The Storm Prediction Center, based out of Norman, Oklahoma has issued a Mesoscale Discussion for a good portion of the state concerning the potential for heavy snowfall. 

A band of snowfall associated with a negatively tilted shortwave through and surface low will result in brief periods of moderate to heavy snow across the Upper Midwest through the evening. 

Meanwhile, a Winter Storm Warning and Winter Weather Advisory remain in effect. 

The forecast winter weather event is unfolding across the state. Here's the very latest update as of 4:15PM:

The National Weather Service has cancelled the Winter Storm Warning for a few counties in the northern half of the state, including Hardin, Grundy, and Black Hawk, and it has been replaced with a Winter Weather Advisory. The warning still continues in some areas, as indicated in pink on the warning map above.

Snowfall forecasts have also been modified, with 4.1" possible in Marshalltown, 2.3" in Iowa Falls, and 2.7" in Waterloo. Although these aren't the massive numbers that were forecast as of last night, they're still enough to create some travel difficulties.

Stay with WolkenWeather.com throughout the evening for further updates.

As we previously warned in the last blog post concerning the approaching winter weather event, any change in the forecast storm track would drastically change forecast thinking.

Well, that scenario just panned out across the state. The latest models and radar imagery show the area of low pressure moving further to the south, which in return means a heavier band of snowfall across a good portion of Iowa. Taking a look at the 48 hour snowfall map to your right, you can see that Marshalltown has been bumped up to 10.5" of snow, Waterloo at 7", and Iowa Falls nearing the 10 inch mark.

Due to the change in track, a Winter Storm Warning has been issued for a large portion of the state, including Hardin, Grundy, Marshall, and Tama counties. 

Conditions may quickly deteriorate Thursday morning into the early afternoon hours. If this holds true, travelling will become quite difficult as visibilites may be reduced to under a quarter of a mile during times of heavier snowfall. 

Be sure to keep up-to-date with the latest watches, warnings, and advisories, road conditions and potential school alerts. 

An extremely complex winter storm system will bring a wide swath of precipitation across the area, starting as rain, quickly transitioning to snow across the watch area.

Firstly, a Winter Storm Watch will go into effect at 3AM Thursday for Grundy, Hardin, Black Hawk and Tama counties just to name a few, view the map above and right for the full spectrum of watches, warnings, and advisories. As of 7:00PM Wednesday evening, Marshall county was not included in any watch, warning, or advisory.

The map on the right depicts the probability for heavy snowfall, the National Weather Service defines heavy snow of at least 4" or more. A slight risk exists for a majority of the state, and a moderate risk lays from the central portion of the state all the way to North Dakota and South Dakota.

So, attempting to break down the approaching system: an area of low pressure will be moving in a general southeasterly direction, and will be close to the state near midnight, and near the Iowa and Nebraska border Thursday. There are definitely some uncertainties with the track, and be advised that any slight shift would drastically change any potential accumulation amounts.

To your left you'll notice 2 weather maps, the first from the 6AM hour Thursday, and the second from around noon tomorrow...both are depicting the precipitation falling in a heavier band of snow in the Marshalltown area. The heaviest snowfall is currently expected to fall during the morning hours into the early afternoon hours if everything holds out.  

It cannot be stressed enough that any small change in the forecast track with this system will significantly impact the current forecast thinking.


The bottom line, hope for the best, whether you're wanting snow or whether you're not, and prepare for the worst. Stay with WolkenWeather.com for the latest updates.

The National Weather Service has issued a Winter Storm Watch for the following counites in Iowa: 

Allamakee, Chickasaw, Fayette, Floyd, Howard, Mitchell, Winneshiek, Benton, Buchanan, Cedar, Clinton, Delaware, Debuque, Iowa, Jackson, Johnson, Jones, Linn, Muscatine, Scott, Black Hawk, Bremer, Butler, Cerro Gordo, Emmet, Franklin, Grundy, Hamilton, Hancock, Hardin, Humboldt, Kossuth, Palo Alto, Pochahontas, Tama, Webster, Winnebago, Worth, and Wright.

We will have a more complete update coming up this afternoon on the WolkenWeather.com Blog. Stay with WolkenWeather.com.

02-22-12 New Market, Iowa (Taylor County) 6:30PM at New Market Community Center
02-28-12 Toldedo, Iowa (Tama County) 7:00PM at Nature Center at Tama County's Otter Creek Park (148 Nature Center Road)
02-28-12 Des Moines, Iowa (Polk County) 7:00PM at Plymouth Congregational Church, 42nd and Ingersol Amature Radio Talk, but public welcome.
02-29-12 Story City, Iowa (Story County) 6:30PM at Story City Fire Station
02-29-12 Grinell, Iowa (Poweshiek County) 7:00PM at Old Glove Factory (733 Broad Street)
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03-01-12 Lamoni, Iowa (Decatur County) 7:00PM at Lamoni Fire Station
03-01-12 Ames, Iowa (Story County) 7:00PM at ISU Campus 4H building (southwest corner of 13th Street & Strange Road in Ames)
03-05-12 Waterloo, Iowa (Black Hawk County) 6:30PM at Hawkeye Community College, Tama Hall
03-06-12 Centerville, Iowa (Appanoose County) 6:45PM at Centerville City Hall
03-06-12 Albia, Iowa (Monroe County) 7:00PM at Fire Station
03-07-12 Williams, Iowa (Hamilton County) 7:00PM at Williams Fire Station
03-08-12 Chariton, Iowa (Lucas County) 7:00PM at Fire Station
03-08-12 Boone, Iowa (Boone County) 7:00PM at Boone Auditorium (923 8th Street)
03-08-12 Prescott, Iowa (Adams County) 7:00PM at Fire Station
03-12-12 Waverly, Iowa (Bremer County) 6:30PM at Wartburg College, Room 214
03-13-12 Buffalo Center, Iowa (Hancock / Winnebago County) 6:30PM at Heritage Town Center, 201 2nd Avenue South West
03-13-12 Ottumwa, Iowa (Wapello County) 6:30PM at Indian Hills Community College, Rural Health Education, Room 111
03-14-12 Lewis, Iowa (Cass County) 7:00PM at Lewus Fire Station
03-14-12 Oskaloosa, Iowa (Mahaska County) 7:00PM at ISU Extension Office, 212 Noth 1st Street
03-15-12 Parkersburg, Iowa (Bulter County) 7:00PM at Parkerburg Fire Department
03-15-12 Crestion, Iowa (Union, County) 7:00PM at Southwest Community College Room 180
03-19-12 Fort Dodge, Iowa (Webster County) 6:30PM at Bio-Science Aud at Iowa Central Community College
03-20-12 Indianola, Iowa (Warren County) 7:00PM at Indianola Activity Center - 2204 West Second Avenue
03-21-12 Mount Ayr, Iowa (Ringgold County) 7:00PM at Assembly Room at Court House
03-22-12 Bloomfield, Iowa (Davis County) 6:30PM at Fire Station
03-22-12 Osceola, Iowa (Clarke County) 6:30PM at Clarke Electric COOP - 1103 North Main (Highway 69)
03-26-12 Carroll, Iowa (Carroll County) 6:30PM at Fire Station
03-27-12 Winterset, Iowa (Madision County) 7:00PM at Farmers & Merchants State Bank - 101 West Jefferson
03-28-12 Jefferson, Iowa (Greene County) 6:30PM at Fire Station
03-29-12 Newton, Iowa (Jasper County) 6:30PM at Jasper County Community Center - 2407 1st Avenue East
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04-03-12 Marshalltown, Iowa (Marshall County) 6:00PM at Iowa Valley Continuing Eductation (DeJardin Hall)
04-03-12 Des Moines, Iowa (Polk County) 7:00PM at Polk County Emergency Management Ops - 1907 Carprnter Ave
04-04-12 Audubon, Iowa (Audobon County) 6:30PM at Courthouse
04-04-12 Estherville, Iowa (Emmet County) 7:00PM at Iowa Lakes Comm College
04-05-12 Ames, Iowa (Story County) 7:00PM at Advanced Spotter Presentaion Hall, ISUm Agronomy Hall Room 2050
04-09-12 Humboldt, Iowa (Humboldt County) 6:30PM at Oxbow - 7 Park Road
04-10-12 Hampton, Iowa (Franklin County) 6:30PM NEW Law Enforcement Center
04-12-12 Grafton, Iowa (Worth County) 6:30PM at Community Center
04-17-12 Clarion, Iowa (Wright County) 6:30PM at Police and EMS Building
04-17-12 Pochahontas, Iowa (Pochahontas County) 7:00PM at Courthouse Assembly room 99 Court Sqaure
04-18-12 Menlo, Iowa (Guthrie County) 7:00PM at Community Center 

The Decorah Eagles have laid their second egg as of Monday evening. Above is a look a Mom and the two eggs, which are expected to hatch sometime in March. 

Active weather is making its return to the Extended Pinpoint Forecast, with several chances of rain, rain/snow mixes, and even wintry mix or two. 

The main focus is this afternoon and overnight. Showers are already popping up on First Alert Pinpoint Doppler in the western half of the state.

Current forecast thinking is as follows. A 20% chance of showers exists today in the Marshalltown area...southern Iowa may get an isolated rumble of thunder. As the day progresses, especially during the overnight hours, precipitation is likely to come in a rain/snow mix. 

Local snowfall accumulations will be light, if any at all. The latest computer model projects 0.3" for the city of Marshalltown. 

The northern counties may receive anywhere from 1 to 3 inches of accumulation.

Stay tuned to WolkenWeather.com, the WolkenWeather.com Blog, and our Facebook fan page for further updates on this approaching weather system.