Alert archive / Kansas / Tornado Watches in 2017

Tornado Watch 238

May 18, 201730 counties in Kansas; 15 counties in Missouri

The Storm Prediction Center issued this tornado watch at May 18, 2017, 3:00 PM CDT for 30 counties in Kansas; 15 counties in Missouri. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 18, 2017, 3:00 PM CDT (20:00 UTC)
Expired
May 18, 2017, 10:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
55 kt
All 45 counties

Anderson County, KS, Atchison County, KS, Brown County, KS, Clay County, KS, Cloud County, KS, Coffey County, KS, Dickinson County, KS, Doniphan County, KS, Douglas County, KS, Franklin County, KS, Geary County, KS, Jackson County, KS, Jefferson County, KS, Johnson County, KS, Leavenworth County, KS, Linn County, KS, Lyon County, KS, Marshall County, KS, Miami County, KS, Morris County, KS, Nemaha County, KS, Osage County, KS, Ottawa County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Shawnee County, KS, Wabaunsee County, KS, Washington County, KS, Wyandotte County, KS, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Chariton County, MO, Clay County, MO, Clinton County, MO, Jackson County, MO, Johnson County, MO, Lafayette County, MO, Linn County, MO, Livingston County, MO, Platte County, MO, Ray County, MO, Saline County, MO

The radar

The Topeka radar (KTWX), 75 km from the middle of the area, began a volume at 20:01 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
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 18, 4:31 PM CDTSevere Thunderstorm WarningTOPGeary, Morris29 min
May 18, 4:38 PM CDTSevere Thunderstorm WarningTOPMorris37 min
May 18, 4:57 PM CDTSevere Thunderstorm WarningTOPGeary33 min
May 18, 5:09 PM CDTSevere Thunderstorm WarningTOPGeary, Morris, Wabaunsee51 min
May 18, 5:13 PM CDTSevere Thunderstorm WarningTOPRiley31 min
May 18, 5:30 PM CDTTornado WarningTOPMorris, Wabaunsee30 min
May 18, 5:45 PM CDTSevere Thunderstorm WarningTOPClay, Dickinson, Geary, Ottawa45 min
May 18, 5:56 PM CDTSevere Thunderstorm WarningTOPGeary, Morris, Riley, Wabaunsee49 min
May 18, 6:27 PM CDTTornado WarningTOPDickinson, Ottawa33 min
May 18, 6:29 PM CDTSevere Thunderstorm WarningTOPClay, Dickinson, Geary, Riley46 min
May 18, 6:37 PM CDTTornado Warning Tornado observedTOPClay, Dickinson, Geary, Riley23 min
May 18, 6:39 PM CDTSevere Thunderstorm WarningTOPWabaunsee51 min
May 18, 6:41 PM CDTSevere Thunderstorm WarningTOPJackson, Pottawatomie, Shawnee, Wabaunsee49 min
May 18, 6:50 PM CDTSevere Thunderstorm WarningTOPJackson, Jefferson, Shawnee40 min
May 18, 6:54 PM CDTFlash Flood WarningTOPDickinson4 hr
May 18, 6:58 PM CDTSevere Thunderstorm WarningTOPDickinson, Ottawa32 min
May 18, 6:58 PM CDTTornado WarningTOPGeary, Riley32 min
May 18, 7:06 PM CDTSevere Thunderstorm WarningTOPGeary, Pottawatomie, Riley24 min
May 18, 7:36 PM CDTSevere Thunderstorm WarningTOPDouglas, Franklin39 min
May 18, 7:41 PM CDTSevere Thunderstorm WarningTOPJackson, Jefferson, Shawnee64 min
May 18, 7:59 PM CDTSevere Thunderstorm WarningEAXLeavenworth46 min
May 18, 8:06 PM CDTSevere Thunderstorm WarningEAXAtchison, Leavenworth54 min
May 18, 8:18 PM CDTSevere Thunderstorm WarningTOPCoffey, Lyon, Osage42 min
May 18, 8:19 PM CDTSevere Thunderstorm WarningEAXJohnson, Leavenworth, Wyandotte41 min
May 18, 8:45 PM CDTSevere Thunderstorm WarningEAXLeavenworth, Wyandotte30 min
May 18, 8:57 PM CDTSevere Thunderstorm WarningEAXJohnson, Leavenworth, Wyandotte48 min
May 18, 9:22 PM CDTSevere Thunderstorm WarningTOPDouglas, Franklin, Jefferson, Shawnee38 min
May 18, 9:33 PM CDTSevere Thunderstorm WarningEAXClay, Clinton, Platte27 min
May 18, 9:41 PM CDTSevere Thunderstorm WarningEAXJohnson, Miami49 min
May 18, 9:50 PM CDTSevere Thunderstorm WarningEAXJohnson, Leavenworth, Wyandotte40 min
May 18, 9:55 PM CDTSevere Thunderstorm WarningTOPDouglas, Jefferson20 min
May 18, 9:55 PM CDTSevere Thunderstorm WarningEAXClay, Clinton35 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 (KFOE), launched 12:00Z, 8.0 hours before the alert went out and 33 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, Topeka, KS at 12:00Z on 2017-05-18Temperature 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, Topeka, KS at 12:00Z on 2017-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 204 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
1033 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
204 m²/s²
0-3 km storm-relative helicity
335 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

198 
WWUS20 KWNS 181958
SEL8  
SPC WW 181958
KSZ000-MOZ000-190300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 238
NWS Storm Prediction Center Norman OK
300 PM CDT Thu May 18 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  northeast Kansas
  parts of northwest Missouri

* Effective this Thursday afternoon and evening from 300 PM until
  1000 PM CDT.

* Primary threats include...
  A couple tornadoes possible
  Scattered large hail and isolated very large hail events to 3
    inches in diameter possible
  Scattered damaging wind gusts to 65 mph possible

SUMMARY...Thunderstorms are forecast to increase in coverage mainly
over the western half of the watch area in the next couple of hours,
and then expand eastward with time.  Along with risk for very large
hail, a couple of tornadoes -- including potentially a strong
tornado -- will be possible.  Locally damaging winds may also occur
with stronger storms -- particularly into this evening when storms
are likely to congeal into one or more organized bands capable of
more widespread damaging winds.

The tornado watch area is approximately along and 45 statute miles
north and south of a line from 25 miles west southwest of Manhattan
KS to 50 miles southeast of Chillicothe MO. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU8).

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 235...WW 236...WW 237...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 3 inches. Extreme turbulence and surface wind
gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 23035.

...Goss

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 18, 2:00 PM CDTMesoscale DiscussionSPCBarber, Barton, Butler, Chase, Chautauqua, Clark and 20 more90 min
May 18, 2:16 PM CDTMesoscale DiscussionSPCAnderson, Chase, Coffey, Douglas, Franklin, Johnson and 7 more119 min
May 18, 3:21 PM CDTTornado Watch PDSSPCBarber, Barton, Butler, Chase, Chautauqua, Clark and 31 more7 hr
May 18, 3:42 PM CDTMesoscale DiscussionSPCGove, Grant, Greeley, Hamilton, Kearny, Logan and 8 more93 min
May 18, 5:15 PM CDTMesoscale DiscussionSPCHarper, Sumner60 min

Nearby

Tornado Watches in Kansas, 2017Tornado Watches in Missouri, 2017Every tornado watch in 2017

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.