Last Month of 2017 Looking More Active

Posted by Donovan Neal on Sunday, November 26, 2017
Has anyone noticed how dry it has been across the Continental United States?  If you need a refresher for November (and some of October), here are a few points...

*For much of the southern and central U.S, it has been at least more than two weeks since they have had at least two inches of accumulated precipitation

*Temperatures in most spots have been generally above average for much of the Central and Western part of the country 

*On November 2, DFW Airport recorded a temperature of at least 90 degrees, the first time a temperature of 90 or above has been recorded in North Texas in the month of November.  The record high was set in November 2, 2012, with a high of 87 degrees.

*For the Deep South, autumn is a wet season between the drier summer and winter seasons.  So far this year, this season has been drier than normal, and below average precipitation is expected this winter.  As a result, drought conditions continue to emerge for many places in the south, especially extending from Missouri to Northeast Texas.

*Due to the worsening drought and above-average temperatures, the risk for fires has been more elevated this year than in recent years, especially in parts of the south-central Plains.

*There have been no destructive tornadoes (EF3+) so far this month.

*There have been only 41 confirmed tornadoes in the month of November, which is below average especially in Dixie Alley.

Based off of that information, you could come to the conclusion that November 2017 has been kind of dry and boring to some degree.  With only less than a week away from December, not much rapid change will take place within a time span of a 6 days. 

So, when do things start to get more active???

WHAT YOU CAME HERE FOR - Since we are about to conclude this month, we can already starting looking at certain data for December and early 2018.  While we are unable to give any specific details about these coming days, we can tell you that mid December through early January looks more active in terms of precipitation.  The long range European Ensemble (ECMWF EPS) model has trended towards a wetter end to the year in some places across the south.  Here is one example...

While temperatures in many spots are still projected to be above average, the increase in precipitation means that rain and storm potential will start to increase in December, especially across Dixie Alley.  

Keep in mind we are still in the midst of late severe weather season, where tornadoes are still a possibility in regular tornado alley, but become more likely in the southeast's Dixie Alley.  

DAY BY DAY? - Now that we have the general idea of a wetter upcoming month, we can now have a start to have a glimpse for what's to come through the next 16-days.

The GFS and the European models both show multiple chances of Arctic air reaching the U.S for at least early December.  Some of the climate models have shown multiple plunges of cold air around mid to late December.
BUT... - Do not get too excited based off of one or two runs of the GFS or European.  Those models are known for high inaccuracy past ten days (the land of voodoo).  For example, the 12Z run of the GFS today showed potential for a wintery mix for the South-central U.S on December 9.  The 18Z run now shows nothing but possibility for more cold air to come through the region, but we still stay dry.  

If something looks out of the ordinary coming off of global models, I will assure you that people all across social media will be making a buzz about it.  If something like that happens, usually wait a few days or so for the next several runs to see any consistency.  Additionally, do note that there is really no skill in creating a specific forecast past ten days as model consistency is very rare at that point.  

One way or another, the overall pattern for December gives us all something to watch for, regardless of where you are in the United States.  It looks to be more of an active month to close out 2017 as we look ahead as to what's to come in 2018.  

Expect the next regularly scheduled blog update and the Texas Weather Discussion Video Monday morning @ 7 AM CDT.

Have a great rest of the weekend.

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