The parade of strong mid to upper level closed lows to affect large portions of the nation will continue over the next few days.
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The next strong closed upper low will be ejecting out of the Southwest tonight and into the Southern to Central Plains on Tuesday.
Low level southerly flow is expected to strengthen off the western Gulf of Mexico ahead of this northeastward moving closed low.
This will increase moisture values to above average levels across much of the Plains, Mississippi Valley and into the Great Lakes, supporting increasing chances of widespread precipitation across these regions.
At the same time, a surface low will also be deepening late Tuesday into early Wednesday across the Upper Mississippi Valley into the Upper Great Lakes region.
Most of this precipitation associated with this first northeastward moving upper low is expected to be in the form of rain, except for eastern portions of the Northern Plains into the Upper Mississippi Valley where snowfall is expected.
The overall quick movement of this system will keep precipitation amounts, both rain and snow, from being very heavy.
Subsequently, there is not expected to be a flash flood threat for areas receiving rainfall.
While snowfall totals on the northern end of this system are not expected to be very heavy, the increasing winds from the deepening surface low may produce blizzard conditions late Tuesday into early Wednesday over eastern portions of the Northern Plains into the Upper Mississippi Valley.
In the wake of the first strong upper low ejecting northeastward across the Plains/Mississippi Valley, the next in the series of strong upper lows will dive southeast from the Pacific Northwest, through the Great Basin and into the Southwest on Tuesday and then eastward into the Southern Plains during Wednesday.
This system will have the potential to produce heavy snows in the Washington and Oregon Cascades, across the Mogollon Rim region of Arizona, through much of the Rockies and into the Central High Plains over the next 2 days.
Winter storm watches, warnings and advisories are currently in effect across all of these region.
In addition to the heavy snow threat across the above mentioned regions, temperatures will be falling to 10 to 20 degrees below average from the high plains, westward through the Rockies and into the Great Basin.
In contrast to this, much above average temperatures are expected over the next two days from the Plains, eastward to the east coast.
High temperatures across these areas are expected to run anywhere from 10 to 30 degrees above average. ■