1/31 - 11:15pm - Snowy to Our North, but Clear Here!

An Alberta Clipper system moving through the Lower Ohio Valley is spreading snow all the way down to I-40 in Tennessee this evening. Those of you in Starkville hoping we might get some flakes tonight will be disappointed to know that this system is running out of steam over the Jackson, TN area and will have trouble even generating any clouds for us this evening. Behind the cold front associated with this Clipper is some cooler air that will be working in overnight. This means we'll get down into the mid 20's by morning in the Golden Triangle and only reach into the lower 40's for highs tomorrow. Ouch! Luckily we'll have full sunshine as we end the workweek but a few showers are poised to move through the area for the early half of Saturday. Check out the video below for your detailed CampusConnect forecast!

1/29 - 5:45pm - Serious Severe Weather Concerns Tonight

Latest Severe Weather Updates

Tweets by @RyanHoke

A severe weather setup that we see normally in the springtime is about to unfold on this late January night across a large expanse of the Southeast. While not "unprecedented" or "once-in-a-lifetime", this outbreak is going to impact quite a few people and it's important that everyone have what they need to be prepared and safe. This post is mainly for folks in North Mississippi and West Tennessee, but you can figure out pretty well how you'll be affected if you're not in these areas by some of the maps and information below. Everyone needs to be aware of what's going on because this will be happening at a very bad time of night when even the night owls are asleep.

Fast Facts

A MODERATE Risk of severe weather has been issued by the Storm Prediction Center for the overnight hours in West Tennessee and most of North Mississippi. Tornadoes, damaging winds, and hail are all on the table for these areas as storms move through. Even though places like the Golden Triangle in Mississippi are just outside of the Moderate Risk area I would treat this as if you were in it because these storms are going to be very, very strong still as they move through this region. Please, please, please have a weather radio or smartphone app that's armed and ready to alert you if a Tornado Warning is issued for your location tonight. This will be hitting when most people are asleep so it's a very dangerous situation.

Timing - North MS and West TN

8pm - Midnight - Small chance for some isolated storms. These would carry a tornado, wind, and hail threat.

Midnight - 2am - Slightly better chance for isolated storms, small line of storms may try to form ahead of main line.

2am - 7am - Main line of severe thunderstorms moves through. This will affect everyone. Tornadoes, severe damaging winds, and hail are a good bet during this time.

Discussion

A line of storms stretches from the Great Lakes to Texas right now and will continue to move eastward through the evening. A few reports of severe weather have come in already from this but the main show will be overnight as this line of storms encounters a more rich environment for severe weather.

The main storm mode for tonight will be a squall line of storms with embedded rotation in portions of it (AKA what's termed a QLCS). Supercell storms will be possible ahead of the main line of storms too and could easily produce tornadoes if they develop. Tornadoes in QLCS lines of storms like the one we'll have tonight are more difficult to identify on radar since they're embedded within the line. While not as strong as supercell tornadoes, QLCS tornadoes can be strong and cause massive damage in the right environment.

While directional shear, which is needed to produce tornadoes, isn't very good for this event, the speed shear or tendency for winds to increase in speed with height will be very good. But, the directional shear may just be enough to cause problems. When you combine helicity (caused by shear) with instability in a formula you get what's called the Energy Helicity Index (EHI). This, in my mind, is a good determinant of tornado ingredients in an environment. The NAM model has increased levels of the EHI throughout West Tennessee and Mississippi tonight as this squall line is moving through so these QLCS tornadoes may have some kick to them if they develop. Not good news at all.


Also, since winds at 850 mb (about 5,000 feet) will be howling it will not take much for any part of this line of storms to pull these winds down to the surface and create straight-line wind damage. I wouldn't be surprised if folks affected by the worst of these winds thought they were hit by a tornado. I'm hearing the word Derecho being thrown around a bit with regard to how this system will develop tonight. That's certainly a possibility with this system but I think it's a relatively small chance.

One more thing to mention, and this is not the least important at all, is the fact that moisture and warm air continues to stream in from the south in advance of this system. When the dry line that's triggering these storms hits this richer air tonight you'll know. The whole line of storms should really begin to light up by then. Having air this warm and moist in January is never a good thing because Mother Nature intends to correct it in a violent way.

Follow me on Twitter and my Facebook page for the latest updates tonight!

12/2 - 4:15pm - A Needed Shot of Rain on the Way

A few brief showers scraped across northern portions of West Tennessee this morning as expected. The disturbance causing those morning showers has left behind some cloud cover across the region with peeks of sun here and there. More of the incredibly warm weather that we've seen for the past few days arrives tomorrow just in time for the Jackson Christmas Parade at 6:45pm. 75 still looks like a good bet for a high temperature during the afternoon as we start the workweek on Monday.

Much of the area is experiencing moderate drought conditions right now. Even though the growing season is pretty much over it is still important for rainfall to keep up so that we don't have an already-in-place drought come spring. The good news here is that we have a chance for a good soaking rain on Tuesday with over a half inch possible in most places. The front causing this rain will leave behind only slightly cooler temperatures in the 60's, which is still warmer than average for this time of year. The next round of rain on Friday and Saturday is the one to watch as it could bring much, much cooler weather to the area next weekend behind it.

Check out the video below from yesterday night's newscast on WBBJ for your full forecast!

11/26 - 2:15pm - Rainy Start to the Week, Severe to the Southwest

Had enough of the rain in Starkville this morning and afternoon? Just wait, there's more! An area of moist air ahead of a cold front that will move through tonight is inspiring the development of numerous showers and those will eventually lead to some thunderstorms late tonight. Some of the storms to our southwest could be severe but it's looking more and more like we won't have quite enough moisture and instability to get that kind of storm activity closer to the Golden Triangle. A Slight Risk of severe weather has been issued for areas west of I-55 due to the possibility for severe storms toward Jackson and Vicksburg. Once the cold front sweeps through tonight it'll leave us with cloudy skies for a good chunk of the day tomorrow before things clear out for Wednesday and Thursday.

The weekend will feature some clouds and possibly a shower here and there but overall we'll be seeing one warm end to the month of November as temperatures get close to and surge past 70 degrees! Check out the video below for your detailed CampusConnect forecast.

11/5 - 2:15pm - Quick Shot of Rain on the Way in Mississippi

Showers and a few storms are moving eastward through the I-55 corridor of Central Mississippi right now. The eastern extent of these showers and storms are just about to enter Oktibbeha County and we'll keep them around until we get to midnight or so this evening. Temperatures overnight will get only into the mid 40's thanks to the rain and cloud cover, but get ready for cooler temperatures for election day tomorrow with highs near 60.

An interesting aspect of tonight's rain is that the area of low pressure associated with it will be the same one that will exit off the east coast of Florida and blow up to be a significant Nor'easter by Wednesday. This comes on the heels of Hurricane Sandy causing devastation in the Northeast so folks up there are not looking forward to the one-two punch. This Nor'easter will certainly hamper clean-up efforts but the good news is that it will not be as strong or as long-lived as Sandy.

Full sunshine will return to Mississippi by Wednesday and temperatures will recover well into the 60's to 70 or better by the weekend. We'll be watching a storm system make its way through the middle of the country next weekend that has the potential to impact us on Monday of next week. It's not entirely clear how severe the storms we'll have will be but just keep in the back of your mind that we could be off to a stormy start next week. Check out the video below for your complete forecast for the Golden Triangle area.

9/17 - 2pm - Tropical Rains Overtake Mississippi

Like heavy rain? Neither do I. That's what we have going on right now across most of Mississippi as an approaching cold front and a low moving onshore from the Gulf of Mexico are combining to give us a good soaking. The downpours and storms across the Golden Triangle area of Mississippi are definitely tropical in nature because moisture is streaming in right from the Gulf as the low pressure center out there continues to move our way. Storms will continue, and rain be at times heavier, this evening across the northeast quarter of Mississippi. Storms will remain likely tomorrow morning but thankfully the front will be moving through at that time and replace the rainy, tropical air with much more pleasant dry and cool air from the north. The middle of this week behind the front looks beautiful! Check out your full Mississippi State University CampusConnect forecast below for all the details on this week's forecast.



Like the new intro video and 5 Day Forecast background in the above forecast? I've been working on those graphics for the past few months and we're rolling them out today as we kick off the official start of our CampusConnect forecasts for the year here at MSU.

9/16 - 2:40pm - Rainy Start to the Week in West Tennessee

As promised, a few light showers are moving across West Tennessee and they will become more numerous and heavier this afternoon. Not everyone will see rain but those that do can expect some gentle rains with not much accumulation and possibly a clap of thunder. Tomorrow is a different story though as a larger, more potent upper-level disturbance moves through and generates heavier rains and possibly some thunderstorms. This will be a day when most folks see rain with some areas, especially closer to the Mississippi border, seeing over an inch of rainfall accumulation. Tuesday morning will feature some showers but the cold front at the surface that will be moving through with the upper-level disturbance should be moving east of the area throughout the day. The rain and clouds will be on their way out with the front, so expect the second half of your Tuesday to be much nicer than the first. Cooler temperatures behind the front mean highs in the mid 70's and lows possibly into the 40's by Wednesday morning. That's some fall-like weather right there! Check out my full forecast from last night's 10pm show on WBBJ below.



If you watched the video you probably saw some changes from previous ones that I've posted. WBBJ debuted an all-new HD weather graphics system that has full 3D rendering capabilities. It's very slick, easy to use, and most of all, fun! The 3D zooms to Jackson's tonight and tomorrow forecast I built from scratch between shows yesterday and it was pretty amazing what the machine could do with so little time.

This is also my 2nd anniversary with WBBJ. A lot has changed since I started working there in September 2010 but one thing that hasn't changed is how much I enjoy doing shows there! Can't wait to keep going back there on select weekends during this school year.

9/5 - 11:35pm - Stormy Week, Cooler Weekend, and TV Tomorrow!

It's been a stormy day across West Tennessee and North Mississippi as a complex of storms moved through the region this evening generating multiple instances of severe wind. The storms that caused these are still moving southeastward through Northeast Mississippi but have lost their severe punch. Even though it appears these storms will miss Starkville and the Golden Triangle in Mississippi there is the possibility that an isolated storm or two will try to form off the western end of these tonight.

Storms will once again be a possibility tomorrow but they shouldn't be as potent or widespread. We'll have the moist, warm air in place to fuel storms but there won't be any real trigger besides a small upper-level disturbance or two that could try to form and move through. Friday night will be the best chance for storms in the near future though as a cold front sweeps through West Tennessee and North Mississippi. Since these storms will move through earlier in the evening across West Tennessee there is the possibility of a few of these going severe. The chance for severe weather decreases as you move southward into North Mississippi thanks to the later timing during Friday night that they'll be moving through. Will the rain be out of the picture in time for the Mississippi State/Auburn game on Saturday at 11am here in Starkville? It looks like that may be the case at this point but it's too far out to know for certain since the front will be exiting the region sometime during the morning. The big story instead of the storms will be the much cooler, much drier air behind the cold front. We're talking about highs in the upper 70's this weekend in West Tennessee and highs in the lower 80's across North Mississippi, both with low humidity. What a change! We just have to get through a Thursday and Friday full of the deplorable heat and humidity we've seen lately before the wonderful weekend weather arrives.

Looking for something to do tomorrow night? On the Travel Channel at 10 pm/9c tomorrow night a show called Extreme Tours will be airing and the first segment of the show will feature me and my pals at Storm Chasing Adventure Tours! A crew from the show came out to film and interview us as we chased this past spring in New Mexico and their footage along with clips from my library of tornado video will be airing. This program will showcase what we do as a tour group and how we make it happen. Quite a few of our tour guests and tour guides were interviewed for this and the camera crew that came rode along with us for a few hours. I did a sit-down interview with them along with an extensive round of showing off our vehicles and equipment. This should be a good show tomorrow and I'm certainly looking forward to my first appearance on a non-news national TV program! If you can't make it home in time to watch tomorrow be sure to set your DVR.

7/22 - 10:30pm CDT - Heat Cranks Up in West Tennessee

A few showers at 3:25pm today

Some showers and downpours did make it a little further north than expected today across West Tennessee. Last night's model guidance and thinking was that any of these scattered "pop-up" showers would stay mostly south of the Mississippi border, but a complex of storms moved a bit further north than expected out of Alabama into Middle Tennessee. This complex of storms brought with it a small boundary in the atmosphere that helped get these widely scattered showers going over portions of West Tennessee this afternoon. These have all since faded away and the region should have a stretch of hot and mostly clear weather through at least the middle of the week. Humidity will be on the increase as temperatures get into the upper 90's, so expect some dangerous heat index values well over 100 degrees. Storm chances look like they will now be increasing toward the end of the week as a front drops from the south but temperatures still appear to be heading toward the triple digits since this front likely won't make it far enough south to pass through.

My weathercast from last night's 10pm news on WBBJ in Jackson is available to watch below.

7/15 - 7pm CDT - The Heat Returns!

A few showers are ongoing across West Tennnessee right now, but this is quite a bit less than what was expected today. Dry air rotating around a area of high pressure has moved into the region because this high has nudged a bit further westward than originally forecast. This means that a majority of the shower activity has stayed west of the Mississippi River, but a couple thundershowers could still pop up before sunset. These should mostly dissipate before the overnight hours.

Heat and humidity are on their way back as a large ridge of high pressure moves eastward over the next few days. This should surpress storm chances a little bit, but not entirely because temperatures aloft will still be a little cool. This heat at the surface and the slightly cool air aloft should create the typical "summertime pop-up storm" environment that we're used to seeing in the afternoons this time of year. Temperatures underneath this ridge of high pressure should be in the lower to middle 90's in West Tenneessee and middle 90's until Wednesday in Kentuckiana. A front dropping south on Thursday will trigger higher rain chances in both Kentuckiana and West Tenneessee and there could be some slightly cooler temperatures behind the front for Kentuckiana. Things look to remain hot all week long in West Tennessee!

I'm in Jackson, TN right now getting ready for the 10 O'Clock news on WBBJ this evening before going back to Louisville tomorrow. Check out my Hokey Weather Fact from last night's show on the left and be sure to tune in to WBBJ tonight at 10 for a new one!

 

5/11 - 11am CDT - A Crazy Chase in South Texas Yesterday

Our timing yesterday was just about perfect. As we surged southward from Carlsbad, New Mexico to the Del Rio, Texas area we began tracking storms that were forming in the mountains of Mexico near the Texas border. One fairly supercell formed along a boundary of converging wind just north of Laredo, TX in Mexico and we knew that this was the storm we needed to chase. It merged with another supercell that was moving north quickly to create a big storm with some intense rotation. We were able to get to the south side (where a tornado would be) just in time so that the hail and intense rain wouldn't cut us off from our road down to that area. Once we were there we saw some definite rotation and a couple wall clouds, but the storm was moving fast so we had to keep moving toward Laredo. We pulled over in a parking area just north of the city and continued to watch a wall cloud form that had a tiny hint of a funnel cloud in it. It was so small that it was barely visible, but it was certainly in rotation and was on the correct part of the storm. That was about all the storm had to offer tornado-wise.

By the time we made it east from Laredo the storm had merged with others to form a line of storms called an MCS (mesoscale convective system). This pretty much killed the tornado risk for this storm so we watched a very impressive lightning show from it as the sun set. Given the excitement that we had while chasing the storm while north of Laredo yesterday, it was a pretty good day! You can find more storm chasing photos from yesterday and earlier this week on my Flickr and Facebook albums.

Today we're traveling back to Oklahoma City so that our guests on Tour 1 can depart on their flights tomorrow. Tour 2 starts tomorrow night with our orientation and then we set out on Sunday for another week of storm chasing!

Follow me on Twitter and Facebook anytime for storm chasing updates.

5/10 - 11:20am MDT - A Change in Plans Today

Our original plan to stay in Southeast New Mexico today has been altered because of some new weather data that came in overnight. We did visit Calsbad Caverns this morning, but we're now on our way to the Del Rio, Texas area where storms are ongoing at the moment. This activity is definitely not making it easy for our forecast this morning because having clouds and storms in the hours before an afternoon severe weather setup is never a good thing. Nonetheless, we'll be looking for holes in this activity and/or for it to die off a bit this afternoon so that stronger storms can develop. The good thing is that wind shear today looks promising due to a cut-off low in Mexico creating strong southwesterly winds aloft that will contrast with the easterly winds at the surface.

The Storm Prediction Center has issued a Slight Risk for severe storms in the region, which includes a 5% tornado risk. Should this pan out today even with the ongoing storms this morning, this could be the best setup we've seen so far this week. Here's an interesting snippet from the SPC's 1630z discussion:

THE EWD PROGRESSION OF MID AND HIGH-LEVEL JET STREAKS ACROSS THE LOWER RIO GRANDE VALLEY WILL RESULT IN PRONOUNCED VERTICAL VEERING OF WINDS WITH HEIGHT WITH EFFECTIVE BULK SHEAR STEADILY STRENGTHENING TO 50-60 KT. AS SUCH...THE ENVIRONMENT WILL BECOME INCREASINGLY SUPPORTIVE OF INTENSE SUPERCELLS CAPABLE OF VERY LARGE HAIL...TORNADOES...AND DAMAGING WIND GUSTS.

Up-to-the-minute updates will continue today on Twitter and Facebook.

5/8 - 12:10pm CDT - Targeting New Mexico Today

We're on the road west today from Fort Stockton, Texas as we move toward Southern New Mexico. This is one of two areas we considered chasing in this morning, with the other being in Southern Texas. The reason we are not in Southern Texas is because there are thunderstorms going on already down there and the cool air and cloud cover from those will act to contaminate the environment for storm development this afternoon. Even though the very same cold front we saw yesterday and the day before will act as a focus for storms down there today, this contamination should rule out most of the chance for nice, isolated supercells.

Even though 500 mb (18,000 foot) winds will be stronger in Texas because a shortwave disturbance on the edge of an upper-level low is moving through the region, they should be ample in New Mexico. The southwesterly flow at that level and the fact that winds will be spreading apart (diverging) should lead to rising air in this region near the surface. These winds coupled with easterly surface winds will create wind shear, which is needed to sustain and cause a storm to rotate.

The Storm Prediction Center has issued two Slight Risk areas for today in Texas and New Mexico. There is a 2% tornado risk in Southern Texas, but this may not play out well down there thanks to the ongoing storms and clouds this morning. There's no tornado risk area in New Mexico, but my hunch is that there might be the potential for one or two little ones there today based on the directional shear that will be present with even a little bit of speed shear. Moisture will be a bit limited today, but you don't need as much in the upslope areas of New Mexico because elevation compensates for a lack of moisture. We're keeping an eye on conditions as they develop and hopefully I'll have more great pictures to share later today!

My constant updates on Twitter and Facebook will continue today during our chase.

2/4 - 4pm - Storms Come to an End Across West TN

After a round of showers and storms this morning, a cold front is now moving across the Mississippi River into the state. The cold air and clouds with the storms this morning stabilized the atmosphere considerably, so storms will not re-fire this afternoon as previously forecast. This also means that our marginal risk for severe weather today is done. Instead a few areas of drizzle may pop up as the front moves through by this evening. After a few showers tomorrow, calm and mostly clear conditions should prevail for the rest of next week. Check out my forecast from this morning on WBBJ below:



This morning I walked into the studio and our weather center was completely gutted! WBBJ is starting to disassemble it to make room for our new set, which will include a shiny new weather center once completed. For now our weather operations are running from a temporary location just off-camera, which you can see in the panoramic photo I shot this morning:

9/19 - 12:45pm - Rain's Coming Our Way!

After seeing some showers this morning, more rain in on its way to Starkville. Scattered showers and storms will continue through tomorrow with a small break thrown in on Tuesday evening before more storms push through on Wednesday and Thursday. Check out your latest forecast in the video below:

9/17 - 3:30pm - Spotty Showers in West Tennessee

We saw a few showers across West Tennessee this morning, but as expected they've mostly cleared out of the area for the afternoon. More showers are possible tomorrow, but the big show (relatively speaking) arrives on Monday with some appreciable rain chances as a cold front approaches the region. Check out my forecasts from last night's 10pm show and this morning's Good Morning West Tennessee newscast on WBBJ below:

8/7 - 5:15pm - More Storms in Our Future

Did the storms in Louisville wake you up this morning? I slept through them, which is probably a good thing because those that couldn't sleep through them early this morning sure looked tired today. Locations near Downtown Louisville saw rainfall amounts exceed one inch this morning, but most of the suburbs and outlying areas received under an inch. Click the image on the left from NWS Louisville to see a complete map of the rainfall totals from this morning. More storms are possible this afternoon and especially tomorrow as a cold front to our north provides a focus for development.

I've been watching the radar and satellite image for the past couple hours and it appears that ongoing storms dropping southeastward near Indianapolis may send out a some outflow boundaries toward Louisville over the next few hours. Outflow boundaries are like miniature cold fronts created by the cool air flowing out from a thunderstorm's downdraft. They also can cause storms to develop because they are a source of lift and that's why they're so important when forecasting short-term storm development. Since we have a little bit of wind shear and a very unstable atmosphere over the Louisville area right now, a kick from one of these southward-moving outflow boundaries may cause a few isolated storms to develop this evening. Storms may also form without the boundary if another small-scale feature or surface heating gets things going first. So, a vast majority of the area will stay dry, but if you happen to get under one of these wildcard isolated storms get ready for some heavy rain and wind.

There's a much better chance for storms tomorrow as a shortwave disturbance moves through the region. These storms will likely cluster together into an MCS (Mesoscale Convective System - complex of storms) and severe weather is possible. These scattered or MCS storms will roll through Louisville sometime tomorrow late afternoon or evening. Damaging winds, frequent lightning, and small hail will be the main threats from these storms. If they cluster together in a line, wind damage probabilities will be higher. The Storm Prediction Center has placed much of Kentucky, including Louisville, in a 30% Slight Risk area for severe weather tomorrow due to these factors.

7/3 - 12:30pm - Fantastic Fourth Forecasts

A cold front sliding southward through Indiana and Kentucky this morning has triggered some thunderstorms in Southwest Indiana that likely won't make it to the Louisville area this afternoon, but more storms could develop later on. While any storm that forms this afternoon could have heavy rain, lightning, and some gusty winds, most if not all will stay below severe limits. Temperatures are already in the upper 80's around the Louisville area, so a high near 93 today looks good at this point.

How about those Fourth of July forecasts? Hot and humid will be the rule for most locations, but scattered afternoon thunderstorms covering quite a large area could drench a few of those outdoor barbecues. The storms will be large in coverage due to a trough hanging around the eastern half of the US and a stationary front near the Ohio River.


Here are some Independence Day forecasts for selected regional locations from the National Weather Service:

Louisville, KY: Partly Sunny | 89 degrees | 40% afternoon storms
Lexington, KY: Partly Sunny | 86 degrees | 40% afternoon storms
Evansville, IN: Mostly Cloudy | 87 degrees | 50% afternoon storms
Indianapolis, IN: Mostly Sunny | 85 degrees
Cincinnati, OH: Partly Sunny | 86 degrees | 20% afternoon storms
Jackson, TN: Mostly Sunny | 93 degrees | 30% afternoon storms
Memphis, TN: Mostly Sunny | 95 degrees | 30% afternoon storms
Nashville, TN: Mostly Cloudy | 92 degrees | 30% afternoon storms
Knoxville, TN: Partly Sunny | 91 degrees | 40% afternoon storms
Tupelo, MS: Mostly Sunny | 96 degrees | 20% afternoon storms
Starkville, MS: Mostly Sunny | 96 degrees | 20% afternoon storms
Jackson, MS: Mostly Sunny | 97 degrees | 30% afternoon storms
Birmingham, AL: Partly Sunny | 94 degrees | 30% afternoon storms
Atlanta, GA: Mostly Sunny | 94 degrees | 50% afternoon storms

6/23 - Expecting the Unexpected: The Louisville Tornadoes

A horse barn at Churchill Downs
Image: NWS WFO Louisville

The city of Louisville is recovering from an outbreak of tornadoes that even the most seasoned weather watchers didn't expect. As of this writing there have been four confirmed tornadoes (two EF-1's and two EF-2's) inside the Jefferson County/Louisville city limit. A fifth tornado in Harrison County, IN has been confirmed of EF-0 strength that started off the event. The iconic Churchill Downs received damage to barns, several power poles near the University of Louisville's Papa John's Cardinal Stadium were brought down, and buildings in Jeffersontown sustained damage along with massive tree damage as a result of three of the four tornado touchdowns in the county. Thankfully there were no reports of injuries or fatalities as these tornadoes ripped through a city containing three quarters of a million people.

Below is a rough map I've put together based on the NWS WFO Louisville storm survey page of the tornado tracks through Louisville . Purple tracks indicate EF-2 rated tornadoes (the indicated tornadoes only reached this strength briefly) and the red tracks indicate EF-1 rated tornadoes. Be sure to click the image for a larger view.

Timeline of Tornadoes

Information used in this section about each tornado can be found on NWS WFO Louisville's storm survey page.

Yesterday started off cloudy and even misting at times across the city as a cloud shield from overnight persisted well into the morning hours. The Storm Prediction Center had a Slight Risk for severe weather out for a good portion of the Mississippi and Ohio Valleys northward to Michigan, but this was a very conditional risk for Kentucky and Indiana because the cloud cover in the morning inhibited destabilization of the atmosphere. A cold front sagging southeastward from Indiana would be the trigger for any afternoon storms should they form as temperatures warmed. The clouds finally moved east of the Louisville area at around 2:30pm yesterday and temperatures topped 80 degrees by 3pm. By 6pm there were showers on the radar to the north of Louisville and a few specks on the radar to the west.

Just after 7:30pm a Tornado Warning was issued for Harrison County, IN and western portions of Jefferson County/Louisville because a tornado was spotted near Elizabeth, IN. The "storm" that triggered this warning was no more than a shower because it had no lightning strikes associated with it. I'll admit that I was skeptical of this tornado report because there was really no significant rotation on radar. I thought the report was an improper identification of moving scud clouds or even a gustnado. The storm seemed to weaken and spotters near the Shively area reported no funnel clouds, so the warning was allowed to expire. About ten minutes later the storm began to strengthen again in West Louisville and another Tornado Warning was issued just after 8pm for Jefferson County. Multiple reports of a tornado and associated damage began coming in from Churchill Downs around that time.
This time the storm had lightning and the visual tornadic hook echo with prominent rotation on radar, so it was clear at this point that this thing meant business. To the right is a radar image with the supercell and hook echo near Churchill Downs and below is the velocity data with the green/red couplet signifying where the rotation was at the time. Click either image to see a larger view:

This tornado strengthened briefly into an EF-2 with 120 mph winds near the intersection of Floyd and Central Avenue at the University of Louisville campus where the power poles came down. Here's a video from YouTube user kehdsh that was posted on the WAVE 3 Weather Facebook page this afternoon. It's a little far away, but it clearly shows the funnel cloud above and debris cloud on the ground near Churchill Downs. Note that a tornado does not need to have a visible funnel snaking all the way to the ground. The debris dust-up and tube near the ground verifies that a tornado is there. Watch the center of this video closely:

Bent light pole in Jeffersontown
Image: NWS WFO Louisville

The next three tornadoes to hit Louisville were actually from the same storm and you could argue that it was the same tornado that lifted and touched down three separate times. From 9:29pm to 9:41pm (a total of twelve minutes with two short breaks in between) these tornadoes pestered the Louisville incorporated city of Jeffersontown, the suburb of over 26,000 people in Jefferson

Tree on dentist office in Jeffersontown
Image: Ryan Hoke

County that I've lived on the southeastern fringe of for nearly ten years. The initial touchdown occurred in the neighborhood just behind (west of) the Meijer store on South Hurstbourne Parkway west of Jeffersontown. This is just due south of the Stonybrook Cinemas. The tornado continued eastward to downtown Jeffersontown and lifted at the St. Edward School and Church, causing EF-1 (95-100 mph winds) damage along the path. It dropped again just east of the school and went on to cause tree damage at Tully Elementary School and structural damage at an apartment complex and the Good Samaritan Center in downtown Jeffersontown. The Good Samaritan Center had EF-2 winds of 115 mph that tossed and flipped cars about 20 yards. The tornado then went on to cause significant damage at the industrial park just east of Jeffersontown before lifting again. It sat down again in the industrial park causing more warehouse damage and continued on toward the Gene Snyder Freeway (I-265) where it lifted just after damaging a bed and breakfast on Tucker Station Road. This storm wasn't as well-defined on radar as the Churchill Downs supercell because of the merger of multiple storms in the county. The embedded supercell structure with rotation was certainly there as you'll see with the red/green boundary of wind velocities north of the Jeffersontown dot in the image below:

Why it Happened

Caution: This section gets a little technical on the meteorology side of things.
I explain why I think tornadoes hit Louisville unexpectedly and in such a small area.

Nobody expected this rash of tornadoes in Louisville at all. This includes the National Weather Service, local media, and me. In my blog post yesterday morning I even stated: "The tornado risk for [Southern Indiana, Kentucky, and Tennessee] will be quite low." The Storm Prediction Center issued a Slight Risk with a 2% tornado risk area in the morning with mention of wind-driven linear storms possible across the Lower Ohio Valley. Later on in the day they issued a Mesoscale Discussion that indicated they may issue a Severe Thunderstorm Watch for a broad area from Cincinnati to Memphis if storms developed more, but they never did. Some folks are asking why they didn't issued a Tornado Watch as soon as the storms unexpectedly began producing a spotter-confirmed tornado in Central Louisville, especially when the tornado threat dragged on for roughly an additional two and a half hours. My guess is that the very small lead time they would give with the issued watch and the unknown end time for this already unexpected tornado outbreak led them to scrub any plans of issuing one. Not to mention that the watch would be extremely small given that tornadoes occurred across two counties. The National Weather Service office in Louisville did a very good job of handling all the reports and translating that information into warnings for folks in the path of these storms.

These storms formed in a highly speed-sheared environment meaning winds were very fast aloft, but much slower at the surface. The direction of the winds at the surface were forecast to be from the southwest according to most of the computer forecast models. Aloft at 18,000 ft the winds were forecast to be from about the same direction, but slightly more west. This means that there was little directional shear forecast, meaning the chances of storms rotating were slim. The setup was more favorable for damaging straight-line winds. Here's where things get interesting. At 2:43pm, surface observations showed southwest winds in Louisville as forecast. All is well, but watch that southerly wind vector (down-pointing flag) east of Evansville, IN in the top picture on the left. Just before 5pm this southerly surface wind vector is in Louisville as a south-southeast wind. This increased directional shear between the surface and 18,000 ft quite a bit. The timing also lines up with the development of small showers just to our west and north. The surface winds were from the south in Jefferson County between 5pm and just before 10pm. In between these times we had the tornado pandemonium in Louisville. The timing and location is just too perfect for these southerly winds to not be a contributing factor to this event. Low-level wind shear (the kind that produces tornadoes) would have been much higher in Jefferson County than the surrounding area with the surface wind out of the south given the winds aloft being from the southwest.

It's also interesting to note that the bulk shear output on SPC's mesoscale analysis had a 50 kt maximum right over Central Kentucky and Southern Indiana. I make no claim of being a research meteorologist, but this surface wind reasoning comes from my four years of chasing storms in the Plains and the experience I've gained from books on severe weather.

The RUC and NAM models yesterday morning did pick up on the fact that storms would indeed form in the afternoon near Louisville after the clouds cleared. The 12z RUC yesterday in particular seemed to pick out the linear nature of the storms that were to form less than twelve hours later. It was nowhere near perfect, but the timing and shape of the storms were in the ballpark. Check out the comparison of a live radar capture late last night and the aforementioned RUC reflectivity (simulated radar) output:

Finally, I wanted to point out that this all happened with less than 1500 J/kg of CAPE or instability. Usually you need a little more instability than that to get severe storms going, but I think the directional wind shear compensated for that. None of the other storms outside of the localized southerly winds around Louisville were severe. That plus the fact that we had a tornado touch down in Harrison County, IN (just west of Louisville) with little to no lightning present in the storm makes this a once-in-a-lifetime event that could have been much worse if people did not heed warnings. I'm extremely pleased that there were no reports of injuries or fatalities with these five tornadoes yesterday. Hopefully this event will be the last major population center to be hit by a tornado this year, which has seen tornadoes hit cities including Tuscaloosa, Birmingham, Joplin, MO, Oklahoma City, Springfield, MA, and now Louisville, KY.

Check out NWS WFO Louisville's storm survey page for more information on this tornado event.