Monday, February 7, 2011

Chicago Feb. 7 Lake Effect Snow Assessment

This Chicago lake effect snow was unprecedented. I had not predicted this, and the models hadn't either.
Looking at the last 4 runs of the GFS, only on the 12z run (3rd run out of 4) did the GFS pick up on the lake effect snows. By then, it was approximately noon CDT, and got a solid handle on it at about the same time.

Looking at this, the GFS obviously didn't perform well.

The NAM got a solid handle on the snows at 12z as well, and the NAM latched onto GFS thinking that the lake effect snows would hit Chicago at the 12z run.

The SREF, which typically is the best in short-hand situations, always had a thinking that lake effect snows would occur in SE Wisconsin, but never got the feeling for it hitting Chicago until it was happening.

In conclusion, the models did not handle this well at all, and the rating I would give the models a rating of a D+.

Forecast for the next 14 days

The images are from the CPC. Brown is below normal precipitation. Green is above normal precipitation. Blue is below normal temperatures. Red is above normal temperatures.
Below is the precipitation for the next 6-10 days.
In the above image, I totally agree with the forecast, as the models have been showing lingering high pressure over the Plains. The below image is the 6-10 day forecast for temperatures.

For the above forecast, I would pull away the big warm sector, since the high pressures over the Plains are from Canada and the Arctic. Below is the 8-14 day forecast for temperatures.

I would be OK with this, as some storms come through the area, Gulf air will be pulled up, bringing warm temperatures. Below is the 8-14 day forecast for precipitation.

I do agree with this, as the models are showing clippers come through the Great Lakes and Upper Midwest.

Droughts spreading across the South

Droughts are becoming more and more widespread across the South, and no end is in sight.
Below, in a CPC graphic, we can see the level of drought across the US. Focus in on the South central and Southeast US portions.
If you are in a drought area, conserve water whenever possible, especially across Florida, Louisiana, Texas, Arkansas.

Light snow moving across the area

Light snow will be on and off throughout the rest of the day as arctic air plunges southward.
Areas closest to the lake will get the most snow.
Below is realtime radar.
from foxchicago