December 11, 2015 - UNITED STATES - After a mild week across much of the eastern U.S., record-breaking warmth will build for the second weekend of December. One of the storms from the western United States will produce a swath of
drenching rain, snow and severe weather over the Plains, Mississippi
Valley and Great Lakes this weekend. Meanwhile, cold weather lovers in the West will be getting another present from Mother Nature during the third week of December.
Record-Breaking Warmth to Surge Across Eastern US This Weekend
Temperatures are forecast to climb to levels more typical of October.
For most of the East, high temperatures will range 10 to 20 degrees Fahrenheit above normal for this time of year. Temperatures in some areas could climb to 30 degrees above normal this weekend.
"Areas across the East will have several days in a row of record or near-record warmth through Monday," AccuWeather Senior Meteorologist Dan Pydynowski said.
Some records that will be challenged have held since the 1800s.
"For example, highs in the upper 60s in Washington, D.C., this Saturday will come very close to the record high of 71 set in 1873. Sunday's record of 71 from 1889 will also be challenged," Pydynowski said.
Records will also be challenged across most of the East including Little Rock, Arkansas; Nashville; Detroit; Charlotte, North Carolina; Pittsburgh; Baltimore; Philadelphia; New York City and Buffalo, New York.
"To put into perspective how mild it will be, overnight low temperatures will be higher than the average daytime high temperature for this time of year," AccuWeather Meteorologist Michael Doll said.
Dry and sunny conditions will compliment the warmth for much of the East.
The only exception will be a few showers across the Ohio Valley and into the Great Lakes, western Pennsylvania and upstate New York on Saturday, which will swing into northern New England on Sunday.
Both days will not be a washout by any means across these locations as showers will be brief and light.
Holiday shoppers should have no issues with any weather-related delays on the roadways when heading out to the local malls or markets this weekend.
The weather will also cooperate for the Army vs. No. 21 Navy football game in Philadelphia on Saturday and NFL football games on Sunday. Fans could leave jackets in the closet both days as partial sunshine and warmth are expected.
While warmth is in store through the weekend, a storm that is forecast to bring flooding, severe weather and snow to the central United States will
arrive in the East on Monday with drenching rain.
"This front is expected to sweep through the region late on Monday, bringing lower temperatures for Tuesday. Many areas [across the East], however, will still be rather mild and above normal for this time of year," Pydynowski said.
The lack of any winterlike chill across the East has not been uncommon for the past couple of months. The month of November was one of the warmest months on record for many Eastern cities. This unseasonably warm pattern has continued right through the beginning of December and is forecast to
hold through Christmas.
This is in contrast to last November and December when blasts of arctic air were common across the Midwest and East.
Storm to Lash Central US With Flooding, Snow and Severe Weather
While the central United States will remain in the midst of tranquil weather into the second week of December, a major storm will take shape during the second weekend of the month.
According to AccuWeather Chief Meteorologist Elliot Abrams, this will be a dynamic storm as it swings from the West into the Central states.
"In addition to bringing locally heavy precipitation, the storm will bring a good deal of wind, which will be quite a switch from the tranquil, stagnant and foggy conditions over the past week or so," Abrams said.
While the exact details on which areas will be hit the hardest with
rain versus severe thunderstorms and snow will unfold in the coming
days, the storm will bring general travel disruptions to the Central
states this weekend.
Following the storm impacts in the Central states, big temperature swings are in store for the region.
Northwest Flank of Storm to Bring Snow
As
the storm traverses the Rockies, locally heavy snow will fall on
portions of Colorado, Utah, Arizona and New Mexico spanning Friday night
to Saturday night.
Denver could receive a few inches
of snow on Saturday into Saturday night. Enough snow will fall to create
slushy and slippery travel along portions of Interstate 25, I-70, I-78
and I-80 in
During Sunday into Sunday night, a stripe
of snow is likely to stretch from central Nebraska to eastern South
Dakota, southeastern North Dakota and western and northern Minnesota. A
bit of snow can occur at the beginning and the end of the storm in
northern Wisconsin and the Upper Peninsula of Michigan.
While this does not look like a major snowstorm for much of this
area, enough snow could fall to make for slippery travel in some
communities.
Wet snowflakes could mix in at the tail
end of the storm from Kansas City, Missouri to Omaha, Nebraska, Des
Moines, Iowa and Minneapolis.
The area of accumulating
snow could shift farther to the southeast or northwest across the
region, depending on the track of the storm as it emerges from the
southern Rockies as well as the availability of colder air.
Enough Rain May Fall to Renew Flooding
Another
1-3 inches of rain will fall with locally higher amounts from portions
of Texas and Louisiana to Illinois and southern Wisconsin spanning
Saturday and Sunday. Much of this area had two to three times their
average rainfall during November.
Soil conditions
remain wet and streams levels remain high in much of this area. As a
result, the risk of flooding will extend beyond flash and urban concerns
to small streams and unprotected areas along some of the rivers.
The greatest potential for flooding will be from the lower part of
southern Plains to the middle and lower Mississippi Valley. This
includes portions of the Red River basin.
The
combination of drenching rain and poor visibility could slow travel in
the major metro areas of St. Louis, Chicago, Milwaukee and Kansas City,
Missouri.
Storm to Bring Severe Weather Potential
The combination of warm, moist air and strong winds aloft could be enough to spark severe thunderstorms this weekend.
While
the intensity of the storms will be partially contingent on the amount
of warming that takes place both days of the weekend, the risk of severe
weather will extend through the nighttime hours.
Severe
thunderstorms could roll through Oklahoma City; Shreveport, Louisiana;
Little Rock, Arkansas; Memphis, Tennessee; Dallas and Houston.
During
Saturday afternoon and evening, the greatest risk for a few isolated
tornadoes and damaging wind gusts will extend across the central and
eastern portions of Texas and Oklahoma into southeastern Kansas,
southwestern Missouri and western Arkansas.
The risk of thunderstorms with damaging wind gusts will push eastward from parts of coastal and northeastern Texas to Louisiana, eastern Arkansas and Mississippi on Sunday.
During Sunday night into early Monday, the severe weather risk, including the potential for a few tornadoes, may extend from eastern Mississippi to parts of western Alabama and middle areas of Tennessee and Kentucky.
Abrams stated that gales would buffet the Great Lakes region with building waves and the potential for lake shore flooding during Sunday into Monday.
Cold Air to Plunge Into Western Half of US During Third Week of December
The jet stream will take a big southward dip over the western half of the nation during much of the third week of the month.
The jet stream is a river of high-speed air high above the ground that guides weather systems along. It often marks the boundary between cold air to its north and warm air to its south.
According to AccuWeather Chief Long Range Meteorologist Paul Pastelok, "The air that settles into the western United States next week will originate in part from Alaska and part from the Pacific Ocean."
"The end result of the air mass blend will deliver temperatures of 10-20 degrees Fahrenheit below average," Pastelok said. "For much of the interior West and in portions of the Rockies and Great Basin, this will be the coldest weather of the season so far."
An area that may escape the brunt of the cold air will be west of the Cascades in the Northwest, where more ocean air will dominate.
An extensive area of highs in the teens, 20s and 30s will develop over the interior West next week. Nighttime temperatures will dip into the teens in Salt Lake City and Boise, Idaho, and the single digits in Denver.
A substantial amount of cold air will also nose onto the Plains and part of the Midwest, before fading farther to the east next week. Minneapolis will have multiple days with highs below freezing, following an temperature departures of 6-10 degrees above normal during much of the autumn.
The cold will dip into central and Southern California.
The pattern will set up multiple nights with a significant frost or freeze over the Sacramento and San Joaquin valleys, as well as the Inland Empire. Temperatures are likely to dip several degrees lower than the chill that struck during late November into the start of December.
As the cold air settles in and is funneled southward and westward through the canyons and gaps in the mountains of Southern California, moderate Santa Ana events can occur.
"From Tuesday through the end of the week, there will be some chilly and gusty winds every day in the traditional Santa Ana areas of Southern California," AccuWeather Meteorologist Dave Samuhel said. "Wednesday could bring the strongest winds."
The winds may not become strong enough to down tree limbs and cause sporadic power outages. However, the main effect will likely be to cause low AccuWeather RealFeel® Temperatures. So even though some areas may not eclipse the lowest temperatures of the season so far in the coastal areas, it will feel like it. RealFeel Temperatures could dip into the 20s from time to time, factoring in the wind, actual temperature, humidity and other conditions.
The leading edge of the colder air will spread southeastward with areas of snow over the mountains and interior of the West during Monday into Tuesday.
A reinforcing batch of cold air with the possibility of more areas of snow will spread southeastward Wednesday into Friday.
The cold air may have staying power over the interior West.
"Once cold air settles into the Great Basin and the Intermountain West this time of the year, it is difficult to rout out," Pastelok said. "And, this certainly looks like a situation where the cold will linger with areas of fresh snowcover offering assistance."
In some cases, the cold may actually intensify over the interior West as the month progresses.
The cold air with and without snow in the West should have the ski industry in prime condition for the upcoming holiday season.
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AccuWeather.
