Alert archive / Iowa / Frost Advisories in 2012

Frost Advisory 2, NWS Des Moines, IA

April 7, 201217 counties in Iowa

NWS Des Moines, IA issued this frost advisory at Apr 7, 2012, 3:41 PM CDT for 17 counties in Iowa. It took effect at Apr 8, 2012, 4:00 AM CDT. It was in force for .

The area

The counties it named.

The facts

Issued
Apr 7, 2012, 3:41 PM CDT (20:41 UTC)
In effect from
Apr 8, 2012, 4:00 AM CDT
Expired
Apr 8, 2012, 3:51 AM CDT
In force
Issued by
NWS Des Moines, IA

Counties Adair County, IA, Adams County, IA, Audubon County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Crawford County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Humboldt County, IA, Kossuth County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Taylor County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 90 km from the middle of the area, began a volume at 20:40 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

Omaha, NE (KOAX), launched 12:00Z, 8.7 hours before the alert went out and 168 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, Omaha, NE at 12:00Z on 2012-04-07Temperature 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, Omaha, NE at 12:00Z on 2012-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 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
502 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
232 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

344 
WWUS73 KDMX 072041
NPWDMX

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE DES MOINES IA
341 PM CDT SAT APR 7 2012

.LIGHT WINDS...CLEAR SKIES AND A DRY AIRMASS WILL ALLOW
TEMPERATURES TO DROP NEAR THE FREEZING MARK OVERNIGHT. THIS IS
FORECAST TO PRODUCE AREAS OF FROST DURING THE EARLY MORNING HOURS
OF SUNDAY.

IAZ004-005-015-023-024-033>035-044>046-057-058-070-071-081-092-
080400-
/O.NEW.KDMX.FR.Y.0002.120408T0900Z-120408T1300Z/
EMMET-KOSSUTH-PALO ALTO-POCAHONTAS-HUMBOLDT-SAC-CALHOUN-WEBSTER-
CRAWFORD-CARROLL-GREENE-AUDUBON-GUTHRIE-CASS-ADAIR-ADAMS-TAYLOR-
INCLUDING THE CITIES OF...ESTHERVILLE...ALGONA...EMMETSBURG...
POCAHONTAS...HUMBOLDT...SAC CITY...ROCKWELL CITY...FORT DODGE...
DENISON...CARROLL...JEFFERSON...AUDUBON...GUTHRIE CENTER...
ATLANTIC...GREENFIELD...CORNING...BEDFORD
341 PM CDT SAT APR 7 2012

...FROST ADVISORY IN EFFECT FROM 4 AM TO 8 AM CDT SUNDAY...

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 4 AM TO 8 AM CDT SUNDAY. 

* TEMPERATURE...READINGS ARE FORECAST TO DROP FROM 32 TO 35
  DEGREES DURING THE EARLY MORNING HOURS. THE COLDEST READINGS
  WILL BE IN RIVER VALLEYS SUCH AS THE NISHNABOTNA VALLEYS AND
  OTHER LOW LYING AREAS.

* IMPACTS...SENSITIVE VEGETATION MAY BE IMPACTED BY THE FROST... 
  PLEASE TAKE PRECAUTIONS TO PROTECT ANY OUTDOOR PLANTS THAT MAY 
  BE AFFECTED. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$

CC
2 follow-up statements
691 
WWUS73 KDMX 080145
NPWDMX

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE DES MOINES IA
845 PM CDT SAT APR 7 2012

.LIGHT WINDS...CLEAR SKIES AND A DRY AIR MASS WILL ALLOW
TEMPERATURES TO DROP NEAR FREEZING OVERNIGHT. THIS IS FORECAST TO
PRODUCE AREAS OF FROST DURING THE EARLY MORNING HOURS OF SUNDAY.

IAZ004-005-015-023-024-033>035-044>046-057-058-070-071-081-092-
080945-
/O.CON.KDMX.FR.Y.0002.120408T0900Z-120408T1300Z/
EMMET-KOSSUTH-PALO ALTO-POCAHONTAS-HUMBOLDT-SAC-CALHOUN-WEBSTER-
CRAWFORD-CARROLL-GREENE-AUDUBON-GUTHRIE-CASS-ADAIR-ADAMS-TAYLOR-
INCLUDING THE CITIES OF...ESTHERVILLE...ALGONA...EMMETSBURG...
POCAHONTAS...HUMBOLDT...SAC CITY...ROCKWELL CITY...FORT DODGE...
DENISON...CARROLL...JEFFERSON...AUDUBON...GUTHRIE CENTER...
ATLANTIC...GREENFIELD...CORNING...BEDFORD
845 PM CDT SAT APR 7 2012

...FROST ADVISORY REMAINS IN EFFECT FROM 4 AM TO 8 AM CDT
SUNDAY...

* TEMPERATURE...READINGS ARE FORECAST TO DROP INTO THE LOWER 30S
  OVERNIGHT WITH THE COLDEST READINGS WILL BE IN RIVER VALLEYS SUCH
  AS THE NISHNABOTNA VALLEYS AND OTHER LOW LYING AREAS.

* IMPACTS...SENSITIVE VEGETATION MAY BE IMPACTED BY THE FROST... 
  PLEASE TAKE PRECAUTIONS TO PROTECT ANY OUTDOOR PLANTS THAT MAY 
  BE AFFECTED. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
660 
WWUS73 KDMX 080851
NPWDMX

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE DES MOINES IA
351 AM CDT SUN APR 8 2012

.THE AIR MASS IN PLACE OVER IOWA IS SO DRY THAT FROST FAILED TO DEVELOP
OVERNIGHT. DUE TO THE LACK OF WIDESPREAD FROST DEVELOPMENT THE ADVISORY
WILL BE CANCELLED. HOWEVER...PATCHY FROST IS STILL A POSSIBILITY.

IAZ004-005-015-023-024-033>035-044>046-057-058-070-071-081-092-
081000-
/O.CAN.KDMX.FR.Y.0002.120408T0900Z-120408T1300Z/
EMMET-KOSSUTH-PALO ALTO-POCAHONTAS-HUMBOLDT-SAC-CALHOUN-WEBSTER-
CRAWFORD-CARROLL-GREENE-AUDUBON-GUTHRIE-CASS-ADAIR-ADAMS-TAYLOR-
INCLUDING THE CITIES OF...ESTHERVILLE...ALGONA...EMMETSBURG...
POCAHONTAS...HUMBOLDT...SAC CITY...ROCKWELL CITY...FORT DODGE...
DENISON...CARROLL...JEFFERSON...AUDUBON...GUTHRIE CENTER...
ATLANTIC...GREENFIELD...CORNING...BEDFORD
351 AM CDT SUN APR 8 2012

...FROST ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS CANCELLED THE
FROST ADVISORY. 

VERY DRY AIR IN PLACE OVER CENTRAL IOWA KEPT WIDESPREAD FROST
FROM DEVELOPING. AS A RESULT THE ADVISORY WILL BE CANCELLED.

$$

FAB

Nearby

Frost Advisories in Iowa, 2012Every frost advisory in 2012

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.