Alert archive / Iowa / Winter Weather Advisories in 2012

Winter Weather Advisory 2, NWS Des Moines, IA

January 20, 20129 counties in Iowa

NWS Des Moines, IA issued this winter weather advisory at Jan 20, 2012, 3:27 AM CST for 9 counties in Iowa. It was in force for 13 hr.

The area

The counties it named.

The facts

Issued
Jan 20, 2012, 3:27 AM CST (09:27 UTC)
Expired
Jan 20, 2012, 3:57 PM CST
In force
13 hr
Issued by
NWS Des Moines, IA

Counties Boone County, IA, Calhoun County, IA, Greene County, IA, Jasper County, IA, Marshall County, IA, Polk County, IA, Poweshiek County, IA, Sac County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 30 km from the middle of the area, began a volume at 09:28 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 00:00Z, 9.5 hours before the alert went out and 272 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 00:00Z on 2012-01-20Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2012-01-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.1939587897117136156175Sfc1 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
1787 m above ground
0-6 km bulk shear
86 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
239 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this winter weather advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this winter weather advisory went out at Jan 20, 3:15 AM CST, 12 minutes earlier.

Area forecast discussion, Jan 20, 3:15 AM CST, 12 minutes before
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Hazardous weather outlook, Jan 19, 3:26 PM CST, 12 hours 1 minute before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
326 PM CST THU JAN 19 2012

IAZ004>007-015>017-023>028-035>039-050-201200-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-WEBSTER-HAMILTON-
HARDIN-GRUNDY-BLACK HAWK-TAMA-
326 PM CST THU JAN 19 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MUCH OF NORTHERN IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

MODERATE TO HEAVY SNOW WILL DEVELOP ACROSS NORTHERN IOWA EARLY
FRIDAY MORNING. A WINTER STORM WARNING IS IN EFFECT FOR THIS AREA.
PLEASE REFER TO THE NATIONAL WEATHER SERVICE WEBSITE AT
WEATHER.GOV/DESMOINES FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A WINTER STORM WARNING REMAINS IN EFFECT FOR NORTHERN IOWA FRIDAY
WITH CONTINUED MODERATE TO HEAVY SNOW ANTICIPATED. PLEASE REFER
TO THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES
FOR FURTHER DETAILS.

DANGEROUS WIND CHILLS OF 15 TO 20 DEGREES BELOW ZERO ARE ALSO EXPECTED
FROM FRIDAY EVENING INTO SATURDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED. HOWEVER...SNOWFALL REPORTS
ARE ENCOURAGED AND APPRECIATED.

IAZ033-034-044>049-057>062-070>075-081>086-092>097-201200-
SAC-CALHOUN-CRAWFORD-CARROLL-GREENE-BOONE-STORY-MARSHALL-AUDUBON-
GUTHRIE-DALLAS-POLK-JASPER-POWESHIEK-CASS-ADAIR-MADISON-WARREN-
MARION-MAHASKA-ADAMS-UNION-CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-
RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS-
326 PM CST THU JAN 19 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
SOUTHERN IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SNOW IS LIKELY FROM LATE TONIGHT THROUGH FRIDAY. LIGHT TO
MODERATE ACCUMULATIONS ARE EXPECTED WITH THIS SYSTEM.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED. HOWEVER...SNOWFALL REPORTS
ARE ENCOURAGED AND APPRECIATED.

SMALL

Nearby

Winter Weather Advisories in Iowa, 2012Every winter weather 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.