Sunday, December 5, 2010

Potential GL Snowstorm Models Update #1

0000Z GFS: 11/12 SNOW, 12/12 PRECIP, 1/12 MIX
0000Z CMC: 4/16 SNOW, 10/16 PRECIP, 3/16 MIX, 3/16 RAIN
0600Z GFS: 11/12 SNOW, 11/12 PRECIP
1200Z GFS: 9/12 SNOW, 11/12 PRECIP, 2/12 MIX
1800Z GFS: 11/12 SNOW, 12/12 PRECIP, 1/12 MIX

46 indicate SNOW
7 indicate MIX
3 indicate RAIN

Chance of PRECIP: 88%
Chance of SNOW: 72%
Chance of MIX: 11%
Chance of RAIN: 5%


The CMC indicates a strike on Chicago and Milwaukee. It shows the same set-up as this weekend's storm in the Lower GL, except this time, the models show it veering slightly into Chicago and not out as much towards the Quad Cities, Iowa.
Thickness remains fine, and Relative Humidity centered in Western Illinois again. However, it is still affecting most of the area around the GL.

The NOGAPS shows the clipper-like system completely missing the Quad Cities, Chicago and barreling into the Upper Great Lakes as a weak system but stronger by the lakes.
Relative Humidity and Thickness fine for the Upper GL.

The GFS shows Madison, Milwaukee, and all of Wisconsin facing the storm head on while clipping North Illinois. However, RH (Relative Humidity) will be conductive for the entire East Illinois area. Thickness will be fine.

48 indicate SNOW
7 indicate MIX
3 indicate RAIN

Chance of PRECIP: 87%
Chance of SNOW: 72%
Chance of MIX: 10%
Chance of RAIN: 5%

Potential GL Snowstorm Models

This is the models and ensemble updated run for the possible GL snowstorm.
Before we start, this is a lot of controversy. The models say it'll be a nice storm, but the sites say it'll be light snow. This is a tough one. The storm is forecast for Thursday into Friday.
Models by e-WALL.

The CMC model says that Milwaukee and Chicago will be hit nicely, spot on, with the same set-up that occurred with yesterday's storm. The thickness is fine, the relative humidity mainly centered over Chicago, IL and Madison and Milwaukee Wisconsin.
Relative humidity is meant to show where the water droplets are most heavy and able to form precipitation in clouds.

The GFS model says that North Illinois and Wisconsin will get the worst of the storm, but the relative humidity will be maximized in Wisconsin and the east half of Illinois.
Thickness will be acceptable.

The NOGAPS indicates that the storm will completely miss the area and come through as weak snow showers way up north in the high Upper Midwest. Relative Humidity will be too scarce as well.

Massive Lake Effect Snows to Occur in GL

A massive lake effect situation is forecast to happen in the NW Indiana area in the next week or so as cold air continues to flow over the warm waters of Lake Michigan. Below are images from different agencies.

Midwest Storm Totals (NWS)

Weather Explained: Greenland Blocking Pattern

This is Weather Explained, talking about the Greenland Blocking Pattern. The below image is from the NWS.

The Greenland Blocking Pattern is when a high pressure sets up over Greenland with mild air in that area. This makes the jet stream collapse down south, providing cold air into the areas affected as seen above.

This jet stream set-up is a particularly good conductor for snowstorms in cities such as Chicago, Rockford, and sometimes Springfield Illinois. Madison, Milwaukee Wisconsin can be affected as well.

So this will continue for the next few days, then milder temps, then some colder temps again.

Potential GL Snowstorm Watch Zone