Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 103, NWS Tulsa, OK

April 21, 1999Creek County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Apr 21, 1999, 11:46 PM CDT for Creek County, Oklahoma. It was in force for 44 min. 1 report 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: Apr 21, 1999, 11:46 PM CDT (04:46 UTC)
Expired: Apr 22, 1999, 12:30 AM CDT
In force: 44 min
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Creek County, OK

What was reported inside it

Time	Report	Where	Remark
Apr 22, 12:07 AM CDT	Thunderstorm Wind 52	Mannford, 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.

Issued	Product	Office	Lasted
Apr 21, 6:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 4.8 hours before the alert went out and 120 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: 1907 J/kg
Mixed-layer CIN: -135 J/kg
Mixed-layer LCL: 1058 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 233 m²/s²
0-3 km storm-relative helicity: 210 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 5.5

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Apr 21, 9:33 PM CDT, 2 hours 13 minutes earlier.

Area forecast discussion, Apr 21, 9:33 PM CDT, 2 hours 13 minutes before

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
933 PM CDT WED APR 21 1999

STORMS STILL DEVELOPING ON SW FLANK OF LINE ALONG SURFACE
BOUNDARY FROM NEAR EMPORIA KS TO PONCA CITY BACK TO NEAR
CLINTON. CAP IS WEAKENING STORMS AS THEY MOVE EASTWARD HOWEVER...
AND THERE IS SOME QUESTION ABOUT HOW FAR EAST THEY
WILL MAKE IT. SEVERE WX AND HEAVY RAINFALL A DEFINITE
POSSIBILITY WITH TRAINING STORMS. FOR NOW WILL UP POPS
TO LIKELY IN ZONES W/NW OF TULSA AND INCREASE POPS ELSEWHERE
OVER NE OKLAHOMA. WILL MONITOR RADAR TRENDS AND MAY DECIDE TO
ISSUE FLASH FLOOD WATCH IF HEAVY RAIN LOOKS AS THOUGH IT WILL
MAKE IT INTO WESTERN ZONES.

00Z RUC DEEPENS SURFACE LOW OVER WC OKLAHOMA WITH BOUNDARY EXPECTED
TO REMAIN STATIONARY. CAP IS EXPECTED TO LIMIT CONVECTION IN E/S PART
OF THE AREA OVERNIGHT...SO WILL LEAVE 10-20% POPS THERE. IF ONGOING
PRECIP PERSISTS OUTFLOW BOUNDARY WILL PUSH FURTHER SE THAN RUC SHOWS
SURFACE FEATURES AND COULD BECOME FOCUS FOR DEVELOPMENT LATER TONIGHT
AND THURSDAY. WONT TINKER WITH LATER PERIODS THIS UPDATE BUT MAY
TAKE A LOOK AT OTHER 0Z MODELS AND CHOOSE TO UPDATE AGAIN PRIOR TO
MIDNIGHT. /13

AR...NONE.
OK...TORNADO WATCH UNTIL MIDNIGHT FOR ZONES
OKZ054>055...OKZ059...OKZ064>065.

In the hours before

Local storm report, Apr 21, 10:49 PM CDT, 57 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 10:11 PM CDT	Severe Thunderstorm Warning	TSA	Pawnee	64 min
Apr 21, 10:44 PM CDT	Tornado Warning	TSA	Pawnee	31 min
Apr 21, 10:54 PM CDT	Tornado Warning	TSA	Osage	36 min
Apr 21, 11:29 PM CDT	Severe Thunderstorm Warning	TSA	Pawnee	46 min
Apr 22, 12:07 AM CDT	Severe Thunderstorm Warning	TSA	Osage, Tulsa	53 min
Apr 22, 12:30 AM CDT	Severe Thunderstorm Warning	TSA	Nowata, Rogers, Washington	45 min
Apr 22, 1:03 AM CDT	Severe Thunderstorm Warning	TSA	Craig, Mayes	42 min
Apr 22, 1:22 AM CDT	Severe Thunderstorm Warning	TSA	Delaware, Ottawa	38 min
Apr 22, 3:07 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Washington	38 min
Apr 22, 3:39 PM CDT	Severe Thunderstorm Warning	TSA	Nowata, Washington	36 min
Apr 22, 3:55 PM CDT	Tornado Warning	TSA	Nowata, Washington	35 min
Apr 22, 4:25 PM CDT	Tornado Warning	TSA	Craig	35 min
Apr 22, 4:52 PM CDT	Severe Thunderstorm Warning	TSA	Nowata	38 min
Apr 22, 5:01 PM CDT	Tornado Warning	TSA	Craig	29 min
Apr 22, 5:14 PM CDT	Tornado Warning	TSA	Delaware, Ottawa	46 min
Apr 22, 5:27 PM CDT	Tornado Warning	TSA	Craig	33 min
Apr 22, 5:28 PM CDT	Severe Thunderstorm Warning	TSA	Rogers, Tulsa	47 min
Apr 22, 5:37 PM CDT	Severe Thunderstorm Warning	TSA	Rogers	53 min
Apr 22, 5:55 PM CDT	Severe Thunderstorm Warning	TSA	Mayes, Rogers, Wagoner	50 min
Apr 22, 6:00 PM CDT	Severe Thunderstorm Warning	TSA	Craig, Delaware	45 min
Apr 22, 6:33 PM CDT	Tornado Warning	TSA	Mayes, Rogers, Wagoner	42 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1999 Every 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.