Tuesday, June 9, 2015

2015 Summer Outlook for Kentucky

We're nine days into meteorological summer, but astronomical summer doesn't begin until 21st of June.  It's time to take a look at how summer might shape up for Kentucky this year.

First off, let me show you the federal government forecast for summer this year.  Here is their outlook for temperatures:



And here is their outlook for precipitation:



As you can see, they have Kentucky in the "EC" zone on both.  This stands for "equal chances" which means they expect an equal chance of above and below average conditions.  In other words, it should be about average here.  Temps and rainfall should be about normal for the time of year in Kentucky.  No extremes are expected.

Now, having said that, if you've followed me long enough you know that I don't put a lot of faith in these Climate Prediction Center outlooks.  I haven't seen a lot of accuracy in them over the years.  So, how do I think it's going to shape up in the Bluegrass State this summer?  Could they be on to something?

Well, one of the things I look at is history.  In prior years, what happened in summers that followed winters and springs similar to what we've just had?  This can often be a good clue.  I used this method to do a winter forecast for 2014-2015 and after a slow start, the cold weather hit hard in January and then the snow hit hard in February and March, as predicted.  So you can sometimes have good success using the "history repeats itself" method.

Another thing I look at is the overall mean pattern that we've been seeing.  If the eastern U.S. has been in a trof most of the time for several months, it's a good bet that pattern will be slow to break up.  Likewise if we've been in a ridge and/or have seen drought conditions, that will also be slow to break up.  Remember, drought breeds drought.  So I look at the average of the current pattern and take that into consideration.

You also need to look at global teleconnections such as the ENSO pattern and forecast and the various indices.  These don't affect Kentucky quite as much in summer as they do in winter, but they do have some influence.  We are currently seeing the El Nino phase in effect.  The last two summers we had neutral conditions where neither El Nino or La Nina were being seen.  This summer we've got warmer conditions in the eastern Pacific and that is expected to continue through summer.

Taking all these things into consideration here is what I expect for Kentucky this summer:

Temperatures - Mostly average.  I think we'll have more heat at times this summer than we've had the last two summers, but it will be short lived.  By that I mean that days in the mid-90s and higher will likely only come in groups of two or three in a row before cooling back off again.  This will likely be because of more frequent weather systems impacting the Ohio Valley.  Big warm ups ahead of a cold front may push temps really high for a day or two, then cool back off behind the front.  As a whole though, summer temps should average out about normal for Kentucky.

Precipitation - Above average.  Summer in Kentucky is typically somewhat dry with only about 10.5" of rainfall over the course of the entire season.  I think this summer will bring more frequent weather systems which will lead to above average rainfall.  Obviously this means that I do not expect drought conditions to plague Kentucky farmers this year.  I think we'll see plenty of rain to keep crops going and keep trees and lawns healthy.  Severe weather will be possible in July.  Insects are already swarming in higher than usual numbers so outdoor activity will require more bug spray as a result.  I'm not saying summer will be a wash out.  I'm just saying I feel there'll be more rain than we typically see.

So there you have it.  Overall, not a bad summer.  I personally hate hot and dry summers like we had in the late '00s so these cooler and wetter summers of the '10s have been a welcome occurrence to me.