Blizzard eases, benefits of a cold sunny week

Just in case we needed a reminder that it's February, in Minnesota.

Northwest winds gusted to over 40 mph getting snow airborne. Many locations reported visibility at or under 1/4 mile with blizzard conditions in progress. National Weather Service storm reports listed multiple Minnesota counties with blizzard conditions this morning.

• Olivia [Renville Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED WHITEOUT CONDITIONS OVER THE SOUTHERN HALF OF THE COUNTY...MAINLY SOUTH OF HWY 4.

• Redwood Falls [Redwood Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED BLIZZARD CONDITIONS THROUGHOUT THE COUNTY...INCLUDING SEVERAL VEHICLES OFF THE ROAD.

• NEW ULM [Brown Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED BLIZZARD CONDITIONS THROUGHOUT THE COUNTY.ST James [Watonwan Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED BLIZZARD CONDITIONS THROUGHOUT THE COUNTY.

• Fairmont [Martin Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED BLIZZARD CONDITIONS THROUGHOUT THE COUNTY.

• Blue Earth [Faribault Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED BLIZZARD CONDITIONS OVER MUCH OF THE COUNTY WITH NUMEROUS VEHICLES OFF THE ROAD.

• Mankato [Blue Earth Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED WHITEOUT CONDITIONS OVER MAINLY WESTERN HALF OF THE COUNTY.

• ST Peter [Nicollet Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED MANY AREAS WITH WHITEOUT CONDITIONS.

• LE Center [Le Sueur Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED VERY POOR VISIBILITY...INCLUDING SOME BLIZZARD CONDITIONS...THROUGHOUT THE COUNTY.

• Albert LEA [Freeborn Co, MN] LAW ENFORCEMENT reports BLIZZARD at 3:00 AM CST -- POLICE DISPATCH REPORTED WHITEOUT CONDITIONS AND ZERO VISIBILITY IN SOUTHERN HALF OF THE COUNTY.

Driving in a blizzard can be like Russian roulette. One second you see the road, the next second it's like somebody threw a sheet over your windshield and you can't see your front bumper. That's why driving in a blizzard can be deceptively dangerous, and why so many vehicles end up off the disappearing roadway.

Here's how the American Meteorological Society describes a blizzard:

A severe weather condition characterized by high winds and reduced visibilities due to falling or blowing snow.

The U.S. National Weather Service specifies sustained wind or frequent gusts of 16 m per second (30 kt or 35 mi per hour) or greater, accompanied by falling and/or blowing snow, frequently reducing visibility to less than 400 m (0.25 mi) for 3 hours or longer. 

Conditions gradually improve

Travel gradually improves as winds fall below blizzard criteria this afternoon south and west of the Minnesota river. Arctic high pressure noses south this week into Minnesota.

This will likely be the second coldest week of winter in Minnesota. Daytime highs hover in the teens, overnight lows bounce a few degrees either side of zero this week. Temps in the 30s return as soon as next week.

Easy winter overall?

Even with this morning's blizzard, and our semi-arctic forecast this week we're getting off easy this winter when it comes to heating bills.

The NWS calculates Heating Degree Days (HDD) to keep track of comparative accumulated heating costs in winter. The HDD calculates the difference in daily average temperature from 65 degrees based on the likely heated temperatures inside your home.

For example, if the daily average temperatures was 35 degrees, that's 30 HDD for that day. Adding up daily HDD gives us a running tally on how a winter season is going with regard to energy usage.

Here's why your heating bill has been about 20 percent lower that average so far this winter.

• 4887 average HDD to date since July 1st at Minneapolis-St. Paul International Airport

• 3987 actual HDD since July 1

• -900 vs. average

• -19% vs. average

Sunshine matters

Early in my weather career I was an operational meteorologist for a company in Chicago. At Weather Command we issued forecast to several gas and electric utility companies to help them estimate their daily load.

The HDD was a valuable tool. Once we calculated the forecast HDD, we applied correction factors based on wind and sunlight. High winds create additional heating needs by stripping your home of heat through drafts, etc. Bright sunlight reduces heating needs in your home through passive solar effect.

The sun's rays coming through your windows convert into additional heat inside your home, reducing your overall heating demand. The difference can be well over 10 percent on bright sunny days. That can effectively add several degrees to the temperature inside your home.

February is the sunniest month of winter in Minnesota. The higher sun angle, increasing solar intensity and longer daylight help ease your heating bill on sunny days like we'll see this week. So there is a plus side to sunny cold Minnesota winter days.

• 59 percent of possible sunshine on average in in Minnesota in February

• Sunniest month of winter on average in Minnesota

• 79 minutes of daylight gained since Dec. 21

Milder air ahead?

The longer range forecasts suggest a return to milder air again next week.

The National Oceanic and Atmospheric Administration's long range Global Forecast System suggests temps approaching 40 degrees again in about 14 days.

If spring arrives on time or early this year, this could be one of the shortest winters on record.

Stay tuned.