Alert archive / Missouri / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 196

April 27, 20126 counties in Kansas; 7 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Apr 27, 2012, 7:18 PM CDT for 6 counties in Kansas; 7 counties in Missouri. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2012, 7:18 PM CDT (00:18 UTC)
Expired
Apr 27, 2012, 8:53 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
50 kt

Counties Atchison County, KS, Doniphan County, KS, Johnson County, KS, Leavenworth County, KS, Miami County, KS, Wyandotte County, KS, Bates County, MO, Buchanan County, MO, Cass County, MO, Clay County, MO, Clinton County, MO, Jackson County, MO, Platte County, MO

The radar

The Pleasant Hill radar (KEAX), 74 km from the middle of the area, began a volume at 00:21 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
10%
One or more gusts of 65 knots or more
5%
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
50%

Discussions around it

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

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.3 hours before the alert went out and 261 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, Omaha, NE at 00:00Z on 2012-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Omaha, NE at 00:00Z on 2012-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 596 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1176 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
596 m²/s²
0-3 km storm-relative helicity
669 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.

212 
WWUS20 KWNS 280021
SEL6
SPC WW 280021
KSZ000-MOZ000-280400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 196
NWS STORM PREDICTION CENTER NORMAN OK
720 PM CDT FRI APR 27 2012

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

       NORTHEAST KANSAS
       WEST CENTRAL AND NORTHWEST MISSOURI

EFFECTIVE THIS FRIDAY EVENING FROM 720 PM UNTIL 1100 PM CDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 60
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 35
STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH
NORTHWEST OF SAINT JOSEPH MISSOURI TO 50 MILES SOUTH SOUTHEAST OF
OLATHE KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

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 194...WW 195...

DISCUSSION...ELEVATED SUSTAINED STORMS/SUPERCELLS POSING A RISK FOR
SVR HAIL WILL AFFECT THE LAWRENCE/KANSAS CITY/ST JOSEPH AREAS THIS
EVE AS NARROWING...ELEVATED TONGUE OF HIGH THETA-E AIR PIVOTS NE
ACROSS REGION ON SRN FRINGE OF EJECTING UPR IMPULSE IN SRN NEB.
DEAMPLIFICATION OF UPR DISTURBANCE...AND PERSISTENT WAA ATOP
SFC-BASED COOL DOME...SUGGEST THAT STORMS MAY PERSIST OVER WW AREA
INTO MID EVE.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM
MOTION VECTOR 23035.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 27, 7:00 PM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Jefferson, Johnson, Leavenworth and 1 more30 min
Apr 28, 1:17 PM CDTMesoscale DiscussionSPCFranklin, Gasconade, Jefferson, Lincoln, Montgomery, Osage and 7 more88 min
Apr 28, 1:48 PM CDTSevere Thunderstorm WatchSPCCrawford, Franklin, Gasconade, Jefferson, Lincoln, Montgomery and 6 more7 hr
Apr 28, 2:56 PM CDTMesoscale DiscussionSPCSaint Charles, Saint Louis, City of Saint Louis64 min
Apr 28, 5:15 PM CDTTornado WatchSPCJefferson, Perry, Sainte Genevieve, Saint Francois, Washington5 hr
Apr 28, 5:59 PM CDTMesoscale DiscussionSPCFranklin, Gasconade, Jefferson, Lincoln, Montgomery, Pike and 4 more2 hr
Apr 28, 6:12 PM CDTMesoscale DiscussionSPCJefferson2 hr

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.