Alert archive / Iowa / Severe Thunderstorm Watches in 2019

Severe Thunderstorm Watch 554

August 5, 201927 counties in Iowa

The Storm Prediction Center issued this severe thunderstorm watch at Aug 5, 2019, 3:16 PM CDT for 27 counties in Iowa. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Aug 5, 2019, 3:16 PM CDT (20:16 UTC)
Expired
Aug 5, 2019, 11:00 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 27 counties

Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Crawford County, IA, Emmet County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Kossuth County, IA, Marshall County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 131 km from the middle of the area, began a volume at 20:18 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 5, 5:34 PM CDTSevere Thunderstorm WarningDMXEmmet24 min
Aug 5, 7:24 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Worth36 min
Aug 5, 7:48 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock, Wright57 min
Aug 5, 7:56 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Franklin, Hancock, Wright49 min
Aug 5, 8:07 PM CDTSevere Thunderstorm WarningDMXFranklin, Wright38 min
Aug 5, 8:30 PM CDTSevere Thunderstorm WarningDMXButler, Franklin, Grundy, Hardin, Wright45 min
Aug 5, 8:32 PM CDTSevere Thunderstorm WarningDMXHamilton, Humboldt, Webster, Wright28 min
Aug 5, 8:58 PM CDTSevere Thunderstorm WarningDMXFranklin, Hamilton, Hardin, Wright32 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

Minneapolis, MN (KMPX), launched 12:00Z, 8.3 hours before the alert went out and 228 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, Minneapolis, MN at 12:00Z on 2019-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1431 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, Minneapolis, MN at 12:00Z on 2019-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.1939587897Sfc1 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
1431 J/kg
Mixed-layer CIN
-115 J/kg
Mixed-layer LCL
1018 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
80 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 5, 1:18 PM CDTMesoscale DiscussionSPCHoward, Kossuth, Mitchell, Winnebago, Worth117 min
Aug 5, 1:45 PM CDTSevere Thunderstorm WatchSPCAllamakee, Chickasaw, Floyd, Howard, Mitchell, Winneshiek8 hr
Aug 5, 2:43 PM CDTMesoscale DiscussionSPCBoone, Buena Vista, Butler, Calhoun, Carroll, Cerro Gordo and 19 more2 hr
Aug 5, 6:14 PM CDTMesoscale DiscussionSPCAllamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 22 more2 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2019Every severe thunderstorm watch in 2019

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.