Monday, October 31, 2016

Update 10/31/2016 - I sure hope I'm not being tricked!

I wrote up a lengthy post on Friday (click here to read it) and there were a couple of items I discussed that I want to revisit as some major changes appear to be taking shape.  Just in the past three days a few items have really gotten my attention!  Although I had a pessimistic view on precipitation chances coming up, I did mention that the pessimistic view was in the presence of at least several systems that could benefit the area.  This is what I said:

"Although there "could" be something around the 2nd-5th time frame, I have zero confidence in anything at all.   There are systems, but the flow is going to have to transition soon, or it won't happen."

I think that flow is already showing signs of a transition!

Read on....

First, the snow cover across Asia or Eurasia.  I showed that graphic in Friday's post but major changes have shown up in just these past three days!  Here they are side-by-side (27th on the left, 30th on the right):

click for a large version

I'm now reading that RECORD snow for this early has been laid down across much of Siberia.  In concert with the snow cover, record cold has gripped part of that region.  In that post on Friday I talked about the negative Arctic Oscillation and the cold being displaced on that side of the northern hemisphere.  But over the weekend temperatures started to plummet across northern Canada as surface pressures start to rise there.

Another  item I discussed was the Southern Oscillation Index (SOI).   Here is what I said:

" But, what is VERY interesting to me is that the Southern Oscillation Index (measurement of the state of the atmosphere across the Tropics) has crashed in the past few days.  The numerical index is as low as it has been since early June when we were still in the El Nino regime!"

This is happening in the presence of water temperatures that have cooled over the past 2-3 months across the equatorial Pacific.  The values continued to drop over the weekend.  The 30 day average is now as low as it was back in the spring!  This is SIGNIFICANT! 

The following is a chart of the SOI since December 2013 (current on the right):

click for a large version

What is very interesting is this rapid decrease that began around October 1st.  October 1st!  Yes, at about the same time that a "new" pattern starts forming!  Here is the close up of that period:

The last time there was a crash like this was back in mid April.  Do you remember how stormy it got in May?  Coincidence?  Does this signal a major change in the upper flow?  The only thing I have confidence in, is that it does signal an upcoming change in the flow aloft. 

Here is the latest satellite image of the western Hemisphere:

There were several notable features on the image.  The first is circled in red.  This is a rather moist and active area of the equatorial Pacific.  Maybe this is partly responsible for the crash of the SOI?  Really it shouldn't be this robust if the atmosphere was really in a La Nina state.  The wind flow out of this entire area was already responding to all this activity. 

Second, the jetstream across the northern Asian continent and Siberia was responding to the  massive snow cover and very cold that had developed.  The jet stream was starting to expand across the northern Pacific.  Combining this flow of air with the bursts of wind coming out of the area within the red circle will no doubt result in downstream amplification in several areas. 

Get ready for a change!

One of these amplified areas, initially, is shown on the next satellite image:

The red "L" off the western coast of the U.S. has shown some amplification over the weekend.  There is still a lot of uncertainty of where it will track.  But, combining that system as it moves into the Inter-mountain West with the tropical jet stream coming out of the eastern Pacific (green line across Baja California into AZ and NM), the prospects for precipitation have drastically increased for at least New Mexico and far West Texas later in the week.

Two other systems of note...the red X over west central Canada and the second red X on the far left.  The Canada system is starting the process of a developing cold airmass over northern Canada (the source).   The other X is in a prime position and location to help amplify an upper level ridge across western Canada.  Downstream propagation in this developing ridge and with energy flowing from the tropics and northern Pacific should trigger the first widespread cold into the central U.S., most likely between November 10-15.  I wouldn't be surprised that a vigorous storm could develop out of that developing scenario (placement or location somewhere across the central U.S.) that could even contain white chaos.

So get ready!  First, lets hope this system coming into the west coast will be strong enough to get some precipitation going (and obviously hoping it will be far enough north to bring rain to ALL the high plains).   Second, summer will be coming to an abrupt end by November 10-15 as a widespread season ending freeze will finally arrive (maybe not quite into west Texas yet).

Here is the Weather Prediction Center's forecast for precipitation through the 7th:

Don't take the actual amounts or locations literally, but at least know that there is an increased probability of moisture later this week and weekend. There are still uncertainties in the track of the first system so this could be off, but at least it's a start!

Friday, October 28, 2016

Long discussion - 10/28/2016

This is going to be long (and click on the image for a bigger version)....

I've had a little bit of time to do some analysis on this developing weather pattern.  But in reality the more I look, the more conflicting signals I get!  I have a lot to discuss and hopefully I can make some sense of this mess.

Starting with ENSO (essentially El Nino and La Nina).  Do you recall the outlook from the "experts) last fall of the Godzilla of all El Nino's bringing massive and flooding rains to California?  It DID NOT happen!  I for one was not surprised.  Go back and read those posts if you have time.  You see, it's just not El Nino or the sister La Nina that create or control our weather.

Fast forward to the present.  You might have heard that we're in for a weak La Nina (cooling of the equatorial Pacific waters).   Based on that, the Climate Prediction Center (the experts) came out with a forecast on the 20th.  I did a quick post on that and you can read it here.  The CPC went with a composite forecast based on La Nina.  What that means is taking an average of weather during a bunch of La Nina's (without regard to strength and location) and posting that as a probabilistic forecast.  It might work for a small percentage of the country but that is it (if El Nino or La Nina dominate the forcing)! 

It's ironic that the general upper level flow the past 2 to 3 weeks has actually been more what we see during an El Nino!  In other words the atmosphere is responding and behaving like the forcing from the tropics across the Pacific is in control.  Will that last?  Nobody knows.  But, what is VERY interesting to me is that the Southern Oscillation Index (measurement of the state of the atmosphere across the Tropics) has crashed in the past few days.  The numerical index is as low as it has been since early June when we were still in the El Nino regime!  This really boosts my confidence that there may NOT be a La Nina this winter, rather it should stay in a neutral phase.  So, I'm somewhat confident that the tropical Pacific will not be the main influence this winter.

Before I move on, as many of you know there was a weak system that came through earlier this week.  Some areas got "lucky" and got some much needed rain.  Unfortunately for most of us we got zilch.  Here is the map of precipitation:


For the past week you may have seen some optimistic forecasts from the NWS and others about an increased chance for rainfall later next week.  Computer models have been all over the place.  One will be wet, then dry, then wet, etc.  Although there "could" be something around the 2nd-5th time frame, I have zero confidence in anything at all.   There are systems, but the flow is going to have to transition soon, or it won't happen.  Here is an optimistic outlook from the Weather Prediction Center (I hope it verifies but don't count on it):

We're desperately going to need something soon.  With this ridiculously warm October, the soil moisture is depleting rapidly.  Here is the latest U.S. Drought Monitor:

Back to the October temperatures... 

At the Dodge City airport, this October should end up as the 3rd warmest on record (back to 1874).  Right now we are on pace to set an all-time record for the warmest Fall (Sep-Nov) if things don't change soon.  Also, some areas have not had more than a quarter inch of rain since late August.  If you go back to earlier posts I did this summer, this was expected (especially the September into October).

Looking ahead:

If you have been following this blog (started April 15, 2014) for a while you know that I have several posts about how the pattern establishes during the fall and then cycles or repeats for the next 10-11 months.  Often the cycle length is around 40 to 50 days but can be much shorter or even longer.  Since the formation doesn't even begin until around October 1, it is impossible to predict the cycle length until the first obvious repeating begins.  This "new" pattern is only 3 to 4 weeks old.

The initial formation of the pattern may be influenced (by varying amounts) from many different forcing mechanisms.  One is from the equatorial Pacific area.  Another from the northern Pacific.  Others from the Arctic region, northern Atlantic, landmass/ocean interactions, perhaps the huge northern Asia continent, solar output, etc.   How each of these contribute or interact with each other would be a lifetime of research. 

I don't like to jump to conclusions in October, but so far I'm a little concerned.  I would have liked to have seen a storm or two develop into the southwest U.S., but so far that has not been the case.  Yes, there have been a few minor systems that brought SOME areas rainfall but nothing widespread.  There have been quite a few frontal passages, but without cold air since that source has been bottled up near the north pole or particularly across the northern Asian continent.

Now if you want to search the internet, there are already a lot of outlooks out there.  Here are four of them:

Quite a difference!  Are any of them correct?  Quite possibly!  But what are they based on?

Like I said earlier in this post, there are conflicting signals (without taking into account that I'm waiting for this initial weather pattern to cycle).  In no particular order....

First, most of the cold air so far this Fall has been bottled up over the pole or Asia.  Here is the current snow cover for North America:  (It is actually a little less than last year at this time)

Something I look at regularly is the Arctic Oscillation (AO) which takes into account surface pressures across the Arctic region.  When pressures get high cold air is dislodged towards the equator, and much of the time into the continental U.S.  When the AO has a negative value those pressures are climatologically high.  This fall, so far, much of the cold air has dislodged into Siberia and not the states.  The AO has been strongly negative so far and is forecast to be that way for much of the time into January.  Eventually the cold air that builds up will also come into the U.S., or at least should.

Another index I look at is the North Atlantic Oscillation.  This looks at the pressures from Greenland into the north Atlantic.  When this index goes negative the upper flow tends to buckle and allow cold air to sweep south into the U.S..  So far this index reading has been forecast to lower after a very recent spike.

Looking at the ocean temperature anomalies.

Three forcing areas from the Oceans that I think contribute to the pattern are the ENSO region, the North Pacific and the North Atlantic.


There has been a cooling of the equatorial Pacific but not quite long enough or cold enough to be a full fledged La Nina (and may not be based on some ideas):

For the Pacific Decadal Oscillation:

The index has cashed to near neutral.

For the AMO:

There is a blob of colder than average water across the north Atlantic.

All three areas may influence the pattern (or have already).

Another item that has caught my attention is the anomalously warm water in the Gulf Of Mexico. This would be a great source of moisture for any storm that could get going later this fall or winter.
I would think the threat of tornadoes across the deep south and perhaps up the Lower Mississippi Valley would surely be higher than normal.  Maybe into Oklahoma and eastern KS?

I've already established that I don't like making outlooks this early since the pattern just started to develop and hasn't cycled yet.  So, at this point I can only go on some climate history or I could just make a big WAG!

For the Winter months (December, January, February), look at this from Dodge City:

Since 1998/99, the average temperature for the three month period has been trending colder.  The past two winters had above normal temperatures.  Can it be three in a row or do you think it would be colder based on this trend?  I say based solely on this colder (at least at the normal value).   But does this fit the atmospheric forcing?  Maybe, maybe not.

Looking at the index value for ENSO and of the PDO (discussed above), the only two times on record that I can find that represent a similar phase and progression of ENSO and PDO are 1995 into 1996 and 1959 into 1960.  The best fit was the 1959/1960 winter (based on the indices) and second best was 95/96. 

I did a little figuring using a dry October and a warm October for Dodge City.  Out of the top 20 warmest Octobers, the follow winter was dry 10 times, wetter than average 4 times and the remainder near average.  The following winter was warmer than average only six times, colder than average 7 times and near normal the rest.

For the top driest Octobers, the following winter was  drier than normal 13 times, wetter three and normal 4.  For temperatures the following winter was warmer than average 6 times, colder 7 times and normal the rest.

Taking into account both the top warmest AND driest winters yields about the same.  Well, that really doesn't help, does it?  The only thing that stands out is that the top three warmest and driest Octobers were followed by above average temperatures for the winter, but one dry, one normal and one wet.  Geez.

Back to the 1995/96 and 1959/60 ENSO transitions.  October of 1995 was colder than average, but 1959 was above (but not top 20).  October of 1995 was the 8th driest on record (only 0.08" at Dodge City).  October 1959  was wet recording 3.30" of precipitation.  Geez.

I think what I'm pointing out is that making predictions based solely on what happens during the fall is pointless.  I've got to know what the pattern is doing and how it will start to cycle or repeat. 

If you want a guess at stage in the game (without the first completed cycle)...

It appears more than likely that this dry pattern will persist into November and honestly I'm not feeling really good about anything changing for a while.  That is being pessimistic but all the while that there are actually a few systems that "could" bring a brief change.  Let's hope and pray.

The first widespread killing freeze is still a week or more away.   Overall on average, temperatures will likely remain above normal through much of November.  But, there will be a couple of strong pushes of cold air, especially by the middle of the month.

For the winter months of December, January, and February.  My guess is that temperatures will average out around normal.  But there will likely be some really cold periods (highs in the single digits, lows 5 to 15 below across western KS).  These periods will be offset by several really mild periods too!  Deep penetrating bitter cold into west Texas is likely a couple of times.

Optimistically precipitation will be near average (normal to above on snowfall).

Since the cycle of the pattern hasn't repeated, I can't give much on the forecast for the spring and summer (at this time).  Looking at yearly precipitation

A couple of above average years are typically followed by below average rainfall (there have been exceptions, especially in the 70s and 80s).  I've been expecting 2017 to be below anyway (based on long term trends and cycles).  I hope it is closer to average.  But don't put too much stock in that yet until the cycle of the pattern is established.

I've got more coming up on my plate so I won't be able to update this blog until about the 7th or 8th.

Thursday, October 20, 2016

Update 10/20/2016

This post will have to be abbreviated...

 Yippee, the "official" winter outlook has been released.  Just as I had suspected, the experts at the Climate Prediction Center went with a "La Nina" outlook for the winter.  What does this mean?  Take 10 winters that had a La Nina, average out the weather, and go with that prediction.  For some parts of the county this might work out pretty good, or 8 out of 10 times.  For the high plains, maybe 5 out of 10 years.  Meh.  Do you remember the Godzilla of all El Nino predictions for last winter?  California was to have massive rains and flooding.  The predicted weather DID NOT occur!

Here are the graphics for CPC's outlook for the winter (temperature first, then precipitation)....

The average for the three month period (December, January and February) is depicted by these maps.  For instance in the precipitation map above, for south Texas the odds have shifted significantly towards drier than normal. For Nebraska, the odds don't favor one direction or another.  For Kansas, the odds are shifted every so slightly towards drier.  This really looks like nothing more than a La Nina based composite forecast.   Again, for Kansas this type of forecast my verify half the time.

Unfortunately I don't have time to update my outlook this week.  I have other obligations I have to attend to.  But Monday (24th) I should be able to do a more in-depth and thorough discussion.

In the meantime, watch out on social media and web pages.  I'm starting to see a lot of  viral graphics being sent around.  One is a forecast map that has made the rounds three years in a row.  It's fake!  Another was a post just yesterday about a snowstorm that is to occur on the 2nd of November.  That was nothing more than ONE iteration of a forecast computer model output that wasn't even interpreted correctly. 

I'll shoot for late Monday afternoon....check back then.

Wednesday, October 19, 2016

Brief note - 10/19/2016

Give me another day or two for a more in-depth discussion.  The "official" winter outlook from the Climate Prediction Center will be released on Thursday (19th) and I want to see what they are looking at.  I'm getting an idea as the pattern is forming/establishing.  I'm not liking the early part of this pattern that is forming but I need to do some more evaluating.

Friday, October 7, 2016

Brief update 10/07/16

The minimum temperatures this morning (10/7) got close to freezing or below.  There were some mid 20s at several locations.  But, I'm wondering how much damage was done to sensitive plants as the mercury was below 32 for a relatively short period of time.

Here is a map from the Kansas State mesonet low temperature observations....

As discussed in the post that I did two days ago (read it here), I mentioned possible rainfall for Sunday and Monday and that is still on track.  The question at this point is how widespread and how much will fall.  In general, it doesn't look like much but it could be very beneficial where it does manage to rain.

Beyond the early week system, nothing significant is showing up for at least another week.  But, October can be a very changeable month.

If you're at the 3i show in Dodge City next week (10/13-15), make sure and stop by the National Weather Service booth (I-294). 

Wednesday, October 5, 2016

Update on 10/5/2016

In the previous post I did on Friday (click here), I discussed a weather maker that was approaching the west coast but because of several negative factors, I wasn't confident in it providing much moisture for the high plains.

That system has come and gone (it brought some severe weather and locally heavy rain to Oklahoma and eastern Kansas on Tuesday).   Before the system even made it to the plains there were isolated pockets of beneficial (and some very heavy rains) late in the weekend and on Monday.  Here is a map showing the rainfall for the past week:
Also in this previous post I reiterated my thoughts that October or at least the first half of the fall could be on the dry side, in general.   I also hinted at the next chance of rain being around the 11th or 12th.  As of today (Wednesday), it still appears to be a possibility.

Looking at the satellite image from this afternoon....

There were several features to point out.  First, Hurricane Mathew.  There was still a lot of uncertainty to eventual path.  The most likely area of the U.S. to be impacted is Florida, but really any where from Miami to Charleston South Carolina should be prepared for a major hurricane.  The atmosphere is going through changes across the northern hemisphere and the outlook beyond about Saturday is challenging (including the hurricane and other systems moving across North America).

The second feature is the dip in the jetstream out west and the system denoted by the red X on the image above.  This will move rapidly into the plains by Thursday and will help initiate another round of thunderstorms (and some severe) on Thursday.  But again, east of the high plains.

The earlier thinking of a chance of moisture by the 11th or 12th still appears possible (system does not show up on the satellite image), but it may actually be closer to the 9th or 10th.  The Weather Prediction Center has an idea on the potential for precipitation through next Wednesday.  That might be slightly optimistic but I can't argue with it too much.   
If we don't see much rain by Wednesday of next week, the prospects for additional rain does NOT seem great, at least through about the 18th or 19th.

One final thought...I also mentioned frost or a light freeze for the middle part of this week.  That is still in the offing as some "cold" air will spill in behind the system that brings the weather on Thursday.  The coldest temperatures will likely be Friday morning.  Again, a killing or growing season ending freeze is not expected, yet.