Change in Wx pattern brings Chaos to the Wx Models

Oh GFS and your lovely pros and cons...Here is a quick run down of how I think things will play out early next week.

Typical GFS fashion with its horrible feedback issues at times. Let me show you here with two graphics which indicate the same time period. However the first one was created during the 0z run Tuesday evening and the second one is only 6 hours later from the 6z run. Notice any difference to the 500mb patter and heights? Ya you can say huge difference as the first run has low 60s and breezy in St. Louis. While 6 hours later its says its probably sunny and in the upper 70s.



Now when I say feedback issues this is what I mean. Models sometime have a hard time trying to determine the production and how to transfer latent heat in the atmosphere. Well on this example you can see in the 0z a very powerful trough digging south with a strong vorticity max in front of the trough. The 6z model still has the energy by splits it into two separate energy bundles. One across the four corners and another piece connected with the trough in Canada. You'll see a lot of this this winter as we'll likely have a stronger than average southern jet and the Polar jet diving southeast trying to merge. As there will likely be a split flow in the west with the two jet streams merging across the Central and East.

In this example and why I have hinted at the pretty strong outbreak of cooler than normal temperatures next week and into the following weekend. The models see it but it just doesn't know how to handle it. So instead of the energy being bundled ahead of the trough in the Ohio Valley. The energy will be back a little farther west and stretched a little more west to east. As the trough will want to dive south toward Oklahoma, Arkansas, Louisiana area. As compared to the 0z where the trough axis will head toward Georgia and the southeast states.

So expect places like Northern and Central Plains to see their pinpoint forecast that the NWS uses to vary a lot over the next couple of days. Typically the GFS figures these kinds of issues out about 2-4 days prior to the event. I believe the Northern Plains will see their end to the growing season by next week. This colder air will filter into the Great Lakes and into the Ohio Valley. Overnight lows will probably dip down to near or below freezing north of I-80 (Dakotas, Minnesota, Wisconsin). As temperatures in the 40s will be common elsewhere. Right now MOS numbers for Indianapolis for Wednesday morning is 61 Thursday morning 58. I will go with both mornings around the 44 to 47 degree range.

High temperatures down in my area by next Tuesday and Wednesday will be in the Lower to middle 70s. MOS temperature prediction has a high temperatures in Lawton on Tuesday and Wednesday of 87 degrees.

So we'll see if I'm correct or if the model is correct on our first big push of cold air from the northern reaches of Canada.

Alright time to get some sleep... Justin