December fall flashback: String of 40s for southern Minnesota
Bare ground and sunlight adding several degrees this week.
This is a pretty unusual weather pattern for early December in Minnesota.
As a meteorologist in early December, I am typically posting deepening snow cover maps, babbling about brisk northwest winds and potentially sub-zero wind chills. I’m also usually tracking our next inbound snow event.
Not this year. Take a look at the National Oceanic and Atmospheric Administration’s latest snow cover map across Minnesota. Most of Minnesota is snow-free on Dec. 1.
That’s a big reason why temperatures will run between 5 and 10 degrees warmer than average later this week into next week. The lower albedo of bare ground absorbs sunlight and reradiates it to warm up the lower atmosphere. Snow cover reflects around 90 percent of incoming sunlight before it can warm the air near the ground where we live.
Create a More Connected Minnesota
MPR News is your trusted resource for the news you need. With your support, MPR News brings accessible, courageous journalism and authentic conversation to everyone - free of paywalls and barriers. Your gift makes a difference.
That physics of sunlight reflectivity with bare ground and sunlight are why temperatures soared into the mid to upper 40s in southwest Minnesota Tuesday afternoon.
Highs will reach the 40s much of this week across southern Minnesota. The warmest days will likely be Thursday and Friday. Check out Friday’s high-temperature forecast map below. I think this will be a few degrees too conservative. I think temperatures in the Twin Cities will rise (well) into the 40s Friday afternoon.
The overall weather pattern suggests we could see fall-like mildness linger through most of next week before colder weather arrives.
Stay tuned.