Cold, Ice, and Snow Assault U.S.; Windstorm Xaver Kills 6 in Europe

A frigid winter cold blast has most of the U.S. in an icy grip, as cold air plunging southwards from Canada will bring temperatures 10 - 40 degrees below average to more than 80% of the contiguous U.S. on Friday, Saturday, and Sunday. The most notable cold temperatures were in the West on Wednesday and Thursday, where numerous daily lows were set in Montana, Colorado, Nevada, Wyoming, Oregon, and Washington. The high temperature on Thursday in Havre, Montana reached only -14°F, with a low of -28°. Ely, Nevada hit 17 degrees below zero on Wednesday, crushing the old record of 5 degrees below zero for the date. The cold air brought a hard freeze Friday morning to portions of California's Central Valley, where growers have mobilized defenses to protect fragile crops. More freezing nights are expected this weekend. Riding up the edge of this cold airmass is Winter Storm Cleon, which is spreading a nasty mix of snow, freezing rain, and sleet from Texas to the Ohio Valley. Hardest hit has been Texas, where combined sleet/freezing rain accumulations reached 1.5" in Fort Worth and 1" in Dallas Friday morning, according to the National Weather Service. Ice accumulations of 1.25" were reported in Greenwood, Arkansas, and 1" in Poteau, Oklahoma. At least 200,000 customers have lost power in Texas, and American Airlines and American Eagle were forced to cancel about 900 flights system-wide due to the bad weather in Texas. Freezing rain and significant power outages from this dangerous ice storm will likely affect a swath from Southeast Oklahoma through Central Arkansas, Southeast Missouri, Southeast Illinois, Western Tennessee, Western Kentucky, Southern Indiana, and Southwest Ohio. Just to the north of this swath if ice will be a band of 5 - 8 inches of snow. Heaviest snows so far from Cleon include:

• Minnesota: 35.3 inches, Two Harbors
• Colorado: 30 inches, Douglas Pass
• Idaho: 30 inches, Gibbonsville
• Illinois: 10 inches, Mount Vernon
• Missouri: 9 inches, Fredericktown
• Arkansas: 7 inches, Bentonville
• Indiana: 7 inches, Spencer



Figure 1. A statue of George Washington is covered with freshly fallen snow at the village in Beaver Creek, Colo., Dec. 4, 2013. (AP Photo/Charles Krupa)

New storm gathering strength over California
Once Cleon exits stage right on Saturday, we will have a new winter storm entering stage left, as Winter Storm Dion is now gathering strength over California. Dion is expected to follow a track very similar to Cleon's. Dion will bring snow of 1 - 2' to California's Sierra Mountains by Saturday, and will begin spreading snow east of the Rockies on Saturday night. Freezing rain, sleet and snow will fall from northeast Texas and southeast Oklahoma to the mid-Mississippi Valley and Ohio Valley, including Little Rock, Ark., Memphis, Tenn. and Cincinnati. Accumulations will be far less than for Cleon, but impacts could still be significant, since none of Cleon's snow and ice accumulations will have melted. The nasty weather will push into the Mid-Atlantic and Northeast Sunday into Sunday night, with Washington, D.C., Baltimore, Philadelphia and New York City all seeing a wintry mix of snow, sleet and freezing rain. However, with warmer air moving in, it appears a changeover to rain is likely late Sunday into early Monday.

Windstorm Xaver kills six in Europe
Windstorm Xaver killed at least six people and caused extensive damage in Northern Europe, after raking the area with near-hurricane force winds that brought a huge storm surge to the coasts of England, the Netherlands, Germany, and Denmark. Two people were killed by high winds in the U.K., three in Poland, and one in Denmark. Xaver's powerful northwest winds blowing along the length of the North Sea piled up a massive storm surge that was the highest since 1953 in portions of Eastern England, and the second highest of the past 200 years in Northern Germany. A storm tide 3.7 meters (12.1') above the high tide mark hit Hamburg, Germany, flooding the historic fish market and low-lying regions of the Elbe River. This storm tide was just 0.35 meters below the record set in January 1976. At Bremerhaven, Germany the storm surge peaked at 4 meters, but came at low tide. The highest storm tide was 3 meters above the high tide mark early Friday morning, falling about 0.2 meters short of the all-time record, also set in January 1976. Winds gusts as high as 92 mph (148 kph) and 98 mph (158 kph) were recorded along the Danish and German coasts, respectively. A few notable winds from the storm:

Oil platform Ula off the coast of southern Norway: sustained winds of 91 mph, gusting to 108 mph, at 2 pm local time Thursday.
Copenhagen, Denmark: sustained winds of 45 mph, gusting to 65 mph at 12:20 am Friday
Sylt, Germany: sustained winds of 58 mph at 3 am Friday
Norderney, Germany: sustained winds of 60 mph at 8 pm Thursday


Figure 2. A 14 meter (46') high, 1000 kilogram (2200 lb) Tyrannosaurus replica that was standing in front of the German climate museum Klimahaus in Bremehaven had the bolts which connected its base plate to the ground sheared off by the force of Xaver's wind Friday morning, sending the unfortunate T-Rex sliding to the edge of a quay. The T-Rex stood in a place where the air was channelled around the Klimahaus building and got greatly accelerated. Luckily, the beast had only some minor abrasions. A peak wind gust of 78 mph (126 kph) was recorded in Bremerhaven during the storm.


Figure 3. The Klimahaus T-Rex in a more festive holiday mood before the great wind storm. Credit for both images: Christine Sollmann and Michael Theusner of Klimahaus. According to Dr. Theusner, "There has been surprisingly small damage for this type of storm in Germany. This may be due to the extensive preparations and warnings that were provided to the public. I think it also played a role that "Christian" had already removed weak trees and other weak structures (roofs etc). Additionally, people were sensitized due to their experience with "Christian" and stayed home."
 

Figure 4. Day-night satellite image of Windstorm Xaver taken at 21 UTC Thursday December 5, 2013. Image credit: Navy Research Lab, Monterey.

Jeff Masters