Alert archive / Iowa / Frost Advisories in 2021

Frost Advisory 1, NWS Quad Cities, IA

April 13, 202113 counties in Iowa; Clark County, Scotland County, Missouri; 9 counties in Illinois

NWS Quad Cities, IA issued this frost advisory at Apr 13, 2021, 2:47 PM CDT for 13 counties in Iowa; Clark County, Scotland County, Missouri; 9 counties in Illinois. It took effect at Apr 14, 2021, 1:00 AM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Apr 13, 2021, 2:47 PM CDT (19:47 UTC)
In effect from
Apr 14, 2021, 1:00 AM CDT
Expired
Apr 14, 2021, 8:00 AM CDT
In force
7 hr
Issued by
NWS Quad Cities, IA
All 24 counties

Cedar County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Bureau County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, McDonough County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Warren County, IL, Clark County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 73 km from the middle of the area, began a volume at 19:49 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, 7.8 hours before the alert went out and 78 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 2021-04-13Temperature 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 2021-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -107 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
1104 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
-107 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.

473 
WWUS73 KDVN 131947
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
247 PM CDT Tue Apr 13 2021

IAZ076>078-087>089-098-099-ILZ024>026-034-035-MOZ009-010-140400-
/O.NEW.KDVN.FR.Y.0001.210414T0600Z-210414T1300Z/
Keokuk-Washington-Louisa-Jefferson-Henry IA-Des Moines-Van Buren-
Lee-Mercer-Henderson-Warren-Hancock-McDonough-Scotland-Clark-
Including the cities of Sigourney, Washington, Wapello, 
Fairfield, Mount Pleasant, Burlington, Keosauqua, Fort Madison, 
Aledo, Oquawka, Monmouth, Carthage, Macomb, Memphis, and Kahoka
247 PM CDT Tue Apr 13 2021

...FROST ADVISORY IN EFFECT FROM 1 AM TO 8 AM CDT WEDNESDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Portions of northeast Missouri, southeast Iowa and 
  northwest and west central Illinois.

* WHEN...From 1 AM to 8 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
745 
WWUS73 KDVN 140103
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
803 PM CDT Tue Apr 13 2021

IAZ063>065-067-068-ILZ015>018-140915-
/O.EXA.KDVN.FR.Y.0001.210414T0600Z-210414T1300Z/
Iowa-Johnson-Cedar-Muscatine-Scott-Rock Island-Henry IL-Bureau-
Putnam-
Including the cities of Marengo, Iowa City, Tipton, Muscatine, 
Davenport, Bettendorf, Moline, Rock Island, Geneseo, Princeton, 
and Hennepin
803 PM CDT Tue Apr 13 2021

...FROST ADVISORY IN EFFECT FROM 1 AM TO 8 AM CDT WEDNESDAY...

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

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

* WHEN...From 1 AM to 8 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.

&&

$$

IAZ076>078-087>089-098-099-ILZ024>026-034-035-MOZ009-010-140915-
/O.CON.KDVN.FR.Y.0001.210414T0600Z-210414T1300Z/
Keokuk-Washington-Louisa-Jefferson-Henry IA-Des Moines-Van Buren-
Lee-Mercer-Henderson-Warren-Hancock-McDonough-Scotland-Clark-
Including the cities of Sigourney, Washington, Wapello, 
Fairfield, Mount Pleasant, Burlington, Keosauqua, Fort Madison, 
Aledo, Oquawka, Monmouth, Carthage, Macomb, Memphis, and Kahoka
803 PM CDT Tue Apr 13 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 8 AM CDT
WEDNESDAY...

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

* WHERE...Portions of northeast Missouri, southeast Iowa and 
  northwest and west central Illinois.

* WHEN...From 1 AM to 8 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
563 
WWUS73 KDVN 140803
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
303 AM CDT Wed Apr 14 2021

IAZ063>065-067-068-076>078-087>089-098-099-ILZ015>018-024>026-034-
035-MOZ009-010-141300-
/O.CON.KDVN.FR.Y.0001.000000T0000Z-210414T1300Z/
Iowa-Johnson-Cedar-Muscatine-Scott-Keokuk-Washington-Louisa-
Jefferson-Henry IA-Des Moines-Van Buren-Lee-Rock Island-Henry IL-
Bureau-Putnam-Mercer-Henderson-Warren-Hancock-McDonough-Scotland-
Clark-
Including the cities of Marengo, Iowa City, Tipton, Muscatine, 
Davenport, Bettendorf, Sigourney, Washington, Wapello, Fairfield,
Mount Pleasant, Burlington, Keosauqua, Fort Madison, Moline, 
Rock Island, Geneseo, Princeton, Hennepin, Aledo, Oquawka, 
Monmouth, Carthage, Macomb, Memphis, and Kahoka
303 AM CDT Wed Apr 14 2021

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

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

* WHERE...Portions of northeast Missouri, southeast Iowa and 
  northwest and west central Illinois.

* WHEN...Through 8 AM Today.

* 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
954 
WWUS73 KDVN 141304
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
804 AM CDT Wed Apr 14 2021

IAZ063>065-067-068-076>078-087>089-098-099-ILZ015>018-024>026-034-
035-MOZ009-010-141415-
/O.EXP.KDVN.FR.Y.0001.000000T0000Z-210414T1300Z/
Iowa-Johnson-Cedar-Muscatine-Scott-Keokuk-Washington-Louisa-
Jefferson-Henry IA-Des Moines-Van Buren-Lee-Rock Island-Henry IL-
Bureau-Putnam-Mercer-Henderson-Warren-Hancock-McDonough-Scotland-
Clark-
Including the cities of Marengo, Iowa City, Tipton, Muscatine, 
Davenport, Bettendorf, Sigourney, Washington, Wapello, Fairfield,
Mount Pleasant, Burlington, Keosauqua, Fort Madison, Moline, 
Rock Island, Geneseo, Princeton, Hennepin, Aledo, Oquawka, 
Monmouth, Carthage, Macomb, Memphis, and Kahoka
804 AM CDT Wed Apr 14 2021

...FROST ADVISORY HAS EXPIRED...

Temperatures have warmed above freezing across the area with the
sunrise. Therefore, the frost advisory has been allowed to expire.

$$

www.weather.gov/dvn

Nearby

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