GOOD IN THE NEIGHBORHOOD...

Some very pleasant weather moved into the Midwest Wednesday, that by December temperature standards gets downright balmy Thursday and Friday. A combination of sunshine, southwest winds, and Pacific air will push highs into the 50s across the board Thursday. In fact, if the far south can squeeze out a little extra sunshine, a 60 degree high is a distinct possibility. When you consider how short the days are and the diminished power of the sun in December, those are colossal numbers.

These are the highs the GFS suggests Thursday afternoon.

Just as impressive are temperatures at 850mb (5,000 ft. level). They are up around 11-12 degrees C., nearly summer-like in scope. When you consider 0 degrees C. is the level necessary for snow, there's essentially no cold air left in the Midwest. Even at International Falls, Minnesota, the 850 temp. is +7. You won't see that often in the nation's ice box in December.

While we're at it, we'll throw in another mild day for free on Friday, with similar highs expected. About the only difference will be an increase in clouds as our next precipitation producer arrives from the west.

It makes its presence felt by Friday evening, sending a wave of low pressure along a cold front that slips east of the Mississippi by midnight. Not only does that bring sharply colder air, it's the forcing required to produce rain. With less phasing and an open wave, the rain that starts Friday evening moves quickly and exits the south Saturday morning and the north by early Saturday afternoon.

Some areas should see some welcome amounts, but there's a track discrepancy with the GFS about 75 miles further west with the more substantial rains than the EURO. This will get worked out Thursday, but for now I'm liking more of a middle ground compromise. I also think the GFS may be a bit heavy. Here's what I'm seeing.

The EURO

The GFS

There is still a chance that at the tail end of the system, rain could mix with or change to snow in the far NW. Again, the track will influence whether that includes my NW counties. The EURO thinks that's possible. I sure don't look for much, if any. Here's what guidance is indicating.

The EURO

THE GFS

With the storm passing Saturday, brisk NW winds allow colder air to enter the region. Temperatures will gradually fall Saturday into the 30s NW to around 40 SE. Sunday will be a cold day, with highs only in the low to mid 30s, a few degrees below normal.

After that, we get another surge of warmth around December 12th that could last at least to December 17th or 18th. That is based on the GFS showing low heights (pressures) over much of the polar regions (in blue). That promotes ridging to the south here in the mid-latitudes and up go temperatures, similar to what is going on now.

This also make sense with the MJO (Madden Julien Oscillation). It's in phase 4 on its way to 5 and 6 between now and December 15th. In the middle panel of the phase diagram below, you can see the temperature analogs for those phases are quite warm in the month of December. That's a strong signal for above normal temperatures through mid-December.

MJO PHASE DIAGRAM

December 14th's temperature departures on the GFS are certainly delivering the warmth.

DO WE FLIP THE PATTERN BY CHRISTMAS?

After that, the MJO moves into phase 7 around December 15th and begins a cycle that takes it through 8 and 1 the remainder of December through January 5th. (see the phase diagram above). By then the GFS shows a significant change at 500mb with the low heights I showed you earlier at polar regions being replaced by building heights (in red). That higher pressure is forcing cold air out of the polar regions and displacing it in the eastern half of the U.S.

Look at the temperature departures December 22nd. A major reversal has taken place. That's assuming the GFS is interpreting the pattern correctly.

If you believe in the MJO, this would totally fit its temperature analogs for a tour of phases 7, 8, and 1 in December. See the right panel of the phase diagram above for those phases in December. They are clearly cold.

WHAT ARE THE CHANCES?

Now the qualifier, this is the first time I've seen the colder trend show up on the deterministic models, specifically the GFS. I've been expecting it but until today, there was not much evidence to that effect. Not only that, the EURO is not yet showing the colder trend. Maybe this was a fluky run of the GFS. Who can say they know for sure?

Typically, I would be all in on the idea of a much colder pattern leading up to Christmas, with virtually every model showing the move to colder MJO phases. However, this El Niño is a weird one. When you look at the sea surface temperatures (SST's) you can clearly see the warm waters of the tropical Pacific that represent it. But what is really odd is that almost the whole Pacific Ocean from Japan to the United States (Within the blue box) has above normal temperatures. Typically, there would be areas of colder water, such as you see off the coast of southern South America.

With climate change and so much warm water, I wonder if that disrupts the tried and true analogs and their temperature correlations. Otherwise, this El Niño is headed to Modoki standards and the MJO is signalling warmth to mid-December and then a turn to a colder weather Christmas week and beyond. That's my interpretation, but maybe mother nature has other ideas. Something to ponder and watch. Roll weather...TS

HOT HOLIDAY DEALS AT OUR LITTLE WHITE CHURCH IN GALENA

A HEAVENLY RETREAT

Enjoy some Holiday Magic at the Little White Church of Galena! Terry and I are offering fantastic holiday discounts from now through the end of January. Book now and any weekend from today through January 2024 is $600. That is the total price. The only exception is if you bring Rover. There is a small pet fee. This is a 50% savings, even dear old St. Nick can’t match it!

The Little White Church is a fully renovated 18th century church nestled in the valleys of Jo Daviess county…just a little over five miles to the center of downtown Galena. With all the amenities of a five-star hotel, the Little White Church offers beautiful historic touches with comfort and style. Every group we have hosted to date has given us a perfect 5-star rating. We are considered a Superhost by Arbnb.

We have five beds, three full bathrooms, full kitchen with dishware, small appliances, ice maker, a luxurious private master suite with en-suite and private deck, a large main floor deck, attached two car garage, fire pit, gas grill, and 2700 sq feet of space to sprawl out You will not find a more modern and historic place to unwind and get away from it all. Furthermore, we are now decorated for the holidays, so get your holiday spirit cranked up and come and join us. I also can arrange a talk about the Christmas Eve weather scenario with Santa’s favorite meteorologist! Just text me at 563 676 3320. https://www.tswails.com/galena-airbnb

Carolyn