Alert archive / Kansas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 237

May 4, 201213 counties in Kansas

The Storm Prediction Center issued this severe thunderstorm watch at May 4, 2012, 1:43 AM CDT for 13 counties in Kansas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 4, 2012, 1:43 AM CDT (06:43 UTC)
Expired
May 4, 2012, 4:12 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
65 kt

Counties Butler County, KS, Chase County, KS, Chautauqua County, KS, Cowley County, KS, Elk County, KS, Greenwood County, KS, Harvey County, KS, Kingman County, KS, Marion County, KS, McPherson County, KS, Reno County, KS, Sedgwick County, KS, Sumner County, KS

The radar

The Wichita radar (KICT), 45 km from the middle of the area, began a volume at 06:45 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 4, 3:08 AM CDTSevere Thunderstorm WarningICTButler, Greenwood52 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lamont, OK (KLMN), launched 00:00Z, 6.7 hours before the alert went out and 159 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, Lamont, OK at 00:00Z on 2012-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3670 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, Lamont, OK at 00:00Z on 2012-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 189 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
3670 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1544 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
189 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
1.1
Supercell composite
20.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

913 
WWUS20 KWNS 040645
SEL7
SPC WW 040645
KSZ000-041000-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 237
NWS STORM PREDICTION CENTER NORMAN OK
140 AM CDT FRI MAY 4 2012

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

       SOUTH CENTRAL KANSAS

EFFECTIVE THIS FRIDAY MORNING FROM 140 AM UNTIL 500 AM CDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTHEAST OF
HUTCHINSON KANSAS TO 40 MILES SOUTHEAST OF WICHITA KANSAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU7).

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...THIS SEVERE THUNDERSTORM WATCH REPLACES
TORNADO WATCH NUMBER 234. WATCH NUMBER 234 WILL NOT BE IN EFFECT
AFTER 140 AM CDT. CONTINUE...WW 235...WW 236...

DISCUSSION...CONCENTRATED AREA OF INTENSE CONVECTION HAS EVOLVED
OVER THE PAST 90 MINUTES OVER S CNTRL KS...ALONG NRN FRINGE OF RICH
MOIST AXIS.  SIZABLE NATURE OF THE LOFTED PRECIP AREA...QUALITY OF
MOISTURE INFLOW /PW > 1.10 INCH/...AND STRENGTH OF LLJ /45+ KTS/
SUGGEST POTENTIAL FOR DMGG PRECIP-ENHANCED DOWNDRAFTS.  THE STORMS
MAY EVOLVE INTO A SMALL FORWARD-PROPAGATING CLUSTER THAT EXTENDS THE
SVR THREAT GENERALLY E ACROSS THE REMAINDER OF S CNTRL KS.
MARGINALLY SVR HAIL ALSO MAY OCCUR.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 27025.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 3, 7:09 PM CDTTornado WatchSPCDoniphan6 hr
May 3, 11:18 PM CDTMesoscale DiscussionSPCDoniphan27 min
May 4, 12:20 AM CDTMesoscale DiscussionSPCBarber, Clark, Comanche, Edwards, Harper, Harvey and 6 more55 min
May 4, 12:53 AM CDTSevere Thunderstorm WatchSPCDoniphan4 hr

Nearby

Severe Thunderstorm Watches in Kansas, 2012Every severe thunderstorm watch in 2012

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.