Artic Air Gathers, Winter Storm Develops

[dyndrite]

Cold air will pool and move south on Tuesday. Snow will develop Montana, South Dakota.

Wednesday am, Heavy snow develops NE Colorado, western Nebraska, Temps fall to below zero North Dakota and Montana

At this time Snow will move NE to Iowa, Minnesota and Wisconsin Later in the week. Severe cold and snow with blowing snow looks likely for the western great lakes area.

I will post updates on this developing Winter Storm.

Dyndrite

[dyndrite]

The 18z models continue to develop this major Winter Storm. Tuesday night snow and blowing snow across North Dakota.

Absent of upper level data will disperse. We will look at the 12Z data

Dyndrite

[dyndrite]

Latest guidance still has artic air posed to move south out of southern Canada. High pressure over Texas may cut off gulf moisture and limit storm totals. Current thinking looks like 1-3 inches from Montana across the Dakotas and Minnesota beginning late Monday and interacting with the great lakes on Wednesday and Thursday. A second impulse will move East out of Wyoming along the arctic boundary On Thursday.

Temperatures will fall to near zero with 15-25 mph winds Montana and North Dakota by Wednesday Morning. This Air mass will modify and move South East by the end of the weak.

dyndrite

[dyndrite]

Winter Storm Watches have now been posted for the mountains of Montana.

The first impulse looks like it will be weaker with limited moisture and deferred energy to a stronger impulse moving into the pacific northwest late Wednesday and Thursday.

This second impulse looks to merge with a southern stream system over the Rockies on Thursday and Friday and be the major storm. Abundant moisture, Artic air, could generate the biggest and coldest storm of the season.

Dyndrite

[dyndrite]

Morning update.

Modified CP air mass just north of Lake Superior is taking on artic characteristics, temperatures at or below Zero. Warm core gulf low now in western Kentucky will move northeast and create a weakness that will allow the weight of this artic air to move south over the northern Great Lakes. This will form a supper lapse rate and heat Low and lake effect snow will develop in advance of the Tuesday system moving into Montana.

The core of the Artic air remains over western Canada. Will update the future movement of this air mass and interactions with lower 48 systems early afternoon EST.

Dyndrite

[dyndrite]

The fun is about to began.

Figured I would post a pre-storm snap shot of surface observations in southern Canada northern USA.

Let it be known that a storm has many parts and phases. This storm will last for a couple of weeks as the upper level vortex spins east. That is why I love it so much. Bits and pieces and a climax we all hope as November turns to December.
http://www.rap.ucar.edu/weather/surface/displaySfc.php?region=yqr&endDate=20071126&endTime =-1&duration=0

[dyndrite]

I tried to include this in the last post sorry for the double post.

Surface data (METARs) plot [yqr, ]
Dyndrite

[dyndrite]

Monday up-date

Today and tonight,

Artic air is moving east a little early chasing the southern stream storm now over southern Ohio. Wet snow accumulations in lower southern Michigan could be 1-2 inches.

Snow developing in weakness in the arrow head of Minnesota will continue this afternoon with locally heavy lake effect developing late tonight in the UP of Michigan. This will spread east and SE over the next 48 hrs.

Tuesday the system moves into Montana. Snow locally 1-2 ft in the higher elevations, 2- 4 inches ND with secondary Artic push. Winds NW 15-25 mph.

Tuesday night into Wednesday secondary lake enhanced event. Storm totals up to 1ft.

Any long term forecast are a pipe dream past 72 hrs. As the Artic air moves Se and modifies and disturbances move East Residents north and west of a line from Amarillo TX. To Paducah Kentucky, To west Virginia should monitor this intrusion.

Residents of Western Va. Western NC an NE Ga should monitor this for a potential Ice storm next weekend.

Dyndrite

[dyndrite]

Weather update.

Artic air has crossed the US, Canadian border. North winds up to 30 mph in North Dakota.

Dyndrite

[dyndrite]

Weather update.

Storm intensifying. Wet sow of 2-4 inches across Southern and SE Michigan. As modified CP air mass interacts. Conditions in the UP and lee of lake Michigan will deteriorate tonight.

Dyndrite