Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 239, NWS Tulsa, OK

August 19, 2012Sequoyah County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Aug 19, 2012, 3:57 PM CDT for Sequoyah County, Oklahoma. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 19, 2012, 3:57 PM CDT (20:57 UTC)
Expired
Aug 19, 2012, 4:30 PM CDT
In force
33 min
Issued by
NWS Tulsa, OK
Area
Storm-based polygon

County Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 38 km from the middle of the area, began a volume at 20:57 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.

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 9.0 hours before the alert went out and 170 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-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2012-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 478 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 2012-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
478 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
975 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

104 
WUUS54 KTSA 192057
SVRTSA
OKC135-192130-
/O.NEW.KTSA.SV.W.0239.120819T2057Z-120819T2130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
357 PM CDT SUN AUG 19 2012

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL SEQUOYAH COUNTY IN EAST CENTRAL OKLAHOMA

* UNTIL 430 PM CDT

* AT 353 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 3 MILES NORTH OF
  BRUSHY...MOVING SOUTH AT 5 MPH.

  STORM HAZARDS INCLUDE...
  WIND GUSTS TO 60 MPH...

* SOME LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE...BRUSHY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PEOPLE OUTSIDE SHOULD MOVE TO A SAFE SHELTER...PREFERABLY INSIDE A
STRONG BUILDING. STAY AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

&&

LAT...LON 3547 9452 3547 9482 3564 9479 3564 9460
TIME...MOT...LOC 2057Z 345DEG 4KT 3559 9472

$$
2 follow-up statements
941 
WWUS54 KTSA 192114
SVSTSA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
414 PM CDT SUN AUG 19 2012

OKC135-192130-
/O.CON.KTSA.SV.W.0239.000000T0000Z-120819T2130Z/
SEQUOYAH OK-
414 PM CDT SUN AUG 19 2012

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM CDT FOR
CENTRAL SEQUOYAH COUNTY...

AT 410 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR BRUSHY...
MOVING SOUTH AT 5 MPH.

STORM HAZARDS INCLUDE...
WIND GUSTS TO 60 MPH...

THIS STORM WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT CLOUD TO GROUND LIGHTNING IS ALSO OCCURRING WITH THIS STORM.
LIGHTNING IS ONE OF NATURES MOST SIGNIFICANT KILLERS. REMAIN INDOORS
AND AWAY FROM WINDOWS. DO NOT USE ELECTRICAL EQUIPMENT OR TAKE A BATH
OR SHOWER DURING A STORM. REMEMBER...IF YOU CAN HEAR THUNDER...YOU
ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

&&

LAT...LON 3561 9479 3561 9459 3547 9452 3547 9482
TIME...MOT...LOC 2114Z 345DEG 4KT 3556 9467

$$
236 
WWUS54 KTSA 192127
SVSTSA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
427 PM CDT SUN AUG 19 2012

OKC135-192137-
/O.EXP.KTSA.SV.W.0239.000000T0000Z-120819T2130Z/
SEQUOYAH OK-
427 PM CDT SUN AUG 19 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL SEQUOYAH COUNTY
EXPIRES AT 430 PM CDT...

THE THUNDERSTORM HAS WEAKENED BELOW SEVERE LIMITS...THEREFORE THE
SEVERE THUNDERSTORM WARNING WILL BE ALLOWED TO EXPIRE.

GUSTY WINDS TO 40 MPH AND VERY HEAVY RAIN WILL STILL BE POSSIBLE 
WITH THIS STORM AS IT MOVES ACROSS EASTERN SEQUOYAH COUNTY.

LAT...LON 3561 9479 3561 9459 3547 9452 3547 9482
TIME...MOT...LOC 2127Z 345DEG 4KT 3555 9467

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 2:33 PM CDTSpecial Weather StatementTSACherokee27 min
Aug 19, 2:57 PM CDTSpecial Weather StatementTSAAdair, Cherokee33 min
Aug 19, 3:21 PM CDTSpecial Weather StatementTSAAdair, Cherokee24 min
Aug 19, 3:30 PM CDTSpecial Weather StatementTSASequoyah30 min
Aug 19, 3:43 PM CDTSpecial Weather StatementTSAWagoner32 min
Aug 19, 4:26 PM CDTSpecial Weather StatementTSASequoyah34 min
Aug 19, 5:43 PM CDTSpecial Weather StatementTSAHaskell32 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2012Every severe thunderstorm warning in 2012

Sources

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