Thursday, October 29, 2015

The Halloween Strom - updated 10/29/15

In the previous post I did on Tuesday (click here), I discussed a an upper pattern suggesting a cold shot into the plains.  This morning, low temperatures bottomed out quickly across much of northern Kansas and Nebraska.  Some of the coldest readings across southern Kansas were only at those levels for an hour or less, right around sunrise.  Here is a map of this mornings lows (10/29) provided by the Kansas Mesonet (Kansas State University operated) for a larger map

The Halloween storm that I have referred to during the past 2 or 3 posts has been developing and was headed towards the southern and central plains.  On the afternoon satellite image, you can see it denoted by the X over Arizona.

This system will be strong enough to bring widespread rainfall to much of the central and southern plains and eventually to the lower Mississippi Valley and southeast U.S.. (some of this precipitation will fall later next week, so it's not ALL from this Halloween storm).

Once this Halloween system slides by, there should be rapid clearing (much of the plains by Saturday afternoon).  But there is no additional cold air associated with it. So, even though temperatures will be quite chilly during the rain and Saturday night in it's wake under clearing skies, daytime temperatures will actually start to warm up Sunday and into next week.  The reason?  Look at the following map...

The jet stream (strong winds aloft) will carve out what we call a trough during the week.  The air aloft across the plains will allow mild air to develop.  There is also the likelihood that a few rounds of thunderstorms could occur sometime next week.  Details are uncertain this far out, but I have a hunch it could get pretty wet again and with the possibility of some severe weather.  More details sometime next week...

Tuesday, October 27, 2015

Update 10/27/15

In the previous post (click here), the rain event that impacted much of the high plains was shifting south and Hurricane Patricia was moving into Mexico.  As the remnants of the hurricane moved into south Texas, additional very heavy rains fell across the Lone Star State and parts of the lower Mississippi Valley.  Here is the 7 day precipitation map...

It's unfortunate that much of eastern Kansas and northern Okaloma missed out.  Even a small area in central Texas missed out too!  The area northeast of Waco or southeast of Dallas received over 25 inches of rain!

Currently the central plains is experiencing several minor systems.  The first brought scattered rains to Kansas and Nebraska (I saw a 1 inch amount in Norton County Kansas) overnight and into Tuesday morning.  On the satellite image that follows, that system in question is the #1 X.  It also was bringing a little precipitation to the Kansas City area which may impact the Royals/Mets game for game one of the World Series.  BTW, if you're wondering, the green line with arrows represents the wind flow at about 30,000 feet.

The #2 X on the image above, was moving out of Wyoming towards Kansas this Tuesday afternoon.  It will bring more showers tonight and into Wednesday.  The #3 X  was the strongest system and it will carve out an upper low into the midwest.  It will bring a shot of colder air into the plains late Wednesday and Thursday.  There will likely be some freezing temperatures, but still no widespread season ending freeze.

Looking ahead...

In the satellite image above, you might have noticed the whiteness on the left hand side which corresponded to pacific moisture and clouds across the western U.S..  This is in advance of another developing storm that will drop into the southwest U.S. by Thursday.  This system is poised to bring another round of heavy rain to Texas but also addition rains into Kansas and Oklahoma.  This is the Halloween storm I've discussed over the past few posts!  It still could be too far south to impact much of Kansas but it looks like a slam dunk for Texas.  Here is the latest thinking from the Weather Prediction Center (rainfall through next Tuesday).

Beyond this Halloween system, there are signals for yet another storm by the following weekend! But confidence in that system is low.    I also might add, the signals for a widespread freeze deep into Kansas and Oklahoma are STILL not showing up!  I would bet though we'll have one between the 7th and 14th of November.   This time of year it can happen and develop quickly!

Thursday, October 22, 2015

Heavy rain and no freeze, yet...Updated 10/22/15

In the previous post I did on the 19th (click here for that  discussion), I eluded to the deep tropical flow that was headed towards the plains.  If you look at the forecast map of possible precipitation that was in that post and as discussed, I was expecting that excessive rainfall could fall early in the period.  Looking at the rainfall map of the past few days, I think you would agree that excessive rainfall did indeed fall. (click for a larger map)

Any color in the blue is at least an inch of rain and this has to be beneficial for wheat that had emerged.  In the Texas Panhandle there had been several flood and flash flood warnings, especially where the 6 to 8 inches of rain fell.

The upper low responsible for the storm had moved into northern New Mexico.  But a strong "chunk" of energy had already ejected to the north, taking the majority of the rainfall with it.  Heavy rains are still expected across parts of Oklahoma and especially Texas on the trailing end where additional development will take place.

Here is the satellite image...

As eluded to in the previous posts, there could still be an influence from possible tropical activity.  A hurricane had formed (Patricia) and it is expected to turn north into Mexico.  There is also another disturbance off the southern Texas coast.   The combination of this disturbance and remnants of Patricia (if that hurricane does turn north) will enhance the rainfall potential across Texas (except the west and panhandle).  Excessive and flooding rains will be highly likely.

Much of the rain you see across the plains in the map above had already fallen, so emphasis is the expected rain across Texas.

Looking ahead a bit, there is still some question about a possible system around Halloween.  Unfortunately this is the time of year when patterns are changing rapidly and have not been established which makes it very difficult to forecast.  I will just say that there is a small possibility at this time.  Also, any widespread freeze is not showing up, except for the upper midwest where there has already been a freeze.  For much of the high plains, a widespread killing freeze is still at least 7 to 10 days out which would be a little unusual.  I was looking for snow cover up north where some of our cold air masses form and so far there isn't much to speak of.

Monday, October 19, 2015

Quick update - 10/19/2015

In the previous post I did on Friday (click here for that post), I discussed the changing weather expected for this week.  The original "wobbling and wondering low" had weakened and as of this afternoon was lifting into the northern Rockies.  It did not bring precipitation to the plains but did bring rain and snow to the Rockies.  However, as discussed on Friday, the flow has become southwesterly aloft and there are disturbances headed this way.

The afternoon satellite image shows several features.  (Click for a larger version)....

The decaying system referenced was located over western Wyoming and lifting north.  A more important feature was over central California (denoted by the red X).  It was dropping south but also strengthening.  Overall there was a deep fetch of the atmosphere headed northeast out of the tropics.   This will certainly be good news for much of the plains and even southern Rockies as precipitation chances will increase and some areas will receive substantial moisture!  But, I guess it could also be a bad thing if the wheat has not emerged or fall crops haven't been harvested as some areas may get excessive amounts.

The Weather Prediction Center has the following forecast of precipitation for the 7 day period ending next Monday evening...(keep in mind that this is an expected average, some will get more, some less).

You might also recall in the last post I discussed briefly about a tropical system that could move into the gulf and intensify.  Looking at the satellite image above, it is located just about in the same area as last Friday.  It hasn't moved much!  But indications are that it will start to influence Texas late in the week or early weekend (and depicted by large amounts of predicted rainfall).

Friday, October 16, 2015

Interesting weather is not too far away! Updated 10/16/15

First I wanted to show the morning low temperature map.  In earlier posts I had eluded to the possibility of some freezing temperatures that were expected for today and tomorrow.  (click for a larger version)

Here is a map showing where a "killing" freeze has occurred (temperatures at 28 or colder) this fall...

In the post I did on the 5th and again on the 13th, I discussed an upper system that moved into Arizona and New Mexico and then headed south and west.  During the past few days it has helped to bring heavy rains and severe weather to California.  Here is a crazy loop of this system (animated gif)...

This track of the upper system has been amazing and considering that it intensified over the warm waters off of Baja California, it is pretty rare.  Those heavy rains across California are NOT an El Nino response!  I can't stress that enough.  A "typical" El Nino response is for an extended west to east jet stream across the Pacific that moves systems in from near Hawaii, not for closed lows to wonder around as this one has done.  Regardless, at least some rain fell out west which is great news!  Too bad for the mud slides though.

The satellite image from this morning shows this system.  Also note the red X way south - I'll discuss that at the bottom...

In the previous post I mentioned that this system that is now over California would likely go through a decaying process as it moved into the plains.  Indeed it appears that will happen but the flow aloft may bring addition disturbances late next Monday through Wednesday.  So, there should still be showers and even thunderstorms during that period, at least scattered.  Starting tomorrow (17th) and continuing into mid-week it also appears that the wind will be picking up and will become pretty strong during the afternoon hours, just about anywhere across the plains (central and east).

I've mentioned numerous times that a new weather pattern gets established during the fall.  In the previous post on the 13th I was not seeing much evidence of major changes.  WOW, have things changed!  First there is strong tropical activity that has developed across the western Pacific (normally leads to changes across the U.S. a week to 10 days later).  Second, the jet stream is increasing in velocity across the Pacific and is beginning to buckle.  It now appears (at least there is strong evidence) that the flow aloft will buckle substantially enough that the flow will become southwesterly across the plains next week and into the following week.  If computer guidance is even close to being correct, there should be many ingredients coming together to produce an active wet and strormy period, especially in the 7 to 14 day period.  I would not be surprised to see several episodes of severe weather across the plains.  In addition, excessive rainfall may actually be a threat.  Here is the latest precipitation outlook from the Weather Prediction Center (7 days through next Friday morning)...

Beyond next Friday morning more rain could fall into the following week, so some locations from New Mexico, west Texas and into Kansas could see double this amount!  I hope by that period most of the winter wheat has emerged or replanting will be in someone's future.  At the same time, unharvested cotton, sorghum and corn may be sitting is some pretty muddy fields.  Confidence is growing for this scenario but of course this is still early in thinking, i.e. not set in stone.

Finally, about that "X" that is way down south.  With some of the western tropical activity (primarily the presence of a Madden Julian Oscillation) favoring development in this area, I would have a concern a tropical storm or even a hurricane could impact the Gulf states.  Even if a TC or hurricane fails to develop, it appears  much of the western Gulf coast will get excessively wet later next week as this "X" moves north.

Tuesday, October 13, 2015

Update 10/13/15

In the post I did on the 5th (click here) I discussed an upper low that was spinning across California and moving towards New Mexico.  As expected the low became cut off from the flow and never made it past Albuquerque.   As a result, the rainfall across much of Kansas was limited although a few locations got over an inch!  The bulk of the rainfall, as expected, was across New Mexico and west Texas.  Here is the map of the 7 day rainfall ending yesterday.

In a typical pattern the low would have moved out into the plains and would have brought copious moisture to many areas.  But in this case, the low drifted south and then west.  What is somewhat amazing is that this low is still alive and well!  As of Tuesday afternoon the low was southwest of San Diego and drifting north.  Here is the satellite image....(click for a larger map)

There is a small chance that the jet stream across the Pacific could move this low towards the plains by the end of the weekend.  The only problem is that it would likely undergo a degeneration process as it does.  The result would be only a small chance for precipitation.  But even if it does decay, the trough across the Pacific (the dip in the jet stream or green line) will be approaching and this may be enough to bring some showers and storms to the center of the country.

The Weather Prediction Center offers the following precipitation possibility through next Monday....

That is not a lot of moisture for the wheat belt, unfortunately.  Looking slightly ahead to the balance of the month, there is only a small indication of decent moisture towards Halloween.  I'm leaning on the pessimistic side right now.  I'll try and update at the end of the week and see if anything starts showing up.  As far as a freeze, there is nothing significant in the near term although scattered frost could certainly occur later this weekend.

Monday, October 5, 2015

A rant and a forecast - Updated 10/5/15

Nothing irritates me more and makes my blood boil than an inaccurate assessment of the atmosphere by the media and others.  I'm sure many of you have heard of the deadly and tragic flooding that occurred (and still ongoing) across the Carolinas.  Many outlets have said that the torrential rainfall and subsequent flooding was the result of Hurricane Joaquin coming ashore over the weekend.


The Hurricane NEVER came close to the mainland!  In addition, the Hurricane was NOT the result of global warming!  Dang my veins are popping right now.  BTW, the U.S. mainland has not had a major hurricane in 10 years now.

Go back to the last post I did (click here).  Did you remember the forecast track of Joaquin?   Computer models (and humans that fall into the category of forecasting what the models say) were woefully wrong!  It was an extremely tough forecast.  But at the same time I had pointed out that an upper system was going to amplify and intensify into a strong upper storm.  It was this upper storm that combined with just the right set up to produce the copious rainfall.  The presence of Joaquin near the Bahamas may have added a bit of moisture from the very warm ocean waters.  But everything else was in place to provide an environment to generate the exceptional amount of rain.

First, here is that one forecast with various model output tracks with the eventual track on Joaquin on top (the green trace).  (click for a larger version).

 and the track without the forecast junk....

 A satellite loop shows the progression of the Hurricane and the developing upper storm.


Rainfall was copious where the thunderstorms "trained" across the same area.  Look at South Carolina....while some areas in the state had 2 feet plus, other areas didn't even have a half of an inch of rain!

 And the bigger picture including much of the Atlantic Seaboard....

Back in Kansas and the plains...the beneficiaries from the blocking pattern were mainly the southern high plains, although there were certainly some good rains in Kansas, just isolated to widely scattered.  Here is a map of the rainfall the past 4 days...

The rains in this area are not over!  There is an upper low over southern California that will move east to near New Mexico before it gets "cut off" and then drifts south and wanders around.  The result will be much more rain across Arizona, New Mexico and the western half of Texas.  Parts of Kansas and eastern Colorado may also see a bit of rain, but it will likely be limited in areal coverage and amounts.

The Weather Prediction Center offers the following forecast through Sunday....

The National Weather Service office in Dodge City will be at the 3i show later this week in Dodge.  If you're there, stop at our booth (inside - 298) and say "howdy".