Thursday, December 22, 2016

Quick update - 12/22/16

The brutal Arctic air finally retreated this week.  The coldest reading I saw in Kansas during the cold spell was -27 (yes that is 27 degrees below zero) and that was NOT a wind chill reading.  Many locations observed 18 to 22 below zero.  But now, all that brutal cold air has sloshed back into Eurasia and Siberia, much like it was in November!  I'm betting it will return again this winter!

Here were the current temperatures:


In the posts I've done over the past 2 to 3 weeks I discussed two systems for the current period.  The first I thought might move out into the plains around the 22nd, or that would be today.  Indeed there is a system poised to head this way.  It will be weakening as it does move out late tonight and Friday, but it should be strong enough (despite really dry surface air and unfavorable surface conditions) to produce a little rain or light wintry mix later today into early Friday.  It shouldn't be a big deal.

You can see this system on the satellite image:

click for a larger version

In the past 2 to 3 weeks I had also "hinted" at a storm around Christmas.  Well, it does appear that there will be a storm!  But, with the retreat of the Arctic air, any white Christmas snow will end up in the Dakotas!  Such is life in the plains.

In the satellite image, the "developing" system (not yet a storm) is denoted by the blue "M"...

click for a larger version

This developing system (M) should become a vigorous storm as it moves into the western U.S. but it appears that it will move too far north to bring any wintry precipitation to the high plains of Kansas.  BUT, it will likely bring a threat of thunderstorms, at least to eastern Kansas, much of Oklahoma and central and north Texas on Christmas Day!   In the post I did on October 28, I said "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?".  

Well, we'll see what happens!

Hopefully the storm will be strong enough to bring at least a brief period of rain or showers to part of the high plains.  I just don't know how far west at this point since the storm has not even developed yet.

Here is the Storm Prediction Centers outlook for severe storms for Christmas Day:

Since I'm headed for surgery, I may not be able to update this blog for a while.

Merry Christmas everyone!

Thursday, December 15, 2016

The Cold and potential for any moisture - update 12/15/2016

I'm sure most of you have NOT enjoyed the cold the plains have been experiencing this past 10 days.  Unfortunately, the coldest air has not occurred yet but is on schedule and will be here very soon.

In the past few posts I had mentioned a "gut" feeling of a storm or precipitation event between the 18th and 22nd.   There is going to be a minor event Saturday (17th) so that would be just a little ahead of schedule, and not that significant as far as snowfall goes.  But what is going to be very impactful is the magnitude of the cold along with wind!

Looking at the satellite image from this afternoon, there were several important features:

Click for a larger map

Normally the position of X1 on the map would be ideal to bring a significant storm to the plains.  But this time the flow is rather complicated.  The X2 and X1 will merge into one (maybe), but even if they don't, both will be weakening significantly as they move east and northeast into what I call the "background ridge position".  In other words, the overall pattern is not aligned correctly to allow these systems to retain their amplitude or even intensify.  In addition, the F on the map is a developing system.

BTW, did you ever wonder what  systems denoted on satellite look like on a regular upper level weather map?  The map below shows the level of 500 millibars, or roughly around 18,000 to 22,000 feet.  The solid lines represent a height of the pressure level and in general the wind flow at that level follow these black lines from left to right.  The colors represent the magnitude (speeds) of the wind.

All three systems approaching the central part of the U.S. will interact with a strong gradient of temperatures from the snow packed tundra of the northern plains to relatively warm air across south Texas.  First, the wind machine will crank up across much of Oklahoma and Texas, along with warm temperatures on Friday.  As the systems come out, the surface will be overtaken by Arctic air which will allow temperatures to plunge to values not seen in several years.  Jetstream dynamics will allow for a band of snow to develop in the Arctic air and where ever the energy can consolidate, there may be be a narrow band of relatively moderate snow for several hours.  The snow will be fluffy and will be blown around by the north winds and won't contain much moisture (dry snow).  Temperatures will dramatically fall and even as much as 60 degrees in less than a 12 hour period!  Lows (actual temps - not just wind chill readings) by Sunday morning should be well below zero across the high plains!

Here were the current temperatures across Canada and the northern U.S. at Noon on Thursday. 

The good news is this brutal cold air will move out rather quickly by the first of the week (19th).  But recirculating the cold will result in coldness, just not quite as cold if that makes sense.

You might also be interested in the X3 on the satellite and upper air map.  It was north of Hawaii but instead of moving east and becoming potentially another storm, it appears (according to computer forecast models) as if it will move south and west!  Hmmm.  I need to watch that.

The L (upper level low) west of the Aleutian Island chain will help produce another system that looks like it will drop straight south all the way to the Gulf of California or the Baja.  Now if this happens, eventually it will move east and north and "could" bring some precipitation by the 22nd, give or take a day.  I'll watch that one.

Finally, with the configuration of the upper flow across the north Pacific (including the upper level low west of the Aleutians), that presents an opportunity for perhaps another system around Christmas.  If you remember in that last post, I had a "hunch" of a white Christmas across parts of Nebraska, Kansas (and maybe the panhandles).  But it is WAY TOO early to predict that with any amount of certainty.  What is likely though, is that there will be a significant warm up before Christmas!  More on that as we get closer.

I'll try and update by the 20th.

Saturday, December 10, 2016

Feed bales will be flying - Update 12/10/2016

This is just a quick update on the cold and "potential" for a storm.  On the post I did on the 5th (read it by clicking here), I discussed a system that was dropping southeast out of the far NW and would bring some snow.  After the system went by, the largest amount I saw in the plains was about 4 inches in far north central Kansas.  Light fluffy snow with hardly any moisture content did fall farther south but did nothing to cause problems or unfortunately to benefit soil moisture.  I also discussed the arrival of the cold and the up-and-down that was to be expected for the high plains.  Temperatures have "warmed" up to seasonal values for this current weekend and that will extend into Monday.  But, then the bottom falls out again, and this time it could potentially be even colder than the first surge (I discussed this too and was to be expected).  For a while now I've discussed the brutal cold and snow that had been across the hemisphere (Eurasia and Siberia) and was expected to "slosh" back to this side.  Look at temperatures early this afternoon across Canada!

click for larger map

This is the coldest air so far this season for that part of our hemisphere.   That source region won't change anytime soon.

Looking at the satellite image (click for larger version)...

The red X1 and X2 will move east during the next several days and will unleash more of that cold air across Canada by Tuesday for the central plains.  Hardest hit will be the northern plains and midwest.  But that won't be the only outbreak of cold.  More will be coming later.

In that previous post on the 5th I also mentioned a time frame for perhaps the next potential storm for the high plains.  Despite nothing showing up on the computer forecast models at the time, I had the period from the 18th through 22nd on my mind.  I'm sticking with that period and there is actually something showing up that "might" help that happen!  On the satellite image above, there are two very important features.  One is an anomalously strong and moist flow of air from the deep tropics up across Hawaii and then curving east, slamming into California.  Guess what?  During a La Nina (which the "experts" with the Climate Prediction Center and others have claimed to be going on), this type of flow should NOT exist!  Ha!  More in the coming weeks on this.

Also on the satellite image is the X3.  This appears to be a new system that is just starting to form.  I have a hunch that this particular system just might become a weather maker for the high plains in a week to 10 days.  I'll keep and eye on that and update later in the week.

In the meantime, nothing or very little moisture is expected across the high plains during the next 7 days.  There will likely be fluffy meaningless snow with the cold surges but no impacts are expected.

Here is the Weather Prediction Center's outlook...

Look at how much moisture is expected along the west coast!  WOW!  For the high plains of Kansas through West Texas and eastern New Mexico, as I mentioned, not much if anything.   But maybe there is some hope by next weekend and for the period leading up to Christmas.

The screaming message...a brief "warmup" followed by the deep freeze once again by Tuesday and this should persist for a week or two or three (except maybe a day or two of a brief moderation). At this point it is appearing that average temperatures for December will end up below normal across much of the area.  I'm thinking there will be a lot of breaking of ice and supplemental feeding for livestock.

Also, a gut feeling is for a "white" Christmas for much of Kansas and Nebraska (and maybe even the Texas/Oklahoma Panhandle region. Ha, we'll see how that one goes, i.e. don't tell anyone. ;-)

Monday, December 5, 2016

Update 12/5/2016 - the cold is on it's way

In the post I did last week on the 30th (read it by clicking here), I showed a system that was along the northern border of Washington state and was expected to dive way south into southwest Texas.  Did that happen?  Look at this mornings satellite image:

click for a larger map
This system did develop as expected.  On the map, the system is denoted by the red "L" near El Paso.  It has brought very heavy rain to much of Texas, parts of Oklahoma and is now soaking the lower Mississippi Valley and eventually the parched southeast U.S.  Good for them!  What I was not expecting was enough lift of the atmosphere across the central U.S. from a passing upper level trough (mostly unrelated to the upper low but the northern branch of the westerlies) to produce much precipitation.  Some areas of the central U.S. did receive some beneficial rains (and a little bit of wet snow)!

Here is a map of precipitation from over the weekend:

Click for a larger map

Anything from about Amarillo to OKC south is related to the upper low.  The remainder north of that line is a gift from the northern branch of the westerlies!

In the previous post I also talked about an upstream system that could bring snow Tuesday and Wednesday, but also cautioned to seeing predictions.  Computer models are and have been all over the place!

On the satellite image above, there are actually 2 systems.  One was over northern Wyoming and will become a pretty decent storm for the northern Plains and upper Midwest/Great Lakes region.  Nothing for the central U.S. other than providing a cold front that will sweep across the high plains Monday night into Tuesday..

The other X (2) was approaching Washington state and you can see the expected path it should take.  It will be a compact system and thus will bring a narrow band of precipitation (snow) as it moves out across the central U.S. on Wednesday.  It looks like any significant snow will be confined to northeast Colorado and western Nebraska and perhaps far northwest Kansas.  Lighter snow (less than 2 inches) will fall on a line across mainly the I-70 corridor as far east as Manhattan.  Some of that snow could creep a little farther south, but it shouldn't be much (a dusting to 1 inch).

Through the next 7 days, here is the outlook from the Weather Prediction Center:

After this second system moves through, a brief period of even colder air should spill south across most of the area Wednesday and Thursday.  That would be just a couple of days faster than I originally expected (in the previous post).  But as I also previously expected, it will likely be just a brief visit as there will be a warm up (to seasonal values) Friday and Saturday.  But, that might just be the start. There is some pretty cold air to be tapped into and it looks like this cold air will slosh back and forth for at least 10 days to 2 weeks (maybe longer) centered on the central and northern plains.  Thus, areas of the high plains will see wild swings from really cold to brief warmups.  The upper midwest and northern plains may be set for the deep freeze for an extended period well into December.  The first slosh back into the really cold might be as early as the end of the weekend.  Every time that happens, there might be a brief period of fluffy light snow.

Here is the morning map of temperatures:
December is typically (based on climatology) the driest month of the year.  At this point it sure doesn't look like it will be any different.  As the repeating pattern length starts to reveal itself, I might be able to pin down the next chance for a "significant" chance of a storm.    I'd like to say between the 18th and 22nd, but the confidence in that period is near zero but it's stuck in my mind.  I'll try and update towards the end of the week or weekend so check back.  In the meantime, prepare for periods of really cold air and then it's back to near seasonable temperatures for a few days before going back into the deep freeze.Break out the feed bales!