“Snowtober” Update: Red River Valley Winter Storm rages; 6″to 12″ whiteout

Rain & snow shield wrapping up nicely in Red River Valley & NW MN today on northwest side of deepening low. Lightning & thunder reported on front edge of rain shield near Park Rapids and Bemidji...that indicates strong updrafts capable of producing "thundersnow" with heavy snowfall rates of 1" to 2"+ per hour today in NW MN as cold air works in from the west.

Look for heaviest snowfall rates in Red River Valley & NW MN through 6pm tonight. Grand Forks NWS already reports 3" in Grand Forks and snowing briskly as of 7 am.

0700 AM HEAVY SNOW GRAND FORKS 10/04/2012 M3.0 INCH GRAND FORKS ND OFFICIAL NWS OBS

-Grand Forks radar loop

-Grand Forks NWS updates

-Latest snowfall totals here

Winter Storm Warnings for Red River Valley & NW MN

6" to 12"+ snow totals according to fairly reliable NAM model output

Blizzard? Winds gusting 40 to 50 mph could create blizzard & "whiteout" conditions Thursday

Updated Thursday language from the Grand Forks NWS:

Major Early Season Snow Storm Will Impact Region

Snow will be heavy at times today, and north winds will increase and gust to 45 mph or even higher at times. This may produce near blizzard conditions when strong winds combine with heavy falling snow. Snow accumulations from 6 to 12 inches are expected across the northern Red River Valley into Northwestern Minnesota by tonight. The heaviest snowfall will occur near the International border in Minnesota, where a foot or more is possible. This early season snow storm will produce hazardous travel. Stay tuned to the latest statements on this dangerous early season snow storm.

UND Med School webcam in Grand Forks

Source: UND-Grand Forks

1 month early 1st 1" snowfall comes in early November on average in NW MN -details below

5am Cold front reached metro - temps falling through 50s into 40s by late Thursday

Source: Grand Forks NWS

Winter 2012-'13: 1st major winter storm comes early for Red River Valley & NW MN

"So it begins."

The season's 1st major winter storm is pounding eastern North Dakota, the Red River Valley, and northwest Minnesota today. By the time it winds down Friday, a wind whipped coating of 6" to 12"+ will fall in some areas.

The System:

A rapidly deepening low pressure storm will track from Sioux Falls to St. Cloud by Thursday morning, to International Falls by lunchtime Thursday. That track favors heavy snow in the Red River Valley region.

Precipitation type & Timing:

Rain changes to snow overnight into early Thursday as cold air feeds in from Canada behind the low. Snowfall rates will be heavy- up to 1" to 2" per hour Thursday morning and midday in NW MN.

Snowfall totals:

The NAM model is the most aggressive and lays down a band of 6" to 12"+ over the RRV including Grand Forks. , Northwest Minnesota's Kittson County (Hallock & Karlstad) is in the snow "bull's eye" where the NAM suggests as much as 12" to 16" snowfall.

Source: NOAA NAM model via http://wxcaster.com/gis-snow-overlays.php3?STATIONID=MVX

These totals may be on the high side....but they are possible given the intense deepening of the system. If the cold air arrives in time, many locations in and around the Red River Valley will see a foot of snow by Friday morning.

Wind: Blizzard to whiteout conditions possible:

I am very concerned about the rapid onset of potentially blizzard like conditions with this system Thursday. Winds will ramp up to between 20 and 40mph, with gusts to near 50mph possible by Midday.

Source: NOAA

Heavy snow and driving winds may create near "whiteout" conditions.

Early start: Snow arrives about 1 month early

This snow will fall much closer to early season October snowfall records than to "average." The earliest 1" of snowfall on record in Grand Forks is October 2, 1950. The average 1st inch is November 15th!

Here are the details from the Grand Forks NWS.

Notable early season snows in the Red River Valley and Devils Lake Basin include the October 2 1950 snowstorm and the October 7 and 8 snowstorm of 1985. Western North Dakota has seen heavy snows in mid to late September.

Below is a table of the earliest one inch observed snow fall based on the 1940 to 2010 period of record. While this is not a comprehensive list it is designed to give an idea as to when the earliest 1 inch of snow has fallen. Due to the variability of weather from year to year and between any given location, the first inch of snow can be more than two months later than a neighboring site. The average first inch snowfall is based on the 1981 to 2010 climatology. Please note that by "measurable" snow we are speaking of 1 inch or more having been reported at the official observation location.

This early season winter storm is coming a full month earlier than average. This early snow storm seems to fit with the pattern I hinted at two weeks ago in an earlier post.

Stay tuned for updates as the snow flies!

PH