Ghosts of Thanksgiving Past

Thanksgiving weekend 2001.  

We traveled to with the kids to Seattle to enjoy the annual feast with family.  

When we departed, most likely on November 21, there was no skiing.  A look at the Alta-Collins data on MesoWest suggests a 10" natural snow depth.  My recollection was that there was no snow, but perhaps their was a little.  

When we returned, there was skiing.  Plenty of skiing.  

At around 0000 MST 22 November 2001, the start of Thanksgiving Day, it started snowing.  Eventually, 108 inches fell at Alta-Collins, including one hundred inches in one hundred hours.  The press called it the hundred inch storm.  Pretty catchy.  It led to one of the funner papers I've written during my career. 

The hundred inch storm was really produced by two storms or should I say two frontal systems.  Snow at Alta came ahead of each front, with each front, and behind each front, with both post-frontal periods producing incredible lake bands.  

Example radar imagees from the two lake-effect bands that contributed to the Hundred Inch Storm. Source: Steenburgh (2003).

One of my former graduate students, Kristen Yeager, went back several years later and found that the second of the two lake-effect periods was the largest on record from 1998, when KMTX radar archives began, to 2009 when she ended her study.  It produced an unbelievable 3.15 inches of water at the Snowbird SNOTEL.  We really haven't seen anything like it since, so it most likely was the biggest lake-effect storm since 1998 and possibly since the installation of the radar in 1994 (radar data from the first few years of KMTX operations were not archived).  

The snow depth time series from Alta-Collins for the period shows it becan with a scant 10" or snow on the ground (sometimes the calibration of the depth sensor is off so it's possible it was less than this).  The first storm raged through early on the 23rd when the snow depth reached 50".  Then there was a break.  Then the second storm pushed the total depth to 80".  Roughly a 70" increase in four days. 

Source: Mesowest

That number is less than the 100" total because the total snow depth is subject to compaction whereas new snow totals are based on interval samples on a snow board.  

The Salt Lake Tribune ran the photo below of a what appears to be an Alta Ski Patroller getting the goods following the storm.  

Source: Steve Griffin, Salt Lake Tribune

My notes indicate the east bench got 30-33" and the Salt Lake City airport 15".  I do remember having to dig the car out from the airport parking lot when we returned.  

Things can change fast.