Alberta Clippers, Panhandle Hooks and Lake Effect Snow

    Alberta is a Canadian province that shares a border with a portion of Montana and an Alberta Clipper is a storm system during the winter months that originates from the Canadian province of Alberta although sometimes the system can originate from Saskatchewan, Manitoba or even Montana.
     The term "clipper" originates from the clipper sailing ships because of their quick speeds. They were ships built in the 1840s and 1850s with three masts that were created to transport small loads of cargo. The clipper ships could travel up to 400 miles a day which was a great distance at the time. 
     An Alberta Clipper is a quick-moving storm, or low-pressure system, that develops on the lee side of the Canadian Rockies, gets caught up in the jet stream and travels southeastward into the northern Plains, through the Great Lakes and eventually off the mid-Atlantic coast into the Atlantic Ocean. 
     A clipper will usually bring smaller amounts of snow (generally 1-3 inches) because of its speed and lack of deep moisture, but higher amounts are possible. Along with the quick burst of snow, a clipper generally brings colder temperatures and, often times, gusty winds. However, when lake effect snow is factored in, snow accumulation can double with a clipper swinging through the Great Lakes regions. 
     Most clippers occur between December and February, but can also occur occasionally in November and is the most common winter system for the upper Midwest. 
     A Panhandle Hook is a low pressure systems that originates in the panhandle of Texas and Oklahoma which initially move east and then "hooks" or curves more northeast toward the upper Midwest or Great Lakes region. 
     In winter, these systems usually deposit heavy snows north of their surface track. Thunderstorms may be found south of the track. 
     They are ugly. For example, on February 13-14, 2007 snow began falling in Cleveland, Ohio on the morning of the 13th and finally let up during the morning of the 14th. Wind gusts of 30-35 mph were blowing the newly fallen snow around. Then a Panhandle Hook developed, moved into the Mississippi River valley and into the central Appalachians which affected all of Ohio. Snow totals ranged from a foot near Toledo in the northwest of the state to a swath of 17 inches and greater from Mansfield, Medina and the southern Cleveland suburbs. Temperatures were in the 20s while the snow was falling, but in the nights following the snow, temperatures dipped into the single digits. On the 15th, Cleveland Hopkins Airport dipped to -4 degrees F. 
     Old Man Winter wasn't done. In Cleveland on Lake Erie temperatures had warmed into the 70s at the end of March and on April 3rd the high was 80 degrees! That was a distant memory two days later when the high temperature dropped to 29 degrees. 

     A strong cold front had swept across the area and lake effect snows started. A reinforcing trough of low pressure moved over the area during the 7th and 8th. This trough, combined with a steady northerly flow over Lake Erie, allowed for lake effect snow to continue and one band formed across downtown Cleveland dumping two feet of snow in the heart of the city. Amounts to the east in the snowbelt topped 30 inches from April 5 through April 8th. Lake-effect snow recently dumped 65 inches on Erie, Pennsylvania. 
     People who live outside the Great Lakes may well have never experienced this weather condition because the Great Lakes is the only place where it happens in the United States, except occasionally at the Great Salt Lake in Utah. 
     It happens when very cold, windy conditions form over a not-so-cold lake. For example, the lake might be 40 degrees and the air zero degrees. That temperature differential creates some instability and the water provides a moisture source and when it gets over land, it deposits water vapor as snow. Lake-effect snow generally doesn't fall over the water because it needs the friction and topography of the land to squeeze out the snow. 
     Winds usually blow west to east in the Northern Hemisphere, so the lake-enhanced snow is pushed to the eastern side of the Great Lakes. Lake-effect snow can be extremely localized, especially when hills and mountains cause these little weather systems to stall out and deposit a lot of precipitation in one spot. They can dump 20 to 30 inches of snow in one spot and five miles away only a couple of inches and the sun may be shining just a mile or two away in either direction. 

     Upstate New York and the cities of Rochester, Buffalo and Syracuse are notorious for lake-enhanced snow in the United States. That area is located east of Lake Erie and Lake Ontario, which have a more east-west orientation than the other Great Lakes. That means there's more time and distance for the lake-enhanced snow to build up and the snow can pile up with amazing speed. Recently in Erie, Pennsylvania 34 inches fell in one day and 26.5 inches the next.