Alert archive / Iowa / Frost Advisories in 2021

Frost Advisory 2, NWS Quad Cities, IA

April 14, 20218 counties in Iowa; 5 counties in Illinois; Clark County, Scotland County, Missouri

NWS Quad Cities, IA issued this frost advisory at Apr 14, 2021, 2:45 PM CDT for 8 counties in Iowa; 5 counties in Illinois; Clark County, Scotland County, Missouri. It took effect at Apr 15, 2021, 1:00 AM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Apr 14, 2021, 2:45 PM CDT (19:45 UTC)
In effect from
Apr 15, 2021, 1:00 AM CDT
Expired
Apr 15, 2021, 8:00 AM CDT
In force
7 hr
Issued by
NWS Quad Cities, IA

Counties Des Moines County, IA, Henry County, IA, Jefferson County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Van Buren County, IA, Washington County, IA, Hancock County, IL, Henderson County, IL, McDonough County, IL, Mercer County, IL, Warren County, IL, Clark County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 109 km from the middle of the area, began a volume at 19:43 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 115 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 2021-04-14Temperature 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 2021-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1502 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

371 
WWUS73 KDVN 141945
NPWDVN

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

IAZ076>078-087>089-098-099-ILZ024>026-034-035-MOZ009-010-150345-
/O.NEW.KDVN.FR.Y.0002.210415T0600Z-210415T1300Z/
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
245 PM CDT Wed Apr 14 2021

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

* WHAT...Temperatures as low as 32 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 Thursday.

* 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
4 follow-up statements
575 
WWUS73 KDVN 150146
NPWDVN

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


IAZ076>078-087>089-098-099-ILZ024>026-034-035-MOZ009-010-151000-
/O.CON.KDVN.FR.Y.0002.210415T0600Z-210415T1300Z/
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
846 PM CDT Wed Apr 14 2021

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

* WHAT...Temperatures as low as 32 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 Thursday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
110 
WWUS73 KDVN 150813
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
313 AM CDT Thu Apr 15 2021

IAZ076>078-087>089-098-099-ILZ024>026-034-035-MOZ009-010-151300-
/O.CON.KDVN.FR.Y.0002.000000T0000Z-210415T1300Z/
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
313 AM CDT Thu Apr 15 2021

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

* WHAT...Temperatures as low as 32 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 Thursday.

* 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
217 
WWUS73 KDVN 150815
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
315 AM CDT Thu Apr 15 2021

IAZ076>078-087>089-098-099-ILZ024>026-034-035-MOZ009-010-151300-
/O.CON.KDVN.FR.Y.0002.000000T0000Z-210415T1300Z/
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
315 AM CDT Thu Apr 15 2021

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

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

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

* WHEN...Through 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
145 
WWUS73 KDVN 151310
NPWDVN

URGENT - WEATHER MESSAGE
National Weather Service Quad Cities IA IL
810 AM CDT Thu Apr 15 2021

IAZ076>078-087>089-098-099-ILZ024>026-034-035-MOZ009-010-151415-
/O.EXP.KDVN.FR.Y.0002.000000T0000Z-210415T1300Z/
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
810 AM CDT Thu Apr 15 2021

...FROST ADVISORY HAS EXPIRED...

Temperatures have warmed and the threat for frost has diminished.

$$

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.