9:00pm Weather Update - Winds of Concern

Seems like I've been talking about a lot of different type of weather the last two days.  Thunderstorms, tornadoes, snow and wind.  I want to take a minute and talk about the wind for Thursday.  It is going to be strong.

In the St. Louis area they could be sustained 30-35mph with gusts to 45-50mph tomorrow afternoon.  Indianapolis they could be 30-40mph with gusts to 50mph.

At times tomorrow the wind is going to be hauling just a few thousand feet up in the atmosphere.  Here is a cross section of what the 18z NAM computer model is projecting winds to look like at different altitudes tomorrow for St. Louis.  To give a frame of reference, each colored line indicates what the wind speed will be doing.  The white horizontal lines are indicators of height in thousands of feet.  Look to the right of the image to see the altitude.  (1k = 1,000 feet)  Finally, time goes from right to left.  Yes, backwards.  I didn't write the program. ;)

(Click the image to see larger version.)

Notice the area pointed marked with the "Strong Winds Aloft!" arrow.  Those are winds that will be 70-75 mph 2,300 feet above the ground.  Go lower in the atmosphere and they are 46mph at 500 feet.  That is pretty close to the surface.  There will be times that we can mix down some of the stronger winds aloft.  That is why there has been talk of strong winds in the Midwest tomorrow.

Here is another graphic I want to show you.  This is off the high resolution 4km RPM computer model.  I have used this product several times in the past with some success (ice storm 2009 in southeast Missouri and western Kentucky).  This uses alogrithms developed for energy companies and energy traders.  This shows potential power outage areas due to weather elements.  This can caused be a mixture of wind, snow, hurricane, ice, etc.

(Click the image to see larger version.)

Special thanks to Brian Wilkes at FOX59 in Indianapolis for passing this along.

Take a look over Missouri and you will see that the model is indicating "widespread" to "extensive" power outages over north central and west central Missouri to northeast Missouri.  It also shows "scattered" power outages over parts of southeast Missouri, extreme southern Illinois and all of western Kentucky.  If you live in any of these areas, this might be something you have to deal with.  That being said, this is definitely not a guarantee.  The model can be wrong and sometimes is.  Also, don't get too hung up on the lowest threshold "scattered".  This means there could be a "heightened" threat.

Signs of Snow

There are signs that snow may arrive to parts of the Midwest early next week.

For several days forecast models have been hinting at a storm developing over the southwest United States, eventually moving through the Midwest. The models haven't been jiving too well with each other to the course the storm will take. If you follow me on Facebook you might remember a status update that said, "Models are flip flopping around..."

Last night's runs started coming together and this morning's model runs are pretty similar in to the track of the surface low. (See graphic below.)

(Click image to see larger version.)

The above graphic was created by AccuWeather but is pretty close to what the models are showing regarding the track of the storm.

Northwest of the surface low cold air is expected to move in. This will allow for some significant snowfall in parts of the country.

It is interesting to compare the amount of moisture north of the surface low that could interact with the cold air and fall as snow. Models are not on the same page with this feature.

The European forecast agency's computer model is more bullish on the liquid amounts compared to NOAA's computer model. Here's a closer look at what the models are indicating for liquid available during the time it would fall as snow.

European Model:

• Kansas City - 0.77"
• Kirksville, Mo - 0.44"
• Columbia, Mo - 0.09"

GFS Model:

• Kansas City - 0.09"
• Kirksville, Mo - 0.03"
• Columbia, Mo - 0.00"

If the European model is correct, Kansas City could end up with 6"-9" of snow (maybe more). If the GFS is correct Kansas City could get 1" of snow. That is a pretty big difference.

I should mention that areas along and south of the track of the surface low will see good ole' rain.

Stay tuned...

- Posted from my iPhone