Friday, December 2, 2011

Update on Winter Storm for the Rockies and the Plains...

The latest water vapor satellite image above shows an upper-level low pressure center swirling over the Southwest.  I've noted the location of stronger middle and upper-level jet stream winds associated with the system in yellow.  These stronger winds aloft will gradually spread Eastward over time and cause pieces of energy to break away from the upper-level low and move Northeastward across portions of the southern and central Rockies and adjacent High Plains.

East to Southeast winds are pulling moisture back into central and southeast Texas, as you can see by the latest radar image below.  Light, showery precipitation has broken out in association with the moisture feed over the central third of the state:

A variety of winter weather watches, warnings and advisories are in effect across much of the middle third of the country, as shown on the image below:

The first region to be impacted will be the southern Rockies and adjacent High Plains tonight and early Saturday.  Locally heavy snows of 8-12 inches will fall across portions of New Mexico and Colorado, as indicated on the image below, which is valid 6am CST (5am MST) on Saturday morning:

Strong, gusty North winds will create widespread blowing and drifting snow across this region, with travel highly discouraged tonight and into Saturday.
Another round of snow is likely across much of the same region by late Sunday and into Monday.  We'll have more on that in later posts...

Further East along the High Plains, freezing drizzle and/or light freezing rain is forecast to break out across far eastern New Mexico, far west-central Texas and the Texas/Oklahoma panhandle region by tonight.  The potential exists for one-tenth to one-quarter of an inch of ice accumulation within the dark green shaded areas on the image below, which is also valid at 6am CST Saturday:

Roads will become very hazardous tonight into early Saturday across this region.  Also, any locally heavy accmulations of one-quarter inch or more could cause damage to tree limbs and power lines.  Please make preparations to have some extra food and supplies on hand today just in case a power outage were to threaten your area tonight or Saturday.

During the day Saturday, snow will develop and increase in a band from northwest Kansas and east-central Colorado into much of southern and eastern Nebraska and into northwestern and west-central Iowa.  Locally heavy snow of 8-10 inches or more is possible in this region, particularly within the lighter green and orange shaded areas on the image below, which is valid 6pm CST on Saturday evening:

Strong and gusty North winds will create widespread blowing and drifting snow in this region as well, which will create very hazardous conditions.

The snow will then spread Northeastward into northeastern Iowa, southeastern Minnesota and into Wisconsin on Saturday night and early Sunday.

Colder than normal temperatures will cover the majority of the lower 48 U.S. next week in the wake of this system, as shown on the latest departure from normal temperature forecast image shown below:

The combination of already cold air with clearing skies and snowcover on the ground could lead to temperatures at or below zero across portions of the region next week, as shown by the darker purple shaded areas on the minimum 5 day temperature forecast image below:

The coldest temperatures would most likely take place on the morning(s) of the 5th and/or 6th (Monday and Tuesday of next week).

Folks living all across the above mentioned areas should have their winter weather preparations complete today.  Listen to local media or NOAA Weather Radio for later updates, watches and warnings for your specific area.

We are also monitoring the end of the weekend/early next week for another round of winter weather, possibly further South into Oklahoma and Texas.  Stay tuned for updates on this one...

If you enjoy reading 'The Original Weather Blog', please be sure to "like" our facebook page!

No comments: