THE HOUNDS OF HORROR WILL BE HOWLING...
Usually I create these blogs the traditional way, I start at the beginning and work my way to the end. On this one we're going to begin with a broad view of a 16 day period because in one quick glimpse you can see the future of our temperatures. I present the GFS meteogram through November 15th.
I presume you noticed the 6 day stretch of 60s that begins near election day and ends November 8th. The 500mb pattern that drives the warmth looks like this. Man, that's a screeching zonal flow.
It cuts off access to any cold air and delivers temperature departures 15-25 degrees above normal during that period. This is the departure shown Sunday morning November 8th.
The pattern is projected to break with a bang thanks to this buckle in the jet around November 13th.
That allows colder air free access to the Midwest and at least for now produces departures in the GFS that look like this the evening of November 14th. Many readings a good 15 degrees below normal.
If this were to happen, it would mean a drop in Cedar Rapids temperatures of 47 degrees from a max of 68 the 6th to a low of 21 the 12th.
While forecasts out 2 weeks are far from certain I do believe there are reasons the overall trend has merit. First, the EURO and GFS both have the MJO (Madden Julien Oscillation) rotating into phase 1 about that time. Phase 1 as you can see is cold during November. This is when the trough and associated cold is shown coming into the Midwest.
On top of the MJO, the AO (Arctic Oscillation) is going negative
The EPO (Eastern Pacific Oscillation) is also headed negative pointing to a western ridge.
Last but not least, the NAO (North Atlantic Oscillation) is also shown moving into a negative phase.
All of these teleconnections are strong signals for cold around and beyond November 10th. In other words, the deck is stacked in the favor of the cooling trend. While the Climate Prediction Center hasn't quite reached the Midwest with the cold through November 13th, you can see they are picking up on the idea with a moderate risk of hazardous cold the 7th-13th just to our northwest.
Circling back and ending with the present, Halloween is going to be mild with highs upper 50s to low 60s. But don't turn your back, the hounds of horror will be howling with winds that could gust 35 to 40 mph. Trick or treat? Roll weather and have a safe and happy Halloween...TS
On a side note I also want to remind you that I am pre-selling copies of my new book Derecho 911, Iowa's Inland Hurricane. I've had a fantastic response to the book and copies are limited so order yours today before we sell out. Click on the link below for details. It will make a good Christmas gift for that challenging person on your list!