Oskaloosa.com

December 27, 2012

NWS provides insight into blizzard

By ANDY GOODELL
The Oskaloosa Herald

OSKALOOSA — With temperatures staying below freezing for a while, the snow that fell during the blizzard this past week is likely here to stay.

According to the National Weather Service, additional snowfall is possible today and Friday. However, conditions aren’t expected to mirror those of last week.

NWS Meteorologist Miles Schumacher said most of the snowfall this week will take place in northern Iowa, noting that a lack of wind will make conditions unlike those during the end of last week.

During the blizzard this past week, the Oskaloosa area’s snow totals were very different from those in other parts of the state. In a report on the Blizzard of Dec. 19 and 20, the NWS notes that Oskaloosa received 4 inches of snow, while Des Moines snow totals sat at 12.4 inches.

Schumacher said the snow total differences in last week’s storm were dependent on the storm track. He noted that, because some of the precipitation Oskaloosa received came in the form of rain rather than snow, this helped reduce the area’s snow totals.

The strong winds that came with this precipitation on Dec. 20 are what helped blizzard conditions form, noted Schumacher. He said blizzard conditions occur when sustained or frequent winds of 35 miles per hour for three hours or more take place.

“Technically, it doesn’t have to be snowing at the time,” added Schumacher.

In September, the NWS in  Des Moines upgraded to Dual-Pol radar.

Dual-Pol is expected to show significant improvements in the estimation of precipitation rates, as well as the ability to tell the difference between hail and rain, according to the NWS. The radar upgrade will also improve the ability to identify areas of heavy rainfall typically linked with flash flood events. It is also expected that there will be improved detection and mitigation of non-weather related radar echoes such as smoke plumes and ground clutter. The “melting layer,” which is helpful in identifying snow levels in higher terrain is also expected to see improvement with Dual-Pol radar.

On Wednesday of this week, Schumacher said the Dual-Pol really helps with what can be seen, noting that it helped in seeing the rain/snow changeover line during last week’s weather event.

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Herald City Editor Andy Goodell can  be reached at news2@oskyherald.com.