Alert archive / Iowa / Frost Advisories in 2020

Frost Advisory 5, NWS Des Moines, IA

October 15, 202026 counties in Iowa

NWS Des Moines, IA issued this frost advisory at Oct 15, 2020, 5:26 PM CDT for 26 counties in Iowa. It took effect at Oct 16, 2020, 1:00 AM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Oct 15, 2020, 5:26 PM CDT (22:26 UTC)
In effect from: Oct 16, 2020, 1:00 AM CDT
Expired: Oct 16, 2020, 8:00 AM CDT
In force: 7 hr
Issued by: NWS Des Moines, IA

All 26 counties

Adair County, IA, Adams County, IA, Appanoose 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, Jasper County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Polk County, IA, Ringgold County, IA, Story County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Wayne County, IA

The radar

The Des Moines radar (KDMX), 43 km from the middle of the area, began a volume at 22:32 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

Davenport, (KDVN), launched 12:00Z, 10.4 hours before the alert went out and 289 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 909 m above ground
0-6 km bulk shear: 98 kt
0-1 km storm-relative helicity: -39 m²/s²
0-3 km storm-relative helicity: -19 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this frost 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 frost advisory went out at Oct 15, 3:16 PM CDT, 2 hours 10 minutes earlier.

Area forecast discussion, Oct 15, 3:16 PM CDT, 2 hours 10 minutes before

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Hazardous weather outlook, Oct 15, 1:47 PM CDT, 3 hours 39 minutes before

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    <section class="card" role="status" aria-live="polite">
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 15, 1:38 PM CDT	Freeze Warning	DMX	Black Hawk, Bremer, Butler, Davis, Grundy, Mahaska and 3 more	18 hr

Nearby

Frost Advisories in Iowa, 2020 Every frost advisory in 2020

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.