Sunday, January 22, 2017

It’s been well advertised for the past  ten days or so – an upper level pattern change that was due to begin late this week.  That would shift the major storm activity from the Pacific coast into the eastern U.S., setting up the winter-weather favoring “East Coast trough – West Coast ridge” pattern that would open eastern North America to renewed outbreaks of arctic air.  We haven’t seen this pattern much this winter.  It set up for about 2-3 weeks during December and then again briefly in early January.  Each time, it could not establish a foothold and returned blasting the western U.S. with heavy rain and snow.  That has been good for California, as the years-long drought has been wiped out (for now).

As usually happens when forecasters try to look out a week or two in advance,  the expectations don’t meet the reality when it finally arrives.  That seems to be happening this time as well.  Colder weather appears likely by late week and the weekend.  But, current forecasts for temperatures are running 5-10 degrees warmer than they were a few days ago.  So, it looks as though the first attempt to establish the east coast trough will only drop us into the “near normal” range rather than the previous “below normal” expectations.

But, snow lovers,  there is some good news.  The GFS and the European model continue to deepen (strengthen) the troughing over the eastern U.S. so that Super Bowl weekend should see the beginning of some strong cold air outbreaks ( and maybe some snow(s)).

Although I have repeatedly stated that long range forecasts can be highly unreliable, I will take a stab at what happens after that.  The U.S. has a forecast model known as the Climate Forecast System (CFS) designed to project the months ahead in general terms.  Since I usually concern myself with current weather and a few days ahead,  I’ve never paid much attention to the CFS.   But, if you want to dream big, the CFS is predicting that once the east coast trough really establishes itself (11-14 days from now), it will hold until the end of February!  That could make for a lot of fun next month

(And that could be our last chance as the CFS expects March to return to above normal temperatures.)

Current weather

I seems pretty obvious by now that those forecasts for heavy rains (Thunderstorms?) and possible flooding (especially south of Louisville) are not going to materialize tonight and tomorrow. We’ll probably see some rain tonight, mostly after midnight.  Total should be a quarter-inch or less.  After that, the next few days should be dry with continued mild temperatures.

Stuff

If you were asked,” How many Presidents has Kentucky produced?”, the obvious answer would be “one.”  But, some people count Jefferson Davis as a second President.  That’s a “trick answer” as he was President of the CSA not the USA.  But, in a little-known historical quirk, Abraham Lincoln was actually the second Kentuckian to serve as President of the USA.  Here’s the story from the very interesting website, www.mentalfloss.com. …

In 1849, Zachary Taylor refused to be sworn in on a Sunday, because he was very strict about “keeping holy the Sabbath.” The position of president couldn’t just be vacant until Monday, so the President Pro Tempore of the Senate, David Rice Atchison, was brought in as a pinch hitter. There’s some debate as to whether this actually makes him the 12th president and Zachary Taylor the 13th, but obviously, it’s generally accepted that he doesn’t count. He didn’t even stake claim to the title, and repeatedly told people that he slept through most of his day as president. He must have had a good sense of humor about the whole thing, though, as evidenced by the inscription on his gravestone.

Monday, November 20, 2016

Two weeks ago I wrote about the upper atmosphere’s attempting to evolve into a different, colder, weather pattern.  It tried, as several weak systems attempted to bring in colder air.  However, the upper air winds were unable to generate the anticipated west coast ridge- east coast trough.  As tv’s Colbert would say, we got some east coast “troughiness”, but not the real thing.

So, two weeks later we find a pattern that still contains a strong upper trough from the Gulf of Alaska southward.  New to the scene has been the development of weak troughing over the northeastern U.S.  The upper ridge over the southeast U.S. has moved westward and weakened quite a bit.  It’s now centered as a very flat ridge over the western Gulf and Texas.

So, what was expected has happened, but to a much smaller degree than anticipated.  Now the atmospheric jet stream over North America has been left in an unusual pattern – too little spacing between the two troughs.  That sets up an unstable situation  which will result in much more weather activity over the next two weeks.  We’ll see a big increase in storms and weather changes as energy pockets swing around the big west coast trough, rapidly swing across the U.S. and hook up with the weak east coast trough.

This situation looks to have two possible solutions – 1).  The increased atmospheric instability shifts enough energy from the western trough to the eastern trough to allow it to become the dominant system. That results in a colder than normal eastern U.S. for December (and probably most of the winter.  Or, 2).  The western trough remains dominant and the eastern one never really establishes much strength.  That would mean a wet, mild December.

So, which scenario is more likely?  Today, both the GFS and European models are favoring scenario number 1.  If it works out this way, we could have a very interesting December, weather-wise!

Stuff

Grey Poupon wasn’t given its name because of the color of the mustard. The moniker actually comes from the names of two 18th century mustard firms from Dijon, run by Maurice Grey and Antoine Poupon.