Severe Thunderstorm Watch 620

Issued

Sep 5, 2012, 2:43 PM EDT (18:43 UTC)

Expired

Sep 5, 2012, 7:36 PM EDT

In force

5 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The Louisville radar (KLVX), 75 km from the middle of the area, began a volume at 18:46 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.

Two or more tornadoes

10%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

70%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

5%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 1891Sep 5, 2:10 PM EDT
• Mesoscale Discussion 1897Sep 5, 6:31 PM EDT

901 
WWUS20 KWNS 051849
SEL0
SPC WW 051849
ILZ000-INZ000-KYZ000-OHZ000-060300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 620
NWS STORM PREDICTION CENTER NORMAN OK
245 PM EDT WED SEP 5 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

       FAR SOUTHEAST ILLINOIS
       SOUTHEAST INDIANA
       WESTERN AND CENTRAL KENTUCKY
       SOUTHWEST OHIO

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 245 PM UNTIL
1100 PM EDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTHEAST OF
CINCINNATI OHIO TO 30 MILES SOUTHWEST OF BOWLING GREEN KENTUCKY.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 619...

DISCUSSION...STORMS IN SRN IND SQLN LINE SHOULD MOVE GENERALLY
EWD...WITH PREFERRED NEW DEVELOPMENT EXPECTED TO BE TOWARD THE S.
THIS MAY YIELD A ROUGHLY ESE OR SE OVERALL MCS MOTION. DIURNAL
HEATING...PRESENCE OF RICH LOW-LVL MOISTURE AND EWD-MOVING MO/IL UPR
IMPULSE SUGGEST CONTINUED POTENTIAL FOR SMALL BOWS WITH LOCALLY DMGG
WIND/MARGINALLY SVR HAIL. ISOLD STORMS MAY FORM AHEAD OF LINE IF
ELEVATED CONVECTION NOW OVER WRN KY ROOTS INTO THE BOUNDARY
LAYER...AND/OR OTHER STORMS FORM IN WEAKLY CONVERGENT LOW-LVL FLOW
OVER CNTRL KY/SE IND.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 29025.


...CORFIDI

Severe Thunderstorm Watches in Kentucky, 2012Severe Thunderstorm Watches in Ohio, 2012Severe Thunderstorm Watches in Indiana, 2012Every severe thunderstorm watch in 2012

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.