Friday, January 6, 2012

After a Quiet Start to 2012, Weather to Become Colder, More Active Next Week...

Other than the eastern third of the nation being in the deep freeze early on, it's been a rather quiet week to start off 2012 weather wise across much of the nation.  That is about to change...

A series of upper-level weather disturbances are coming together and approaching the Pacific Northwest Coast, as you can see on the latest water vapor satellite imagery:  

This energy is forecast to organize into an upper-level low pressure system that will take a position over the southern Rockies by late Sunday (yellow circled area on the upper-left quadrant of the latest GFS computer model forecast shown below):

...and will the move out into the southern Plains on Monday and Tuesday:

GFS Computer Model Forecast Valid 6pm CST Monday, 1-8-12

GFS Computer Model Forecast Valid 6pm CST Tuesday, 1-9-12

Rain will become widespread ahead of this system across much of the southern Plains and lower Mississippi Valley beginning on Monday.  The latest rainfall forecast from the HPC for Monday is shown below:

The rains will then spread Eastward on Tuesday and Wednesday, with the two day forecast totals shown below:

A surge of cold air will cause rain to change to snow across portions of the region on Monday into Tuesday.  Locally heavy snows of 6-12 inches will take place across portions of the southern Rockies, mainly in New Mexico on Monday:

The potential will exist for lighter snows, generally on the order of 1-3 inches, to spread Eastward into the Oklahoma/Texas panhandle region late Monday and into Tuesday:

An even stronger surge of cold air is instore for late week, and will cover a much larger geographic area.  The images below show the forecast departure from normal temperatures as indicated by the GFS computer model valid 6am CST on Wednesday, Thursday, Friday and Saturday, respectively:

The green and blue shaded areas on the images indicate where temperatures will average 10 to 20 degrees below normal.  As you can see, the heart of the cold air will begin across the central third of the nation by late Wednesday and into Thursday, and spread East/Southeastward over time into the weekend.

We'll need to keep an eye on several disturbances that are forecast to move over the upper Midwest and Ohio Valley region late in the week for the possibility of wintry precipitation.

Stay tuned for updates as this situation unfolds over the coming days...

If you enjoy reading 'The Original Weather Blog', please be sure to "like" our facebook page and/or follow us on twitter!

No comments: