Thursday, October 23, 2014

Halloween Forecast for Central Kentucky

As we wait to see how El Nino is going to shape up for winter and what impact it may have on our temperatures and snowfall, we are currently soaking up the final nice days of the year in Kentucky.  Sunshine has returned after a week or two of ICKY weather and by the weekend we’ll see the 70s for highs come back for several days…well into next week.  Ahhh…  enjoy it!!  The leaves are peaking at this time as well, which will make for some absolutely delightful days to finish out October.

Speaking of finishing out October…the last day of the month, Halloween, falls on a Friday this year and that means big plans for trick-or-treat and parties/social events/etc.  What’s the weather going to look like?  Will it look great like a piece of hot pumpkin pie with whipped topping or will it look scary like a headless horseman carrying a bloody sword?

The models are hinting at a cold front that would sweep through mid to late week and that would usher in much colder air for the weekend.  At the same time that is going on, a Nor’easter will move up the east coast.  This *may* throw enough moisture back into parts of KY to interact with the cold air advection sweeping in behind the front and allow a few snowflakes Halloween night.  The weather for that weekend does indeed look active and there will be a LOT of eyes on this forecast in coming days.  We are over a week out and there is lots of uncertainty right now.  I will update later today with the new 12Z data and show you the current thinking on the situation.

Now go outside and enjoy this nice weather!

UPDATE: Here's today's 12Z GFS run.  You can see the low wrapped up in the northeast with strong cold air advection bringing the CHILL into Kentucky Halloween night.  It's conceivable that we *could* possibly see a few flakes.  As always, I'll fine tune this forecast in a few days.





Shawn

Wednesday, September 17, 2014

Winter 2014-2015 in Kentucky

Update 24-September-2014:

Just for kicks, let's look at the official government projection for the upcoming winter.  Specifically, the 3-month period running December to February which is meteorological winter.  The Climate Prediction Center issues these seasonal forecasts and updates them generally during the third week of each month.  The brand new outlooks are showing something interesting.  

First of all, they expect temperatures in the Ohio Valley to be average.  There is no signal for warm or cold temperatures, compared to average.  They are calling for normal temperatures for this winter period.


What about precipitation?  I.e., snow chances?  Well, they are predicting the Ohio Valley to be drier than average.  So, less rain and less snow than we'd typically get in a winter.  Take a look:




Now, of course, I do not agree with their assessment.  It's worth noting that I've been watching these outlooks for many years and they rarely have ever panned out to be correct.  But, it IS the official government outlook for the upcoming winter after all, and I thought I'd post it for your viewing pleasure.

I am expecting quite the opposite, with cold temperatures and frequent precipitation, especially for Indiana, Ohio, Illinois, and Kentucky.

One of the big keys to the forecast this year will be the ENSO cycle.  The El Nino/Southern Oscillation refers to the temperatures of ocean water out in the pacific and the flows and patterns that govern it.  This is the breeding ground for storm systems that eventually make their way into the United States, and so by watching this area closely we can get a good idea of how our weather here may be affected.

Let's take a look at history:

You can see that last year we were sort of in a neutral phase.  The end of 2012 had a weak El Nino, while the beginning of 2013 went into weak La Nina conditions, and basically the 2013-2014 period was neutral to ever so slightly La Nina.  These neutral conditions meant that the ENSO cycle didn't play much of a part in our weather here, and other variables were allowed to take over.

Here's the current predition for the upcoming months:



On the chart, 0.0 is neutral.  Anything 0.5 or greater is considered El Nino.  Anything -0.5 or less is considered La Nina.  You can see that most computer models are predicting us to see a weak El Nino return this winter, with some models getting toward a moderate El Nino.

If this does occur, it will likely influence our winter weather here in the Ohio Valley and my forecast for a cold, snowy, harsh winter may be a bust.  In my experience, El Nino brings mild winters to Kentucky.  Look at the strong El Nino of the late 1990s on the above chart.  That period of time had 70s around Christmas and nice weather all winter for a couple of winters in a row!

Having said all this, the models have been predicting El Nino to begin all year, and as of late September we are still in neutral conditions.  There are some who believe it'll never pan out...and I'm one of them.  I think we'll stay close to neutral going into winter.  It's something to definitely keep an eye on.

Autumn just began and obviously winter is anyone's guess.  There is very little skill in forecasting months in advance.  For now, I'm relying on history and also current conditions and two week model forecasts and I'm sticking to my guns...  this winter is going to be harsh.

More info coming later...  

Previous discussion below.


-Shawn



Astronomical Autumn begins on Monday, but it’s also time to start thinking about Winter.  After the record setting winter we had last year I started to dig into history and see where it stacked up on the all time list.  And something I noticed was that our ferocious winters typically came in twos or threes in history.  There’s one bit of evidence that points toward another horrendous winter this year. 

Another thing I’ll be doing soon is looking at seasonal models, watching current trends, looking at pattern tendency in the medium range models, and a few other things.  Generally speaking, the eastern half of the nation has been in a trough for a couple of years now.  This has led to two cool summers in a row, and a terrible winter last year as well.  There is no evidence pointing toward this pattern breaking up any time soon.

I’m expecting a cold, snowy, harsh winter again this year.  In the coming weeks I’ll be adding more charts and details as we begin to track the pattern and make a forecast for Winter 2014-2015.  Check back every so often.



-Shawn

Tuesday, July 8, 2014

Possible Wind Damage Today

A cold front to our NW brought a round of thunderstorms for many in central Kentucky last night.  This was the "appetizer" if you will.  Today, the main course will be served as the front pushes into the state.

The sun is now shining in the Bluegrass of Kentucky as of 9:30EDT and instability is on the way up.  Outflow boundaries from last night's storms have left areas to generate new storms upon.  Moisture is there and forcing will be there later today as the front approaches.  This should set the stage for another round of storms that will be more widespread across Kentucky this evening.

The tornado threat will be higher to our NE across parts of PA but it will still be non-zero across KY as well.  The main threat though is wind damage here and SPC has included most of KY in the high-end Slight Risk for wind damage today.

Stay weather aware!




-Shawn

Monday, June 2, 2014

Derecho? Maybe! Severe Weather Outbreak Possible

Good morning everyone, and welcome to Summer!  June 1st was not only the beginning of hurricane season but also the beginning of meteorological Summer!

It's been a while since I made time for a blog post but I think it's time to discuss what's going on in the world of Kentucky weather.  First of all, how about this humidity?!  Crazy isn't it?  Typically we get into the middle part of Summer before it really gets sticky.  This year however we've already gone straight to 70°F dewpoint temps before May even came to an end.  I admit, I did not expect that after the Winter we just came from.  My Spring outlook worked out pretty good in Kentucky overall though with a calm severe weather season that picked up a little as time moved forward.  But now we're staring straight at Summer and the weather is becoming very active.

For this upcoming week what we've got to keep an eye on is a possible outbreak of severe weather that could stretch from South Dakota all the way into the Appalachian mountains by week's end.  The models are indicating this to occur as a large MCS (mesoscale convective system) that would race eastward and leave large amounts of damage in it's wake, possibly even as a Derecho.  However, the exact storm mode is not known just yet.  Here's how the WRF model sees things as of the wee hours of the morning on Wednesday:



Even though I'm not sure of what mode this storm activity will take on, I am pretty confident in saying that there will be an outbreak of storms across the nation's midsection this week and it will likely end up leaving quite a bit of damage behind.  Kentucky may get in on this action Wednesday, as the MCS strikes us from the northwest.  Here is the current convective outlook from the Storm Prediction Center valid on Wednesday the 4th of June:



So keep in mind if you will be outdoors this week that severe weather is a good possibility and plan accordingly.  As of right now, I believe that wind damage will be widespread and will be the main threat, especially in areas to our northwest.  However, tornadoes and some hail will also be possible.  As always, stay alert and keep the NOAA weather radios on.  You can follow me on Twitter @WXinKY



-Shawn

Wednesday, May 7, 2014

April Showers Bring May Flowers

The lack of severe weather has been pretty astonishing this Spring.  But it wasn’t totally unexpected.  And though we did have one outbreak with fatalities last week, people are thankful that it hasn’t been a typical season.

 

We do have a slow moving system headed toward the Ohio Valley this weekend that will usher in a pattern change.  Say bye bye to the 80s for a while as thunderstorms and rain become common Friday-Tuesday, followed by cooler weather for next week.

 

Right now it appears that the parent low will scoot off into Canada and take the dynamics with it, so severe weather looks unlikely in Kentucky this weekend.  Plenty of rain for the flowers and trees coming up though.

 

I know I haven’t written much lately, but there hasn’t really been much to write about!  The weather this entire year has been benign of t-storms so far.  Business may still pick up later in May and into early Summer.

 

Take Care,

 

Shawn