Updraft: November 17, 2011 Archive

Saturday Snow; Drought deepens; Metro sized Antarctic iceberg?

Posted at 9:02 AM on November 17, 2011 by Paul Huttner
Filed under: Climate, Winter 2011-12, Winter storms

Updraft Headlines:

-6 degrees - in Hallock this morning!
(Season's first sub-zero temp in Minnesota)

16 degrees at MSP Airport - coldest since March 27th

4% - approximate indoor relative humidity in your home today

Growing chance of snow Saturday from the metro north

-6.69" rainfall deficit in the Twin Cities since August 1st!

99.52% of Minnesota in some stage of drought according to latest U.S. Drought Monitor

Metro sized iceberg ready to break off in Antarctica according to NASA

6 dead and counting in southeast tornado outbreak

Coldest so far...

We'll hear that line again many times over the next month or two. Today it was tiny Hallock in far northwest corner of Minnesota that recorded the first sub-zero temperature of the season in Minnesota. The mercury dipped to a frigid -6 at Hallock this morning!

The Twin Cities bottomed out at 16 degrees around 7 am today! That's the coldest since March 27th, nearly 8 months ago.

The Arctic Desert: Just add water!

Welcome to the Arctic Desert. This bone numbing air mass is also extremely dry. Dew points are in the single digits in much of Minnesota today.

As you take that dry air indoors and heat it up, relative humidity plunges inside your home. The approximate relative humidity if you heat your home to 65 degrees is around 4% today!

No wonder you're getting door knob zapped, and your skin is cracking like crazy.

It's a good time to check the indoor humidifier on your furnace or add water to the air in your home if you can.

Saturday Snow: Still on track

The early Thursday model runs are still on track for snow Saturday from the metro north.

The GFS, NAM and other models seem to mostly agree on tracking low pressure through Iowa to south of La Crosse Saturday. As the fast moving system zips by, it should lay down a few inches of snow.

Still to early to pinpoint totals, but what we can credibly say is the quick pace of the system will not give it time to gulp down hugs amounts of moisture from the Gulf of Mexico. That should keep snowfall totals down into the manageable (but potentially shovelable) range. I don't see a Mega Storm with double digit snowfall totals this time.

At this time the most reliable advice is to plan on snow Saturday and Saturday evening from the metro north and west, with lesser amounts south and east.

NAM model hints at lighter snow totals near the metro, with heavier snow in northwest Wisconsin.

Stay tuned, there are still model snowfall differences for the metro and possible track changes. I'll put some numbers out tomorrow.

Drought Deepens

The latest U.S. Drought Monitor shows a full 99.52% of Minnesota is now "abnormally dry" or in some stage of drought. Severe drought now extends form the southwest metro to the Iowa border, and from near Ely to the North Shore.

The metro is running nearly 7" behind on rainfall since August 1st, with deficits as high as 9" in southern Minnesota near Mankato, Waseca, Northfield, Faribault and Owatonna.

The average date of soil freeze is nearly here, and we desperately need significant rainfall to soak into the ground before the soil is locked up until spring. Unfortunately the weather maps look relatively dry the next two weeks.

It's crazy how we've transitioned from one of the most extreme severe weather barrages in Minnesota history last year to deep drought in just a few weeks!

Metro sized Antarctic Iceberg ready to break off?

This caught my eye.

According to NASA a huge 18 mile long crack on the edge of the Antarctic Ice Sheet is ready to break off and form a huge iceberg. The giant crack is anywhere from 260 feet to 820 feet wide.

NASA scientists discovered the gaping crack on a flyover in October.

The resulting iceberg may be about 300 square miles. That's about the size of the Twin Cities inside the 494 - 694 ring!

Death toll rises in southern severe outbreak

As many as 6 people are now dead in last night's tornado outbreak in the southeast.

Preliminary data from SPC indicates 12 tornado reports from Mississippi to North Carolina.

Stay tuned as new model runs come in today and tonight as we track the potential for the first real snow of the season for the metro and much of central Minnesota Saturday!

PH

Saturday Snow Update: Plowable north, Metro on the edge

Posted at 11:45 PM on November 17, 2011 by Paul Huttner (3 Comments)
Filed under: Winter, Winter 2011-12

Friday AM Update:

Overnight models are in support the Weather Lab thinking below. If any shift is noticed, it may be a slight shift to the north. This keeps the Metro on the southern edge of the storm, and could mean a rapid cut off in accumulations over the Twin Cities from northwest to southeast.

Latest NAM model shows heavy snow band of 6"+ through Alexandria, Brainerd and Duluth Saturday. Metro would see coating to 2" in this scenario.

Let's see if the Friday morning model runs confirm, or shift a little north again. Any further shift to the north could mean accumulating snowfall would mostly miss the metro to the north.

Enjoy the milder weather Friday!

PH

****

Updraft Headlines:

Winter Storm Watch posted for eastern South Dakota and far western Minnesota

Morris-Alexandria-Brainerd-Duluth Most likely axis for heaviest snowfall band of 3" to 6"+

80% chance Weather Lab estimate of a plowable (2"+) snowfall in Alexandria, Brainerd, Little Falls and Duluth

On the edge - Twin Cities on the southern edge of this storm

Getting closer!

We're within 48 hours of our first significant snowfall for much of central Minnesota.

The System & Track:

Most models agree on a relatively fast moving, moisture lean system that will track through Iowa into Wisconsin Saturday.

Here's what we think we can say with a high degree of confidence in the weather lab as of Thursday night.

-Confidence is growing that the heaviest snow band (3" to 6"+) will set up from eastern South Dakota through central Minnesota toward Duluth.

-A "plowable" snow of at least appears likely from Brown's Valley to Morris, Alexandria, Little Falls, Brainerd, Mille Lacs to Duluth.

NAM Model paints heaviest snow through central Minnesota, with Twin Cities on the edge. Yellow and green colors indicate 3"+ forecast snowfall.

-Model solutions still show some degree of variability, especially for the Twin Cities which lies on the southern edge of this system. As of Thursday night, the two most likely scenarios for the metro are light snow in the 1" to 3" range or a near miss to the north, with just a coating in many metro communities. Accumulating snow could still largely miss the (southern) metro to the north, or yet another shift south could increase snow totals. We'll make the final call Friday PM. At this point, little or no accumulation is expected south of the metro.

NAM & GFS model out put for metro varies between 0.7" and 2.9" snowfall Saturday.

-Bottom Line: Expect snow from the Twin Cities north Saturday and Saturday night. Significant accumulations are likely along I-94 between St. Cloud and Detroit lakes, and along I-35 north between North Branch and Duluth. Lesser accumulations are possible in the Twin Cities metro area Saturday night.

Stay tuned as we crunch the latest and hopefully definitive model runs tonight and Friday morning!

Soils beginng to freeze up!

My MPR colleague Mark Seeley highlights our first wintery outbreak in his Weather Talk blog.

"Topic: Snow across the north on November 15th

Tuesday, November 15th brought measurable snow across northern Minnesota. Starting in the west in parts of Polk and Marshall Counties the snow moved east toward Lake Superior later in the day depositing amounts from a half inch to over 3 inches.

Some of the snowfall reports included:
0.8 inches at Duluth
1.6 inches at Ely
1.8 inches at Bemidji
2.0 inches at Kettle River, Virginia, and Silver Bay
2.1 inches at International Falls
2.4 inches at Cotton
2.5 inches at Thief River Falls
2.8 inches at Warren
3.0 inches at Roseau and Grand Rapids
3.4 inches at Cook
3.5 inches at Newfolden

In many places the snow did not last long as temperatures warmed into the 30s F. But the snow ushered in the coldest air of the season so far.

Topic: Coldest Temperatures of the Season

Wednesday (Nov 16) and Thursday (Nov 17) of this week brought the coldest temperatures of the season so far to many parts of the state. Many observers reported lows in the teens F. The Twin Cities fell to just 16 degrees F on November 17th, the coldest reading since March 27th. Some western Minnesota observers were even colder, with single digit readings and even below 0 degrees F. Hallock was the coldest spot in the state (and the 48 contiguous states) with -6 degrees F, while Donaldson was -1 degrees F on November 17th. Fosston fell to 0 degrees F. Others who reported single digit lows included: Crookston and Thief River Falls with 1 degrees F; Benson was 3 degrees F; Mahnomen reported 4 degrees F; Morris and Windom fell to 5 degrees F; Park Rapids reported 6 degrees F; and Pipestone and Fergus Falls fell to 7 degrees F.

As a result of the very cold temperatures, the top 3-4 inches of soil began to freeze at University of Minnesota Research and Outreach Centers located at Waseca, Lamberton, Morris, and Crookston. This was true of the soils on the St Paul Campus as well. Drier soils more readily freeze up than wetter ones."

PH

(3 Comments)