Alert archive / Iowa / Heat Advisories in 2018

Heat Advisory 9, NWS Des Moines, IA

July 11, 201825 counties in Iowa

NWS Des Moines, IA issued this heat advisory at Jul 11, 2018, 3:44 PM CDT for 25 counties in Iowa. It took effect at Jul 12, 2018, 1:00 PM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Jul 11, 2018, 3:44 PM CDT (20:44 UTC)
In effect from: Jul 12, 2018, 1:00 PM CDT
Expired: Jul 12, 2018, 8:00 PM CDT
In force: 7 hr
Issued by: NWS Des Moines, IA

All 25 counties

Appanoose County, IA, Black Hawk County, IA, Bremer County, IA, Butler County, IA, Cerro Gordo County, IA, Davis County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Jasper County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Poweshiek County, IA, Story County, IA, Tama County, IA, Wapello County, IA, Wayne County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 67 km from the middle of the area, began a volume at 20:49 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.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.7 hours before the alert went out and 316 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 303 J/kg
Mixed-layer CIN: -235 J/kg
Mixed-layer LCL: 1021 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 182 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.7

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this heat advisory went out at Jul 10, 6:40 PM CDT, 21 hours 4 minutes earlier.

Area forecast discussion, Jul 10, 6:40 PM CDT, 21 hours 4 minutes before

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Nearby

Heat Advisories in Iowa, 2018 Every heat advisory 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.