Somewhat Important Note:

Due to the popularity of the blog, I receive numerous Facebook requests before potential snowstorms. Although I am flattered that you want to follow me on Facebook, I would ask that you not friend request me unless you know me in real life. It's nothing personal, I've just decided I don't want too many friends on Facebook.

Thanks, John

Thursday, January 29, 2009

Still looking decent for a potential blizzard early next week!

Sorry that this is a really late entry, but I figured the extended forecast model discussion would get people to more clearly understand why I believe the track of this storm will end up being to the west of what is currently forecasted.

Alright, so, with no further ado, here's what I believe is going to go down with this storm next week.

A surface low will form somewhere in the Gulf of Mexico, and then move to the NNE. Forecast models have come to a fairly good agreement that this storm will track through Central PA. This track would result in SE Michigan getting some, but not a lot, of snow from this storm.

However, I'm actually satisfied that we are on the western fringe of the snow from this storm considering the weather pattern we're in. In this weather pattern, forecast models often adjust the tracks of storms to the west as time goes on. Take, for example, the comparison images I've used of the 12Z (7 a.m.) and 18Z (1 p.m.) runs of the GFS forecast model.

The above image is the forecasted position of the low pressure system at 120 hours from this morning's 12Z (7 a.m.) run of the GFS. AKA this is where the low is supposed to be at 7 a.m. Tuesday. Note that it is too far east to give Michigan any significant snow. The GFS at that time was the furthest east of any forecast model with this storm track.

Now, here's the forecasted position of the low pressure system at 114 hours from this afternoon's 18Z (1 p.m.) run of the GFS. I've used this image as a comparison image from the last image because it's shows the low's forecasted position at the same time (7 a.m. Tuesday).


Note that the forecasted position of this storm has shifted hundreds of miles west from the 12Z to 18Z run; in fact, so far west that Michigan is forecasted to receive significant snow if you took this run of the GFS as the absolute truth (although you never want to take one forecast model as the absolute truth). Now, the 18Z run of the GFS is admittedly less reliable than the 12Z run of the GFS, but it is usually somewhat of a "trendsetter"; AKA other runs of the GFS usually follow the trends that the 18Z GFS starts - in this case, a further west track of the surface low, and significant snowfall for Michigan.

So, the bottom line for now is that I expect the models to adjust the track west as time goes on, and I expect us to be adversely affected by this storm.

Why? Because this storm is strong and large enough that even if the current forecasted track doesn't move one inch to the west, we would probably still get a few inches of snow from this storm. And with this storm, a few inches of snow will be enough to cause blizzard conditions, as this storm will likely be a "meteorological bomb", or a storm that drops it's lowest pressure by 24 millibars in under 24 hours. Anytime a storm drops it's pressure by that much, extremely high winds result.
For the area that receives the brunt of this storm, I expect 12-18" of snow and also expect everything to basically shut down in that area for several days, as 12-18" of snow combined with 40+ mph wind gusts (which I'm expecting from this storm) is enough to cause whiteout conditions and snow drifts high enough to shut down almost any road.

This storm will be a fun one to watch, and if everything plays out correctly, this could be much worse than even the New Year's Day Blizzard that occurred last year.

1 comment:

Anonymous said...

We can only hope!