Alert archive / Missouri / Tornado Watches in 2018

Tornado Watch 403

October 9, 201815 counties in Arkansas; 9 counties in Kansas; 25 counties in Missouri

The Storm Prediction Center issued this tornado watch at Oct 9, 2018, 12:17 PM CDT for 15 counties in Arkansas; 9 counties in Kansas; 25 counties in Missouri. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Oct 9, 2018, 12:17 PM CDT (17:17 UTC)
Expired
Oct 9, 2018, 8:00 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
55 kt
All 49 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Washington County, AR, Allen County, KS, Bourbon County, KS, Cherokee County, KS, Crawford County, KS, Labette County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Woodson County, KS, Barry County, MO, Barton County, MO, Benton County, MO, Camden County, MO, Cedar County, MO, Christian County, MO, Dade County, MO, Dallas County, MO, Douglas County, MO, Greene County, MO, Hickory County, MO, Jasper County, MO, Laclede County, MO, Lawrence County, MO, McDonald County, MO, Morgan County, MO, Newton County, MO, Ozark County, MO, Polk County, MO, St. Clair County, MO, Stone County, MO, Taney County, MO, Vernon County, MO, Webster County, MO, Wright County, MO

The radar

The Springfield radar (KSGF), 91 km from the middle of the area, began a volume at 17:21 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
40%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 9, 12:22 PM CDTSevere Thunderstorm WarningICTLabette, Montgomery32 min
Oct 9, 12:34 PM CDTTornado WarningICTLabette, Montgomery17 min
Oct 9, 12:54 PM CDTSevere Thunderstorm WarningTSABenton66 min
Oct 9, 1:12 PM CDTSevere Thunderstorm WarningICTLabette32 min
Oct 9, 3:36 PM CDTTornado WarningLZKJohnson, Logan24 min
Oct 9, 3:38 PM CDTTornado WarningTSAFranklin37 min
Oct 9, 3:58 PM CDTSevere Thunderstorm WarningTSAFranklin, Madison32 min
Oct 9, 3:59 PM CDTTornado Warning Tornado observedLZKJohnson, Newton16 min
Oct 9, 4:09 PM CDTTornado WarningTSAMadison20 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, 5.3 hours before the alert went out and 44 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 2018-10-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 372 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 2018-10-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 159 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
372 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
747 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
159 m²/s²
0-3 km storm-relative helicity
112 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

716 
WWUS20 KWNS 091716
SEL3  
SPC WW 091716
ARZ000-KSZ000-MOZ000-100100-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 403
NWS Storm Prediction Center Norman OK
1220 PM CDT Tue Oct 9 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northwest Arkansas
  Southeast Kansas
  Southwest Missouri

* Effective this Tuesday afternoon and evening from 1220 PM until
  800 PM CDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 65 mph possible

SUMMARY...Line of showers and embedded thunderstorms may intensify
across the Ozarks this afternoon. Low-level rotation may be
sufficient to yield a couple brief tornadoes along with strong wind
gusts.

The tornado watch area is approximately along and 70 statute miles
east and west of a line from 60 miles southeast of Fayetteville AR
to 75 miles north northwest of Springfield MO. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 402...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 55 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 23030.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 9, 11:31 AM CDTMesoscale DiscussionSPCBenton, Crawford, Madison, Washington89 min
Oct 9, 6:22 PM CDTMesoscale DiscussionSPCBaxter, Boone, Calhoun, Clark, Cleburne, Cleveland and 26 more83 min
Oct 9, 9:09 AM CDTMesoscale DiscussionSPCChautauqua, Cherokee, Cowley, Elk, Labette, Montgomery2 hr
Oct 9, 1:46 PM CDTTornado WatchSPCAnderson, Atchison, Doniphan, Douglas, Franklin, Jefferson and 5 more7 hr
Oct 9, 3:06 PM CDTMesoscale DiscussionSPCDouglas, Franklin, Jefferson, Johnson, Leavenworth, Linn and 2 more84 min
Oct 8, 7:03 PM CDTMesoscale DiscussionSPCAndrew, Buchanan, Caldwell, Clinton, Daviess, DeKalb and 7 more57 min
Oct 9, 12:59 PM CDTMesoscale DiscussionSPCAdair, Clark, Grundy, Knox, Mercer, Putnam and 3 more3 hr
Oct 9, 8:48 AM CDTTornado WatchSPCAdair, Atoka, Bryan, Cherokee, Choctaw, Coal and 31 more5 hr

Nearby

Tornado Watches in Missouri, 2018Tornado Watches in Arkansas, 2018Tornado Watches in Kansas, 2018Every tornado watch in 2018

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.