Alert archive / Iowa / Winter Storm Warnings in 2009

Winter Storm Warning 6, NWS Des Moines, IA

April 4, 200929 counties in Iowa

NWS Des Moines, IA issued this winter storm warning at Apr 4, 2009, 4:23 AM CDT for 29 counties in Iowa. It took effect at Apr 5, 2009, 1:00 AM CDT. It was in force for 18 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 4, 2009, 4:23 AM CDT (09:23 UTC)
In effect from
Apr 5, 2009, 1:00 AM CDT
Expired
Apr 5, 2009, 7:00 PM CDT
In force
18 hr
Issued by
NWS Des Moines, IA
All 29 counties

Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Crawford County, IA, Emmet County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Kossuth County, IA, Marshall County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 90 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

Omaha, NE (KOAX), launched 00:00Z, 9.4 hours before the alert went out and 249 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 00:00Z on 2009-04-04Temperature 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, Omaha, NE at 00:00Z on 2009-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 square meters per square second.1939587897117Sfc1 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
2383 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
155 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 storm warning 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 storm warning went out at Apr 4, 3:56 AM CDT, 27 minutes earlier.

Area forecast discussion, Apr 4, 3:56 AM CDT, 27 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Hazardous weather outlook, Apr 3, 3:02 PM CDT, 13 hours 21 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
302 PM CDT FRI APR 3 2009

IAZ004>007-015>017-023>028-033>037-044>047-057-058-042015-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-CRAWFORD-CARROLL-GREENE-BOONE-AUDUBON-
GUTHRIE-
302 PM CDT FRI APR 3 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF CENTRAL IOWA
THIS ENCOMPASSES MAINLY THE NORTHWEST THIRD OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A SIGNIFICANT WINTER STORM IS POSSIBLE THIS WEEKEND. RAIN
CHANGING TO SNOW IS ANTICIPATED LATE SATURDAY AFTERNOON AND
SATURDAY NIGHT. PERIODS OF MODERATE TO HEAVY SNOWFALL WITH
SIGNIFICANT ACCUMULATIONS MAY OCCUR BY SUNDAY MORNING. SNOWFALL
AMOUNTS COULD BE AS HIGH AS 5 TO 10 INCHES. AN INCREASING NORTH
WIND ON SUNDAY COULD CREATE BLIZZARD LIKE CONDITIONS.

A WINTER STORM WATCH IS IN EFFECT FOR THE AREA. PLEASE REFER TO
THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUESTED SATURDAY NIGHT AND SUNDAY FOR
SNOWFALL AND WINTRY CONDITION REPORTS.

IAZ038-039-048>050-042015-
GRUNDY-BLACK HAWK-STORY-MARSHALL-TAMA-
302 PM CDT FRI APR 3 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF CENTRAL IOWA
MAINLY BETWEEN HIGHWAY 20 AND HIGHWAY 30.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A WINTER STORM IS POSSIBLE THIS WEEKEND. RAIN CHANGING TO SNOW IS
ANTICIPATED LATE SATURDAY AND EARLY SUNDAY. BRIEF PERIODS OF
MODERATE TO LOCALLY HEAVY SNOWFALL MAY OCCUR BY SUNDAY
AFTERNOON...WITH ACCUMULATIONS OF 3 TO 5 INCHES POSSIBLE. AN
INCREASING NORTH WIND ON SUNDAY COULD CREATE SOME BLOWING AND
DRIFTING SNOW ESPECIALLY IN OPEN AREAS.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME BUT SNOWFALL
REPORTS WOULD BE APPRECIATED.

IAZ059-060-070>072-081-042015-
DALLAS-POLK-CASS-ADAIR-MADISON-ADAMS-
302 PM CDT FRI APR 3 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF CENTRAL IOWA
MAINLY BETWEEN HIGHWAY 30 AND INTERSTATE 80.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SCATTERED THUNDERSTORMS ARE POSSIBLE MAINLY FROM SATURDAY
EVENING THROUGH SATURDAY NIGHT. AN ISOLATED SEVERE STORM MAY
OCCUR IN THE EVENING. THEREAFTER...RAIN WILL CHANGE TO SNOW ON
SUNDAY WITH ACCUMULATIONS OF 1 TO 3 INCHES POSSIBLE.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME BUT SNOWFALL
REPORTS WOULD BE APPRECIATED.

IAZ061-062-073>075-082>086-092>097-042015-
JASPER-POWESHIEK-WARREN-MARION-MAHASKA-UNION-CLARKE-LUCAS-MONROE-
WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS-
302 PM CDT FRI APR 3 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF CENTRAL IOWA
MAINLY ALONG AND SOUTH OF INTERSTATE 80.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SCATTERED THUNDERSTORMS ARE POSSIBLE FROM SATURDAY EVENING THROUGH SUNDAY
MORNING. AN ISOLATED SEVERE STORM MAY OCCUR SATURDAY EVENING. IN ADDITION...
RAIN WILL CHANGE TO SNOW ON SUNDAY WITH ACCUMULATIONS OF AROUND AN
INCH POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

FAB

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 4:23 AM CDTBlizzard WarningDMXCalhoun, Carroll, Cerro Gordo, Crawford, Emmet, Hancock and 9 more24 hr
Apr 4, 4:23 AM CDTWinter Storm WatchDMXAdair, Adams, Cass, Dallas, Jasper, Madison and 9 more11 hr
Apr 4, 3:26 PM CDTWinter Weather AdvisoryDMXAdair, Adams, Audubon, Boone, Calhoun, Carroll and 25 more28 hr

Nearby

Winter Storm Warnings in Iowa, 2009Every winter storm warning in 2009

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.