Alert archive / Indiana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 233, NWS Louisville, KY

September 20, 2002Crawford County, Harrison County, Indiana

NWS Louisville, KY issued this severe thunderstorm warning at Sep 20, 2002, 2:40 PM EST for Crawford County, Harrison County, Indiana. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 20, 2002, 2:40 PM EST (19:40 UTC)
Expired: Sep 20, 2002, 3:15 PM EST
In force: 35 min
Issued by: NWS Louisville, KY
Area: Counties, with a storm outline in the text

Counties Crawford County, IN, Harrison County, IN

The radar

The Louisville radar (KLVX), 42 km from the middle of the area, began a volume at 19:42 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Sep 20, 11:30 AM EST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 7.7 hours before the alert went out and 237 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: 719 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 749 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 203 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.0

Open this sounding in Storm Lab

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 Louisville, KY wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 20, 2:36 PM EST, 4 minutes earlier.

Area forecast discussion, Sep 20, 2:36 PM EST, 4 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
300 PM EDT FRI SEP 20 2002

LINE OF STG TO SVR STORMS CONTS TO PROGRESS EWD INTO CNTRL KY/SCNTRL
IN THIS AFTN. STORMS WL ENCOUNTER SFC TEMPS IN MID TO UPPER 80S AND
DWPTS ARND 70 RESULTING IN SFC BASED LI VALUES FROM -4 OR -6. THUS
ORGANIZED LINE WL CONT AND EVEN STRENGTHEN WITH EMBEDDED BOWING
SEGMENTS PRODUCING WIND DAMAGE AND PSBLY ISOLD TORNADOES GIVEN MDT
TO STG LOW LVL SPEED SHEAR. TRAILING STRATIFORM RAIN WL THEN LAST A
CPLE HOURS AFTER INITIAL CNVCTV LINE. AHEAD OF THE LINE...SMALL
SCALE N-S ORIENTED CNVRGNC ZONES ARE RESULTING IN BANDS OF SCT
CNVCTN EAST OF I-65 IN CNTRL/E-CNTRL KY. GIVEN PW VALUES AROUND 2
INCHES (VERY HI FOR THIS TIME OF YEAR)...VERY HEAVY RAIN ALSO WL
ACCOMPANY THE STORMS.

MODELS IN GOOD AGREEMENT THAT DEEP LYRD MSTR WL MOVE ACRS OUR AREA
THIS EVNG AND OUT OF FCST AREA BY SAT MRNG. VIS IMAGERY SHOWS SOME
POST FRNTL LOW CLDS BUT THESE SHOULD NOT LINGER TOO LONG...RESULTING
IN MIX OF SUN AND CLDS DURG DAY SAT FROM WEST TO EAST.

ON SUN...AVN DEPICTS CHANNELLED S/WV (JET MAX) ROTATING THRU BROAD
UPR TROF. SINCE LOW-LVL MSTR WL BE SWEPT OUT BY TODAYS SYSTEM AND
GIVEN LACK OF SUFFICIENT BACKING TO FLOW ON SUNDAY...THIS NEXT S/WV
AND ASSOCD CDFNT SHOULD COME THRU DRY WITH JUST SOME CLDS...AS ANY
PRECIP RMNS FARTHER NORTH WITHIN BEST DYNAMICAL FORCING. A SIMILAR
SCENERIO IS PAINTED LATE MON INTO TUES AS ANOTHER S/WV ROTATES THRU
THE TROF WITH SOME CLDS...BUT LIKELY NO PRECIP.

NOT MUCH CHG TO EXTENDED FCST WITH BASICALLY BENIGN WX FCST AT THIS
TIME.

GUIDANCE MOS TEMPS WITHIN REASON...BUT PREFER SLIGHTLY WARMER
MAV/MET DATA AS FWC VALUES HAVE BEEN RUNNING A BIT COOL LATELY.

.SDF...NONE.
TWF

In the hours before

Local storm report, Sep 20, 1:54 PM EST, 46 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE, KY
254 PM EDT FRI SEP 20 2002

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0245 PM    5 E ORLEANS               IN   WIND DAMAGE
09/20/02   ORANGE                         TREES DOWN.

VB

The office that day

Everything else NWS Louisville, KY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 20, 2:01 PM EST	Tornado Warning	LMK	Ohio	29 min
Sep 20, 2:41 PM EST	Severe Thunderstorm Warning	LMK	Breckinridge	34 min
Sep 20, 3:02 PM EST	Severe Thunderstorm Warning	LMK	Meade	28 min
Sep 20, 12:50 PM EST	Severe Thunderstorm Warning	LMK	Dubois	40 min
Sep 20, 1:33 PM EST	Severe Thunderstorm Warning	LMK	Orange	27 min
Sep 20, 1:55 PM EST	Severe Thunderstorm Warning	LMK	Washington	35 min
Sep 20, 2:11 PM EST	Severe Thunderstorm Warning	LMK	Crawford, Orange, Washington	19 min

Nearby

Severe Thunderstorm Warnings in Indiana, 2002 Every 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.