Alert archive / Iowa / Tornado Watches in 2023
Tornado Watch 710
The Storm Prediction Center issued this tornado watch at Oct 13, 2023, 1:30 PM CDT for 26 counties in Iowa. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Oct 13, 2023, 1:30 PM CDT (18:30 UTC)
- Expired
- Oct 13, 2023, 6:38 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 50 kt
All 26 counties
Benton County, IA, Boone County, IA, Calhoun County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hardin County, IA, Humboldt County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Story County, IA, Tama County, IA, Wapello County, IA, Washington County, IA, Webster County, IA, Wright County, IA
The radar
The Des Moines radar (KDMX), 67 km from the middle of the area, began a volume at 18:30 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
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 10%
- 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
- 50%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 13, 3:25 PM CDT | Tornado Warning | DMX | Boone, Story | 15 min |
| Oct 13, 3:44 PM CDT | Tornado Warning | DMX | Jasper, Polk | 19 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, 6.5 hours before the alert went out and 256 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
- 781 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 45 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
246 WWUS20 KWNS 131827 SEL0 SPC WW 131827 IAZ000-140100- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 710 NWS Storm Prediction Center Norman OK 125 PM CDT Fri Oct 13 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central into southeast Iowa * Effective this Friday afternoon and evening from 125 PM until 800 PM CDT. * Primary threats include... A few tornadoes possible Isolated damaging wind gusts to 60 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...Scattered low-topped thunderstorms will form this afternoon along a slow-moving front across central Iowa. The storm environment will favor of mix of multicells and some supercells capable of producing a few tornadoes, along with isolated marginally severe hail and wind gusts. The tornado watch area is approximately along and 35 statute miles north and south of a line from 35 miles west northwest of Fort Dodge IA to 30 miles south of Cedar Rapids IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 50 knots. A few cumulonimbi with maximum tops to 350. Mean storm motion vector 18020. ...Thompson
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 13, 12:12 PM CDT | Mesoscale Discussion | SPC | Boone, Hamilton, Hardin, Humboldt, Jasper, Mahaska and 11 more | 93 min |
| Oct 13, 3:26 PM CDT | Mesoscale Discussion | SPC | Benton, Boone, Calhoun, Davis, Franklin, Greene and 23 more | 94 min |
| Oct 13, 5:19 PM CDT | Mesoscale Discussion | SPC | Des Moines, Henry, Iowa, Johnson, Keokuk, Lee and 4 more | 86 min |
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.