Alert archive / Iowa / Freeze Warnings in 2021

Freeze Warning 4, NWS Quad Cities, IA

October 31, 20217 counties in Illinois; 8 counties in Iowa

NWS Quad Cities, IA issued this freeze warning at Oct 31, 2021, 2:22 PM CDT for 7 counties in Illinois; 8 counties in Iowa. It took effect at Nov 1, 2021, 12:00 AM CDT. It was in force for 9 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Oct 31, 2021, 2:22 PM CDT (19:22 UTC)
In effect from
Nov 1, 2021, 12:00 AM CDT
Expired
Nov 1, 2021, 9:00 AM CDT
In force
9 hr
Issued by
NWS Quad Cities, IA

Counties Des Moines County, IA, Henry County, IA, Jefferson County, IA, Keokuk County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Washington County, IA, Bureau County, IL, Henderson County, IL, Henry County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Warren County, IL

The radar

The Quad Cities radar (KDVN), 51 km from the middle of the area, began a volume at 19:25 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, 7.4 hours before the alert went out and 55 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, Davenport, at 12:00Z on 2021-10-31Temperature 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, Davenport, at 12:00Z on 2021-10-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.19395878Sfc1 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
810 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

774 
WWUS73 KDVN 311922
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
222 PM CDT Sun Oct 31 2021

IAZ067-068-ILZ015>018-010330-
/O.NEW.KDVN.FZ.W.0004.211101T0500Z-211101T1400Z/
Muscatine-Scott-Rock Island-Henry IL-Bureau-Putnam-
Including the cities of Muscatine, Davenport, Bettendorf, Moline,
Rock Island, Geneseo, Princeton, and Hennepin
222 PM CDT Sun Oct 31 2021

...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM CDT
MONDAY...

* WHAT...Sub-freezing temperatures as low as 30 expected.

* WHERE...In Iowa, Muscatine and Scott Counties. In Illinois, 
  Rock Island, Henry IL, Bureau and Putnam Counties.

* WHEN...From midnight tonight to 9 AM CDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. 

&&

$$

www.weather.gov/dvn
3 follow-up statements
371 
WWUS73 KDVN 010118
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
818 PM CDT Sun Oct 31 2021

IAZ076>078-087>089-ILZ024>026-011100-
/O.EXA.KDVN.FZ.W.0004.211101T0500Z-211101T1400Z/
Keokuk-Washington-Louisa-Jefferson-Henry IA-Des Moines-Mercer-
Henderson-Warren-
Including the cities of Sigourney, Washington, Wapello, 
Fairfield, Mount Pleasant, Burlington, Aledo, Oquawka, 
and Monmouth
818 PM CDT Sun Oct 31 2021

...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM CDT
MONDAY...

* WHAT...Temperatures in the lower 30s.

* WHERE...In Iowa, Keokuk, Washington, Louisa, Jefferson, Henry 
  IA and Des Moines Counties. In Illinois, Mercer, Henderson and 
  Warren Counties.

* WHEN...From midnight tonight to 9 AM CDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation, and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

IAZ067-068-ILZ015>018-011100-
/O.CON.KDVN.FZ.W.0004.211101T0500Z-211101T1400Z/
Muscatine-Scott-Rock Island-Henry IL-Bureau-Putnam-
Including the cities of Muscatine, Davenport, Bettendorf, Moline,
Rock Island, Geneseo, Princeton, and Hennepin
818 PM CDT Sun Oct 31 2021

...FREEZE WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM
CDT MONDAY...

* WHAT...Temperatures in the lower 30s.

* WHERE...In Iowa, Muscatine and Scott Counties. In Illinois, 
  Rock Island, Henry IL, Bureau and Putnam Counties.

* WHEN...From midnight tonight to 9 AM CDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation, and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

www.weather.gov/dvn

Uttech
151 
WWUS73 KDVN 010724
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
224 AM CDT Mon Nov 1 2021

IAZ067-068-076>078-087>089-ILZ015>018-024>026-011400-
/O.CON.KDVN.FZ.W.0004.000000T0000Z-211101T1400Z/
Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-Henry IA-
Des Moines-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-
Including the cities of Muscatine, Davenport, Bettendorf, 
Sigourney, Washington, Wapello, Fairfield, Mount Pleasant, 
Burlington, Moline, Rock Island, Geneseo, Princeton, Hennepin, 
Aledo, Oquawka, and Monmouth
224 AM CDT Mon Nov 1 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM CDT THIS MORNING...

* WHAT...Temperatures in the lower 30s.

* WHERE...In Iowa, Muscatine and Scott Counties. In Illinois, 
  Rock Island, Henry IL, Bureau and Putnam Counties.

* WHEN...From midnight tonight to 9 AM CDT Monday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation, and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

www.weather.gov/dvn
537 
WWUS73 KDVN 011402
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
902 AM CDT Mon Nov 1 2021

IAZ067-068-076>078-087>089-ILZ015>018-024>026-011515-
/O.EXP.KDVN.FZ.W.0004.000000T0000Z-211101T1400Z/
Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-Henry IA-
Des Moines-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-
Including the cities of Muscatine, Davenport, Bettendorf, 
Sigourney, Washington, Wapello, Fairfield, Mount Pleasant, 
Burlington, Moline, Rock Island, Geneseo, Princeton, Hennepin, 
Aledo, Oquawka, and Monmouth
902 AM CDT Mon Nov 1 2021

...FREEZE WARNING HAS EXPIRED...

Temperatures are warming above freezing and the threat for frost
and freeze is ending. Thus, the Freeze Warning was allowed to 
expire at 9 AM CDT.

$$

www.weather.gov/dvn

Nearby

Freeze Warnings in Iowa, 2021Freeze Warnings in Illinois, 2021Every freeze warning 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.