Christmas Forecast for Kentucky

It is looking like Christmas this year is going to be pretty much par for the course.  With GFS and ECMWF both showing cold temperatures and no major storms in the area, the holiday doesn't look to be affected by nasty weather.  Save for the stray clipper that may streak in from the north with a light dusting of snow, I don't see any weather really coming our way for the 25th.  It looks to be seasonably cold with only a small chance of snow in the air.

The bigger story looks to be what happens between now and then.  After a mostly dry week this week and moderating temperatures, the weekend will turn very soggy.  Both major computer models are in step with one another showing a frontal zone setting up near the OH River this weekend.  Lots of Gulf moisture will spread northward and Kentucky will be in the prime area just south of the front to see the rainfall.  Areas of low pressure will develop along the front and move northeastward into Kentucky enhancing the rainfall throughout the weekend.  Right now it appears that we will stay on the warm side of the front, so all of the precipitation here should fall as rain.  However, just to our north a major snowstorm will be possible once again.  Some of the model data is showing 4-6" of rainfall, especially across western KY.  This axis of heaviest rainfall may set up farther east or west...it just depends on the exact position of the front.  Regardless, Kentucky is in for a very wet weekend and flooding may be the big weather story.  You can see the conveyor belt of the waves of rain coming northeastward toward Kentucky in the ECMWF model data from today:

In addition, this storm could end up becoming a travel nightmare for people looking to fly out of airports in the eastern U.S. to visit family for the holidays.  I expect that delays and cancelled flights will be a common occurrence this weekend and into early next week.

So the monster storm will come through just before Christmas, and then we go relatively calm and colder for Christmas, and then beyond that I expect winter to stay active for a little while longer.  It is not yet officially winter, so after the holidays I'll write a little bit about what January-March could hold for us this year.  I do think it's going to be interesting.

-Shawn

It's been a long time since Kentucky had an ice storm...

The GFS model is harping on another one this weekend.  The weather has turned very active this fall just as I expected.  From abnormal cold at times, to severe weather outbreaks, and snow/sleet...we've seen it all since October.  Here is how I see things playing out to end this first week of December:

Tonight the rain will start to push into Kentucky.  By tomorrow the rain may be heavy at times.  Guidance suggests that some counties could see a few inches of rain before it's all said and done.  This may create flooding issues.  The ground stays wet this time of year due to the low sun angle.  If you live near a creek or stream, or a low lying area that floods frequently, keep an eye on this!

Going into Friday the freezing line at the surface starts to move south of the Ohio River.  It will be a slow process...crossing into the Lexington area by evening.  With the freezing line obviously will come a changeover in precip. type.  I expect that rain in central KY will go over to a period of sleet during the afternoon.  There may also be some freezing rain also.  The precip. will end during the wee hours Saturday morning as snow.  The concerning part is the freezing rain possibility.  It doesn't take much ice to create a nightmare.  Here is the current forecast for ice accumulation of at least a tenth of an inch.  Notice that some areas in central Kentucky are as high as 80% chance!

This may also create an interesting situation with our schools since early Friday morning we'll just have plain rain, and the weather should deteriorate during the day while the kids are in school.  Going to be a tough call for administrators probably.

After this system departs on Saturday, the weather should go dry for a time.  This will allow those Christmas parades around central Kentucky to be squeezed in between weather systems.  However, it's going to be cold!  Some models are showing wind chill values in the 10-15°F range Saturday!  So if you're going off to see a parade take lots of clothes and blankets.

Sunday round two moves in.  This is the part that I'm most concerned about.  I just mentioned that arctic air will establish itself across Kentucky on Saturday.  With moisture once again moving into the area from the south this could be very bad news.  Warm air and precip. falling from above onto a surface that's been well below freezing could create a really bad situation with ice.  As the models are showing it right now, I expect that Sunday morning driving conditions will be very treacherous.  Keep in mind also that on Sunday, road crews are at a minimum.  Who wants to work on Sunday??  So I suggest keeping a close eye on this.  There could be lots of church cancellations on Sunday.  Let's hope that the ice doesn't accumulate to the point where we start to see tree damage and power outages.

The GFS model shows the situation well.  The blue line is the surface freezing line on this particular chart.  Notice the huge slug of precip. moving into the below freezing airmass.  Yuck.

So the bottom line is that we've got a huge mess coming up.  Rain, freezing rain, sleet, and snow are all possible at various times from Thursday-Sunday in the Bluegrass of Kentucky.  Buckle up and enjoy the ride!  And be safe out there...slow down and take your time.

-Shawn