Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 228, NWS Tulsa, OK

July 18, 2002Sequoyah County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Jul 18, 2002, 2:48 PM CDT for Sequoyah County, Oklahoma. It was in force for 42 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
Jul 18, 2002, 2:48 PM CDT (19:48 UTC)
Expired
Jul 18, 2002, 3:30 PM CDT
In force
42 min
Issued by
NWS Tulsa, OK
Area
Counties, with a storm outline in the text

County Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 46 km from the middle of the area, began a volume at 19:49 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 7.8 hours before the alert went out and 175 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 2002-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2076 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 2002-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 134 square meters per square second.1939Sfc1 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
2076 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
601 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.5

Open this sounding in Storm Lab

The text

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

175 
WUUS54 KTSA 181948
SVRTUL
OKC135-182030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
248 PM CDT THU JUL 18 2002

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

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

* UNTIL 330 PM CDT

* AT 248 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 4  
  MILES NORTHWEST OF SALLISAW...MOVING EAST AT 10MPH.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...SALLISAW...
  MULDROW...BRUSHY AND MARBLE CITY.

HAIL TO THE SIZE OF DIMES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED IN
THE WARNED AREA. STAY INDOORS AND AWAY FROM WINDOWS UNTIL THE STORM
HAS PASSED.

LAT...LON 3564 9493 3541 9497 3537 9453 3563 9450

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 Tulsa, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 18, 11:06 AM CDT, 3 hours 42 minutes earlier.

Area forecast discussion, Jul 18, 11:06 AM CDT, 3 hours 42 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OKLAHOMA
1106 AM CDT THU JUL 18 2002

MORNING ANALYSIS SHOWS UPPER TROUGH AT 500 MB EXTENDING FROM CENTRAL
MISSOURI INTO NORTHERN OKLAHOMA. RADAR SHOWED AREA OF SHOWERS AND
THUNDERSTORMS...ASSOCIATED WITH 850 MB WARM ADVECTION AHEAD OF THE
UPPER TROUGH...MOVING EAST ACROSS NORTHWEST ARKANSAS. EXPECT THE
CURRENT CONVECTION TO EVENTUALLY MOVE OFF TO THE EAST THIS
AFTERNOON...BUT SOME REDEVELOPMENT EXPECTED THIS AFTERNOON IN
VICINITY OF UPPER TROUGH.

WILL SEND AN UPDATE BY 1120 AM TO MAKE FIRST PERIOD CHANGES TO POPS
AND TEMPERATURES. WILL KEEP IN CHANCE CATEGORY POPS ACROSS EASTERN
AND SOUTHERN ZONES...AND WILL INSERT SOME LOW POPS ACROSS EXTREME
NORTHEAST OKLAHOMA NEAREST THE DEVELOPING CONVECTION IN SOUTHEAST
KANSAS. WILL ALSO RAISE HIGH TEMPERATURES ACROSS WESTERN PARTS OF
NORTHEAST OKLAHOMA WHERE CURRENT TRENDS SUGGEST READINGS WILL MAKE
LOWER 90S.

NO SIGNIFICANT CHANGES TO LATER PERIODS OF FORECAST.

FCSTID = 9

.TSA...
AR...NONE.
OK...NONE.

In the hours before

Special weather statement, Jul 18, 1:15 PM CDT, 1 hour 33 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-191200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
115 PM CDT THU JUL 18 2002

...SCATTERED THUNDERSTORMS EXPECTED THIS AFTERNOON OVER EXTREME
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...

SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER EXTREME EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS THROUGH THE AFTERNOON...MAINLY TO THE
SOUTH AND EAST OF TULSA. THUNDERSTORMS HAVE DEVELOPED OVER FAR
EASTERN OKLAHOMA EARLY THIS AFTERNOON AS A RESULT OF DAYTIME HEATING
AND THE PRESENCE OF AN UPPER LEVEL TROUGH EXTENDING FROM MISSOURI
INTO NORTHEAST OKLAHOMA. BRIEF HEAVY RAIN AND FREQUENT LIGHTNING WILL
ACCOMPANY STRONGER STORMS. THUNDERSTORMS ARE EXPECTED TO DIMINISH
THIS EVENING WITH LOSS OF DAYTIME HEATING.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 6:36 PM CDTSevere Thunderstorm WarningTSADelaware39 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2002Every severe thunderstorm warning in 2002

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.