Monday, December 1, 2014

One Wild and Crazy November

We're back with the CoCoRaHS Blog after a four-week break while Steve was on medical leave.

Today marks the start of meteorological winter, though residents in much of the eastern half of the country no doubt feel like winter started a month ago, with good reason!

Most of the contiguous 48 states from along and east of the Rockies, from the U.S. Canadian border to the Gulf of Mexico experienced temperatures below normal in November. The core of the cold air was in the upper Midwest and Northern Plains where temperatures were more then 9°F below normal. California and Nevada experienced another month of warmer than normal temperatures.

The wild weather really kicked into gear with the outbreak of Arctic air which plunged through the U.S. the second week of the month.

Surface weather map for 6:00 a.m. CST November 12
This set the stage for days of lake-effect snow in Michigan, Wisconsin, and particularly western New York in and around Buffalo. There were actually three separate lake-effect events around Buffalo - November 12-14, November 17-19, and November 19-21. The first event on November 12-14 was with the initial cold air outbreak and produced snow downwind of Lakes Erie and Ontario.  You can read a summary of this event on the NWS Buffalo web site. The second lake-effect event on November 17-19 was historic. A band of heavy snow developed off of Lake Erie and settled south of Buffalo - and didn't move for 36 hours. Snowfall rates reached 6 inches per hour at times, and when it was all over on Wednesday morning 65 inch of snow had piled up in south Cheektowaga east of Buffalo. Snow off of Lake Ontario accumulated to 22 inches in Philadelphia, NY east of Watertown.

For more detail on this event see this summary from the NWS Buffalo. The third lake-effect storm occurred right on the heels of the previous storm. It affected much of the same area that had been clobbered by the previous storm with one to four feet of new snow. When it was over some areas had received more than seven feet of snow from the two storms. The water equivalency of the snowpack was high, with some five to six inches of water contained in three to four feet of densely packed snow. The heavy wet snow caused collapsed roofs and contributed to flooding once warmer weather returned the following week. A summary of the third storm can be found here.

Snowfall records tumbled in Michigan as lake-effect snow piled up.  Gaylord, MI accumulated 65.1 inches of snow,45.5 inches above normal. Sault Ste. Marie in the Upper Peninsula measured 65.4 inches of snow, 50.3 inches above normal. These amounts were also all-time monthly records for both locations. Grand Rapids, MI experienced its snowiest November on record with 31.0 inches, breaking the old record of 28.2 inches in 1895. Muskegon, MI had its second snowiest November on record with 24.5 inches.

While much of the attention was on the lake-effect snow in western New York and Michigan, the cold air had produced early season snow in many parts of the country, including the south.

On November 17, 50.4 percent of U.S. had snow on the ground, remarkable for mid-November.

Snow depth on November 17, 2014.
Source: National Operational Hydrologic Remote Sensing Center

Warming weather following the Arctic outbreak ate away much of that snow and as of today only 22 percent of the country has snow cover. Only three to four inches of snow remain over central Erie County, NY according to our CoCoRaHS observers. That's the natural snow - some of the mountains of snow that were plowed and piled will take a much longer time to melt.

There were thousands of daily temperature records set during November - more than 4800 low maximum temperature records alone. Here is the current summary from the National Climatic Data Center.

Daily record count as of November 30, 2014.
Source: National Climatic Data Center

While snow was plentiful in the lower 48 states, much of Alaska had a mild and not so snowy November. Fairbanks received its first November snow of the season on November 24. Normally they have 23.3 inches by that date. Anchorage received its first snow of November on November 25, a mere 0.1 inch. However, a large storm occurred across much of southeast and interior Alaska this weekend leaving 6 to 12 inches of snow in its wake.

1 comment:

  1. My location is southwest of Springfield, Il., right under that far southwest bubble of blue - temperatures 10+ below normal. Crazy weather, 20 degrees below normal for the start of the month; two days later we were 20 above, then a few more days back to 20 below normal. Ten, hello, another two days we were back up to 60, 20 above. I think we are finally ranging pretty near normal temps.