The initial synoptic setup is remarkably similar. Take this morning's 12Z 500mb analysis from the GFS:
|Fig 1 -- GFS 500mb geopotential height and wind analysis at 12Z, Monday, January 31, 2011.|
|Fig 2 -- NOAA Difax 500mb N. America geopotential height analysis from 12Z, Jan. 1, 1999.|
Back to this current event, twenty-four hours later (12Z on Tuesday morning), the GFS forecast has a well-defined, if somewhat east-west expansive, trough across the central part of the country with embedded short waves.
|Fig 3 -- GFS 24-hour forecast of 500mb geopotential height and winds valid 12Z, Tuesday, February 1, 2011.|
|Fig 4 -- NOAA Difax 500mb N. American analysis of geopotential height valid 12Z, Saturday, Jan. 2, 2011.|
|Fig 5 -- GFS 36-hour forecast of 500mb geopotential height and winds valid 00Z, Wednesday, February 2, 2011|
|Fig 6 -- NOAA Difax surface analysis valid 12Z, Sunday, Jan. 3, 1999.|
|Fig 7 -- GFS 48 hour forecast of surface pressure and temperature valid 12Z, Wednesday, Feb. 2, 2011.|
|Fig 8 -- NOAA Difax analysis of surface pressure (and fronts) for 12Z, Jan. 4, 1999.|
There are cold air intrusions in both events, however the observed 20-25 degree Fahrenheit morning lows in Oklahoma by the time of occlusion in the 1999 event are outstripped by the single-digit lows being forecast by the GFS for this week (NOT that we trust the GFS surface temperature forecasts...). This hints at a stronger baroclinic zone and much colder air behind the front. This becomes important because if we look at snowfall totals from the 1999 event--
|Fig 9 -- NOAA Difax analysis of observed snowfall on the ground at 12Z, Jan.3, 1999.|
Interestingly, according to records at Wiley Post Airport in Oklahoma City, on January 2-3, 1999, snow and rain were both reported in the observations, but no measurable accumulation of either seems to be recorded. The high temperature also hovered in the low to mid 30's with overnight lows in the low teens after the event. Not near the cold weather we're looking at according to current forecasts...
So, in conclusion, there are some general similarities in the evolution of both the 1999 blizzard and this week's event. However, this week's storm will move much more quickly, have much colder air behind it, and bring wintry precipitation further south. Up north, however, the proxy seems to be pretty good--if a storm of that intensity (and perhaps even more limited moisture) in 1999 could bring 17 inches of snow to Chicago, projections in that range would not seem to be out of the question for the upper midwest with this week's storm.
Finally (on a slightly technical note), I just want to leave with a cross-section image generated on the College of DuPage website from this evening's soundings. This cross section runs from Albuquerque in the west to Nashville in the east. We can see that "warm conveyor belt" starting to ramp up with that bulls-eye of moisture (the green contours) in an area of southerly winds to the east.
Also, for all of you reading this at the University of Washington--I will be giving tomorrow's weather briefing in 310C at 12:30 PM and will be going into a fair amount of detail about this event during the presentation. Feel free to come by...