Alert archive / Missouri / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 236
The Storm Prediction Center issued this severe thunderstorm watch at May 4, 2012, 12:53 AM CDT for 4 states. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- May 4, 2012, 12:53 AM CDT (05:53 UTC)
- Expired
- May 4, 2012, 5:00 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 41 counties
Des Moines County, IA, Henry County, IA, Jefferson County, IA, Lee County, IA, Van Buren County, IA, Adams County, IL, Brown County, IL, Doniphan County, KS, Adair County, MO, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Chariton County, MO, Clark County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Knox County, MO, Lewis County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Mercer County, MO, Monroe County, MO, Nodaway County, MO, Putnam County, MO, Ralls County, MO, Randolph County, MO, Ray County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO, Worth County, MO
The radar
The Des Moines radar (KDMX), 159 km from the middle of the area, began a volume at 05:56 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- 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
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 1:10 AM CDT | Flash Flood Warning | DVN | Henry, Jefferson | 6 hr |
| May 4, 1:28 AM CDT | Flash Flood Warning | EAX | Daviess, DeKalb, Gentry | 6 hr |
| May 4, 2:40 AM CDT | Flash Flood Warning | DVN | Lee, Van Buren | 6 hr |
| May 4, 3:07 AM CDT | Severe Thunderstorm Warning | DVN | Lee | 38 min |
| May 4, 3:12 AM CDT | Flash Flood Warning | EAX | Gentry, Nodaway, Worth | 6 hr |
| May 4, 3:55 AM CDT | Severe Thunderstorm Warning | EAX | Harrison | 14 min |
| May 4, 4:03 AM CDT | Severe Thunderstorm Warning | LSX | Adams, Brown | 42 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
Topeka, KS (KTOP), launched 00:00Z, 5.9 hours before the alert went out and 221 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.
- Mixed-layer CAPE
- 3511 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 1105 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 102 m²/s²
- 0-3 km storm-relative helicity
- 196 m²/s²
- Significant tornado parameter
- 2.0
- Supercell composite
- 14.3
The text
As transmitted, in the capitals the NWS used until 2016.
408
WWUS20 KWNS 040556
SEL6
SPC WW 040556
IAZ000-ILZ000-KSZ000-MOZ000-041000-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 236
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT FRI MAY 4 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
SOUTHEASTERN IOWA
A SMALL PART OF WESTERN ILLINOIS
FAR NORTHEAST KANSAS
NORTHERN MISSOURI
EFFECTIVE THIS FRIDAY MORNING FROM 1255 AM UNTIL 500 AM 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 125
STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES EAST
NORTHEAST OF LAMONI IOWA TO 30 MILES SOUTHEAST OF CHILLICOTHE
MISSOURI. 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...THIS SEVERE THUNDERSTORM WATCH REPLACES
TORNADO WATCH NUMBER 234. WATCH NUMBER 234 WILL NOT BE IN EFFECT
AFTER 1255 AM CDT. CONTINUE...WW 235...
DISCUSSION...TSTMS EXPECTED TO PERSIST ALONG SRN FRINGE OF DIFFUSE
W-E FRONTAL ZONE OVER SRN IA/NRN MO...SUPPORTED BY 25-30 KT LLJ THAT
WILL FURTHER VEER FROM SWLY TO WSWLY. OTHER THAN LOW LVL
WAA...FORCING FOR ASCENT WILL REMAIN WEAK. BUT DEGREE OF BUOYANCY
/PER 00Z TOP RAOB/ AND RELATIVELY RICH MOISTURE INFLOW SUGGEST
CONTINUED RISK FOR SVR HAIL AND STRONG...PRECIP-ENHANCED DOWNDRAFTS
AS THE STORMS GRADUALLY EVOLVE INTO A LARGER SCALE...POSSIBLY
FORWARD-PROPAGATING MCS.
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 500. MEAN STORM
MOTION VECTOR 27025.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 3, 7:09 PM CDT | Tornado Watch | SPC | Adams, Brown, Pike, Rock Island | 6 hr |
| May 3, 10:29 PM CDT | Mesoscale Discussion | SPC | Cook, DeKalb, DuPage, Ford, Grundy, Iroquois and 7 more | 61 min |
| May 3, 11:18 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Cass, DeWitt, Fulton and 22 more | 27 min |
| May 3, 11:34 PM CDT | Severe Thunderstorm Watch | SPC | Bureau, Cass, Champaign, DeWitt, Ford, Fulton and 25 more | 5 hr |
| May 4, 2:16 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Cass, DeWitt, Ford and 25 more | 119 min |
| May 4, 11:36 AM CDT | Mesoscale Discussion | SPC | Clay, Clinton, Edwards, Franklin, Gallatin, Hamilton and 17 more | 84 min |
| May 4, 1:29 PM CDT | Severe Thunderstorm Watch | SPC | Edwards, Wabash, White | 5 hr |
| May 4, 1:50 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Cherokee, Clay, Dickinson, Emmet, Ida and 7 more | 25 min |
| May 4, 2:00 PM CDT | Severe Thunderstorm Watch | SPC | Buena Vista, Calhoun, Carroll, Cerro Gordo, Cherokee, Clay and 23 more | 9 hr |
| May 4, 3:52 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Cerro Gordo, Cherokee, Clay, Dickinson, Emmet and 17 more | 53 min |
| May 4, 5:31 PM CDT | Mesoscale Discussion | SPC | Audubon, Benton, Black Hawk, Boone, Bremer, Buchanan and 66 more | 29 min |
| May 4, 5:52 PM CDT | Severe Thunderstorm Watch | SPC | Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more | 5 hr |
| May 4, 6:01 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Black Hawk, Boone, Bremer, Buchanan, Butler and 22 more | 3 hr |
| May 4, 12:20 AM CDT | Mesoscale Discussion | SPC | Barber, Clark, Comanche, Edwards, Harper, Harvey and 6 more | 55 min |
| May 4, 1:43 AM CDT | Severe Thunderstorm Watch | SPC | Butler, Chase, Chautauqua, Cowley, Elk, Greenwood and 7 more | 2 hr |
Nearby
Severe Thunderstorm Watches in Missouri, 2012Severe Thunderstorm Watches in Iowa, 2012Severe Thunderstorm Watches in Illinois, 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.