Updraft: May 11, 2009 Archive

Spring blossoms

Posted at 7:03 AM on May 11, 2009 by Craig Edwards

Mother Nature chose to reveal the splendor of the crab apple blossoms this weekend.

Hopefully you didn't rush out and plant your annuals in eastern Minnesota and western Wisconsin. Early morning temperatures in the upper 20s to middle 30s, outside the metro, along with calm winds allowed for frost to form.

A warm front will show itself from about Canby to Waconia this afternoon, with the best chance for showers and isolated thunder north of the front later today and into tonight.

Best chance for rain in the Twin Cities comes Tuesday night into Wednesday morning.

Still a stray snow shower possible in far northern Minnesota Wednesday night. Milder air having a hard time holding its place over the upper Midwest this spring!

CE

Thunder ahead

Posted at 3:57 PM on May 11, 2009 by Paul Huttner

Storm Prediction Center outlook for Wednesday indicates a moderate risk in Ohio Valley.

These are big days for tornado researchers. Vortex2 kicks off this week. Over 100 research scientists are nomadically roaming the Midwest for a month. It's the biggest tornado research project in history. Here are some numbers.

100 scientists
40 vehicles
10 mobile Doppler radars
10 mobile mesonet vehicles packed with weather instruments
38 "deployable" instruments (think "Dorothy" from Twister)

As teams of researchers stalk tornado prey over the next month they will be measuring rotation, wind speed and circulation patterns as never before. They will fly unmanned aerial vehicles into storms and near tornadoes. They will lay out "tornado pods" ahead of advancing twisters in hopes of scoring a direct hit.

Current tornado warnings have a 70% false alarm rate. The average warning lead time for tornadoes that do touch down is 13 minutes. The goals of Vortex2 will be to reduce the false alarm rate for tornado warnings, increase lead time, and to find out why one storm can drop a deadly tornado while another similar looking storm on radar does not.

Let's hope they find some good answers. We can use them.

Keep an eye and ear out this week for thunderstorms. It looks like a potent cool front will trigger storms Tuesday into early Wednesday. It will be tough to pin down timing with this system, but we will probably get two waves of precip between early Tuesday and Wedneasday noon. Right now Thursday looks like the best bet for a dry sunny day.

PH