12/29 - 7pm - Snow Update, Newspaper Article Tomorrow

The warm air looks to be winning out on the computer models for the system coming through tomorrow and Thursday. Rain should start tomorrow evening and transition to snow showers by Thursday evening. I think we're in for a half inch on the ground by the time Friday morning rolls around, but we could see up to an inch if temperatures drop faster than expected. The precipitation graph on the left was generated from the 18z GFS using BUFKIT, and it shows well how the rain (green bars) switches over to snow (gray bars) on Thursday evening. We may have some road problems on New Year's Eve as the wet roads freeze, so be careful out there!

If you live in Southeast Louisville, particularly the suburbs of Jeffersontown, Middletown, Fern Creek, and Hikes Point, open up the Neighborhoods section of the Courier-Journal tomorrow. They're running a follow-up article on the one they published about my website back in January. This follow-up article may also run in an abbreviated format in other Neighborhoods sections around East Louisville, so be sure to check your paper even if you don't live in the suburbs I mentioned. I'll be sure to post a link to the online version once it becomes available on my website, blog, and Twitter/Facebook. Thanks again to the Courier-Journal for writing these articles!

12/28 - 2pm - A Difficult Snow Forecast

Hope that everyone in Louisville enjoyed the dusting of snow that came last night. Here's a little 6-inch snowman I was able to put together as the snow was falling:


The New Year's snow chance is still on the maps. The computer models are having difficulties trying to hammer down a track for this storm, but I think we may have a shot at 1-4" of snow. The precipitation amounts are different on all of the models right now, so that's about the best estimate I can offer at this point.

The 12z NAM run is a little warm for us in Louisville, but the track of the low is sufficient to generate a good snow around here if temperatures cooperate. There's a coastal low that may form as well, and that could impact how much precipitation we receive and the storm track.

The 12z GFS run is similar to the NAM, but the low is further east by a few miles. This helps to lower our temperatures a little bit, so we wouldn't have as much rain before the precipitation changes to snow. That coastal low shows up on the GFS as well.

The 12z ECMWF (Euro) is difficult to read because of the large time difference between frames this many days out, but you can see that it favors the low pushing further east and pushing off the coast.

Here's what the NWS in Louisville says about this system:

SO...WHAT KIND OF PRECIPITATION WILL IT BE? THAT IS A DIFFICULT QUESTION TO ANSWER AT THIS TIME. TAKING OUR BEST SHOT...FOR WEDNESDAY THROUGH THURSDAY IT LOOKS LIKE THE NORTHERN SECTIONS OF THE AREA /SOUTHERN INDIANA AND NORTHERN KENTUCKY/ COULD SEE PRIMARILY SNOW WITH SOME RAIN MIXING IN DURING THE WARMEST AFTERNOON HOURS. CENTRAL PORTIONS LOOK TO BE A RAIN/SNOW MIX...AND SOUTHERN KENTUCKY SHOULD SEE MOSTLY RAIN WITH SOME SNOW MIXED IN WEDNESDAY NIGHT.

....

CANNOT SAY WITH CONFIDENCE YET JUST HOW MUCH SNOW WILL FALL...BUT IT DOES LOOK LIKE ACCUMULATING SNOWS WILL BE POSSIBLE LATER THIS WEEK JUST ABOUT EVERYWHERE. STAY TUNED.

From what I've seen, I think we may start with a period of light rain on Wednesday evening as the low approaches the area. Cooler temperatures should filter in and change everything to snow by late Thursday as the low moves to our east. How much snow falls on Thursday and Friday will be determined by the track of the low as it moves northward. If this storm rides up the west of the Appalachians, expect more snow than if the storm moves out to sea or if the coastal low overpowers it. I still say this will be a widespread light snow event, but there's still quite a bit of wiggle room for precipitation amounts and storm track at this point.

12/26 - 2:15pm - Still Watching for New Year's Snow

I hope that everyone had a wonderful Christmas yesterday and that the lack of snow around here didn't get anyone down in the dumps.

As we shift our focus to the new year, we may also have to shift our focus to a chance of snow in Louisville. Over the past week, the long-range GFS computer model has been showing a storm tracking through the Gulf states. While the moisture and precipitation with this storm has been suppressed to the south on most model runs, I'm starting to see the (this) season-typical northward trend in the track of this storm.

The Euro model has this storm tracking from the Gulf Coast to Virginia, which would be a fairly decent track for us to have snow in Kentuckiana if enough moisture accompanies the storm. My worry is that there may not be enough cold air in place to counter the warm air being brought north by the storm, and this may negatively affect our snow chances. It's still too early to tell if this will indeed be a problem, but at least the storm track is good at this point.

Basically, the graphic from the last post with the potential storm tracks of this system still applies. There are a lot of factors like phasing, the polar vortex, and model-to-model differences that need time to get hammered out. I'd say this is our best chance for snow so far this season, and I think this is certainly a system that bears watching.

12/23 - 3pm - Plains Blizzard, Snow in Louisville?

The big storm getting ready to spread rain around Louisville on Christmas Eve will slam into the Plains as a major snowstorm with blizzard conditions possible. Ice will be a big issue out there as well, especially in places nearer to the area of low pressure like Omaha and Lincoln, Nebraska. Some places could end up with more than 20" of snow, especially in areas north of Nebraska. Winter Storm warnings and watches have been issued as the storm cranks up today.

Rain should begin in Louisville early tomorrow and taper off as we go through Christmas Day. I know it's a bummer to have rain around Christmas like this, but at least we won't have any travel problems around the region.

The next chance of snow could come just before the new year. A system on the long-range GFS computer model is still showing some potential for us, even though we are not forecast to get any snow as of now. The storm track at the moment is very far south of us, but the GFS model has been notorious for shifting suppressed storms northward a few days before the actual event. This happened with the current storm. As you may remember, the current Plains storm was supposed to track south of us and give us snow, but the northward trend took over and sent the storm west of the Mississippi River. My only concern with the potential New Year's storm is that we may have a surge of warm air from the south, which could limit our snow chances. It's really far out to be making any sort of detailed prediction at this point, but I think this storm will make a snowy impact on parts of the region.

12/21 - 12:45pm - Christmas Rain, New Year's Snow?

Unless there are any major changes in the computer models in the next 24 hours, I think we're in for some potentially heavy rain on Christmas Eve in Louisville. The rain should taper off on Christmas Day, ending as a few snow showers or flurries if we get lucky. There could even be some thunder on Christmas Eve if convection gets going around here. This same storm will give places like Omaha and Lincoln, Nebraska a nasty winter storm with dangerous amounts of ice and snow. I know everyone in Louisville wanted a white Christmas, but quite honestly it's better to have the rain then have another ice storm on our hands during the holidays.

The reason we're missing the snow is because of a lack of high pressure support in Canada. Earlier computer models were forecasting a strong high pressure "block" that would drive this storm southward, but later models have since weakened the effect of this.

On to the next storm... The long range GFS has been consistently displaying some sort of potential New Year's snowstorm for the region. There may even be two storms around this period to watch based on the current runs, so we'll have to watch what happens. It's extremely early to be calling for snow or rain for this time period, but I do believe that the pattern will be better suited for snow here next week. So we have the storms, but now we just need some high pressure in Canada/North US to keep them south of us. Today is only the first day of winter, so don't give up on snow yet!

12/19 - 12:15pm - Update on Snow Chances

Snow did not fall in the Louisville area this morning as forecast because of warmer than expected temperatures both near the surface and just a couple thousand feet aloft. The short-range RUC model runs have been indicating a slow cool down of temperatures over the next few hours, so rain should change to snow later this afternoon. We may pick up a half inch on the grass tonight with any lingering snow showers.

The Christmas Eve snowstorm is having a very difficult time on the computer models right now. The most current 12z GFS run has mostly rain for us because the low cuts up to Chicago, but the previous few runs had been indicating a track just south of Louisville that would give us rain to snow or all snow. With solutions varying wildly from run to run, I don't think we'll have a track narrowed down until the start of next week. I will say that the pattern favors the southern track with snow for us because of high pressure in Canada suppressing any northward movement of the storm. The storm should be following this rule on the models, but unfortunately this is not happening with many of them. At least we still have a chance for snow! Here are some potential storm tracks that the models have been hinting at for the past couple days:

12/17 - 2:30pm - Weather Talk, Snow on Traffic Lights

I talked to a group of kindergarten and pre-k students today at Tully Elementary School in Louisville about weather today. I covered storm chasing, weather safety, snow, ice, and even demonstrated how a NOAA weather radio works. Best of all, each kid walked out of there with a severe weather safety coloring book and brochure, courtesy of the National Weather Service office in Louisville. Here are some pictures:




It was a lot of fun and I hope they enjoyed watching some of the video I brought in, as well as the talk itself.

Since it looks like we may get a couple inches of snow this weekend, I wanted to pass along an article I found about snow covering LED traffic lights, which Louisville has quite a number of. You can discern if a traffic light is LED or not by looking for a pattern of small dots on each light.

MILWAUKEE – Cities around the country that have installed energy-efficient traffic lights are discovering a hazardous downside: The bulbs don't burn hot enough to melt snow and can become crusted over in a storm — a problem blamed for dozens of accidents and at least one death.

[Read more from Yahoo! News]