Monday, February 26, 2018

Update - 02/26/18

Just a quick update.

In the post I did on the 19th (click here to read it), I showed how the Gulf of Mexico moisture had made a run a the western high plains.  It made it into west Texas through southeast Kansas which is a change and "could" be a good sign later in March.   That moisture and the overall configuration of the jet stream brought record flooding rains to much of the Arklatex region and into the Tennessee Valley.  Rainfall of 5 to 10 inches was common with a large area of over ten inches as you can see on the map below.  The largest observed amount I found was in northeast Texas where 13.82 inches was recorded.  The high plains got very little from this setup (mainly less than a tenth of an inch - some areas just a few hundredths of an inch).  BTW, that is an incredible amount of moisture for the central and eastern Cornbelt (3 to 7 inches of rain).  With frozen ground, I'm sure how much this benefited the region.

Looking at the satellite image...the pattern is still changing.  There was a deepening system across the western U.S. and the eventual upper level low will be situated over Arizona by mid-week.  Here is the satellite image from this morning...

This in most years would be an extremely favorable position and pattern to bring widespread precipitation to the high plains. BUT, the background pattern is going to work AGAINST this storm as it appears the system will reach it's maximum magnitude across Arizona and New Mexico before it turns east and northeast towards the central U.S. as it weakens considerably!  This is extremely frustrating to see this type of system behave this way.  I might add, this is NOT a good sign going forward into spring. 

The pattern that we are currently going into resembles what was in place during October.  At that point the brutally cold air dropped into Europe and Siberia.  The same cold is occurring at this point although I'm still thinking the cold will slosh back to our side of the hemisphere in March. I'll update later this week towards Friday when I get some more time.  

Monday, February 19, 2018

Update 02/19/18

Welcome back to winter! After a day in the 70s on Sunday, albeit with nasty wind, winter has returned.  Unfortunately those forecasting on Sunday made huge errors in believing computer models that had this front stalling near the Oklahoma border and actually lifting back north.  Shallow "Arctic" fronts in the winter often move 100's of miles farther south.  This setup though for this Monday (and into Tuesday)  is a change!  A low pressure center will develop across northeast New Mexico and will provide a HUGE gradient of temperatures and moisture as the front slows across Oklahoma.  Look at this mornings surface map...(click for a larger version).

Dew point temperatures have actually made into the 50s across southwest Texas.  This might be a subtle sign going into spring.  More in later posts..   Also dew point temperatures well into the 60s have streamed well north. The setup will be very favorable for excessive rainfall from Texas into the Tennessee valley with flooding likely.  On the cold side there should be quite a swath of freezing rain.

Look at those amounts for the corn belt (especially eastern)!

For the high plains we won't benefit, at least this time.  But it's somewhat of a good sign to see gulf moisture make a run a the central part of the U.S.!

Looking at this mornings satellite image...

That subtropical moisture (btw, see the last post I did discussing this by clicking here) still remains and will be partly responsible for the excessive rainfall mentioned above.  There is a lot going on in this satellite image.  I'm still finding that the presence of this subtropical moisture somewhat encouraging going into the growing season.  There is also a wet system near Hawaii with a "background" ridge extending up into Alaska.

In that previous post I did on the 13th, there were signs of a change:  The fairly robust MJO; both the Arctic Oscillation and North Atlantic Oscillation going strongly negative; and the Southern Oscillation Index dropping to values not observed since September. All four are still moving in a direction of change. And that first change?  I believe it's this widespread precipitation that is expected on the above map.   I also think there may be an opportunity for at least SOME precipitation across the high plains by around the 25th, give or take a day.  It's not a big chance, but at least something to watch.  Keep praying and keep your fingers crossed.

We obviously need something.  This 135 day stretch since Oct 7th continues to be a record.  For Dodge City....

Did you see that there was actually rainfall across west Texas during the past 7 days?  Look at the map!  That is also a change.

Going back to the previous post...I mentioned that going into March and March in general "could" be wild across the plains.  This is a start.   I'll try and update again by the 23rd/24th.

Tuesday, February 13, 2018

Update - Feb 13, 2018

In the previous post I did on the 4th (you can read it by clicking here), I ended with "NOTE:  One or two of these systems between now and the end of February, COULD deepen enough to bring a good shot of moisture.  But that "could" is a long-shot and sure wouldn't bet on it at this point."  So, I'm thinking a few are wondering if anything has changed?   Before I dive into that topic, let me take a minute to share something.

I did a presentation this past week and got into a small discussion about some of the local climate/weather changes that have taken place the past 50 years from perhaps farming practices (irrigation/growing corn, breaking out grass, etc.).  I've noticed a few changes in temperature and the dew point (and rainfall on average) over the decades and have often wondered and suspected that some of the changes were enhanced by agriculture.  This morning I ran across an article that might be worth reading if you have time:  The link to that article "Intensive agriculture influences U.S. regional summer climate..." is:

Back to our weather...

First, I've been doing quite a few presentations this past couple of months and have been sharing a graphic illustrating the dry stretch the high plains has observed.  For the 129 day period from October 7th through today (Feb 13th), only scant amounts of precipitation have fallen on most places across the high plains, generally south of Interstate 70.  For some locations, this is a record for that time period.  For Dodge City, ANY 129 day stretch has actually experienced lower totals.  See the chart below:

The * denotes a record for that location for this exact time period.

It's interesting that the driest 129 day period in Dodge City occurred in late 1879 and into 1880.  But right after that it was a wet in May, July and August. I'm not saying to expect the same this year, I just found that interesting.   Even in 1904 it was wet in May and August.  

Since October 1, 2017, many areas of the plains have missed out on precipitation.  Most of that light blue is well less than an inch of moisture.  During the first few days of October there was a pretty good amount of precip near Amarillo and Dalhart (also farther north and east).


Snowfall this past fall and so far this winter has been varied.  By the way, the maximum of 893.3 inches is somewhere up in the mountains of Washington.  Click for a larger version.


Looking at this mornings satellite image....
There are a few important features showing up. I'm intrigued by the flow from the deep tropics in two different regions.  The first is across the Pacific west of Mexico and it extends up into the southern plains.  It's not bringing rain or snow, but is pumping upper level Pacific moisture into the region. I would really like to see that continue going into the spring.  This feature was also present back on the 4th as mentioned in the previous post.  Then there is flow from the deep tropics north across Hawaii associated with a storm (the big red L) located northwest of the islands.    I always like seeing  this type of flow from the tropics into the higher latitudes.   There won't be any immediate impacts on the high plains weather.  But it's something I'll be watching.

Ok, what about any changes that "could" allow a storm to deepen to our west increasing the odds of getting a decent shot of moisture.  The latest long range outlook with the Global Forecast System computer model has ZERO precip for much of southwest KS into the panhandles through the remainder of February.  Is that going to be right?  Well, I'm seeing something that is SLIGHTLY encouraging.  At least I see a glimmer of hope or at least the "long shot" I've been hoping for.

There are quite a few signs of at least a temporary change.  The Southern Oscillation Index has crashed over the past few weeks and the 90 day average is at it's lowest since early September.  That is likely the result of the Madden Julian Oscillation (MJO) that has been active for a while.  There is a prediction by some of the models and ensembles that this MJO will stall out in phase 7 before it decays in that phase.  In most cases during February, the MJO in phase 7 promotes a better than normal chance of below normal temperatures on average across the plains.   Here is that chart....
The Arctic Oscillation (AO) is forecast to go negative and stay there for a while.  The predictability of the AO is not that good, but it's something to watch. Typically with a negative AO the opportunity for Arctic air spilling into our side of the northern hemisphere is enhanced.  Here is that chart...


The North Atlantic Oscillation (NAO) is forecast to go negative and stay there.  Again the predictability of the NAO is not good either, but what if?  Typically with a negative phase of the NAO there is blocking over Greenland, which also enhances an Arctic airmass into the U.S..  A combined negative AO and negative NAO should force the jetstream farther south.    Here is the NAO chart...


All right....there are some big "ifs" here. IF the sudden decrease in the SOI has a contribution and IF the MJO stalls in phase 7 and IF the AO goes negative and IF the NAO goes negative, then I could see some major changes to the pattern in 10 to 14 days.  I'm hoping this change would lead to a deeper upper level trough that doesn't progress too quickly into the plains. That "should" promote a much better chance of meaningful precipitation.  

This pattern could last into early March.  Lately I've been telling folks that March could be warmer than average, but now I'm leaning just the opposite (colder than average).  In general, March might be pretty active and wild for much of the plains.  I just fear that it will be just north and east of southwest Kansas.  I hope to fine tune that possibility here in a week or two.

BTW, for some reason, back in the fall I told a bunch of people that March 5th was my "gut feeling" date for a high plains blizzard.   Welp, we'll see.  Ha, I'll probably be golfing without a jacket that day.

I'll try to update again later next week.

Sunday, February 4, 2018

Update 2/4/18

Since the last post on the 25th of January (if you want to read it click here), the pattern has started to transition back into a cold one, in general.  This was expected.  What we'll probably see across the high plains will be a great deal of variability instead of getting completely locked into cold.  That is, up and down with a wild swing from mild to bitter cold.  Today (Sunday the 4th) is not exception with bone chilling wind and cold that followed a very mild Saturday.  One reason for the flip-flopping on temperatures is that we are on the western edge of the large and cold airmass.

On the satellite image, several features caught my eye.  The obvious one is the Low (red L) off the Aleutian chain that was helping to pump warmer air into Alaska and thus forcing cold air into the U.S. east of the Rockies. Another was the blue H across northern Baja California.  I'm going to start watching this for a while because this MIGHT be a player as the growing season starts (and that outcome would be really bad).   The other feature is shown by the whiteness across the lower right of the image.  This is tropical moisture and tropical jet that could end up being a player by early spring (and that outcome could be good).  That is something else I'll be watching as time goes on.  Overall, this satellite image is a mirror image of what has periodically been going on since late fall.

For the next couple of weeks there will continue to be wide swings in temperatures with a continuation of frequent fronts and just a little bit of moisture.  Late Saturday evening (yesterday the 3rd) there was a surprise weak system that brought scattered showers but minimal rain.  It sure was nice though to have that "smell" and remove the dust out of the air at least temporarily.  The Dodge City airport got a whopping 0.04" which brings the total to 0.14" since October 7, or during the past 119 days. Wow, that is nuts!.   Other areas around the high plains haven't even had that much.  But, it's also not the driest stretch we have on the record books believe it or not. It's still dismal.....

Today (Sunday) snow that was falling across the northern parts of the high plains and into northeast Kansas.  A few spots may have picked up 3 or 4 inches of snow (it was still snowing as of Sunday afternoon).

As I've mentioned for months, there will continue to be opportunities for "storms" but those chances will be few and far between.  Another system will bring a chance for moisture Monday night and Tuesday and then again late in the week or over the weekend.  At this point, I wouldn't expect significant precipitation, but I guess anything is better than zero.  Unfortunately the southern half of the high plains (Elkhart to Liberal and on south) may not get anything at all.

NOTE:  One or two of these systems between now and the end of February, COULD deepen enough to bring a good shot of moisture.  But that "could" is a long-shot and sure wouldn't bet on it at this point.