Confidence is growing that a significant winter storm will hit parts of the midwest earlier this week. Various locations can see heavy snowfalls, gusts of wind and dangerous accumulations of ice.
At the same time, a number of systems are moving across the southwestern United States, where humidity is very much needed to help alleviate drought conditions.
Widespread rainfall in the southwest desert will be up to 1 inch, but snowfall in California, Arizona and Colorado can exceed 1 foot by Monday.
The snow in the desert may seem like a paradox, but it depends on which desert you are referring to, as elevation plays a key role and mountain peaks vary widely. The forecasting area of the National Weather Service office in Las Vegas includes parts of three major United States deserts: the Great Basin, Mojave and Sonora.
“Elevation is a big factor for snow in the western United States, because elevation varies widely,” said Jenn Varian, a meteorologist at the meteorological service in Las Vegas. “Our forecast area has the highest elevation and the lowest elevation point in CONUS (continental United States). And they are in the same county!”
Varian is referring to Monte. Whitney, the highest mountain in the 48 states with 14,505 feet in the Sierra Nevadas, and Badwater Basin, which is 282 feet below sea level in the Death Valley. They are about 135 km apart in Inyo County, California.
This means that snow accumulation will vary from just a few centimeters to elevations of less than 4,000 feet to more than 30 centimeters of snow at altitudes above 6,000 feet in Arizona, California and Nevada.
Then, another system is scheduled to pass through the region on Wednesday.
“The midweek system in line with a wave of atmospheric moisture has the potential to pour an extreme amount of precipitation, potentially flirting with snowfall duration records, in parts of Southern California and western Great Basin.” said Varian.
The region is in desperate need of rain and snow. Almost 80% of the western United States is under drought conditions, with almost 25% under exceptional drought conditions, the highest level possible.
Heavy snow and ice in the Midwest
The first system will gradually shift from the southwest to the central and midwest plains.
A strip of very heavy snow will extend from northern Kansas to northern Illinois until Monday. Total widespread snow of 6-8 inches, with more than one foot possible in areas of Iowa.
Ice is also in the forecast and can potentially accumulate up to a quarter of an inch in several states. For now, the greatest confidence in the ice exists from Topeka, Kansas, to Philadelphia.
Both Grand Rapids and Marquette, Michigan, are about 30 inches below normal for the season. Strangely, some cities in the south saw more snow than others in the Northeast.
For example, Amarillo, Texas, had more than 15 inches of snow, overtaking Green Bay, Wisconsin, which had 11, as well as Chicago with about 9 inches in total.
On Saturday, Milwaukee increased by 11.9 inches, which is exactly the same amount as Oklahoma City.
San Angelo, Texas, had 5.8 inches, which is more than Cincinnati, Indianapolis and Louisville, Kentucky.
At this point, the forecast of snowfall in the Midwest is probably not enough to make up for the difference in snowfall deficits in some of these cities.
Southeast rain
On the south side of the same system that runs through the midwest, the moisture pulled from the Gulf of Mexico will create conditions for the development of moderate to heavy rainfall. This could lead to an increased threat of excessive rainfall and flash floods, especially for the southern plains and the Ohio and Mississippi River valleys.
From Oklahoma to Kentucky, rainfall totals of 1-3 inches with higher isolated amounts are expected.
There is potential for severe to severe storms in parts of Arkansas, Oklahoma and Texas on Sunday. Nearly 15 million people are at minimal risk of tornadoes, damaging winds and strong hail from Sunday night until early Monday morning.