Posted at 6:00 PM on January 31, 2013
by Paul Huttner
Friday morning brings the coldest morning of the year to many Minnesota locations.
Today in Updraft we look at the perfect recipe for cold. What weather elements conspire to make a cold Minnesota winter night? Weekend Clippers may bring a few bouts of light snow. We preview RadarScope, a popular radar app for your smart phone.
-10 to -15F likely in the inner metro core Friday morning
-20F to -30F in northern & western Minnesota early Friday
Wind chill warnings & advisories until noon Friday
That's how comedian Lewis Black describes -20F in Minnesota in winter. He's got a point.
This is one of those times when weather is literally life threatening in Minnesota if you get caught outside for too long.
Wind chills Friday morning at 7am approach -30F in the metro, and -41F in Duluth and International Falls.
MinnArctica: Recipe for bitter cold
What elements make for the coldest night of the winter?
1) A bitter arctic air mass: Temps upstream hovered around -46F at Yellowknife in Canada's Northwest Territories Thursday morning.
2) Clear skies: What little heat there is radiates out to space with a "cloud blanket."
3) Light winds: With the "inner isobar" of arctic high pressure overahead, winds die off. That allows the atmosphere to "stratify" and the coldest air collects near the ground. It's counterintuitive, but breeze nights are actually warmer as wind mixes the air.
4) Snow cover: The "albedo" of fresh snow cover is perfect for reflecting sunlight that would heat the atmosphere during the day, and radiating back into space at night. Nights with fresh snow cover are easily 10F colder than nights without snow in winter.
Clipperville: Weekend snow chances
A series of weak Alberta Clippers will sail through this weekend in the northwest flow over Minnesota.
Best chances for up to an inch of snow?
Friday night & Saturday, Sunday night & Monday night.
RadarScope: Detailed radar imagery for the "weather enthusiast"
I'm throwing a few Smartphone weather apps your way now and then. I'm not selling here...or judging, I'll leave that up to you. Just informing on what I find that you might want to check out.
Here's RadarScope... a radar app that gets a lot of good reviews. This is more detailed doppler data for the serious user. Cost? $9.99
RadarScope is a specialized display utility for weather enthusiasts and meteorologists that allows you to view NEXRAD Level 3 radar data and severe weather warnings. It can display the latest reflectivity, velocity, and other radar products from any NEXRAD radar site in the United States and Puerto Rico, with the exception of Alaska, Hawaii, and Guam. These aren't smoothed PNG or GIF images, this is real Level 3 radar data rendered in its original radial format for a high level of detail.
Whether you are scanning reflectivity for a mesocyclone's tell-tale hook echo, trying to pinpoint the landfall of a hurricane's eye wall, or looking for small features like velocity couplets in the storm relative radial velocity product, RadarScope gives you the power to view true radial NEXRAD weather radar on your Android smartphone or tablet.
RadarScope displays tornado, severe thunderstorm, and flash flood warnings issued by the National Weather Service. When warnings are in effect, you can tap the warning button in the upper right corner to browse the list of active warnings, select a warning to view the details, and even zoom to the selected warning on the map.
I have radarscope on my phone. Experimented with the product suite during severe weather in Missouri on Tuesday night.
I am fascinated by the data presented in RadarScope, but honestly I don't understand the various radar imaging (reflectivity, velocity, tilt, differential, etc) or how meterologist uses the data to make predictions.
Maybe from time to time you can explain some of the basics to us. Thank you.
had -15 in Richfield when I left this morning..