Update - 12/16/14

Past event

In the last post I did on the 8th (click here) I discussed the potential for a storm a week away.  That storm did materialize and brought widespread precipitation and even at least 3 tornadoes to Kansas and Oklahoma.  If you didn't get a chance to see the tornado video in Harper county, it can be viewed here.  There was at least one other tornado in Harper county and also at least one in Oklahoma.  Tornadoes in December in Kansas are rather rare, occurring about every 10-15  years but usually east of I-35.

In the cold air of northeast Colorado there was up to 12 inches of snow.  Elsewhere in Kansas there was quite a bit of rain in some areas.  (click for a large version)

This was the second mainly rain event in Kansas this month.  For December that is just a bit unusual but also rather typical for an El Nino type winter.  The cold we saw in November WILL eventually make it back into the central U.S., it is just a matter of time.

The precipitation that has fallen this month is certainly good news but there are areas that are still missing out.  The U.S. drought monitor map shows areas that are still exceedingly dry (although the map does NOT take into account the precipitation that fell this past weekend).

For Dodge City in particular, even with above normal precipitation for 2014, the ongoing long term dryness can be seen in the graph below.  That graph shows the deficit of moisture that has been in place since October of 2011.

The current atmosphere

As of this Tuesday morning there was a fair amount of snow cover across Canada and parts of the northern plains.   The good news out of this is the snow accumulations across the drought stricken west.  There has also been copious amounts of rainfall in the lower elevations out west going a long way in reservoir storage and relieving much of the drought.  Back to the snow cover, it is about normal for this time of year.

Looking at the satellite image, there are several important features.  One is the anomalously strong jetstream across the Pacific, meaning wind speeds aloft area VERY fast. This type of setup is unstable and usually leads to downstream amplification of weather systems.  This is NOT the first time we've seen this during the this years fall and winter.  There are several upper level lows or disturbances denoted on the map.  The most important for the near term was the X that was approaching California and the other feature, an "L" just west of the Oregon/Northern California cost.  The X will be approaching the central plains late Wednesday and into Thursday.  The "L" will eventually drop southeast and affect southern Texas.  However, the X system will enhance the opportunity for freezing rain and snow across much of the central plains.  The track of the surface response is in question (as is the exact track the upper system takes).  Somewhere across Kansas there could be a stripe of 1 to 4 inches of snow with freezing drizzle or freezing rain across Oklahoma and perhaps south central and southeast Kansas.  The local updated forecast is the best bet to keep on top of that information.  Go to weather.gov/ and click on the part of country you're interested in for the local NWS office forecast.

The future

I'm not real confident on the eventual evolution of the flow aloft with so much going on across the Pacific.  However, if you go back several posts, I've discussed the likelihood of Arctic air returning for the last part of December.  I need to analyze the repeating pattern and see if I can determine the cycle length.  I've got a pretty good hunch that there will be a high impact storm around Christmas with a dump of Arctic air about the same time.  If you're traveling by air across the county around that time, be prepared for unpleasantness.  I'll try and get additional details later this week so keep checking back.