Alert archive / Iowa / Frost Advisories in 2021

Frost Advisory 6, NWS Des Moines, IA

October 15, 202125 counties in Iowa

NWS Des Moines, IA issued this frost advisory at Oct 15, 2021, 1:08 PM CDT for 25 counties in Iowa. It took effect at Oct 16, 2021, 2:00 AM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Oct 15, 2021, 1:08 PM CDT (18:08 UTC)
In effect from
Oct 16, 2021, 2:00 AM CDT
Expired
Oct 16, 2021, 9:00 AM CDT
In force
7 hr
Issued by
NWS Des Moines, IA
All 25 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Crawford County, IA, Dallas County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Humboldt County, IA, Kossuth County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Taylor County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 83 km from the middle of the area, began a volume at 18:06 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

Omaha, NE (KOAX), launched 12:00Z, 6.1 hours before the alert went out and 201 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, Omaha, NE at 12:00Z on 2021-10-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2021-10-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -71 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1566 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
-71 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

607 
WWUS73 KDMX 151808
NPWDMX

URGENT - WEATHER MESSAGE
National Weather Service Des Moines IA
108 PM CDT Fri Oct 15 2021

IAZ004-015-023-033-034-044-045-057-160215-
/O.NEW.KDMX.FR.Y.0006.211016T0700Z-211016T1400Z/
Emmet-Palo Alto-Pocahontas-Sac-Calhoun-Crawford-Carroll-Audubon-
Including the cities of Estherville, Emmetsburg, Pocahontas, 
Laurens, Rolfe, Fonda, Gilmore City, Sac City, Lake View, 
Odebolt, Wall Lake, Schaller, Early, Rockwell City, Manson, 
Lake City, Pomeroy, Denison, Carroll, Audubon, and Exira
108 PM CDT Fri Oct 15 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM CDT SATURDAY...

* WHAT...Temperatures falling into the mid 30s will result in 
  frost formation.

* WHERE...West Central and Northwest Iowa.

* WHEN...From 2 AM to 9 AM CDT Saturday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if left
  uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

CURTIS
1 follow-up statement
407 
WWUS73 KDMX 160140
NPWDMX

URGENT - WEATHER MESSAGE
National Weather Service Des Moines IA
840 PM CDT Fri Oct 15 2021

IAZ005>007-016-017-024-025-035-036-046-047-058-059-070-071-081-
092-160945-
/O.EXA.KDMX.FR.Y.0006.211016T0700Z-211016T1400Z/
Kossuth-Winnebago-Worth-Hancock-Cerro Gordo-Humboldt-Wright-
Webster-Hamilton-Greene-Boone-Guthrie-Dallas-Cass-Adair-Adams-
Taylor-
Including the cities of Algona, Forest City, Lake Mills, 
Northwood, Manly, Garner, Britt, Kanawha, Mason City, Clear Lake,
Humboldt, Eagle Grove, Clarion, Belmond, Fort Dodge, 
Webster City, Jefferson, Boone, Guthrie Center, Panora, Bayard, 
Casey, Perry, Waukee, Adel, Atlantic, Greenfield, Stuart, Adair, 
Fontanelle, Corning, Bedford, Lenox, and New Market
840 PM CDT Fri Oct 15 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM CDT SATURDAY...

* WHAT...Temperatures as low as 34 will result in frost 
  formation.

* WHERE...Western and Northern Iowa.

* WHEN...From 2 AM to 9 AM CDT Saturday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Krull

IAZ004-015-023-033-034-044-045-057-160945-
/O.CON.KDMX.FR.Y.0006.211016T0700Z-211016T1400Z/
Emmet-Palo Alto-Pocahontas-Sac-Calhoun-Crawford-Carroll-Audubon-
Including the cities of Estherville, Emmetsburg, Pocahontas, 
Laurens, Rolfe, Fonda, Gilmore City, Sac City, Lake View, 
Odebolt, Wall Lake, Schaller, Early, Rockwell City, Manson, 
Lake City, Pomeroy, Denison, Carroll, Audubon, and Exira
840 PM CDT Fri Oct 15 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 9 AM CDT
SATURDAY...

* WHAT...Temperatures falling into the mid 30s will result in 
  frost formation.

* WHERE...West Central and Northwest Iowa.

* WHEN...From 2 AM to 9 AM CDT Saturday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Krull

For more information from the National Weather Service visit
https://weather.gov/desmoines

Nearby

Frost Advisories in Iowa, 2021Every frost advisory in 2021

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.