Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 409, NWS Tulsa, OK

July 1, 1999Tulsa County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Jul 1, 1999, 11:25 AM CDT for Tulsa County, Oklahoma. It was in force for 50 min. 3 reports 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
Jul 1, 1999, 11:25 AM CDT (16:25 UTC)
Expired
Jul 1, 1999, 12:15 PM CDT
In force
50 min
Issued by
NWS Tulsa, OK
Area
Whole counties

County Tulsa County, OK

The radar

The Tulsa radar (KINX), 34 km from the middle of the area, began a volume at 16:29 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

TimeReportWhereRemark
Jul 1, 11:25 AM CDTHail 0.75Collinsville, OKLocation: US Hwy 169 and OK Hwy 20
Jul 1, 11:30 AM CDTHail 0.75Sperry, OK
Jul 1, 11:45 AM CDTHail 0.88Owasso, 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.

IssuedProductOfficeLasted
Jul 1, 8:15 AM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 4.4 hours before the alert went out and 166 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, Norman, OK at 12:00Z on 1999-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 914 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, Norman, OK at 12:00Z on 1999-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 277 square meters per square second.193958Sfc1 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
914 J/kg
Mixed-layer CIN
-447 J/kg
Mixed-layer LCL
769 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
277 m²/s²
0-3 km storm-relative helicity
241 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.

000 
TTAA00 KTUL 011624
SVRTUL
OKC143-011715-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
1125 AM CDT THU JUL 1 1999

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  TULSA COUNTY IN NORTHEAST OKLAHOMA

* UNTIL 1215 PM CDT

* AT 1122 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  CLUSTER OF SEVERE THUNDERSTORMS FROM JUST NORTH OF WESTPORT TO     
  PRUE TO 5 MILES WEST OF SKIATOOK...MOVING SOUTHEAST AT 40 MPH.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...BROKEN        
  ARROW...SPERRY...GLENPOOL...OWASSO...JENKS...BIXBY...SAND SPRINGS  
  AND TULSA INCLUDING THE DOWNTOWN METROPOLITAN AREA.

THIS STORM HAS A HISTORY OF PRODUCING QUARTER SIZE HAIL.  WIND GUSTS 
TO 60 MPH OR GREATER ARE ALSO POSSIBLE.

THIS IS A DANGEROUS STORM. IF YOU ARE NEAR ITS PATH YOU SHOULD
PREPARE FOR VERY LARGE HAIL AND STRONG DAMAGING STRAIGHT LINE WINDS.
S<EEK SHELTER IN A STURDY BUILDING AND STAY AWAY FROM WINDOWS!

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 1, 10:40 AM CDT, 45 minutes earlier.

Area forecast discussion, Jul 1, 10:40 AM CDT, 45 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
1040 AM CDT THU JUL 1 1999

JUST UPDATED THE ZONES AGAIN TO REMOVE 10AM EXPIRATION WATCH.  TWO
STORMS OVER WESTERN OSAGE COUNTY HAVE NOW BECOME ONE AND MAY STILL
PRODUCE SOME PROBLEMS BUT WIDESPREAD ACTIVITY NOT LIKELY SO LET THAT
WATCH GO.  200PM WATCH STILL IN EFFECT AND WILL REQUIRE ANOTHER
UPDATE LATER.  OTHERWISE NO MAJOR CHANGES MADE AT THIS TIME.  LEFT
THE FLASH FLOOD WATCH ALONE FOR NOW.

HOWIESON
FCSTID = 44

.TUL...
AR...FLASH FLOOD WATCH FOR THIS MORNING FOR ZONES ARZ001>002...
ARZ010>011...ARZ019>020...ARZ029.

OK...FLASH FLOOD WATCH FOR THIS MORNING FOR ZONES OKZ054>076.

In the hours before

Special weather statement, Jul 1, 6:10 AM CDT, 5 hours 15 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-021100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
610 AM CDT THU JUL 1 1999

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 AM FOR OSAGE...
   PAWNEE AND CREEK COUNTIES IN NORTHEAST OKLAHOMA...
...A FLASH FLOOD WATCH IS IN EFFECT FOR THIS MORNING FOR MUCH OF
   EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
...A FEW SEVERE THUNDERSTORMS ARE EXPECTED OVER NORTHEAST OKLAHOMA THIS
   MORNING...

.SYNOPSIS...
EARLY THIS MORNING LOW PRESSURE WAS LOCATED OVER THE TEXAS AND OKLAHOMA
PANHANDLES.  A STRONG LOW LEVEL JET HAS DEVELOPED OVERNIGHT OVER THE
SOUTHERN PLAINS AHEAD OF THIS FEATURE.  THIS JET COMBINED WITH
APPROACHING RELATIVELY STRONG WINDS IN THE MID LEVELS OF THE ATMOSPHERE
WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR SEVERE THUNDERSTORMS OVER
NORTHEAST OKLAHOMA THIS MORNING.  WIND FIELDS WILL WEAKEN SOMEWHAT THIS
AFTERNOON AND TONIGHT AND WARMING MID LEVELS OF THE ATMOSPHERE WILL ACT
TO SUPPRESS THE REDEVELOPMENT OF THUNDERSTORMS LATER IN THE DAY AND
OVERNIGHT TONIGHT.

.DISCUSSION...
A COMPLEX OF STRONG TO SEVERE THUNDERSTORMS FORMED OVER SOUTHWEST KANSAS
OVERNIGHT.  THE LEADING EDGE OF THIS COMPLEX OF STORMS IS EXPECTED TO
DEVELOP INTO A SQUALL LINE AND MOVE SOUTHEAST ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS THIS MORNING.  THE THUNDERSTORMS WILL LIKELY
WEAKEN AS THEY CROSS THE AREA.  HOWEVER...THEY WILL LIKELY REMAIN STRONG
ENOUGH TO PRODUCE SOME DAMAGING WINDS AND MARGINALLY SEVERE HAIL ACROSS
NORTHEAST OKLAHOMA . THE STORMS WILL ALSO BRING A PERIOD OF VERY HEAVY
RAINFALL WHICH COMBINED WITH SOILS THAT ARE SATURATED FROM LAST MORNINGS
RAIN COULD RESULT IN FLASH FLOODING.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
CIVIL DEFENSE AGENCIES AND SPOTTER GROUPS OVER NORTHEAST OKLAHOMA SHOULD
BE PREPARED FOR POSSIBLE ACTIVATION THIS MORNING.  INFORMATION
CONCERNING THE DEVELOPMENT OF FLASH FLOODING MAY BE NEEDED OVER THE
WHOLE AREA.
Special weather statement, Jul 1, 6:10 AM CDT, 5 hours 15 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-021100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
610 AM CDT THU JUL 1 1999

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 AM FOR OSAGE...
   PAWNEE AND CREEK COUNTIES IN NORTHEAST OKLAHOMA...
...A FLASH FLOOD WATCH IS IN EFFECT FOR THIS MORNING FOR MUCH OF
   EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
...A FEW SEVERE THUNDERSTORMS ARE EXPECTED OVER NORTHEAST OKLAHOMA THIS
   MORNING...

.SYNOPSIS...
EARLY THIS MORNING LOW PRESSURE WAS LOCATED OVER THE TEXAS AND OKLAHOMA
PANHANDLES.  A STRONG LOW LEVEL JET HAS DEVELOPED OVERNIGHT OVER THE
SOUTHERN PLAINS AHEAD OF THIS FEATURE.  THIS JET COMBINED WITH
APPROACHING RELATIVELY STRONG WINDS IN THE MID LEVELS OF THE ATMOSPHERE
WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR SEVERE THUNDERSTORMS OVER
NORTHEAST OKLAHOMA THIS MORNING.  WIND FIELDS WILL WEAKEN SOMEWHAT THIS
AFTERNOON AND TONIGHT AND WARMING MID LEVELS OF THE ATMOSPHERE WILL ACT
TO SUPPRESS THE REDEVELOPMENT OF THUNDERSTORMS LATER IN THE DAY AND
OVERNIGHT TONIGHT.

.DISCUSSION...
A COMPLEX OF STRONG TO SEVERE THUNDERSTORMS FORMED OVER SOUTHWEST KANSAS
OVERNIGHT.  THE LEADING EDGE OF THIS COMPLEX OF STORMS IS EXPECTED TO
DEVELOP INTO A SQUALL LINE AND MOVE SOUTHEAST ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS THIS MORNING.  THE THUNDERSTORMS WILL LIKELY
WEAKEN AS THEY CROSS THE AREA.  HOWEVER...THEY WILL LIKELY REMAIN STRONG
ENOUGH TO PRODUCE SOME DAMAGING WINDS AND MARGINALLY SEVERE HAIL ACROSS
NORTHEAST OKLAHOMA . THE STORMS WILL ALSO BRING A PERIOD OF VERY HEAVY
RAINFALL WHICH COMBINED WITH SOILS THAT ARE SATURATED FROM LAST MORNINGS
RAIN COULD RESULT IN FLASH FLOODING.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
CIVIL DEFENSE AGENCIES AND SPOTTER GROUPS OVER NORTHEAST OKLAHOMA SHOULD
BE PREPARED FOR POSSIBLE ACTIVATION THIS MORNING.  INFORMATION
CONCERNING THE DEVELOPMENT OF FLASH FLOODING MAY BE NEEDED OVER THE
WHOLE AREA.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 7:42 AM CDTSevere Thunderstorm WarningTSAOsage, Pawnee48 min
Jul 1, 8:13 AM CDTSevere Thunderstorm WarningTSACreek62 min
Jul 1, 8:24 AM CDTSevere Thunderstorm WarningTSAOsage, Pawnee36 min
Jul 1, 8:32 AM CDTSevere Thunderstorm WarningTSATulsa, Washington58 min
Jul 1, 8:53 AM CDTSevere Thunderstorm WarningTSANowata, Rogers52 min
Jul 1, 9:18 AM CDTSevere Thunderstorm WarningTSADelaware, Ottawa42 min
Jul 1, 9:48 AM CDTSevere Thunderstorm WarningTSADelaware, Ottawa42 min
Jul 1, 10:02 AM CDTSevere Thunderstorm WarningTSACherokee43 min
Jul 1, 10:17 AM CDTSevere Thunderstorm WarningTSAAdair43 min
Jul 1, 10:19 AM CDTSevere Thunderstorm WarningTSAOsage41 min
Jul 1, 10:44 AM CDTSevere Thunderstorm WarningTSAPawnee46 min
Jul 1, 10:56 AM CDTSevere Thunderstorm WarningTSAOsage34 min
Jul 1, 11:29 AM CDTSevere Thunderstorm WarningTSAOsage16 min
Jul 1, 11:54 AM CDTSevere Thunderstorm WarningTSARogers, Wagoner51 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1999Every severe thunderstorm warning in 1999

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.