Alert archive / Iowa / Frost Advisories in 2021

Frost Advisory 4, NWS Quad Cities, IA

April 24, 202111 counties in Iowa; 4 counties in Illinois

NWS Quad Cities, IA issued this frost advisory at Apr 24, 2021, 2:25 PM CDT for 11 counties in Iowa; 4 counties in Illinois. It took effect at Apr 25, 2021, 12:00 AM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Apr 24, 2021, 2:25 PM CDT (19:25 UTC)
In effect from
Apr 25, 2021, 12:00 AM CDT
Expired
Apr 25, 2021, 8:00 AM CDT
In force
8 hr
Issued by
NWS Quad Cities, IA

Counties Benton County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Iowa County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Carroll County, IL, Jo Daviess County, IL, Stephenson County, IL, Whiteside County, IL

The radar

The Quad Cities radar (KDVN), 63 km from the middle of the area, began a volume at 19:23 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 65 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 2021-04-24Temperature 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 2021-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.1939587897117Sfc1 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
883 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

622 
WWUS73 KDVN 241925
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
225 PM CDT Sat Apr 24 2021

IAZ040>042-051>054-063>066-ILZ001-002-007-009-250330-
/O.NEW.KDVN.FR.Y.0004.210425T0500Z-210425T1300Z/
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Jo Daviess-Stephenson-Carroll-Whiteside-
Including the cities of Independence, Manchester, Dubuque, 
Vinton, Cedar Rapids, Anamosa, Maquoketa, Marengo, Iowa City, 
Tipton, Clinton, Galena, Freeport, Mount Carroll, and Sterling
225 PM CDT Sat Apr 24 2021

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM CDT
SUNDAY...

* WHAT...Temperatures as low as 32 will result in frost 
  formation.

* WHERE...Portions of east central and northeast Iowa and 
  northwest Illinois.

* WHEN...From midnight tonight to 8 AM CDT Sunday.

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

* ADDITIONAL DETAILS...Some valley or low spots may dip just below
  freezing for several hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
Haase
www.weather.gov/dvn
2 follow-up statements
177 
WWUS73 KDVN 250149
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
849 PM CDT Sat Apr 24 2021

IAZ040>042-051>054-063>066-ILZ001-002-007-009-251000-
/O.CON.KDVN.FR.Y.0004.210425T0500Z-210425T1300Z/
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Jo Daviess-Stephenson-Carroll-Whiteside-
Including the cities of Independence, Manchester, Dubuque, 
Vinton, Cedar Rapids, Anamosa, Maquoketa, Marengo, Iowa City, 
Tipton, Clinton, Galena, Freeport, Mount Carroll, and Sterling
849 PM CDT Sat Apr 24 2021

...FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM
CDT SUNDAY...

* WHAT...Temperatures as low as 32 will result in frost 
  formation.

* WHERE...Portions of east central and northeast Iowa and 
  northwest Illinois.

* WHEN...From midnight tonight to 8 AM CDT Sunday.

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

* ADDITIONAL DETAILS...Some valley or low spots may dip just 
  below freezing for several hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

www.weather.gov/dvn
391 
WWUS73 KDVN 250805
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
305 AM CDT Sun Apr 25 2021

IAZ040>042-051>054-063>066-ILZ001-002-007-009-251300-
/O.CON.KDVN.FR.Y.0004.000000T0000Z-210425T1300Z/
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Jo Daviess-Stephenson-Carroll-Whiteside-
Including the cities of Independence, Manchester, Dubuque, 
Vinton, Cedar Rapids, Anamosa, Maquoketa, Marengo, Iowa City, 
Tipton, Clinton, Galena, Freeport, Mount Carroll, and Sterling
305 AM CDT Sun Apr 25 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM CDT THIS MORNING...

* WHAT...Temperatures as low as 28 to 32 will result in frost 
  formation.

* WHERE...Portions of east central and northeast Iowa and 
  northwest Illinois.

* WHEN...Until 8 AM CDT this morning.

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


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

www.weather.gov/dvn

Nearby

Frost Advisories in Iowa, 2021Frost Advisories in Illinois, 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.