Alert archive / Iowa / Frost Advisories in 2021

Frost Advisory 7, NWS Quad Cities, IA

May 11, 202119 counties in Iowa; 12 counties in Illinois

NWS Quad Cities, IA issued this frost advisory at May 11, 2021, 2:26 PM CDT for 19 counties in Iowa; 12 counties in Illinois. It took effect at May 12, 2021, 1:00 AM CDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
May 11, 2021, 2:26 PM CDT (19:26 UTC)
In effect from
May 12, 2021, 1:00 AM CDT
Expired
May 12, 2021, 7:00 AM CDT
In force
6 hr
Issued by
NWS Quad Cities, IA
All 31 counties

Benton County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Washington County, IA, Bureau County, IL, Carroll County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, McDonough County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL

The radar

The Quad Cities radar (KDVN), 28 km from the middle of the area, began a volume at 19:28 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 35 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 2021-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 15 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -29 square meters per square second.1939587897117136Sfc1 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
15 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
1155 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
-29 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

638 
WWUS73 KDVN 111926
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
226 PM CDT Tue May 11 2021

IAZ053-054-065>068-078-089-ILZ001-002-007-009-015>018-024>026-035-
120330-
/O.NEW.KDVN.FR.Y.0007.210512T0600Z-210512T1200Z/
Jones-Jackson-Cedar-Clinton-Muscatine-Scott-Louisa-Des Moines-
Jo Daviess-Stephenson-Carroll-Whiteside-Rock Island-Henry IL-
Bureau-Putnam-Mercer-Henderson-Warren-McDonough-
Including the cities of Anamosa, Maquoketa, Tipton, Clinton, 
Muscatine, Davenport, Bettendorf, Wapello, Burlington, Galena, 
Freeport, Mount Carroll, Sterling, Moline, Rock Island, Geneseo, 
Princeton, Hennepin, Aledo, Oquawka, Monmouth, and Macomb
226 PM CDT Tue May 11 2021

...FROST ADVISORY IN EFFECT FROM 1 AM TO 7 AM CDT WEDNESDAY...

* WHAT...Temperatures in the lower to mid 30s will result in 
  frost formation.

* WHERE...Portions of east central and southeast Iowa and north 
  central, northwest and west central Illinois.

* WHEN...From 1 AM to 7 AM CDT Wednesday.

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


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

IAZ040>042-051-052-063-064-076-077-087-088-120330-
/O.NEW.KDVN.FR.Y.0007.210512T0700Z-210512T1200Z/
Buchanan-Delaware-Dubuque-Benton-Linn-Iowa-Johnson-Keokuk-
Washington-Jefferson-Henry IA-
Including the cities of Independence, Manchester, Dubuque, 
Vinton, Cedar Rapids, Marengo, Iowa City, Sigourney, Washington, 
Fairfield, and Mount Pleasant
226 PM CDT Tue May 11 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 7 AM CDT WEDNESDAY...

* WHAT...Temperatures in the lower to mid 30s will result in 
  frost formation.

* WHERE...Portions of east central, northeast and southeast Iowa.

* WHEN...From 2 AM to 7 AM CDT Wednesday.

* 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
3 follow-up statements
393 
WWUS73 KDVN 120241
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
941 PM CDT Tue May 11 2021

IAZ053-054-065>068-078-089-ILZ001-002-007-009-015>018-024>026-035-
121045-
/O.CON.KDVN.FR.Y.0007.210512T0600Z-210512T1200Z/
Jones-Jackson-Cedar-Clinton-Muscatine-Scott-Louisa-Des Moines-
Jo Daviess-Stephenson-Carroll-Whiteside-Rock Island-Henry IL-
Bureau-Putnam-Mercer-Henderson-Warren-McDonough-
Including the cities of Anamosa, Maquoketa, Tipton, Clinton, 
Muscatine, Davenport, Bettendorf, Wapello, Burlington, Galena, 
Freeport, Mount Carroll, Sterling, Moline, Rock Island, Geneseo, 
Princeton, Hennepin, Aledo, Oquawka, Monmouth, and Macomb
941 PM CDT Tue May 11 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 7 AM CDT
WEDNESDAY...

* WHAT...Temperatures in the lower to mid 30s will result in 
  frost formation.

* WHERE...Portions of east central and southeast Iowa and north 
  central, northwest and west central Illinois.

* WHEN...From 1 AM to 7 AM CDT Wednesday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

IAZ040>042-051-052-063-064-076-077-087-088-121045-
/O.CON.KDVN.FR.Y.0007.210512T0700Z-210512T1200Z/
Buchanan-Delaware-Dubuque-Benton-Linn-Iowa-Johnson-Keokuk-
Washington-Jefferson-Henry IA-
Including the cities of Independence, Manchester, Dubuque, 
Vinton, Cedar Rapids, Marengo, Iowa City, Sigourney, Washington, 
Fairfield, and Mount Pleasant
941 PM CDT Tue May 11 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 7 AM CDT
WEDNESDAY...

* WHAT...Temperatures in the lower to mid 30s will result in 
  frost formation.

* WHERE...Portions of east central, northeast and southeast Iowa.

* WHEN...From 2 AM to 7 AM CDT Wednesday.

* 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
308 
WWUS73 KDVN 120740
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
240 AM CDT Wed May 12 2021

IAZ053-054-065>068-078-089-ILZ001-002-007-009-015>018-024>026-035-
121200-
/O.CON.KDVN.FR.Y.0007.000000T0000Z-210512T1200Z/
Jones-Jackson-Cedar-Clinton-Muscatine-Scott-Louisa-Des Moines-
Jo Daviess-Stephenson-Carroll-Whiteside-Rock Island-Henry IL-
Bureau-Putnam-Mercer-Henderson-Warren-McDonough-
Including the cities of Anamosa, Maquoketa, Tipton, Clinton, 
Muscatine, Davenport, Bettendorf, Wapello, Burlington, Galena, 
Freeport, Mount Carroll, Sterling, Moline, Rock Island, Geneseo, 
Princeton, Hennepin, Aledo, Oquawka, Monmouth, and Macomb
240 AM CDT Wed May 12 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 7 AM CDT THIS MORNING...

* WHAT...Temperatures in the lower to mid 30s will result in 
  frost formation.

* WHERE...Portions of east central and southeast Iowa and north 
  central, northwest and west central Illinois.

* WHEN...From 1 AM to 7 AM CDT Wednesday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

IAZ040>042-051-052-063-064-076-077-087-088-121200-
/O.CON.KDVN.FR.Y.0007.000000T0000Z-210512T1200Z/
Buchanan-Delaware-Dubuque-Benton-Linn-Iowa-Johnson-Keokuk-
Washington-Jefferson-Henry IA-
Including the cities of Independence, Manchester, Dubuque, 
Vinton, Cedar Rapids, Marengo, Iowa City, Sigourney, Washington, 
Fairfield, and Mount Pleasant
240 AM CDT Wed May 12 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 7 AM CDT THIS MORNING...

* WHAT...Temperatures in the lower to mid 30s will result in 
  frost formation.

* WHERE...Portions of east central, northeast and southeast Iowa.

* WHEN...From 2 AM to 7 AM CDT Wednesday.

* 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
444 
WWUS73 KDVN 121156
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
656 AM CDT Wed May 12 2021

IAZ053-054-065>068-078-089-ILZ001-002-007-009-015>018-024>026-035-
121300-
/O.EXP.KDVN.FR.Y.0007.000000T0000Z-210512T1200Z/
Jones-Jackson-Cedar-Clinton-Muscatine-Scott-Louisa-Des Moines-
Jo Daviess-Stephenson-Carroll-Whiteside-Rock Island-Henry IL-
Bureau-Putnam-Mercer-Henderson-Warren-McDonough-
Including the cities of Anamosa, Maquoketa, Tipton, Clinton, 
Muscatine, Davenport, Bettendorf, Wapello, Burlington, Galena, 
Freeport, Mount Carroll, Sterling, Moline, Rock Island, Geneseo, 
Princeton, Hennepin, Aledo, Oquawka, Monmouth, and Macomb
656 AM CDT Wed May 12 2021

...FROST ADVISORY WILL EXPIRE AT 7 AM CDT THIS MORNING...

Temperatures will quickly climb through the 40s this morning,
ending any threat for frost. 

$$

IAZ040>042-051-052-063-064-076-077-087-088-121300-
/O.EXP.KDVN.FR.Y.0007.000000T0000Z-210512T1200Z/
Buchanan-Delaware-Dubuque-Benton-Linn-Iowa-Johnson-Keokuk-
Washington-Jefferson-Henry IA-
Including the cities of Independence, Manchester, Dubuque, 
Vinton, Cedar Rapids, Marengo, Iowa City, Sigourney, Washington, 
Fairfield, and Mount Pleasant
656 AM CDT Wed May 12 2021

...FROST ADVISORY WILL EXPIRE AT 7 AM CDT THIS MORNING...

Temperatures will quickly climb through the 40s this morning, 
ending any threat for frost. 

$$

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.