December 2011

This trough produced a 998 mb low in Arizona on December 1st. 97 mph Santa Ana winds knocked down large trees and cut power to 200,000 in the Los Angeles area.
By December 3rd, snow had accumulated south of the Mogollon Rim in Arizona.
The flow was so amplified by December 5th, that winter storm warnings were issued for most of New Mexico, winter weather advisories for Big Bend National Park, and hard freeze warnings for the Tucson area.
Tucson had a record low maximum temperature of 48 for two consecutive days on the 4th and 5th.

On December 8th, this 954 mb storm with an unusually tight pressure gradient hit Scotland with 165 mph winds.
Just a few days later, a 944 mb storm swept through the British Isles:
On December 13th, a 950 mb Aleutian Low hit buoy 46072 with 43.5 foot waves.
Two days later, an Aleutian Low was at 944 mb and again produced 43.5 foot waves, this time farther east at buoy 46075:
On December 19th, this storm produced blizzard conditions (blizzard warnings are in red) across the Central and Southern Plains:
On December 24th, a low over Iceland reached 947 mb:
On New Year's Eve, this large trough produced a dust storm in the Central High Plains:
Winds gusted to 63 mph at Dodge City, 77 mph at Goodland, and 126 mph at Frisco, CO, east of Denver at 9,000 feet elevation. The dust could be seen in visible satellite imagery: