Updraft: November 17, 2009 Archive

Early November Warmth: A new trend?

Posted at 8:29 AM on November 17, 2009 by Paul Huttner (2 Comments)

Twin Cities NWS forecasts a high of 50 in the Twin Cities Saturday. The average high is 36 degrees.

The ranking are in for our unseasonably mild first half of November in the Twin Cities.

According to the Minnesota State Climatology Office, our average temperature of 45.5 degrees was the 7th mildest start to November on record. The warmth was widespread this month. Several area cities recorded top ten warm first 15 days of November including:

-Fargo: 4th warmest
-St. Cloud, Rochester & Sioux Falls: 5th warmest
-International Falls: 6th warmest
-Duluth: 7th warmest

In addition to one of the warmest such periods on record for early November, it appears a trend may be emerging in the last decade toward warm spells in early November. Four of the top 10 warmest early November periods have occurred in the past 11 years including:

#1) 51.1 degrees in 2001
#4) 45.9 degrees in 1999
#7) 45.5 degrees in 2009
#9) 44.9 degrees in 2005

The average temperature for the first half of November in the Twin Cities is 36.5 degrees.

Thanksgiving Preview: Colder

It appears our blissfully mild weather will linger though the weekend. The upper air pattern shows signs of cahnging as we move onto next week. Right now the GFS model is indicating a fairly cold shot of air by Thanksgiving Day.

NOAA GFS forecast model surface chart for noon Thanksgiving Day indicates cold air pouring southward from Canada.

This could mean highs in the upper 20s or lower 30s by Thanksgiving Day. There are some signs temperatures could moderate a bit by Saturday and Sunday of Thanksgiving weekend.

This pattern change could be a longer term trend for the rest of November as temperatures return to near or colder than average levels by the end of November.

PH

(2 Comments)

Mild November: Open water in December?

Posted at 4:07 PM on November 17, 2009 by Paul Huttner (6 Comments)

Ice free shoreline soaking up November sun on St. Louis Bay in Lake Minnetonka. (Photos by Paul Huttner)

Things are beginning to look a little odd in Minnesota these days.

This is the week when we would expect to see snow cover blanketing the ground in the Twin Cities. Our average date for the first inch of snow cover is November 21st. That's Saturday folks. No sign that will happen this year. In fact we could be pushing 50 again this weekend.

While springtime "ice-out" data is abundant in Minnesota, ice "freeze-up" data is sparse and hard to come by for Minnesota lakes. Maybe we're all a bit in denial when our favorite lake freezes over.

Still I can remember many years when I was skating (foolishly perhaps) on smaller bays in Lake Minnetonka by Thanksgiving weekend. I would say it is quite common to start seeing the first ice forming on ponds and small lakes and bays by this week. And I've seen many years with Lake Minnetonka covered with ice by the first week of December.

Late season boater out for a mid-November ride on Lake Minnetonka.

So far this year there is not a hint of ice on any area lakes or ponds. In fact, I believe all lakes in Minnesota are ice free as of today. And if you look at the GOES 1km visible satellite image below you can see it appears that lakes are ice free well north into Ontario.

College of DuPage visible satellite image form today shows lakes in northern Minnesota and southern Ontario largely ice-free on November 17th.

The medium-range forecast maps do show a cooling trend in the next two weeks. This should bring down enough cold air to freeze up some ponds and small bays by around the first of December. Still, there are indications of periodic warm spells. That might keep the big water open for several weeks to come. That would mean open water is possible on large Minnesota lakes well into December. There is evidence that supports a climate shift induced trend toward later ice-in and earlier ice-out sates in Minnesota.

It's said there really is no bad weather, just different kinds of good weather. Most of us are enjoying our balmy November. The ice fishing crowd? Not so much.

PH

(6 Comments)