Updraft: January 26, 2009 Archive

Too much, too little

Posted at 7:01 AM on January 26, 2009 by Craig Edwards

This graphic posted last week from the Midwest Climate Center shows the soil moisture deviation in the upper Midwest. Notice the two disparities between the very wet region across the Red River Valley and dry conditions around the Twin Cities and Rochester.

Currently, the National Weather Service is projecting a ninety percent probability that the Red River of the North will reach major flood stage of thirty feet in Fargo. This is a very early outlook. The forecast verification is highly determined by spring snow melt, additional late winter snowfall adding to the water content and spring rainfall.

Grand Forks Hydrologic Outlook

Officials will be meeting regularly, beginning this week, to monitor the conditions and plan preparedness strategies.

No sloppy snowstorms in the immediate offing for our region.

CE
naturesmessenger.com

Snow rollers

Posted at 2:46 PM on January 26, 2009 by Paul Huttner (4 Comments)

Perfect snow and weather conditions combine to create "snow rollers" in a Vermont field. Photo by Allon G. Wildgust and courtesy of meteorologist Sharon Meyer, WCAX-TV Burlington, VT.

Weather has some strange ways of making really cool things. One example is snow rollers. They are fairly rare, but given the right conditions they do occur.

Snow rollers form when the snow has just the right combination of sticky snow that is light enough to be moved by wind. If the wind is strong enough, it picks up snow crystals and begins to tumble them over across "downstream" snow cover. Soon a little mini snowball forms. As it grows and increases surface area, the wind gusts push sheets of snow along.

As it grows and rolls along, it picks up more and more snow just like when you build a snowman in your yard. Since there is no compaction going on by pressure from hands, the center can remain open.

Snow rollers can occur anywhere snow and wind conditions are just right. As you can see from the photo, it helps to have a "downhill lie."

It may not be alien crop circles, but it must be pretty startling to wake up and look out in your field and see snow rollers. Behold the mysteries of weather!

PH

Comment on this post