Thursday, July 26, 2012

Severe Weather in Kentucky Tonight


The 105°F heat index readings are going away today.  This weekend should be very normal for this time of year with beautiful summer weather.  But the transition from miserable to normal isn’t going to happen easily.  A round of severe weather is going to explode today across much of the eastern half of the nation, primarily in the Ohio Valley and into New England.

We have just about all the ingredients to make the cake that we need.  Instability is VERY high (up to 4,000 joules per kilogram!)  The surface is being heated by the sun uninhibited by clouds.  Temperatures are in the 90s to near 100 by afternoon, creating strong lapse rates.  There is decent wind shear of 40-50 knots.  We’ve got lift in the form of a cold front approaching the area.  Dewpoints are running in the 70s so water vapor content for fuel is plentiful.  Basically, this is a prime recipe for severe thunderstorms.

Here is the current wind damage outlook from the Storm Prediction Center:


As you can see, northern sections of Kentucky, basically north of I-64, are in the 30% range.  Cincinnati is in the hatched area, where “significant” wind damage may occur.  Anyone inside the red zone on this chart needs to pay special attention to the weather today.

I think the timeframe we’re looking at is from about 17:00 (5pm) through midnight.   Many of the models are showing convection holding off here until well after dark.  The Hi-Res NAM doesn’t really get things going here until 2:00 tomorrow morning.  But I think that we’ll see a very active squall line threatening Kentucky before sunset tonight. 

In this setup, tornadoes are not a major threat to Kentucky.  Wind damage and flash flooding will be the biggest problems here.  Remember, the #1 killer in thunderstorms is WATER.  Floods kill more people annually than lightning or twisters.  If you see running water across a roadway, do not drive through it, even if you have a Jeep.  It’s tempting, I know.  But don’t do it.  Moving water has significant power.

Keep the NOAA weather radios on today and keep your eyes peeled.  We had storm fatalities in KY last week...let’s have zero this week.


-Shawn

Monday, July 9, 2012

Where is the Kentucky rain?

So when is it going to rain?  That’s the question on everyone’s mind now that Lawrenceburg finds itself firmly in drought conditions.  We saw 0.75” of rain last weekend, but since then we’ve received only a trace of rain, while Harrodsburg, Danville, Lexington, Winchester, and Georgetown have all seen soaking thunderstorms.  In a year that showed no seasonal signs of an impending drought, we are now in the midst of a fairly serious situation which has also been compounded by a record-setting heat wave.  So, what gives?  When is it our turn for some rain?

 

First of all, we can at least be thankful the heat wave is gone.  As of yesterday, July 8, 7 out of the last 11 days saw the air temperature reach 100-104 degrees.  To have this happen beginning in June is record setting in itself.  On Sunday the heat index reading in Lawrenceburg briefly touched 114 degrees.  To say that it’s been miserable lately would be an understatement.  Thankfully, a cold front is working through the state today, and the 100 degree air is gone and doesn’t look to return anytime soon.

 

As far as precipitation goes, I suppose we must be happy for our neighbors who all received good rains from the recent storms.  Every county in Kentucky can use the rain, and so whoever gets it is fortunate.  Going through the remainder of this week, it appears that Friday is our best shot at some rain here in Anderson County.  Stuck between a couple of ridges, we should find ourselves in a favorable environment to generate some rain here.  In fact, take a look at the most recent run of the GFS model.  It shows a bulls eye of 2.5” of rain centered right on the Lawrenceburg area this coming Friday.  We can only hope that this time around we’ll be in luck.

 

 

The current U.S. Drought Monitor has Lawrenceburg on the cusp of the D1 “Moderate Drought” area as of today, July 9.  The new outlook is issued on Thursday and I think with the recent rains, most of KY will remain the same as what we see now.

 

Looking at the rest of July, it appears that the heat ridge won’t build back in until the end of the month at soonest.  Our weather pattern should be a little cooler and wetter over the next 10-14 days and hopefully we can get a few instances of rain during that time.  Remember, we are statistically in the wettest time of the year here in central KY, so if we go into Fall abnormally dry we’re going to have problems.  Let’s hope for some rain to head our way before the heat of late July and August moves in.  I still believe that we do have a good chance at improving our drought conditions before summer is out.

 

 

-Shawn