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Groundhog's Day blizzard pounds U.S.; Category 4 Yasi hits Australia

By: Dr. Jeff Masters, 3:50 PM GMT on February 02, 2011

The great Groundhog's Day Blizzard of 2011 continues to pound a huge swath of the U.S. with heavy snows, destructive freezing rain, and dangerously cold and windy conditions. Over 1/2” of ice has caused power outages in Indianapolis, and up to .9” of ice has hit Columbus, Ohio. Ice amounts in excess of 1/2” have also affected Illinois, Connecticut, New Jersey New York, and Pennsylvania. Blizzard conditions continue in Chicago, where heavy snows of up to two inches per hour in high winds have crippled the city's transportation system. As of 9am CST this morning, Chicago's O'Hare Airport had received 19.5” of snow, making it city's third greatest snowstorm on record. Only the January 2 - 4 1999 blizzard (21.6") and January 2 – 4, 1967 blizzard (23”) have dumped more snow on Chicago. Today's blizzard had stronger winds than Chicago's other two record snowstorms, and thus this storm is probably the worst snowstorm ever to affect the city, as far as impacts on travel go. Huge drifts in excess of 6 feet are common in the city, and residents are finding it difficult to leave their houses, much less travel on area roads. Winds last night at Chicago's Calumet Harbor were sustained at tropical storm force, 39 mph, with gusts to 51 mph, and high winds tore off part of a fiberboard roof panel behind home plate at Wrigley Field, home of the Chicago Cubs. The Chicago buoy, 10 miles offshore in Lake Michigan, had sustained winds of 54 mph, gusting to 66 mph, last night. Winds are slowly decreasing across Chicago, and the blizzard will be over by early afternoon.

Figure 1. Lake Shore Drive in downtown Chicago on the night of February 1, 2011. Image credit: Viewer uploaded photo from WGN.

According to the National Weather Service, since snow records began in 1886 in Chicago, there have been 43 winter storms that produced 10 inches or more of snow. A 10 inch snow occurs about once every 3 years. A 15 inch snow occurs only once about every 20 years. The closest back to back 10 inch
snows were March 25-26 and April 1-2, 1970 (6 days apart). The longest period of time without a 10 inch snow or greater was February 12, 1981 to January 1, 1999 (almost 18 years). The earliest 10 inch snow was November 25-26, 1895 and the latest 10 inch snow was April 1-2, 1970. The most recent 10 inch snow was January 9-10, 2009.

Chicago's 10 biggest Snowstorms:

1. 23.0 inches Jan 26-27, 1967
2. 21.6 inches Jan 1-3, 1999
3. 19.5 inches Feb 1-2, 2011
4. 19.2 inches Mar 25-26, 1930
5. 18.8 inches Jan 13-14, 1979
6. 16.2 inches Mar 7-8, 1931
7. 15.0 inches Dec 17-20, 1929
8. 14.9 inches Jan 30, 1939
9. 14.9 inches Jan 6-7, 1918
10. 14.3 inches Mar 25-26, 1970

The great storm's fury now turns to New England. Boston received 9.7” of snow as of 7am from the storm, and another 4 – 8” is on the way today. Heavy snows in excess of 6 inches are expected in a swath extending from central New York through Massachusetts, Vermont, New Hampshire, and Maine today. Up to 1/4” of ice is expected through New England along the southern edge of the heavy snow belt. Cities near the coast such as New York City and Philadelphia will receive mostly rain from the storm, though.

Some selected snowfall totals from the Groundhog's Day Blizzard of 2011, as of 9am EST:

Spring Grove, IL 20.8”
Miami, OK 20”
Jefferson City, MO 18.3”
S. Fort Scott, KS 18”
Tulsa, OK 15”
Schenectady, NY 9.6”
Boston, MA 9.7”
Detroit, MI 7.5”
Oklahoma City, OK 7”
West Hartford, CT 6.5”
Abilene, TX 6”
Cedar Rapids, IA 4.5”

Figure 2. Satellite image of the Groundhog's Day Blizzard of 2011, taken at 10am EST February 2. Image credit: NASA/GSFC.

Category 4 Tropical Cyclone Yasi hits Queensland, Australia
Tropical Cyclone Yasi roared inland over Queensland, Australia at 12:30am local time this morning as a strengthening Category 4 storm with 155 mph winds and a 930 mb central pressure. Yasi is incredibly strong, its winds falling just 5 mph short of Category 5 status. This makes the storm one of the top-ten strongest cyclones to hit Australia since accurate records began in 1970.

The Australian Bureau of Meteorology had this to say about Yasi in their advisory last night:



Figure 3. Tropical Cyclone Yasi at 03:35 UTC February 2, 2011, as seen by NASA's Aqua satellite.

On Wednesday morning at 9:30am local time, Yasi hit tiny Willis Island, where a minimum pressure of 938 mb and a peak wind gust of 115 mph was observed before Yasi cut communications and damaged the radar.

Queensland faces three major threats from Yasi. The cyclone will bring torrential rainfall to a region with saturated soils that saw record flooding earlier this month. The latest rainfall forecast from NOAA using satellite-based rainfall estimates shows 4 – 6” of rain falling along Yasi's track over the next 24 hours. The GFS model is predicting that a wide swath of Queensland will receive 5 - 10 inches of rain over the next week, due to the combined effects of Yasi and a moist flow of tropical air over the region. Fortunately, Yasi is moving with a rapid forward speed, about 21 mph, and is not expected to linger over Queensland after landfall. The heaviest rainfall will miss Queensland's most populated regions to the south that had the worst flooding problems earlier this month, including the Australia's third largest city, Brisbane.

Yasi brought highly destructive winds to a region of coast between the cities of Cairns (population 150,000) and Townsville (population 200,000). Strong building codes have been in place in Queensland since the 1960s, which will help reduce the damage amounts. The fact that Yasi's eyewall missed these two major cities is lucky, since the coast is less populous between the cities.

A dangerous storm surge in excess of ten feet likely occurred along the left front quadrant of the storm where it came ashore. The tidal was going out when the storm struck, and the inundation from the storm surge will be about 1 meter (3 feet) less than it would have been had the storm hit at high tide.

Yasi is larger and more dangerous than Cyclone Larry of 2006, which hit Queensland as a Category 4 storm with 135 mph winds. Larry killed one person and caused $872 million in damage (2011 U.S. dollars.) Yasi will bring heavy rains to a region with soils already saturated from record rains, and may become a billion-dollar cyclone.

Figure 4. Radar image of Tropical Cyclone Yasi at landfall in Queensland, Australia. Image credit: Australian Bureau of Meteorology.

Links to follow:

Live streaming video from Channel 9 in Cairns, Australia

A new look for wunderground
The Weather Underground was the first commercial weather company to set up an Internet web site, way back in 1995. In the sixteen years since, we've steadily expanded our content, but today—in honor of Groundhog's Day—we've launched our first major site re-design. The WunderPress blog has a introduction to the new site, including a slide show that explains the new layout. You can click through the demo by hitting the “>” button. The launch of the redesigned wunderground.com also features our unique forecasting technology, BestForecast. Utilizing Weather Underground's network of personal weather stations (the largest in the world), BestForecast provides the industry's most localized weather forecasts by producing a forecast for every place in the world that has an airport or personal weather station—over 19,000 locations worldwide. We also provide the latest National Weather Service forecast for each county in the U.S., so users can choose which forecast works best for them. Coming soon: verification statistics, so you can see exactly how well the forecasts are doing for your location. We realize that not everyone will be happy with the newly redesigned site, so we still offer the old design at classic.wunderground.com.

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The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.