A major storm is likely to impact a million square miles over the Plains and West with areas of rain, snow and severe weather next week.
As a large storm begins to spread rain across the South this week, a new and even larger storm is forecast to impact parts of the West beginning this weekend and continuing into the middle of next week with significant moisture for some very needy areas.
The pattern of chilly air in parts of the East and warmth in the West is about to flip long enough to allow a large storm to roll in from the Pacific with moisture and potentially tap Gulf of Mexico moisture.
(Flickr image of driving on I-40 in a torrential downpour by user nathanryan).
The storm would begin to gather moisture and strength over the weekend and would reach its peak during the first part of next week.
In addition to impacting the Northwest, areas of low-elevation rain and high-elevation snow could reach building drought areas of Wyoming, Colorado, southern Montana, Utah, Nevada and southern Idaho.
There is the potential that drenching rain could even reach across parts of big drought areas of Nebraska, South Dakota, Iowa, Kansas, Oklahoma and Texas next week.
Like many storms in the West, the greatly diverse terrain will play a role on enhancing the precipitation in some areas and diminishing it in others.
Where winds are blowing uphill and Gulf of Mexico moisture gets involved, such as the eastern slopes of the Rockies and parts of the High Plains, there is the potential for an inch of rain or more.
Enough cold air could arrive on the scene to make for a heavy snowfall instead of rain over portions of the Plains of Wyoming and the Nebraska Panhandle as well as the Black Hills area.
It will be cold enough for snow at pass level in California. The question is how much moisture is available for the storm this far southwest.
Significant rain and high-elevation snow could reach northern Arizona and New Mexico.
Large Severe Weather Outbreak Possible Next Week
With almost every large storm, benefits could be outweighed by problems and risks to lives and property in other locations.
Just as the storm has the potential to bring significant rainfall to needy places in the West and parts of the Plains, it could also unleash violent thunderstorms. The most likely area for this initially is portions of Texas and Oklahoma to Arkansas, much of Missouri and parts of Kansas and Louisiana.
However, the potential for dangerous and damaging storms would extend farther east into Dixie and perhaps the Ohio Valley states as next week progresses.
The nature of the severe weather event (tornadoes versus straight-line winds) has yet to be determined over Texas, the southern Plains and the South.
Early on, as the storm takes shape and cooler air drives southward into the Southwest, gusty winds and widely separated thunderstorms with hail could erupt from portions of California to Nevada late in the weekend, spreading to Arizona and New Mexico early next week.
The details of the storm will unfold over the next few days and will be released accordingly on AccuWeather.com.
A train of storms will slam into the Northwest United States well into next week and perhaps through much of December.
Downpours will continue the threat for flooding across parts of southern India this week.
Tens of thousands will gather in rainy and mild conditions at 30 Rockefeller Plaza in New York City on Wednesday, Dec. 2, 2015, for the 83rd annual Christmas tree lighting.
Rain will spread across much of the Eastern states into the second day of December 2015.
Snow will linger across parts of the northern Plains to the Upper Midwest as December begins.
Following several days of dry weather, a weak area frontal boundary will bring rainfall to northern France Thursday night into Friday.
Snow fell for 5 minutes in South Florida in the Ft. Myers area.
Eastern Maine (1964)
Down east blizzard 12-18" snow, accompanied by 60 mph winds; 8' drifts. Record snow from Detroit to Pittsburgh: Pittsburgh, PA 8.5" snow, most for date Akron-Canton, OH 24" snowstorm Dec. 1-2 - biggest snowstorm on record Detroit, MI Record 19.2" snow paralyzed city.
Ohio, Ontario (1996)
A line of severe thunder storms moved across the state. In Cleveland, OH there was a 60 mph wind gust. An 18-foot tractor trailer was blown over on I-77 in Richfield, OH. In Guelph, ON a wind gust lifted the roof of a gym, where a church group was playing basketball. Residents of one neighborhood saw a car spinning on its grill like a top.