December chill this week; thaw ahead next week?

Welcome to meteorological winter.

December through February are the three coldest months of the year in the northern hemisphere. That’s why meteorologists break down the seasons a little differently than the seasonal astronomical calendar.

National Oceanic and Atmospheric Administration

Here’s more on the meteorological seasons from the National Oceanic and Atmospheric Administration.

Meteorologists and climatologists break the seasons down into groupings of three months based on the annual temperature cycle as well as our calendar.

We generally think of winter as the coldest time of the year and summer as the warmest time of the year, with spring and fall being the transition seasons, and that is what the meteorological seasons are based on.

Meteorological spring includes March, April, and May; meteorological summer includes June, July, and August; meteorological fall includes September, October, and November; and meteorological winter includes December, January, and February.

Chilly week

We enjoy the chilly weather fruits of our recent fresh snow cover and brisk Canadian breezes this week. An arctic front Wednesday night brings a brisk weather punctuation mark to end this week. Thursday and Friday look downright frigid.

NOAA, via Weather Bell

The arctic front may bring some light snow showers Wednesday night.

Thaw next week?

The upper-air pattern blows in milder Pacific air starting this weekend. An extended thaw looks likely next week.

Check out the mild Pacific flow on the upper-air forecast map starting as soon as Sunday.

Upper-air forecast for Sunday, via NOAA

El Nino flavored winter

Is the coming upper air pattern a symptom of our El Niño flavored winter ahead?  My guess is we’ll see a higher than usual number of thaws this winter.

 

90-day temperature outlook for December through February, via NOAA

Stay tuned.

  • Phelmer says

    I am dismayed how consistently cloudy it has been for many weeks now. Is this within the “normal” range? Anybody else bothered by this?

    • Dave

      Check the updraft posts from this weekend. There was a note in there about this being the cloudiest fall since 1983.

  • Thomas Williford

    I should have asked this back in mid-October, when we had our first measurable snow:
    Given the late April snowfall, it seems that 2018 had less than six months without measurable snow (at least from my view in Excelsior). Is my perception correct? And how common is it for there to be less than six months between first and last snowfall in the Twin Cities metro?

    • Chris C

      I don’t have data to support this. Lived here 23 years. Mid-April snow isn’t that unusual. Oct snow is fairly common. That sets it up for not that uncommon especially if you fudge the actual days a little? Meaning say snow 4/10 and 10/16. Meaning 6 days long of 6 months. Granted recent 10 years seem a little different than my first 10 years with some years winter not getting here until mid-December. Maybe a better question for Mark Seeley at U of M if you can find a contact.

    • Chris C

      And there you go. Mark was the right resource. I found his email and in his blog today:

      MPR listener question:
      For this year 2018 the last measurable snowfall in the Twin Cities in the Spring was April 16 (0.1”) and the first measurable snowfall in the Autumn was October 14th (0.3”) a period of almost exactly six months. How often is the period between last Spring and first Autumn snowfall only six months or less?

      Answer:
      Looking at the Twin Cities snowfall records back to 1884 (a period of 135 years), the last Spring and first Autumn measurable snowfalls have been separated by six months in 48 years, about 36 percent of the time. Remarkably in 1885, 1888, 1925, 1929, 1954, 1961, 1967, and 1976 the last Spring snowfall and first autumn snowfall were only separated by 5 months! Most of those years had snowfall in May.