Alert archive / Missouri / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 649

September 25, 201214 counties in Kansas; 18 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Sep 25, 2012, 5:46 PM CDT for 14 counties in Kansas; 18 counties in Missouri. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Sep 25, 2012, 5:46 PM CDT (22:46 UTC)
Expired
Sep 25, 2012, 9:59 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 32 counties

Allen County, KS, Bourbon County, KS, Butler County, KS, Chautauqua County, KS, Cherokee County, KS, Cowley County, KS, Crawford County, KS, Elk County, KS, Greenwood County, KS, Labette County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Woodson County, KS, Barton County, MO, Benton County, MO, Camden County, MO, Cedar County, MO, Dade County, MO, Dallas County, MO, Dent County, MO, Hickory County, MO, Jasper County, MO, Laclede County, MO, Maries County, MO, Miller County, MO, Morgan County, MO, Phelps County, MO, Polk County, MO, Pulaski County, MO, St. Clair County, MO, Vernon County, MO

The radar

The Pleasant Hill radar (KEAX), 122 km from the middle of the area, began a volume at 22:46 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.

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
30%
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
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 25, 5:55 PM CDTSevere Thunderstorm WarningICTButler, Cowley, Greenwood35 min
Sep 25, 6:23 PM CDTSevere Thunderstorm WarningICTAllen37 min
Sep 25, 6:28 PM CDTSevere Thunderstorm WarningSGFBourbon32 min
Sep 25, 6:31 PM CDTSevere Thunderstorm WarningICTButler, Elk, Greenwood44 min
Sep 25, 6:57 PM CDTSevere Thunderstorm WarningICTAllen21 min
Sep 25, 7:09 PM CDTSevere Thunderstorm WarningICTGreenwood, Wilson, Woodson36 min
Sep 25, 7:38 PM CDTSevere Thunderstorm WarningICTAllen, Neosho, Wilson, Woodson52 min
Sep 25, 7:48 PM CDTFlash Flood WarningSGFBourbon6 hr
Sep 25, 8:08 PM CDTSevere Thunderstorm WarningSGFBourbon, Crawford67 min
Sep 25, 8:26 PM CDTSevere Thunderstorm WarningICTNeosho34 min
Sep 25, 8:33 PM CDTSevere Thunderstorm WarningSGFVernon42 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

Springfield, MO (KSGF), launched 12:00Z, 10.8 hours before the alert went out and 135 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, Springfield, MO at 12:00Z on 2012-09-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 735 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, Springfield, MO at 12:00Z on 2012-09-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 140 square meters per square second.19395878Sfc1 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
735 J/kg
Mixed-layer CIN
-246 J/kg
Mixed-layer LCL
1553 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
140 m²/s²
0-3 km storm-relative helicity
252 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

516 
WWUS20 KWNS 252246
SEL9
SPC WW 252246
KSZ000-MOZ000-260400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 649
NWS STORM PREDICTION CENTER NORMAN OK
550 PM CDT TUE SEP 25 2012

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

       SOUTHEAST KANSAS
       SOUTHWEST AND CENTRAL MISSOURI

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 550 PM UNTIL
1100 PM CDT.

HAIL TO 2 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 25
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 90 MILES WEST OF
CHANUTE KANSAS TO 30 MILES SOUTHEAST OF VICHY MISSOURI.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU9).

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 648...

DISCUSSION...A BROKEN BAND OF STORMS WILL LIKELY INCREASE IN
COVERAGE THIS EVENING...ALONG THE INSTABILITY GRADIENT AND A WEAK
SURFACE BOUNDARY.  DEEP-LAYER VERTICAL SHEAR SUPPORTS PRIMARILY
MULTICELL STORMS...BUT THE STEEP LAPSE RATES/MODERATE CAPE WILL
FAVOR BOTH LARGE HAIL PRODUCTION IN THE STRONGEST UPDRAFTS...AS WELL
AS THE RISK FOR DAMAGING DOWNBURSTS/OUTFLOW FOR THE NEXT FEW HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 28020.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 25, 3:22 PM CDTMesoscale DiscussionSPCBarber, Comanche, Harper53 min
Sep 25, 4:47 PM CDTMesoscale DiscussionSPCAllen, Anderson, Barber, Bourbon, Butler, Chautauqua and 16 more88 min
Sep 25, 12:51 AM CDTMesoscale DiscussionSPCAdair, Audrain, Boone, Caldwell, Callaway, Carroll and 26 more114 min
Sep 25, 12:59 PM CDTMesoscale DiscussionSPCCrawford, Dent, Franklin, Gasconade, Jefferson, Lincoln and 13 more61 min
Sep 25, 5:05 PM CDTSevere Thunderstorm WatchSPCBoone, Callaway, Cole, Crawford, Franklin, Gasconade and 11 more6 hr
Sep 25, 6:57 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Jefferson, Saint Charles, Sainte Genevieve, Saint Louis and 3 more93 min

Nearby

Severe Thunderstorm Watches in Missouri, 2012Severe 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.