Alert archive / Iowa / Winter Storm Warnings in 2021

Winter Storm Warning 1, NWS Sioux Falls, SD

February 21, 2021Ida County, Woodbury County, Iowa; Dakota County, Nebraska

NWS Sioux Falls, SD issued this winter storm warning at Feb 21, 2021, 11:24 AM CST for Ida County, Woodbury County, Iowa; Dakota County, Nebraska. It was in force for 4 hr. 6 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Feb 21, 2021, 11:24 AM CST (17:24 UTC)
Expired
Feb 21, 2021, 3:50 PM CST
In force
4 hr
Issued by
NWS Sioux Falls, SD

Counties Ida County, IA, Woodbury County, IA, Dakota County, NE

The radar

The Omaha radar (KOAX), 122 km from the middle of the area, began a volume at 17:25 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.

What was reported inside it

TimeReportWhereRemark
Feb 21, 12:15 PM CSTHEAVY SNOW 61 Wsw Ida Grove, IACORRECTS PREVIOUS SNOW REPORT FROM 1 WSW IDA GROVE. STILL SNOWING.
Feb 21, 12:20 PM CSTHEAVY SNOW 7Battle Creek, IACORRECTS PREVIOUS SNOW REPORT FROM BATTLE CREEK. STILL SNOWING.
Feb 21, 2:20 PM CSTSNOW 4.53 Nne Sioux City, IACORRECTED FOR STORM TOTAL SNOWFALL.
Feb 21, 2:50 PM CSTSNOW 6.5South Sioux City, NESTORM TOTAL SNOWFALL. REPORTED VIA SOCIAL MEDIA.
Feb 21, 2:50 PM CSTHEAVY SNOW 8Battle Creek, IASTORM TOTAL SNOWFALL.
Feb 21, 3:00 PM CSTHEAVY SNOW 81 Wsw Ida Grove, IACORRECTED TO REFLECT STORM TOTAL SNOWFALL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 5.4 hours before the alert went out and 122 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 2021-02-21Temperature 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 2021-02-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 184 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
590 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
184 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

112 
WWUS43 KFSD 211724
WSWFSD

URGENT - WINTER WEATHER MESSAGE
National Weather Service Sioux Falls SD
1124 AM CST Sun Feb 21 2021

IAZ031-032-NEZ014-220000-
/O.UPG.KFSD.WW.Y.0008.000000T0000Z-210222T0000Z/
/O.NEW.KFSD.WS.W.0001.210221T1724Z-210222T0000Z/
Woodbury-Ida-Dakota-
1124 AM CST Sun Feb 21 2021

...WINTER STORM WARNING IN EFFECT UNTIL 6 PM CST THIS EVENING...

* WHAT...Heavy snow. Additional snow accumulations of up to two
  inches. Storm total snow accumulations of 5 to 7 inches. 

* WHERE...In Nebraska, Dakota County. In Iowa, Woodbury and Ida 
  Counties.

* WHEN...Until 6 PM CST this evening.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ002-003-012>014-020>022-MNZ090-NEZ013-SDZ071-220000-
/O.CON.KFSD.WW.Y.0008.000000T0000Z-210222T0000Z/
Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Jackson-Dixon-Union-
1124 AM CST Sun Feb 21 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...

* WHAT...Snow. Additional snow accumulations of up to one inch.

* WHERE...Portions of southeast South Dakota, northeast 
  Nebraska, northwest Iowa and southwest Minnesota.

* WHEN...Until 6 PM CST this evening.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/siouxfalls
1 follow-up statement
010 
WWUS43 KFSD 212150
WSWFSD

URGENT - WINTER WEATHER MESSAGE
National Weather Service Sioux Falls SD
350 PM CST Sun Feb 21 2021

IAZ031-032-NEZ014-212300-
/O.CAN.KFSD.WS.W.0001.000000T0000Z-210222T0000Z/
Woodbury-Ida-Dakota-
350 PM CST Sun Feb 21 2021

...WINTER STORM WARNING IS CANCELLED...

Heavy snow has exited the region. Light snow will continue to
taper off through this evening. Little to no additional
accumulation expected.

$$

IAZ002-003-012>014-020>022-MNZ090-NEZ013-SDZ071-212300-
/O.CAN.KFSD.WW.Y.0008.000000T0000Z-210222T0000Z/
Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Jackson-Dixon-Union-
350 PM CST Sun Feb 21 2021

...WINTER WEATHER ADVISORY IS CANCELLED...

Heavy snow has exited the region. Light snow will continue to 
taper off through this evening. Little to no additional 
accumulation expected.

$$

For more information from the National Weather Service visit
https://weather.gov/siouxfalls

Nearby

Winter Storm Warnings in Iowa, 2021Winter Storm Warnings in Nebraska, 2021Every winter storm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.