Sunday, November 29, 2015

Winter Storm Cara Brings Icy Conditions to the Plains (FORECAST)

Linda Lam
Published: November 29,2015

Winter Storm Cara continues to produce ice accumulations from freezing rain over a swath of the central Plains.
(INTERACTIVE: Winter Alerts | Radar)
A textbook combination of Arctic air plunging south and tropical moisture surging north has been responsible for the freezing rain across a swath of the southern and central Plains since Thursday. Although the area of freezing rain is now shrinking, some areas have already seen enough ice to cause major power outages and extremely slick pavement for drivers and pedestrians. As of Sunday morning, the most significant freezing rain accumulations were in central Kansas, where there are numerous power outages and downed tree limbs.
(MORE: Latest Impacts from Cara | The Science of Naming Winter Storms)

Winter Weather Alerts
Besides the mess of sleet and freezing rain, there is also heavy rain on the warm side of this storm system.
The coldest air mass of the season so far in the West and the Plains has helped to maintain the prolonged freezing rain event, providing a fresh supply of below-freezing air to slide along the ground underneath a layer of warm, moist air. The setup is allowing precipitation to melt as it falls (and in some cases, to form as liquid droplets in the first place) before freezing on contact at ground level.
(MORE: Thanksgiving Travel Forecast)

Plains Ice Storm


Latest Radar

Observations

Forecast Lows and Precipitation


















































(MORE: Ice Accumulations and Impacts)
Light freezing rain or freezing drizzle will continue to create hazardous driving and walking conditions into Sunday from western Oklahoma to central Kansas, northwest Missouri and southwest Iowa. Even small accumulations of ice can cause extremely slick conditions.
(FORECAST: Amarillo | Oklahoma City | Wichita
The majority of the remaining snow from Winter Storm Cara has dissipated, although a new area of snow is forecast to develop later Sunday across the central to northern Plains. This is associated with a system that is separate from Winter Storm Cara.
(MAPS: Weekly Planner)
If that weren't enough, ahead of the cold front widespread heavy rainfall has brought flooding to parts of Texas, eastern Oklahoma, Arkansas and Missouri.
The aforementioned stuck upper-atmospheric low-pressure system over the Great Basin will finally get moving over the Rockies and into the Plains from late Sunday into Tuesday. This system has been named Winter Storm Delphi and will bring snow to parts of the central and northern Plains and Upper Midwest Sunday night through Wednesday morning.
(MORE: Winter Storm Delphi)

Arctic Blast


Morning Forecast Lows














The upper-level trough, or southward dip in the jet stream, has dug in across the West. Combined with a strong area of high pressure from Canada, the result is the first serious blast of arctic air this season in the West and Plains.
This has led to the coldest temperatures so far this season for many areas. A couple of examples include Helena, Montana, where the lowest temperature recorded so far this season had been 14 degrees on Nov. 21; Helena fell to 6 degrees below zero both Thursday and Friday. Reno, Nevada had seen the mercury drop as low as 21 degrees on Nov. 11; Reno reached 20 on Friday and dipped to 16 on Saturday morning.
According to NOAA, the nation's low Friday was 24 below zero at Antero Reservoir in central Colorado. This is the lowest temperature observed in the contiguous United States so far this season, and the lowest since a reading of 29 below zero was reported at Saranac Lake, New York, on March 6.
In Big Piney, Wyoming, the mercury bottomed out at a record low of 22 below zero Friday.
Even the West Coast has felt the chill. Oakland, California tied a record low Thursday morning when they fell to 35 degrees. Record lows were also tied or set Thanksgiving Day in Montague, California (13 degrees), and Quillayute, Washington (23 degrees). King City, about 90 miles southeast of San Jose, also tied a record low Friday morning (25 degrees).
(FORECAST: Great Falls, Montana | Casper, Wyoming | Denver)
Several daily record lows were set Saturday morning, including Burns, Oregon, which dipped to minus 15 degrees. In California, Sacramento (27 degrees) and Stockton (28 degrees-tie) also set daily record lows.

Ice Reports

Freezing rain first developed in the early morning hours of Thanksgiving in parts of northeast Colorado, eastern Wyoming, Nebraska and southern Minnesota and has spread southward along with the advance of cold air.
Friday and Saturday, freezing rain zeroed in on a part of the southern Plains from eastern New Mexico to West Texas, central and western Oklahoma, as well as further northeast across central and eastern Kansas to western Missouri.
The freezing rain led to damaging accumulations of glaze ice late Friday through much of Saturday over portions of the Texas Panhandle and the western half of Oklahoma.
The most significant ice accumulations appeared to be across the western side the Oklahoma City metro area, westward to roughly the U.S. Highway 183 corridor. In the El Reno and Eakly areas in Oklahoma, numerous photos shared via social media indicated that 1 to 1 1/2 inches of ice had accumulated on trees and other surfaces.
El Reno sustained significant tree and power line damage due to the weight of substantial ice accretion. The National Weather Service relayed reports of downed trees due to the weight of the ice in Yukon, a suburb just west of Oklahoma City.
Emergency management in Enid, Oklahoma, reported 3/4 to 1 inch of ice accretion on trees and power lines. Half an inch of ice glaze built up in Pampa and Claude, both in the Texas Panhandle, according to the National Weather Service in Amarillo.
Automated ice accumulation sensors recorded 0.26 inch of ice accumulation in Winfield, Kansas, and 0.18 inch in Hutchinson and Wichita, Kansas, Friday into Saturday morning.
Power was knocked out in all of Rockwell City, Iowa (population: 1,709) early Friday morning thanks to strong winds downing power lines loaded with about 3/8 inch of accumulated ice. Power lines were also reportedly downed near Lariat, Texas, Thanksgiving night.
Other significant ice accumulation reports Friday included 3/8 inch on sidewalks in Blaine, Kansas, and 0.3 inch in both Beattie, Kansas and Wellington, Texas. Up to 1/4 inch of ice accumulation was reported in Omaha, Nebraska.
Sunday morning, significant icing impacted central Kansas with numerous reports of scattered power outages and tree damage. Widespread power outages occurred in Hutchinson, according to a National Weather Service report. In White City, ice accumulated to an estimated diameter of three quarters of an inch on power lines and tree branches.

Snow Reports

Snow started to pile up on Tuesday across portions of the interior Northwest, Sierra Nevada and far northern Rockies. Some freezing rain was also reported in the Columbia Basin. Snow was reported in parts of Montana, Wyoming and Idaho on Wednesday.
Bend, Oregon, reported 10 to 16 inches of new snow Tuesday night, with snowfall rates of 4 inches in 3 hours. This is quite impressive for this relatively dry plateau to the east of the Oregon Cascades, which only averages about 24 inches of snow each season. This heavy snow brought traffic to a standstill on U.S. 97 Tuesday night.
Farther south, up to 23 inches of snow fell around Crater Lake, which The Weather Channel recently named the snowiest place in Oregon.
Up to a foot of snow in the Sierra Nevada snarled traffic on Interstate 80 over Donner Summit in California Tuesday, as well. Up to 22 inches of snow was reported at Kirkwood Mountain Resort south of Lake Tahoe on the California side of the state line. On the Nevada side, Mount Rose Ski Area tallied 10 inches of snow, the top reported total in Nevada as of Wednesday afternoon.
Here are the top snowfall totals of at least 6 inches by state, so far:
  • Nevada: 25 inches estimated on Tent Mountain, about 30 miles east of Elko
  • Oregon: 23 inches near Crater Lake
  • California: 22 inches at Kirkwood Mountain Resort
  • Colorado: 19 inches at Wolf Creek Pass (72-hour total through 7 a.m. Saturday)
  • Idaho: 14 inches in Buhl, about 100 miles southeast of Boise
  • Wyoming: 14 inches at Sinks Canyon, near Lander in central Wyoming
  • Montana: 8.5 inches near Clancy, which is just south of Helena
  • New Mexico: 8 inches at Taos Ski Area
Lighter snow fell on Thanksgiving Day in parts of South Dakota, Nebraska, Minnesota, Wisconsin and Michigan. It was the first accumulating snow of the season in the Twin Cities, the seventh latest such occurrence on record, there.
By Friday night, what little remained of Cara's snowfall was mainly confined to the Colorado Rockies and High Plains of western Kansas, as most of the precipitation over the Plains was either sleet or freezing rain.
(MORE: State-by-State Impacts)
Check back for updates and the latest information on Winter Storm Cara. The name Cara (CAH-ruh) is taken from the Latin word meaning "beloved."
Meteorologists Linda Lam, Jon Erdman, Quincy Vagell, Nick Wiltgen and Chris Dolce contributed to this report.
MORE: Winter Storm Bella (PHOTOS)

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