Update 122214 - Get ready for the cold

I've been trying to figure out the cycle length and orientation of this years weather pattern and I "think" I have it figured out.  If I've got it right, then expect a pretty severe cold spell starting later this week and progressively getting worse into the first of the year.  Before I discuss that, I want to look back at what recently happened (and is currently on-going).

Past Weather

In the last post on the 16th (click here) I discussed the possibility of snow across much of Kansas.  Indeed it did materialize.  The heaviest amounts were in a stripe from northern Clark county to north central Kansas.  Local to the Dodge City area the most reported was 6 inches near Belpre.  Much of western Kansas only saw a dusting to nothing at all.  Click on the map for a larger version.

In addition to the forecast of snow, I discussed the likelihood of Arctic air returning for the last part of December, plus the hunch of a high impact storm around Christmas.   That is still on track.

Current Weather

As of today (Monday) there was an organizing storm just north of Kansas City.  Widespread rain was falling across northeast Kansas.  There were sprinkles across the western part of the state.

This storm was evolving and deepening with another shot of energy diving southeast across the western high plains which will develop into another storm, east of Kansas.  By Christmas Eve there should be a very strong storm impacting much of the eastern half of the country.  The combination of the two storms mentioned will bring travel headaches to the country.  If you're traveling by air on Christmas Eve or Christmas Day, expect major delays!

Behind these two storms there will likely be a dump of Arctic air into the country.  Looking at the current surface chart from Canada, there is very cold air building up and headed this way.

I've mentioned in several previous posts about trying to figure out the repeating pattern cycle length.  I think I've got a pretty good idea.  If my calculations are correct, then an extended cold period is likely, starting right after Christmas and continuing into the first of January.  The cold could be 20 to 30 degrees below normal. That would mean lows in the single digits to perhaps below zero, and highs in the teens and 20s.

What about moisture?

Looking at the satellite map below, there are several features to point out.

The first is the low that is currently north of Kansas City.  This won't have any impact on the high plains but has been bring the rain discussed above.  The second feature is really not depicted on the map but is essentially a very strong jet stream that will be diving into the deep south bringing the travel impacting storm by Christmas eve, but east of Kansas.  The third feature is the X north and west of Hawaii.  This will be our next weather maker as it will be approaching the plains late Christmas day and into Friday.  It's impossible to predict the strength or location (and track) but it should have an impact on travel across the plains.  In advance of the system, it will cause of surge of  mild air to head north with above normal temperatures possible across Kansas for Christmas Day.  But as the system moves out of the Rockies, it is likely that cold air to the north will be tapped so that there should be wintry precipitation with it.  I just can't say at this point if it will be Nebraska, Kansas or Oklahoma.  Stay tuned.

Another feature is the big blue H over the Pacific.  This is an upper level ridge that will intensify and build into western Canada over the next week.  Depending on the amplitude, a very cold airmass is likely to drop into the states.  This cold will be similar to what happened in November.  Anytime an Arctic airmass resides over the states, any minor disturbance in the flow aloft usually results in some sort of precipitation.    I think the end of the month and into the first of the year could get rather interesting.  I'll attempt to update this again soon.