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

Wednesday, November 12, 2014

Looking for that first snow day in central KY

Update: Friday 14-November-2014

The storm coming up for Monday morning still looks very similar in the model data to the last several days of runs.  Today's GFS run continues to hammer central Kentucky with several hours of snowfall early Monday.  Take a look:


The change in the forecast is that the northern stream system that looked to maybe bring some snow Saturday is now being forecast to stay mostly north of Kentucky.  So, aside from some flurries I don't expect any accumulation on Saturday at this point.  The southern branch system is still on track for a Monday arrival and the models are still hinting at a deformation band of snow to set up just south of the Ohio River.  The Lexington area could see a few inches of accumulation from this if the surface temperatures are near the freezing mark Monday morning.  The higher elevations of eastern Kentucky could also see a nice snowfall.

I expect that headlines will be coming this weekend and we might see the first Advisory or Watch of the season issued by the fine folks at the National Weather Service as early as tomorrow.  A day out of school is a real possibility for many on Monday.

This will be my final blog update.  You can catch me on Facebook or Twitter @WXinKY for daily updates.  Have a great weekend.

-Shawn

Previous discussion:

Good Wednesday morning.  Hope you all enjoyed Veterans Day.  The weather this week has been delightful in the Bluegrass but that is changing today as temperatures have fallen significantly behind a frontal passage late last night. We are now going into a period of more winter-like weather that will carry us through the weekend.

The big question on the minds of kids and teachers alike right now is:  when will there be a snow day?!

Well, it is impossible to say.  But...Monday November 17th is trying to emerge as a possible winner for that "first snow day" award.

I've been tracking this storm for a few days and haven't really said a whole lot about it because, to be honest, the models have struggled lately.  But we are in that 3-4 day window now where it's time to start looking at this more in depth.  The GFS and ECMWF models are starting to agree just a tad on how this is going to play out.  I hope that with the 12:00UTC runs today they will agree even more on a solution.

The idea here is that on Saturday we could have a system streaking in from the northwest.  This will bring snow to the air but probably will not accumulate much in our neck of the woods.  As that's happening, a separate system will organize to our south and lift northward.  This system will strike on Sunday night.  Southern stream systems are really hard to forecast and the computer models do not have a lot of success with them.  But, IF this system organizes as it's show right now and IF there is enough cold air at the surface we will get a snow day for many counties on Monday.  Keep in mind that there are a lot of ifs in that equation.

The ECMWF model shows the freezing line hanging out directly over us...which is usually the case for Kentucky and that's why it's so hard to predict snow around here.   Geographically, we're just always on the fence.  I will keep watching of course.  And I'll leave you with the current ECMWF run valid Monday early morning:

Temps:

Precip:


There is a chance!


-Shawn

Thursday, October 23, 2014

Halloween Forecast for Central Kentucky

UPDATE 30-October-2014:

We've been tracking a storm system for over a week now that threatens to bring the first blast of winter to central Kentucky this weekend.  It appears that things are coming together just as predicted.  A major blast of cold air is coming and temperatures will fall to the 20s by Sunday morning.  Ahead of this, rain will change to snow by Saturday morning and could possibly dust a few cars and trees and Halloween decorations before it's done, especially along and east of I-75.  This will be my final update on this storm.  Get ready because it's about to get COLD!!  I'll leave you with the latest forecast discussion from the fine folks at NWS Louisville:

Latest GFS, NAM, and ECMWF are in pretty good agreement showing an
deep upper low diving SSE across the eastern OH Valley Friday night.
The GFE 18z ensembles showed the trough aloft being 3 to 4 standard
deviations below normal which is significant. With this system will
come cold air advection and dynamic cooling aloft. The model-
indicated pattern suggests possible development of a winter-like
deformation band within a tight isotach (lines of constant wind
speed) gradient in the left exit region of a 300 mb jet streak
diving south over the lower OH Valley. In these types of patterns, a
definitive mesoscale band of wintry precipitation normally occurs
assuming temperatures within the moist layer and at the surface are
sufficiently cold. In this system, the models suggest all this to
occur, which would suggest a band of snow over the eastern half of
the forecast area, especially east central KY late Friday night.
Model soundings show moisture extending up to between 500 and 600
mb, and cold enough in the moist layer for ice crystal formation
which would stay as mostly snow as it fell to the ground.

If this verifies, then scattered rain showers during the day Friday
likely would diminish or end in the evening, with a band of some
snow developing late at night which would move quickly southeast and
end by Saturday morning with up to an inch or so of snow possible
mainly across the Bluegrass, and especially on grassy areas.



UPDATE 27-October-2014:

The Euro model has sort of taken on the look of the GFS that I posted last week (below).  Imagine that.  Low pressure near the Great Lakes may drive a sort of "back door" cold front through here Friday night and into Saturday morning with much colder air arriving.  Both models take us below freezing Halloween night and into the first morning of November.  The question is, will any precipitation accompany this front?  It's still a little early to tell, but there remains a small chance that we could see a few snowflakes early this coming weekend, especially in eastern Kentucky.  

Here are the temps and precip predicted by the European model.  Notice the freezing line dropping into Kentucky by 8:00PM Halloween and then the precip shield which is depicted as getting really close to the Bluegrass that night.  Interesting...  just something to watch.















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