Freeze, thaw, repeat: 40s in southern Minnesota

This Minnesota winter is a mere ghost of last year.

A year ago today Minnesota shuddered through the depths of the dreaded polar vortex.  We had a 17-day run of sub-zero mornings in the Twin Cities; a frigid February that came in 12.3 degrees below average; and the coldest month of the year relative to average in Minnesota. Snow depth at Minneapolis-St. Paul International Airport was 13 inches, on the way to 2 feet.

Fast forward one year later to this weekend.

The afternoon sun feels warm. Bare grass once again emerges on the south facing slopes of the Weather Lab. Snowy plow dregs at the roads edge slowly disappear.

Welcome to another "winter lite" weekend in southern Minnesota. We ride the edge of winter once again this weekend. A nearly stationary front divides Minnesota between winter to the north, and a downright spring like air mass to the south.

With bare ground south, and an increasing February sun angle to warm the brown earth, temps soar again this weekend from the 40s in southern Minnesota to the 70s in Kansas, where it has felt more like spring most of this winter.

Farther north, I see a respectably cool weekend with snow as you move toward the Canadian border.

Actually, this looks like a great weekend for winter recreating along the Gunflint Trail and other northern Minnesota locales. There's still plenty of snow on the ground, and temperatures are ideal for outdoor winter play.

Forecast models continue the northward push of this weekend clipper. That pushes the prospect of accumulating snow ever closer to the Canadian border. The National Oceanic and Atmospheric Administration's recently upgraded Global Forecast System clings to a more southerly solution, but is the outlier right now.

NOAA's North American Mesoscale Forecast System and the European Centre for Medium-Range Weather Forecasts agree Duluth is now on the snowy edge, with heaviest snow in Canada.

Saturday is the milder day this weekend.

The European model is pushing 40 degrees in the metro Saturday afternoon. That's probably a little optimistic with snow cover to the south and a southeast winds. The GFS likes around 34 degrees. The truth probably lies somewhere in between.

Here's a closer look at the next eight days, according the the European model output. We alternate between thaws and colder semi-arctic jabs from Canada. Should that surprise anyone this winter?

Tuesday's snowfall appears to favor the northern half of Minnesota for the heavier totals at this point, with the metro riding the southern edge. This system will have to be watched though.

Storm hammers West Coast

As expected, heavy rains and high winds are pounding the West Coast as a Pineapple Express-style atmospheric river slams ashore. High winds have down trees and knocked out power to thousands.

Rainfall totals exceed 4 inches in some areas.

This is just the first wave of storms. More heavy rainfall is on the way on the next few days.

The system dumps feet of snow on the high Sierra.

SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON-

1048 AM PST FRI FEB 6 2015

...WINTER STORM WARNING REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO 4 PM PST SATURDAY ABOVE 8000 FEET...

* HAZARD TYPES...LOCALLY HEAVY SNOW IN THE HIGH COUNTRY. WIND GUSTS UP TO 75 MPH OVER THE SIERRA NEVADA CREST.

* SNOW ACCUMULATIONS...12 TO 20 INCHES...WITH HIGHER AMOUNTS UP TO 30 INCHES.

* TIMING...SNOW WILL BEGIN FRIDAY EVENING WITH THE HEAVIEST SNOW LATE FRIDAY NIGHT INTO SATURDAY MORNING. SNOW WILL DIMINISH DURING THE DAY SATURDAY.

* IMPACTS...LOW IMPACT EVENT DUE TO HIGH SNOW LEVELS.

* WINDS...SOUTHWEST 35 TO 45 MPH WITH GUSTS UP TO 75 MPH.

Weather Wars: NOAA's upgraded GFS still cutting teeth

NOAA's newly upgraded GFS model is three weeks old. It showed success correctly predicting less snow for the not so NYC blizzard last month.

How is the new GFS doing?

Here's some good early perspective from the Economist.

It is, however, too early for the Americans to celebrate. The GFS projection for the blizzard’s western edge differed from the ECMWF’s by 200km (120 miles)—a weather-forecasting hairs’-breadth. The only reason anyone noticed this discrepancy was that the gap happened to encompass the country’s most populous city.

This episode, moreover, may have been a fluke. During its three weeks of operation, the new GFS remained outclassed. On a standard measure—predicting the altitude at which the atmospheric pressure is half as great as at sea level—it still trails the ECMWF model.

Nonetheless, the GFS’s strong showing during January’s nor’easter offers solace to critics who feared America would never catch up with Europe in matters meteorological. Weather forecasting is fiendishly complex, and improvements tend to arise not from great leaps forward but rather an accumulation of incremental advances.

The ECMWF’s most obvious advantage has been in raw computing power. Its Cray XC30 supercomputer can perform up to 2 quadrillion calculations a second, about ten times more than the GFS hardware before the recent upgrade. As a result, it carves up the Earth’s atmosphere into svelte cells 16km square and 137 layers deep, compared with a bulky 27km and a mere 64 layers for the old GFS. The ECMWF’s computing muscle also lets it start its projections with a replay of the past 12 hours of weather, using 40m data points derived from observations collected by ground stations, aeroplanes, balloons and satellites. In contrast, the GFS begins with a snapshot of a single moment.

 Train vs. snow

Finally for your viewing pleasure. What happens when a Canadian Railway train at high speed hits a wall of snow?

Watch this.

Canadian National Railway locomotive 2304 (ES44DC) plows through huge snow drifts and gives me a big ass snow shower as it leads the daily CN manifest train 406 West (Moncton, NB to Saint John, NB) at Salisbury, New Brunswick.

I'm not sure how the train crew can even see with all that snow on the locomotive's nose!

Southern New Brunswick was hit with three major blizzards in less than a week, and there is more snow in the forecast.

Filmed at 3:05pm, Tuesday February 3, 2015 at mile 11 of the CN Sussex Subdivision.