Friday, December 7, 2018

In the post I did a few days ago on the 4th (you can read that by clicking here), I discussed the upcoming weekend storm moving south of Kansas with the expected precipitation being just south of Kansas.  The storm this morning was near San Diego and that is denoted by the red L on the following satellite image...



In most winters storms in this vicinity moving towards the central U.S., they would benefit the local region with precipitation (whether that be liquid, freezing or frozen).  This particular storm has already brought copious amounts of rain and snow to California and good for them!  But as the storm continues to trek to the east and even southeast, it is also going through a weakening trend.  Regardless it will eventually produce a ton of rainfall across Texas and parts of Oklahoma.  It does appear that it will pass WAY south of the central U.S. and may even be so far south that the northern extent of precipitation may not even reach Oklahoma City!

So far this fall and early winter, the first part was very wet across the central part of the plains, centered on Kansas.  Later weather systems started trending north and impacted Nebraska, the midwest and eastern Kansas as we got deeper into fall.  Now with this weekend storm going so far south, there does seem to be a signal - a signal that I'm a little concerned about as far as future precipitation trends for the high plains, even going well into the growing season (including summer). I'm hoping this is just an adjustment period as the overall weather pattern (upper troughs and ridges) has been set for this next 10-11 months.

I'm not going to change my thoughts on near to below normal temperatures for the winter, nor will I waver from a normal to above normal precipitation outlook - at least just yet.  The change may be just temporary.

For the next couple of weeks it appears that weather systems may weaken as they approach the central U.S., but then intensify again just east of Kansas.   I'm still not seeing a signal for the brutally cold air, even though the Arctic Oscillation and MJO have been in a favorable phase.

Here is the precipitation outlook through the end of next week...

 

I'll try and update again in about a week.


Tuesday, December 4, 2018

Update - 12/4/18

The active pattern continues across the central U.S. but with locations being impacted the greatest shifting north and then south.  The post Thanksgiving "mini" blizzard on that following Sunday was tame compared to the storm that came through this past weekend (1st/2nd). That weather system produced copious amounts of rainfall across eastern Kansas and very heavy snow across Nebraska.  Based on soil moisture profiles, much of the eastern half of Kansas is fully saturated.  Only light amounts of moisture fell on the high plains.  Farther south and east there were two days of severe weather including tornadoes in Oklahoma and then especially Illinois.

In the previous post I had mentioned that weather systems so far this fall have been farther south and stronger than originally forecast.  Although this past system took a northern route, it was expected to do so.

This morning there was a dusting of snow across Kansas from just weak forcing aloft.  No biggie.

In the last post I did on the 26th, I pointed out a system way out in the Pacific near Guam.  That system is now going to be our next impacting storm.  However, this time it appears that it will take a southern track!  While it will be very wet across California and Arizona, the storm will be weakening as it moves east.  It will, however, be strong enough to pull copious amount of moisture northward as it moves into the southern plains.  Oklahoma and Texas and then eventually the gulf coast will most likely receive a lot of rain! On the northern fringes there will be ice and snow, but the details of areal extent are impossible to lay down at this point, since the system is still off the coast.  At this point the northern edge of the precipitation shield will likely be just south of Kansas.  But hold on!

On this mornings satellite image, the low shows up as the swirl in the moisture off the west coast...



Since the system is still off the coast, the exact track is still highly uncertain. Yes, there is still a chance it could move farther north.  The farther north the track, the farther north the precipitation.  In Kansas the temperature profile would support snow.   I might have a chance to throw out another post at the end of the week, but it's best to just follow the National Weather Service (www.weather.gov/) for details as we get closer to the weekend.

Even though temperatures have been below average for a while, there still isn't any indication of the brutally cold Arctic air that's been building.  With the sharp ridge aloft just off the west coast earlier this fall broken down, at least temporarily, it will be difficult to get the really cold stuff.  But that ridge will likely reform yet this month.

Back to that satellite image....there are two areas of flow aloft from the deep tropics across the Pacific near the equator.  In fact, there may be a tropical storm develop southeast of Hawaii!  On the 25th there was just one area of flow from the tropics.  I'll have to watch this because usually exciting things happen across the central U.S. with this tropical energy being transported into higher latitudes.  Regardless, this should keep an active pattern across the country.  For the high plains, it could be Oklahoma/Texas that are impacted the greatest, or it could shift north into Kansas and Nebraska, but not the Dakotas or upper midwest.  More in later posts.

BTW, here is the precipitation outlook from the Weather Prediction Center through next Tuesday the 11th.