Alert archive / Iowa / Tornado Watches in 2018
Tornado Watch 404
The Storm Prediction Center issued this tornado watch at Oct 9, 2018, 1:46 PM CDT for 42 counties in Iowa; 11 counties in Kansas; 37 counties in Missouri. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Oct 9, 2018, 1:46 PM CDT (18:46 UTC)
- Expired
- Oct 9, 2018, 9:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 55 kt
All 90 counties
Adair County, IA, Adams County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hardin County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Linn County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Anderson County, KS, Atchison County, KS, Doniphan County, KS, Douglas County, KS, Franklin County, KS, Jefferson County, KS, Johnson County, KS, Leavenworth County, KS, Linn County, KS, Miami County, KS, Wyandotte County, KS, Adair County, MO, Andrew County, MO, Bates County, MO, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Chariton County, MO, Clay County, MO, Clinton County, MO, Cooper County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Henry County, MO, Holt County, MO, Howard County, MO, Jackson County, MO, Johnson County, MO, Lafayette County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Mercer County, MO, Nodaway County, MO, Pettis County, MO, Platte County, MO, Putnam County, MO, Randolph County, MO, Ray County, MO, Saline County, MO, Schuyler County, MO, Scotland County, MO, Sullivan County, MO, Worth County, MO
The radar
The Pleasant Hill radar (KEAX), 130 km from the middle of the area, began a volume at 18:50 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
- 60%
- One or more EF2 to EF5 tornadoes
- 30%
- 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
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 9, 2:16 PM CDT | Tornado Warning | DMX | Mahaska, Marion, Monroe | 29 min |
| Oct 9, 2:54 PM CDT | Tornado Warning | EAX | Caldwell, Ray | 36 min |
| Oct 9, 3:06 PM CDT | Tornado Warning | DVN | Benton, Iowa | 39 min |
| Oct 9, 3:09 PM CDT | Tornado Warning | DVN | Delaware | 51 min |
| Oct 9, 3:32 PM CDT | Tornado Warning | DMX | Appanoose, Monroe | 43 min |
| Oct 9, 3:38 PM CDT | Tornado Warning | DVN | Benton, Iowa | 52 min |
| Oct 9, 3:42 PM CDT | Tornado Warning | DMX | Mahaska, Marion, Monroe | 22 min |
| Oct 9, 4:03 PM CDT | Tornado Warning | DVN | Iowa, Keokuk, Washington | 27 min |
| Oct 9, 4:21 PM CDT | Tornado Warning | DMX | Poweshiek, Tama | 24 min |
| Oct 9, 4:28 PM CDT | Tornado Warning | DMX | Ringgold, Taylor | 47 min |
| Oct 9, 4:29 PM CDT | Tornado Warning | EAX | Mercer | 31 min |
| Oct 9, 4:31 PM CDT | Tornado Warning | DVN | Iowa, Johnson | 44 min |
| Oct 9, 4:58 PM CDT | Tornado Warning | DMX | Tama | 32 min |
| Oct 9, 4:59 PM CDT | Tornado Warning | DMX | Jasper, Poweshiek | 31 min |
| Oct 9, 5:13 PM CDT | Tornado Warning | DMX | Adair, Adams, Union | 32 min |
| Oct 9, 5:14 PM CDT | Tornado Warning | DVN | Benton, Iowa, Johnson, Linn | 46 min |
| Oct 9, 5:44 PM CDT | Tornado Warning | DMX | Adair | 46 min |
| Oct 9, 5:51 PM CDT | Tornado Warning | DVN | Linn | 24 min |
| Oct 9, 6:11 PM CDT | Tornado Warning | DMX | Adair, Dallas, Guthrie | 49 min |
| Oct 9, 6:30 PM CDT | Tornado Warning | DMX | Polk, Warren | 30 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
Omaha, NE (KOAX), launched 12:00Z, 6.8 hours before the alert went out and 260 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 592 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km storm-relative helicity
- 57 m²/s²
- 0-3 km storm-relative helicity
- 28 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
104 WWUS20 KWNS 091844 SEL4 SPC WW 091844 IAZ000-KSZ000-MOZ000-100200- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 404 NWS Storm Prediction Center Norman OK 145 PM CDT Tue Oct 9 2018 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and eastern Iowa Northeast Kansas Western and northern Missouri * Effective this Tuesday afternoon and evening from 145 PM until 900 PM CDT. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Isolated damaging wind gusts to 65 mph possible SUMMARY...Scattered showers and embedded thunderstorms should increase in coverage and intensity during the late afternoon and early evening. Low-level wind profiles are conducive for a few rotating storms capable of tornadoes and damaging winds. The tornado watch area is approximately along and 70 statute miles east and west of a line from 40 miles south southeast of Olathe KS to 50 miles northwest of Cedar Rapids IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). 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...WW 403... 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 21030. ...Grams
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 8, 7:03 PM CDT | Mesoscale Discussion | SPC | Appanoose, Clarke, Dallas, Decatur, Jasper, Lucas and 9 more | 57 min |
| Oct 9, 12:59 PM CDT | Mesoscale Discussion | SPC | Appanoose, Benton, Buchanan, Clarke, Davis, Decatur and 19 more | 3 hr |
| Oct 9, 2:45 PM CDT | Mesoscale Discussion | SPC | Cedar, Clinton, Dubuque, Jackson, Jones, Muscatine and 1 more | 2 hr |
| Oct 9, 3:53 PM CDT | Mesoscale Discussion | SPC | Appanoose, Benton, Black Hawk, Boone, Buchanan, Clarke and 29 more | 2 hr |
| Oct 9, 5:09 PM CDT | Tornado Watch | SPC | Allamakee, Clayton, Fayette | 4 hr |
| Oct 9, 6:37 PM CDT | Mesoscale Discussion | SPC | Allamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 21 more | 83 min |
| Oct 9, 9:09 AM CDT | Mesoscale Discussion | SPC | Chautauqua, Cherokee, Cowley, Elk, Labette, Montgomery | 2 hr |
| Oct 9, 11:31 AM CDT | Mesoscale Discussion | SPC | Allen, Anderson, Bourbon, Cherokee, Coffey, Crawford and 18 more | 89 min |
| Oct 9, 12:17 PM CDT | Tornado Watch | SPC | Allen, Bourbon, Cherokee, Crawford, Labette, Montgomery and 3 more | 8 hr |
| Oct 9, 3:06 PM CDT | Mesoscale Discussion | SPC | Douglas, Franklin, Jefferson, Johnson, Leavenworth, Linn and 2 more | 84 min |
| Oct 9, 6:22 PM CDT | Mesoscale Discussion | SPC | Ozark, Taney | 83 min |
Nearby
Tornado Watches in Iowa, 2018Tornado Watches in Missouri, 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.