839
SVSTSA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
339 AM CDT THU AUG 20 2009

ARC007-200900-
/O.CON.KTSA.TO.W.0033.000000T0000Z-090820T0900Z/
BENTON AR-
339 AM CDT THU AUG 20 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 400 AM CDT FOR CENTRAL
BENTON COUNTY...

AT 336 AM CDT...WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS STORM WAS
LOCATED NEAR VAUGHN...MOVING SOUTHEAST AT 40 MPH.

SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...BENTONVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE NEAR THE PATH OF THIS STORM...TAKE COVER NOW IF NO
UNDERGROUND SHELTER IS AVAILABLE MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR. MOBILE HOMES AND VEHICLES SHOULD BE ABANDONED FOR MORE
SUBSTANTIAL SHELTER. AVOID WINDOWS

&&

LAT...LON 3636 9446 3642 9429 3639 9396 3625 9435
TIME...MOT...LOC 0839Z 306DEG 36KT 3632 9431

$$

000 
WWUS54 KTSA 200851
SVSTSA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
351 AM CDT THU AUG 20 2009

ARC007-200901-
/O.EXP.KTSA.TO.W.0033.000000T0000Z-090820T0900Z/
BENTON AR-
351 AM CDT THU AUG 20 2009

...THE TORNADO WARNING FOR CENTRAL BENTON COUNTY EXPIRES AT 400 AM
CDT...

THE THUNDERSTORM HAS MOVED OUT OF THE WARNED AREA AND WEAKENED BELOW
SEVERE LIMITS...THEREFORE THE TORNADO WARNING WILL BE ALLOWED TO
EXPIRE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 400 AM CDT.

LAT...LON 3636 9446 3642 9429 3639 9396 3625 9435
TIME...MOT...LOC 0851Z 306DEG 36KT 3625 9419

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 12:18 AM CDT	Special Weather Statement	TSA	Carroll	57 min
Aug 20, 3:03 AM CDT	Severe Thunderstorm Warning	TSA	Benton	57 min
Aug 20, 3:25 AM CDT	Special Weather Statement	TSA	Carroll, Madison	65 min
Aug 20, 4:00 AM CDT	Severe Thunderstorm Warning	TSA	Benton, Carroll, Madison, Washington	9 min
Aug 20, 5:39 AM CDT	Severe Thunderstorm Warning	TSA	Crawford, Sebastian	66 min
Aug 20, 6:17 AM CDT	Severe Thunderstorm Warning	TSA	Crawford, Franklin, Sebastian	58 min
Aug 20, 6:43 AM CDT	Severe Thunderstorm Warning	TSA	Crawford, Franklin, Sebastian	62 min
Aug 20, 7:26 AM CDT	Areal Flood Advisory	TSA	Crawford, Franklin, Sebastian	2 hr
Aug 20, 8:50 AM CDT	Flash Flood Warning	TSA	Sebastian	5 hr

Nearby

Tornado Warnings in Arkansas, 2009 Every tornado warning in 2009 Tornadoes in 2009

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.