Thursday, January 28, 2016

Is there a storm coming? Update 1/28/16

Unfortunately I've been really tied up lately and haven't had an opportunity to update this blog.

Have you heard?  There is a storm coming!  Or, is there?

Views and understanding about predictability of the atmosphere are inherently flawed.  Take for instance, the "storm" that might impact the high plains early next week that could bring significantly impacting weather conditions to the plains. Many folks believe that meteorologists and computer forecast models can pinpoint the location and amount of snow that will fall with a storm that hasn't even formed yet - 4 to 5 days prior to the event!  I've seen so many posts already on social media about details that CANNOT be forecast with any accuracy, even a day or two out.  Many of these posts are originating from non-weather people.  For me, this is extremely frustrating.  It is so frustrating, I think I'll just go out and play a round of winter golf.  :-)

So, is there going to be a storm?  Yes, it's VERY likely.  In fact, if you go back and read my blog posts I've been expecting that possibility for the first few days of February, following this big warm-up that has also been in the cards.

Looking at this mornings satellite image....

There was a disturbance aloft moving across the west coast that will help bring a shot of cold air into the plains later in the weekend.  No biggie.

The storm that isn't a storm yet, was located across the Pacific Ocean, denoted by the "O" on the map above.   It has a tremendous amount of growing to do before it becomes an impacting storm for the plains.  Computer models take this northeast and then east and finally southeast as it rounds the top of what is called the "upper level ridge".  This will happen based on the understanding of downstream energy propagation.  But the first problem...just where will the "O" start amplifying and dropping southeast?  Then, just how will the boundary layer of the atmosphere respond to this amplification and location of "O"?  Those are details that, at this point, are IMPOSSIBLE to predict with any accuracy!  Predicting snow amounts assuming a position of the "O" are frugal since there is absolutely no way to know what the temperature and moisture profile will be and no way to know what type of ice crystal formation will exist.  Thus, posting a map showing where snow will fall and how much (and even down to the nearest tenth of an inch) just adds a layer of anxiety.

So, my take...

First, there is a pretty good snowfield across Canada and the northern states....

Thus, any Arctic air or Canadian air won't be modified much as it moves south.  So, there should be a pretty good source of baroclinicity for any storm that forms.  Based on the atmosphere's areas of forcing and pattern cycle, I do feel confident that a pretty good storm will form.  But the main impacts could potentially be anywhere from Nebraska and Iowa or even as far south as northern Oklahoma and the Panhandles. If it pounds Goodland and NOT Dodge City, I won't be surprised.  If it hits Dodge City and not Goodland.  I won't be surprised.  There are just too many unknowns to pinpoint a location at this time.  As far as amounts...there is a huge range of possibilities from very little to over a foot with a lot of wind.  So, yes it could be a big storm.

It's winter.  Be prepared for winter conditions.  By Saturday, forecasters should have a pretty good idea so you can start making more detailed plans of possible impacts.  I won't be able to update this blog, so as usual stay on top of what is expected by monitoring National Weather Service products at:

Monday, January 18, 2016

Update 1/18/16

For a month or so I was expecting a pretty cold period about mid-month January.  The cold did materialize as I was expecting, but it invaded the high plains only briefly.  Here were the coldest readings this morning...

The reason the coldest air moved farther east, I think, is because briefly the atmosphere had a westerly wind burst off the east Asian continent and the momentum traversed laterally instead of amplifying into a strong meridional component.

I also had been expecting a strong central plains storm somewhere between January 15-21 and in the last post I did Friday I had basically given up that notion.  However, there still is several minor systems that have potential to bring snow to the eastern plains and points east.  I'm really not sure at this point why the systems are amplifying farther east.  There will be one minor one on Tuesday that will bring snow to eastern Nebraska, Iowa, Missouri and probably northeast Kansas.  The second system will amplify but again, affect mainly the same area as the Tuesday system.  That leaves, for the most part, the high plains out of any significant precipitation this time around.

Here is the satellite image from this Monday morning...

The image is busy!  the southern branch of the westerlies had two systems.  The first is the X1 located near Las Vegas.  This will be the fast moving system that will bring snow the areas I mentioned above.  The second system, X2, was just a disturbance.  The issue with this one is it was near a split in the jetstream, so confidence in it's evolution is low.  It looks like it should move rapidly into the Rockies by Wednesday and then amplify over Kansas or Oklahoma on Thursday.  At this point I would put the most significant precipitation across the roughly the same area as what will occur Tuesday.  However, there is still a possibility that it could deepen quicker, moving precipitation farther west into the high plains.

Here is the expected precipitation for this week and into the weekend.

Beyond this week, there should be a warming trend into the weekend and next week.  But, the jetstream will remain active so we'll have to watch for possible storm development later next week and into the first few days of February.  More on that in the next post.

Friday, January 15, 2016

Confusing pattern - Update 01/15/16

In the post I did on the 11th (click here to read that entry), I showed several images displaying the phase of the Arctic Oscillation (AO), North Atlantic Oscillation (NAO), and the Madden Julian Oscillation (MJO).  All three of those indices were significantly above/below "normal" values.  For many weeks I had targeted the period of January 15 through 21 as a period of a possible plains storm.  Wow, it is just not showing up at all, at least in the computer forecast models!  I'm perplexed.

The pattern that got established early in October has, over the past 2-3 weeks, gone through an enormous change.  I "think" it can be tied to several major occurrences.  The first was what is called a Sudden Stratospheric Warming event.  There is a pretty good write-up about SSW's on Wikipedia (click here).  This SSW event may have occurred because of the exceptionally strong MJO that developed that in turn triggered a chain of events to the upper level wind field.  It could be also that the SSW was the culprit and not the MJO.  That is up for debate.  If you recall there was a brief "warm" event at the North Pole (not unprecedented) where temperatures got close to freezing and even now a very early Hurricane near the Azores has formed in the Atlantic.  So, it's been rather unusual lately.

BTW, here is the latest MJO phase space composite chart.

 The indices of this MJO are 3 standard deviations above normal!   Plus with the AO and NAO so deeply negative, it is extremely surprising that the Arctic air has only briefly made it into the western high plains.  Another surge will briefly make it this weekend.  Normally with these types of contributions for January, the Arctic air would have made it well into Texas.

Ok, so what the heck is going on?  Could the El Nino influences be in control at this point?  It doesn't appear so as I can demonstrate on the satellite image.

First, as of early this afternoon there was a disturbance (small scale storm) near the Four Corners that was moving southeast.  Typically this would bring a swath of snow into the plains this time of year.  But this time the atmosphere is just too dry to support much into the plains.  I would say there should be a inch of two of snow possible into the Oklahoma Panhandle.  The system will likely intensify and tap into moisture as it approaches the east coast late this weekend.

There was a large polar low circulating across eastern Canada.  But it was elongated into northwest Canada and this has prevented a big dump of cold air into the states.  More importantly on the map was the huge storm over the Gulf of Alaska.  It will move into the far northwest U.S. and southwest Canada bringing  copious rain and snow to that region.  A second system (the X on the far left) will bring additional heavy precipitation to that region.  Look at the predicted precipitation!

Just like earlier this fall and winter, this area getting that much precipitation IS NOT a signal of an El Nino event!  It's too far north!  On the other hand, the precipitation expected across south Texas and into Florida can be tied to the ENSO event.

Also on the satellite map above, I've drawn in a dotted blue line.  In most El Nino events, the jet stream across the Pacific would be aimed at northwest Mexico or at least southern California.  Currently though it is slamming into the Pacific Northwest.

So what does this all mean for the high plains?  It is so complicated, my confidence has tanked.  I'm going to hold on to a slim thought for a storm forming next week (and it was actually hinted at in the European computer models) but at this point I would not count on it, i.e., don't take any mitigation measures.

I do think the pattern may be returning to it's former self.  What that means is that the chance of several impacting storms will be increasing towards the end of January and into the first few days of February.  Overall the month of February should end up normal to below normal on temperatures and most likely above normal precipitation.  This would be valid for especially the central and southern parts of the plains.

Monday, January 11, 2016

Update 1/11/16

In the post I did on the 8th (click here) I discussed the possibility of a storm, somewhere between the 15th and 18th.  I'm having a difficult time in nailing down this one as during the past 2 to 3 weeks the flow aloft has become a little chaotic.

The U.S. finally got a pretty dose of Arctic air, the first widespread airmass of the year.  The following are maps of the highs and lows this past weekend....

One reason for the abrupt change was due to a anomalously strong Madden Julian Oscillation (MJO). In earlier posts I had been expecting the turn to colder based on the pattern AND this strong MJO, but the coldest air stayed well east and north of the high plains.   The following chart shows that this MJO was 2 to 3 standard deviations above normal, and is forecast to continue that strong as the MJO continues to propagate into the southern Hemisphere.


Meanwhile other teleconnection indices have tanked into the negative, the first time this winter.  Both the North Atlantic Oscillation and the Arctic Oscillations have headed deeply into the negative. 


And here was this mornings snow cover across the country...


Back to the lead statement about a possible storm between the 15th and 18th.  Computer models are still struggling to simulate the current state of the atmosphere and areas of forcing.  I'm not confident at all, but I still have a hunch we'll see another strong shot of Arctic air into the high plains (by the end of the week) and there still is a possibility of a developing storm.  Any development will have to come from a disorganized flow of air across the Pacific AND from high pressure aloft moving "WEST" across the high latitudes near Greenland.

I will update these possibilities on Thursday.

Friday, January 8, 2016

Quick update 1/8/16

In the post I did on Wednesday the 6th (click here) I showed 3 upper level systems that had impacted the plains or were expected to do so.  X2 in the previous post had moved across Kansas as of Friday morning and it brought primarily "RAIN" to parts of the high plains and especially east of the area.  Here is a map of the precipitation:  (click for a larger map)...

There was actually a pretty good soaking across much of central and eastern Kansas, but very little snow except for north central Kansas!  Something that has become very apparent since the late December storm that pounded west Texas and eastern New Mexico with a blizzard.  The El Nino (warm equatorial Pacific waters) influences on the weather pattern has FINALLY  taken place!  In most years, this type of system (X2) would have produced snow and not rain!

Now attention turns to what I labeled as X3 in the previous post.  Look at the satellite image from this morning...

Former X3 has split into pieces! There is no longer one system, but at least 3 smaller scale disturbances.  So, instead of tracking out into the plains from southeast Colorado and into north central Kansas, it appears that the "energy" and what is left of X3 will come out much farther south and in these pieces.  The result will be heavy mountain snows across north central New Mexico and southern Colorado and then a lesser amount of snow into the plains.  Check your local NWS office ( for details on how much will fall, but the majority will skirt across the panhandles and east along the Kansas/Oklahoma border.  It doesn't appear that it will be a major storm.

The other item I discussed in the post I did Wednesday was the turn to sharply colder for the weekend.  It looks like the influences from the equatorial Pacific will win out again as the really cold air will be shunted east into the Great Lakes.  The NFL game in Minneapolis should be entertaining watching players and fans "freeze" in the bitter cold air.

I also posted that on average temperatures should be below normal through 10 to 14 days.  But, I've reassessed that notion given the fact that these influences from the equatorial Pacific have briefly taken over.  I still have a strong hunch of a decent storm dropping out of the Rockies.  Originally I thought around January 17-18, but that possibility may occur sooner (perhaps the 15th instead).  The flow aloft has recently become rather chaotic with many splits in the jetstream.  The weather ought be unsettled during this next few weeks.  I'll give a try at updating on Monday and see where we are at.

Wednesday, January 6, 2016

Update - January 6, 2016

In the post I did on the 30th (read it here) I discussed the challenges in weather forecasting for not only long term periods but even on shorter time scales.  If you did not have a chance to read that post, please do so!

Also, I discussed the change in the jet stream that would finally benefit California.  The influences in the weather this past fall were NOT strictly from El Nino!  But, recently the flow aloft has changed in that, at least temporarily, California would benefit in regards to precipitation.  Looking at this mornings satellite image there are many disturbances in the flow aloft.  But, at the same time, the flow has become rather disorganized and chaotic, in part due to the forcing from the north Pacific, but also from the equatorial warm waters across the Pacific (the "El Nino influences).

In the image above (click for a larger picture if you need to) the green lines with arrows represent the strongest flow aloft (the jet stream) and there were many splits to the flow.  This makes the forecast for the central plains very complicated.  The three primary systems, that could impact the plains, on this map are the X's with the superscripts 1, 2 and 3.  X1 brought brief rain, sleet and a little snow to parts of Kansas, Missouri and now into the upper midwest.   It wasn't much.  X2 was moving out of the southwest U.S. and was bringing snow to mainly higher elevations of the southern Rockies.  This may bring just a bit more precipitation to the central plains, but again, not much.  X3 was probably the strongest of the disturbances and it should bring rain and snow to the center of the country by Friday or perhaps Saturday.  You need to go to to get details about this weather maker.  I don't foresee it being a "huge" storm but probably big enough to bring  2 to 4 inches of snow to parts of Kansas (most likely from southeast Colorado into north central Kansas) - again go to the website for details.

The flow aloft, by the time X3 gets going across the plains, should become dominated by a dip from the north into the midwest.  On the satellite image above that would be where the cold air was building.  Thus, expect a turn to sharply colder into at least Oklahoma and the northern parts of west Texas.  There is some question on how far south the cold will get.  This airmass should be capable of bringing single digit high temperatures as far south as northern Kansas by the weekend, or at least highs in the teens.  One of the products I look at is a graph of something called the Arctic Oscillation.  When the index drops sharply (and especially into the negative), cold air from the high latitudes is dislodged and typically drops well into the states.  Here is the latest index and the outlook....

On average, below normal temperatures should be present across the central and northern plains (and midwest), lasting for 10 to 14 days but with a couple of brief warm-ups across the western high plains.  It should be the coldest period that we've seen this winter.  The southern high plains will get a taste of the cold too, but not near as cold as farther north.

There is a high amount of uncertainty of any possible storm development during the cold period.  I have a hunch there might be one storm that intensifies as it drops south across the Rockies.  The most likely time for this would be around January 17-18, but that is just a hunch and I don't feel really confident at this point.  Computer models have no hint of this at all. 

Towards the end of January there should be a big warm-up but also an increased opportunity of several storms.  Keep checking  back for those opportunities.  I'll try and update again this Friday or Saturday.