Tuesday, December 22, 2015

Where Does Winter Go From Here?

I’ve been using the winters of 97-98 and 98-99 as analogs to compare to as one piece to this puzzle. My winter outlook is spot on so far and I’m happy with how it’s going. So where do we go from here?  If you look at January-March 1998, you see only a few transient cold shots, otherwise conditions were mild to warm the entire period with some 70s in February and some 80s in March!  El Nino certainly keeps things toasty in the eastern U.S.  Could we see the same type of warmth carry us through early 2016?  Looking at November-February 1998-1999 you see more of the same.  Lots of highs in the 60s with quite a few highs in the 70s throughout the period.  Sure, there are brief cold snaps…but overall the winters were VERY mild during those El Nino years.  Just something to think about as we head toward January.  There is a lot of chatter in the meteorological community about a turn to cold and snowy weather in the coming months.  I personally am not sold on that idea just yet.  I am beginning to think more strongly that the last 3-5 years have been our cold phase and now we are going to move toward a warm phase.

Monday, October 12, 2015

Winter Outlook for Kentucky 2015-2016

Updated 29-October-2015

After looking over the latest data on the ENSO cycle, the MJO, NAO, PNA teleconnections, and throwing in a little bit of experience and gut feeling, I have made a few edits to the winter outlook for Kentucky.  I also added a tidbit about possibilities for spring 2016.  This will be the final revision.

Updated outlook:

I can’t believe it but 2015 is winding down now.  We are into the last quarter of the year.  The deciduous trees are beginning to change colors and drop their leaves.  The air is getting cooler.  The sun’s angle is waning.  The nights are getting longer.  We're turning the clocks back this weekend.  And with that, those of us who dwell in the mid latitudes of the northern hemisphere are turning our minds toward winter.

That begs the question; what will winter 2015-2016 be like in Kentucky?  Are we in for another harsh one with sub-zero January cold and frequent snowfall?  Or is this winter going to begin a pattern of milder winters that will carry us for a while?

I suppose this would be a great place to insert my disclaimer.  Obviously nobody except God himself knows for a fact what is coming, and even with all the technology we have today and the supercomputer power we have to run our models on, seasonal forecasting has still proven to be a very difficult task with little accuracy.  It is virtually impossible to predict a white Christmas, for example, from this stage in the autumn season.  Having said that, we can look at the global pattern, history, and computer data and come up with at least a ballpark idea of what to expect in the December-February time frame.  And that's the point of a winter outlook... to give folks an idea of the general type of winter we may be in store for.

Here is how I see the winter of 2015-2016 to play out in fairly simple terms: it’ll be more variable this season with more swings in temperatures and a lesser number of snow events but a higher possibility of a “big one” compared to average.  In other words, I do not think we will see as much snow as we've seen in the past few winters, but due to the wild swings in the pattern what snow we do see may come in the form of larger storms.  Overall, I expect temperatures to be milder than what we've seen in recent winters.

Now, to expand on those thoughts a little more for those of you who are still interested…

El Nino is going to be a big deal this winter.  We haven’t dealt with El Nino in the past three winters.  In fact, ENSO conditions have been fairly neutral going into at least the past two winters.  So the temperature of the Pacific Ocean water hasn’t really come into play regarding our winter weather here in Kentucky in recent years.  Other factors such as blocking patterns in the higher latitudes and the persistence of a mean trough in the eastern U.S. were responsible for the cold and snowy weather we saw last winter and the winter before that also.  That is all going to change for this year.  El Nino conditions are already present and are already strong and are predicted to get a little stronger over the next month or two before peaking.  In fact, a look at the latest model predictions shows that an event peaking above 2.5°C from average is very possible.  



That hasn’t happened since the late 1990s.  So what’s going on out in the Pacific waters is going to be a huge factor in the winter weather here in Kentucky this year.  This is true because our weather comes from the west.  The Pacific is sort of the “breeding ground” of our storm systems.  Warmer water generates more action (hence all the hurricanes nearly striking Hawaii this year and hurricane Patricia which set the record for hurricane strength in the eastern Pacific).  As a result, you normally will see wetter than average conditions east of this area which includes the southern tier of the United States during a strong El Nino.  I think there will be storm systems coming out of the southern part of the country more frequently this year, and it’s those “southern runners” that can result in big snow storms for Kentucky.  That’s why I said I feel like the chances of a “big one” are higher this season compared to average.

However, to make a big snow storm you need another ingredient: cold air.  One of the things that El Nino tends to do (and we saw this in the late 1990s) is that it can create a pattern where temperatures are mild across much of the U.S.  When I was a meteorology student at WKU I remember walking to classes in a t-shirt all the way through final exams before Christmas.  After the holiday break we had some mild weather as well.  So this is why I said that I feel like snowfall will be less frequent this year than the past two years.  We will likely see quite a few cold rain events this winter.  It’s going to take perfect timing of a cold air mass being in place while a strong weather system moves up from the south to make the magic happen.  Hence, less chance for snow events, but a bigger chance for a BIG snow event IF one does happen.

I think the theme of this winter overall is going to be summed up in one word: variable.  Whereas the winters of the last several years were just flat out cold (record setting cold at times), I think this winter will be more variable with periods of cold, but periods of mild weather as well.  Having said that, I think the mild weather will win out and average temperatures will be at or above normal.  Keep in mind that the term "mild winter" doesn't mean that it never gets cold.  It just means that compared to average, it's warmer than normal.  In terms of sky conditions I expect sunny days to mix more often with rainy ones.  The occasional snow event will be with us, and as already mentioned the chance of a big one if things come together just right once or twice.  But overall I think we’ll get a good mix of weather this season.  I think this will happen due to the strong influence of El Nino lasting throughout the winter, and the smaller influences of teleconnections like the PNA, NAO, etc. aligning from time to time to alter our weather for a week or two at a time.  If we can get the PNA to go strongly positive, the NAO to go strongly negative at the same time, and this warm El Nino water to kick out some weather systems all simultaneously…look out!  The superstorm of February 1998 comes to mind.  But it will all have to come together perfectly to make that happen.  Time will tell if we’ll see that or not.  For now, enjoy this warm weather and lower energy bills that are coming over the next several weeks courtesy of our buddy El Nino.  In fact, the first week of November looks to be a very warm one with some record high temperatures possibly in jeopardy.

So to summarize:

Temperatures – Average to slightly above average overall, occasional cold snaps, but overall a milder winter than what we've seen in recent years.


Precipitation – Average to slightly above average with more rain and the possibility of a couple of severe thunderstorm outbreaks.  Snow will be less frequent, but there will be the possibility of a big snow storm at some point if timing aligns just right.

Keep in mind that severe weather can and sometimes does occur in winter here in KY, particularly in these types of patterns.  And that will also be something that we'll have to watch closely from March-May 2016 because many times we do see a large increase in severe weather outbreaks following these El Nino years.

So there you have it.  I have often said that harsh winters strike KY every other decade.  The 1950s, 70s, and 90s all featured terrible winters, and so I expected the '10s to give us some harsh ones and the 2012-2015 period proved to do just that.  I think this winter our utility bills will be a little lower than what we've been seeing.




-Shawn

Thursday, September 10, 2015

More Frequent Updates are on Facebook

Due to the surge in social media and how people prefer Facebook, Twitter, etc…I haven’t been updating the blog often.  You can find more frequent updates on Facebook at:

 

https://www.facebook.com/centralkentuckyweather?pnref=lhc

 

Or on Twitter at:

 

@LburgWXandINFO

 

 

Thanks!

 

 

 

Shawn

 

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.

Thursday, April 9, 2015

Switching Gears... Severe T-storm Season is Here!

Hello everybody.  Like I mentioned in the last post back in February, this blog has been neglected this season.  Seems that social media is really the way things are going.  Everyone seems to be connected to Facebook and Twitter and are checking those news feeds daily anyhow, so they prefer to see weather updates there instead of logging onto a blog.

Having said that, I want to do a quick update here with some thoughts about tonight.  April has brought almost 9" of rain to Lawrenceburg and surrounding areas which is double what we should get in the entire month.  There is a lot more rain coming both today and over the next 7-10 days as well so this may go down as the wettest April ever.  When you consider that March gave us over 6" of rain and 16" of snow, it is just astonishing.  So please keep an eye out for flash flooding and do not drive into areas where water covers the road.  Moving water can and will drag your vehicle downstream.

SPC is focusing on areas just to our west for severe weather concentration today:



This doesn't mean Kentucky is out of the woods yet.  The latest HRRR model shows more storms entering central Kentucky by early afternoon:



It then shows a powerful squall line developing along the front itself and sweeping in overnight:



Tornadoes are a threat with this activity, but the best chance of tornadoes will stay just northwest of Kentucky today I think.  That's where the best dynamics for rotation will exist.  Large hail will be the biggest threat for Kentuckians.  The freezing level is at around 11,000 ft. and there isn't much of a cap showing up in the sounding this morning so the storms will go big fast and drop hail.  Wind damage is a secondary threat today.  In addition, with the very juicy airmass we've got in place, lightning has been incredible with these storms and some houses and structures are being struck.  Cloud to ground lightning is a killer so when you hear thunder, go inside!  These storms are dangerous this week.

Once the front sweeps through tomorrow, the weekend looks really great.  More heavy rain looks to return next week, so enjoy the weekend!


-Shawn

Wednesday, February 18, 2015

Winter Storm Season is Here!

Good morning.  This blog has been neglected this season, I will admit.  I've been focused on Facebook and Twitter updates, since social media is all the rage now days.  People seem to prefer that method.  You can follow me on FB (Shawn Crowe) or look me up on Twitter @LburgWXandINFO

Now, as far as this week goes....WOW.  Lawrenceburg received 9" of snow Monday, about 3" today, and could see another 1-2" early Saturday morning.  This, in addition to record setting temperatures expected tonight and tomorrow night and wind chill values that could drop as low as -30°F!  Winter had been slow during December and January, but February is making up for it.

Over the next 48 hours be sure to check on loved ones...make sure everybody has electricity and heat.  And drip a faucet at night to prevent pipes from freezing.  Power outages are a possibility due to the huge demand on the grid that utility companies will see this week...so prepare for that as well.  This is dangerous weather.  I've already seen 2 fatalities blamed on it in Kentucky this week so far.

Looking ahead...we should see plain old rain this weekend with warmer temps...but by the middle of next week there is a signal that the cold and snow may return.  Winter isn't over yet by a long shot.

I am going to be interested to see how the Kentucky River basin handles this 12-15" of snow melting under 1-2" of rain this weekend.  In the past, a scenario like this has caused flooding issues.  If you live on the river basin, you might want to keep an eye on that.


-Shawn