Saturday, February 25, 2017

Quick update 02/25/17

This will have to be quick.  I've been swamped again but should have time next week for a more in depth review of the atmosphere and outlook.

As expected this past storm impacted areas north of Kansas producing an significant blizzard across Nebraska and into Iowa and the upper midwest.  Kansas and the panhandles as usual got the wind. There was a few light showers around Thursday (and a few snow flakes Friday) but nothing of any significance.

Looking at the satellite image of the eastern Pacific...

What a mess of the flow!  There is a lot going on but I'm afraid the eventual weather for the high plains will be much of the same.  There was an upper low (the red L) and several strong upper level circulations (the red X's), but as these systems eventually move out into the plains there won't be much organization aloft,  There should be a small storm about mid-week (late Tuesday or Wednesday) that will bring a lot of wind again, colder temperatures (after a brief "warm-up") and some precipitation.  But I'm afraid that amounts of precip (whether it's rain or snow), won't be a lot. However, it's at least a chance or opportunity and I guess any amount will be better than nothing at all.

Here is the potential for precipitation through the 4th of March from the Weather Prediction Center, and it looks reasonable.

Later in the week or by Saturday there should be another surge of cold (below normal) but that too won't last that long.

I'll go into a more detailed look in the next post and start discussing the spring and summer outlook. I'm not liking what I'm seeing, but hopefully I can find some hope before I make the post.

Saturday, February 18, 2017

Update 2/18/17

I'm missing my deadlines! I finally found a little time for an update. 

In the previous post I did on the 9th (read it by clicking here) I discussed a weather system that would likely pass south of the central U.S. and benefit mostly Oklahoma and Texas.  That did just about as expected.  There were a few areas in the high plains of Kansas that got some rain, but not a whole lot (the most I saw was 0.28").  Some areas got nothing more than sprinkles.

The atmosphere is still buzzing for some areas of the country.  California is getting battered again by a very wet storm and with several more lined up.  It's been my experience that when central and southern California get slammed with a storm, the plains usually benefit too.  But not this winter!  These storms have been reaching the west coast as mature systems and then they weaken as they move east before re-intensifying somewhere around the lower Mississippi Valley.  This time, it's just the way the atmosphere is set up.  Granted we had the huge storm in mid-January (and maybe that opportunity will return March), but for the most part the storms have been disorganized and in the wrong position for at least western Kansas to benefit.

Current situation (as of Saturday the 18th)...

Looking at the satellite image....

There was an upper low moving into Arkansas.  But, this was mostly a DRY system as moisture had been scoured out by the previous system that was already out to sea.   It became a non-factor for any weather for the high plains.  The next system was very wet and bringing a ton of moisture to the western U.S.  The center of the storm was just barely visible on the satellite image above.  But looking from the Pacific view...

The center of the this very wet storm pounding the western U.S. was moving east and southeast and centered near central Baja California.  But it was also starting to go through a weakening process.  It will bring showers and thunderstorms to the EASTERN parts of the central and southern plains Sunday night and Monday.   

Another system out in the Pacific north of Hawaii will bring more rains and snow to the western U.S. and will impact the central part of the country sometime around Thursday or Friday (23rd/24th).  But instead of going through a weakening phase, it looks like a temporary break in the pattern will allow it to main intensity or even strengthen.  The result will be a powerful storm in the central U.S.  BUT, there is much uncertainty on the eventual location.  It could be as far south as Kansas, but more than likely it will impact Nebraska/South Dakota and on east.  Blizzard conditions will likely occur in the cold sector (again most likely north of Kansas).  One aspect that will be common regardless of the eventual location will be a lot of wind.

Behind that late week storm, cold air will finally return to the high plains and could be present more times than not into early March.  As far as precipitation, there is at least a few opportunities showing up as we get towards the end of the month and into March.

If you have had the time to read a lot of posts I've done in the past, you would have read about how the atmosphere sets up in the fall and then cycles at various lengths throughout the fall, winter, spring and summer before eventually falling apart.  The weather will never be exactly the same, but trends can be forecast and therefore "most likely" scenarios can be presented.  The cycles will repeat with a periodicity of 30 to 70 days.  This years pattern of atmospheric flow looks like it's repeating between 58 and 62 days (maybe closer to 59).

The pattern is currently in the 3rd cycle of repeating.  I BUSTED big time on this 3rd cycle so far!  The beginning cycle brought record warmth during the fall.  The second cycle brought the brutally cold air in December.  This third cycle, so far, has brought a return of the general flow much like what occurred in October!  It may be the extremely robust MJO that threw this off.  I don't know.  The biggest part of the upper flow has been a  persistent in the jetstream pattern that keeps developing across the central part of the country.  That allowed for record warmth during the fall and that has repeated during the first part of this 3rd cycle for February.  

Now the question is will cycles 1, 3, 5 be the same while 2, 4 and 6 resemble each other?  Well, I'll talk more about that in the next post or two.  Regardless, there should be a cooling trend starting right after next weeks storm, and in general the pattern should be much cooler (colder) for 10 to 14 days.  I do know that there has been a westerly wind burst in the western Pacific that has caused the Southern Oscillation Index to absolutely crash.  This type of activity normally causes wild pattern changes across the U.S. about 2 weeks later.

BTW, here is a graph of temperature anomalies showing some of this cycling for Dodge City.  Again, it's not going to be exactly the same, but there are some stark similarities.  The biggest similarities occur in the upper part of the atmosphere.  The second cycle was colder (relative to normal departures) than the first.  The third cycle so far is very close to the first.

I'll shoot for another update late next week.

Thursday, February 9, 2017

Update 02/09/17

In the past month or so in previous posts, I discussed the opportunity for much colder weather arriving between the 10th and 24th with the coldest centered around the 15th of this month.   In one of the posts I had even mentioned brutally cold air, much like occurred in December.   In the last post (read it by clicking here) I talked about some reasons why it was on track.  The biggest reason I gave was the Madden-Julian Oscillation (MJO), that currently is very robust, especially given the supposed base state of a La Nina (although I still say it just barely reached that status depending on the indices that are used).  This MJO will be moving east/southeast in a spatial location of the tropics that would favor Arctic air into the U.S.

BUT, very similar to October the jet stream across the higher latitudes is countering this possibility. Instead of the bulk of the cold air moving into the states, it is instead being restricted to northern Canada and back over across Siberia and the Eurasia region aka what happened during the early fall!  I'm not discounting the possibility of the really cold stuff making it into the high plains later this month, but as of today it's not looking too likely.  We'll see.

The following map may seem confusing....

The green arrow represents the flow aloft (the jet stream) that was in place this 9th day of February.  It was also in this almost EXACT position back in October (around the 8th)! Back then all the cold air that had developed was restricted to far northern Canada and across Siberia, much like what is currently happening.   This was the "beginning" of the atmospheric pattern.  The yellow line/arrows on the above map represents the flow aloft that was in place in December (about 62 days after the beginning of the pattern).  That was enough to allow the brutally cold air to move into the high plains.   But now (again, almost 62 days after the December event) the flow resembles the October pattern.  If that holds, then there ought to be some pretty mild days coming up periodically through February.   The first will be the ridiculous temperatures that are expected this Friday and Saturday!

What about precipitation?  In a couple of posts ago I thought there would be several opportunities this month, and I haven't changed my mind yet.

Looking at this mornings satellite image over the Pacific and western U.S.,

click for a larger version

One of the most notable features was the jet stream that was slamming into the Pacific Northwest with a HUGE ridge poking into southern Canada.  Associated with this jet stream was the red X, a storm system that was pretty strong.  The red dashed line is the projected path of this feature.  I put a couple of question marks by this path down in New Mexico.  There is a bit of uncertainty of the eventual path which will have an impact on expected weather across the plains.  Most likely it will take a path that will be too far south to bring Kansas and Nebraska much precipitation but it will be close!  Most likely Texas and Oklahoma will benefit.  In fact, here is the expected precipitation during the next 7 days (provided by the Weather Prediction Center)....

There still is a chance the system could be farther north, so I'm not discounting the possibility that it will be far enough north to bring some moisture to western Kansas and eastern Colorado.  Most likely that would be late Sunday or Monday.  Just don't count on it, but hope it does occur.

Beyond this system, the weather picture is a bit muddied.   That MJO, that I discussed above, could provide a surprise later next week and into the weekend.  We're not done with winter by any stretch.  I've heard rumblings about an early Spring.  Define what an early Spring is and I can address that.  At this very early stage, I would go as far as mentioning a late freeze (after climatological normal) later this spring.  More on that later.

I'll shoot for an update around the 14th/15th.

Wednesday, February 1, 2017

Update - February 1, 2017

In the last post I did on the 25th (read it by clicking here) I discussed the overall pattern that favored a warmup with just brief cold surges.  As many know, on Monday it got pretty mild with near record temperatures observed.   I just might say it was a great day to dust off the clubs and hit the links.  The brief cold surge that was expected, arrived today (Wednesday) and will persist into Friday.  But then another significant warmup is on tap for the weekend and into early next week.

In the previous post I mentioned that cold fronts would become more frequent and more intense after beyond the 4th with the coldest period expected to be between the 10th and 24th.  I also said the opportunity for a storm or two would be increasing during that period.  I might mention at this point, that someone from my office that I work at, posted on social media that the weather wouldn't become active again until late February or March and by then impacts wouldn't be as great because of the March sun.   I'm sure a lot of you "older" readers know that the biggest blizzards across the high plains occur in March and even well into April.  I'm not saying there will be or not be any active weather - it's just a really dangerous statement to make.

Anyway, looking at the latest satellite image....

click for a larger version

There was blocking in the upper level winds across the eastern Pacific and western U.S.. Even though there was a pretty strong storm off the California coast (note the red L), the flow is not conducive for that storm to stay healthy as it gradually moves east into the states.   Another feature on the map is the red X north of Alaska.  This system is forecast to intensify as it moves southeast but then there is some question to what happens.  It looks like it will deepen but then move west and "hang out" over the Gulf of Alaska.  Other changes should be taking place farther west as this process takes place during the next week.  Impacts, if any, for the plains will be later next week or weekend.

I don't show it on the satellite image, but there is a pretty robust Madden Julian Oscillation (MJO) over the Maritime Continent region of the west Pacific.  If it holds together, it should impact the central U.S. around mid-month.  Combine that with pretty cold air that is already in place across Canada (see the image below), the chance that Arctic air makes a return visit is pretty high. It's not guaranteed, but certainly is worth watching.  So, I stand by my statement that the coldest air during February should occur during the period from February 10th through 24th (most likely the coldest around the 15th give or take a couple of days).

As far as any organized storm, with Arctic air poised to move into the central part of the country and with the MJO, there does appear to be at least several opportunities for something towards the middle part of the February.  No guarantees, but again it's something to watch.

As far as the next 7 days....prospect for moisture is virtually NONE.

I'll try and update again around February 7-8.