Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 414, NWS Tulsa, OK
NWS Tulsa, OK issued this severe thunderstorm warning at Sep 20, 2001, 10:18 AM CDT for Creek County, Oklahoma. It was in force for 42 min. 1 report came from inside the area while it was in force.
The area
The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.
The facts
- Issued
- Sep 20, 2001, 10:18 AM CDT (15:18 UTC)
- Expired
- Sep 20, 2001, 11:00 AM CDT
- In force
- 42 min
- Issued by
- NWS Tulsa, OK
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Creek County, OK
The radar
The Tulsa radar (KINX), 86 km from the middle of the area, began a volume at 15:20 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 |
|---|---|---|---|
| Sep 20, 10:30 AM CDT | Hail 0.75 | Silver City, 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 nearest sounding before it
Lamont, OK (KLMN), launched 12:00Z, 3.3 hours before the alert went out and 109 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.
- Mixed-layer CAPE
- 85 J/kg
- Mixed-layer CIN
- -382 J/kg
- Mixed-layer LCL
- 1285 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 156 m²/s²
- 0-3 km storm-relative helicity
- 257 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
191 WUUS54 KTSA 201518 SVRTUL OKC037-201600- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TULSA OK 1018 AM CDT THU SEP 20 2001 THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... NORTHWESTERN CREEK COUNTY IN NORTHEAST OKLAHOMA * UNTIL 1100 AM CDT * AT 1018 AM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER OILTON...MOVING SOUTHEAST AT 10 MPH. * SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...DRUMRIGHT AND OILTON. HAIL TO THE SIZE OF DIMES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED IN THE WARNED AREA. LAT...LON 3619 9659 3602 9663 3582 9645 3600 9625
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 Sep 20, 9:05 AM CDT, 1 hour 13 minutes earlier.
Area forecast discussion, Sep 20, 9:05 AM CDT, 1 hour 13 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OK 905 AM CDT THU SEP 20 2001 UPDATED TO RAISE POPS FOR SRN ZONES AND INTRODUCE POPS TO NE OK ESP ACROSS OSAGE...WASHINGTON AND PAWNEE COUNTIES FOR SCATTERED SHRA/TSRA. RADAR OBSERVATIONS SHOW TOUGH LOOKING STORMS HOWEVER VISUAL APPEARANCES FROM KTSA SHOW THE STORMS TO BE HIGH-BASED. EXPECT STORMS TO WEAKEN AND COVERAGE TO DECREASE LATER THIS MORNING WITH FAR SOUTHERN ZONES HAVING LINGERING LIGHT PRECIP THE LONGEST TODAY. MIGHT EVEN DISSIPATE BEFORE IT REACHES WESTCENTRAL AR. NW AR SHOULD REMAIN MOSTLY CLEAR. FCSTID = 26 .TSA... AR...NONE. OK...NONE.
In the hours before
Special weather statement, Sep 20, 6:00 AM CDT, 4 hours 18 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-211200- EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TULSA OK 600 AM CDT THU SEP 20 2001 ...A FEW SEVERE THUNDERSTORMS ARE POSSIBLE TONIGHT ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS... A WARM FRONT ALONG THE RED RIVER WILL PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT THIS MORNING ACROSS CENTRAL AND SOUTHEAST OKLAHOMA. ACTIVITY ALONG THIS FRONT SHOULD DIMINISH BY THIS AFTERNOON. A SURFACE COLD FRONT ACROSS THE HIGH PLAINS OF NEBRASKA AND KANSAS WILL CONTINUE TO PUSH SOUTH DURING THE DAY TODAY. THIS FRONT WILL MOVE INTO NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS AFTER MIDNIGHT. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AND A FEW MAY BE SEVERE PRODUCING DAMAGING WINDS AND HEAVY RAINFALL. .SPOTTER ACTIVATION... SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT ACROSS MAINLY NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. .DISCUSSION... SURFACE HIGH PRESSURE IN MISSOURI WILL MOVE EAST TODAY ALLOWING A DEVELOPING LOW PRESSURE SYSTEM IN THE HIGH PLAINS TO MOVE SOUTHEAST INTO THE REGION TONIGHT. THE CONVECTION ACROSS CENTRAL OKLAHOMA SHOULD STAY TO THE WEST OF THE AREA THIS MORNING. ALTHOUGH SOME THUNDERSTORMS MAY DEVELOP ALONG THE WARM FRONT ACROSS THE RED RIVER THIS AFTERNOON...SEVERE THUNDERSTORMS ARE NOT EXPECTED TO DEVELOP ACROSS SOUTHEAST OKLAHOMA. THE ATMOSPHERE ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS WILL BECOME INCREASINGLY UNSTABLE DURING THE DAY TODAY AS TEMPERATURES CLIMB INTO THE LOWER TO MID 80S. BY THIS EVENING...LIFTED INDEX VALUES WILL BE AROUND -5 C WITH CAPE VALUES FROM 1500 TO 2000 J/KG CREATING A MODERATELY UNSTABLE ATMOSPHERE. THE COLD FRONT SHOULD MOVE INTO THE AREA AFTER MIDNIGHT CAUSING THUNDERSTORMS TO DEVELOP ALONG IT. A FEW THUNDERSTORMS MAY BE SEVERE WITH DAMAGING WINDS AND HEAVY RAINFALL MAINLY ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. THREAT TABLE VALID THROUGH 1200 UTC FRIDAY AREA 1...NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS THUNDERSTORM PROBABILITY...60 SEVERE PROBABILITY IF STORMS OCCUR...40 SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...20 THREAT AREAS DEFINE THE GREATEST RISK. PROBABILITIES ARE IN PERCENT. SIGNIFICANT SEVERE IS DEFINED AS F1 OR GREATER WIND/TORNADO DAMAGE AND/OR GOLFBALL SIZE HAIL OR LARGER. RELATED GRAPHICAL INFORMATION CAN BE FOUND AT... WWW.SRH.NOAA.GOV/TULSA AN UPDATED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AROUND 1 PM TODAY.
Nearby
Severe Thunderstorm Warnings in Oklahoma, 2001Every severe thunderstorm warning in 2001
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.