Alert archive / Iowa / Tornado Watches in 2018
Tornado Watch 219
The Storm Prediction Center issued this tornado watch at Jun 25, 2018, 5:40 PM CDT for 19 counties in Iowa. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 25, 2018, 5:40 PM CDT (22:40 UTC)
- Expired
- Jun 25, 2018, 9:00 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Decatur County, IA, Greene County, IA, Guthrie County, IA, Lucas County, IA, Madison County, IA, Polk County, IA, Ringgold County, IA, Union County, IA, Warren County, IA, Wayne County, IA
The radar
The Des Moines radar (KDMX), 81 km from the middle of the area, began a volume at 22:44 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
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 40%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 5:58 PM CDT | Tornado Warning | DMX | Decatur, Ringgold | 32 min |
| Jun 25, 6:47 PM CDT | Tornado Warning | DMX | Madison | 28 min |
| Jun 25, 7:46 PM CDT | Severe Thunderstorm Warning | DMX | Dallas, Madison, 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, 10.7 hours before the alert went out and 172 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
- 118 J/kg
- Mixed-layer CIN
- -61 J/kg
- Mixed-layer LCL
- 796 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- -89 m²/s²
- 0-3 km storm-relative helicity
- -80 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
360 WWUS20 KWNS 252235 SEL9 SPC WW 252235 IAZ000-260200- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 219 NWS Storm Prediction Center Norman OK 535 PM CDT Mon Jun 25 2018 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and southern Iowa * Effective this Monday afternoon and evening from 535 PM until 900 PM CDT. * Primary threats include... A couple tornadoes possible Isolated damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A narrow arc of thunderstorms will offer the potential mainly for a brief tornadoes and damaging gusts into early evening, as it moves northward to northeastward across the watch area. The tornado watch area is approximately along and 45 statute miles east and west of a line from 5 miles south of Lamoni IA to 60 miles northwest of Des Moines IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 218... AVIATION...TORNADOES and A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE and ALOFT TO 1.5 INCHES. EXTREME TURBULENCE and SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION VECTOR 22025. ...Edwards
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 5:14 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Cass, Clarke, Decatur and 14 more | 2 hr |
Nearby
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.