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

Latest Severe Weather Updates

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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!

1/20 - 2:45pm - Bitter Cold Air is Arriving Soon!

Temperatures in the 30's were common last night in West Tennessee and North Mississippi but temperatures are poised to drop much further than that tonight. A dry and relatively marginal cold front is moving through West Tennessee right now and that cold front is the first of two cold shots for the region. This will put lows down into the mid 20's in West Tennessee and lower to mid 30's in North Mississippi as cold air pours in behind the front. This cold air won't allow temperatures to rise much during the day tomorrow either, with highs in the upper 30's closer to Jackson, TN and closer to 50 down toward the Golden Triangle in Mississippi.

During the day tomorrow the second of two shots of cold air will pour in as another cold front passes by. This one will bring the über cold weather that we'll see on Monday night and Tuesday morning. The winds behind this front will be out of the north, meaning the source region (AKA where the air is coming from) for the cold air we'll see during this time will be in the Upper Midwest where they'll be below zero. While that kind of cold isn't expected, mid to upper teens will be common in West Tennessee with readings closer to 20 or 25 degrees down toward North Mississippi. A low of 16 or 17 degrees in Jackson, TN on Tuesday morning looks pretty reasonable given the intensity of the cold air spilling down. While our neighbors to the north may scoff at this being branded as "bitterly cold" in the South, this is still some incredibly cold air. Pets will certainly need to be inside during this time and people need to be bundled up as much as possible. Limit your time outside on Tuesday morning, if possible, and be sure to cover any exposed skin if you do have to be out. Temperatures during the day on Tuesday will warm to a more reasonable lower 30's in West Tennessee and lower 40's in North Mississippi.

Temperatures will moderate during the week thanks to the return of wind flow from the south. This return flow means more moisture in the air across the region. You might guess that this warmer air and more moisture will eventually lead to rain chances... and you'd be right! A low pressure system and associated upper-level shortwave disturbance will track through near the end of the week, bringing rain chances. There's some disagreement between various models over whether this will start on Thursday or Friday. The GFS model's timeline on this is posted below. My guess at this point is that the timeline you see below will be delayed by about 12 hours, so expect rain chances to creep into the region ahead of this low on Thursday afternoon and continue through the night into Friday.

It's not out of the realm of possibility that a little bit of wintry precipitation may fall on the backside of this system on Friday. If cold air flows in behind a cold front associated with this system fast enough then some of the last few rain showers could mix with or change over to a brief period of snow. The GFS identifies Kentuckiana as being the prime target for this but we all know that model has been trending too warm lately in all the winter weather events we've dealt with. So in my mind, West Tennessee is in a potential area for this mix or snow switchover to occur. We're too early for specifics on this so the forecast will have to be fine-tuned during the week. Stay warm!

12/30 - 8pm - Anyone Up for a Third Round of Wintry Weather?

With two winter weather events within a week's time in the books for Kentuckiana, it's apparently time for a third! Unfortunately the timing for this one is pretty bad. Just as folks are going home from New Year's parties in the early hours of Tuesday morning we could have snow, sleet, or even freezing rain falling in the region. The good news here is that regardless of what falls from the sky, there won't be much of it. Precipitation amounts will remain light since heavy rain and storms in the South will be stealing our moisture here up north in Kentucky and Indiana during the time of the event. As far as timing goes, a few snow showers will move through tomorrow afternoon as this system begins to move toward us. Going into the evening is when things get tricky.

As a weak area of low pressure continues to approach we'll see some warming aloft out ahead of it. This warming has the potential to turn our falling snow into sleet or even freezing rain. The GFS is leading the charge at the moment on the potential for freezing rain in Louisville as it has a layer above freezing from 4,000 to 7,000 feet at 4am on Tuesday morning that would support freezing rain. The NAM model keeps us all snow with the entire atmosphere being below freezing. Given that the models have overestimated temperatures aloft with the past two snowstorms we've seen lately, I'm inclined to think that Louisville will stay mostly or all snow. Another thing to focus on will be surface temperatures. Should they be just below freezing this snow, sleet, or freezing rain will stick to the roads and make for tricky travel on late Monday night. If they're just above freezing then only expect to see accumulation on the grass and elevated surfaces. We do have a bit of snowcover in Louisville now, so that might lean us more in the direction of below freezing instead of above for this event overnight Monday into Tuesday. We're going to be awfully close to freezing for much of the night regardless. Areas north of the city will likely stay all snow and below freezing while those areas to the south will see a wintry mix and temperatures just above freezing until the early morning hours. National Weather Service offices across the Plains have issued Winter Weather Advisories due to this system, in purple on the image to the left, but uncertainty about precipitation type and amounts in the Ohio Valley has NWS Louisville waiting for more agreement before they issue any advisories.

Like I said before, accumulations are going to be light for this event. The NAM (right) has up to an inch of snow in many areas and the GFS model has been a little more optimistic at times today with 1-3" across the area. Like the last two snow events, I'm thinking that the amount of precipitation being put out on the models will adjust upward a bit as we get closer to time (tonight and tomorrow morning). Given the trends I'm seeing right now I think we'll see 1-2" of snow in portions of Louisville and points northward with up to an inch of snow and mixed precipitation to the south. Once again... grumble grumble grumble... Louisville is right on the line between feast and famine with the snow. Southern Indiana has been the big winner with snow over the past week while folks south of the Ohio River are raising their hands in favor of more. That is, if you're a snow lover of course. So, we'll be looking to see over the next few hours how the models handle the amount of precipitation forecast, and temperatures both aloft and at the surface. Shifts in these could mean some significant changes to the forecast for many areas!

12/28 - 1:30am EST - Kentuckiana Winter Storm Number 2

Wednesday's winter storm didn't give much snow to folks in the Louisville area and instead confined heavy snow to areas of Southern Indiana. While differences in the models did exist over whether Louisville would get any accumulating snow or not, the overall situation was handled pretty well from a forecast standpoint. The highest snow report in NWS Louisville's coverage area was 7.2 inches in Washington County, IN while Louisville received a trace to a half inch.

The next storm on the heels of the last one is less than 24 hours away as a system arrives from the southwest and stays to our southeast as it moves through the region. This will start as some rain for the Louisville area but as colder air filters in we'll switch over to snow during the later evening hours. This exact time for switchover depends on how warm we get during the day tomorrow (lower 40's versus upper 30's makes a difference!) and how fast the cold air comes in. The 0z NAM that came in earlier tonight has about 3" for the city and after comparing this with other models I'm thinking this may be a number we'll see most commonly reported by Saturday morning in Louisville. Higher totals will be possible just a bit further north from Louisville.

But even as I say this there's a small fly in the ointment. The 3z RPM model is in and it has the possibility of 4-6" of snow just due east of the city and a few very small totals like this scattered throughout areas near the Ohio River. This suggests that totals closer to 4" might be more widespread than previously thought. You can click the RPM output on the left for a larger view. We've seen the trend of increasing snow totals today on the models and this run of the RPM just continues this. We'll need to watch for this trend tomorrow morning to see if other models catch on. Right now this isn't really a factor in my forecast since it's just one model. Below is my snow forecast map for the region. Realize that, like the last storm, a small shift in track or more/less cold air will change things for some folks drastically.

Also worth noting is that the Hyrdrometeorological Prediction Center (HPC) has us in a Slight Risk of a 4" snowfall (think of this like the Slight, Moderate, and High severe weather risks) while areas closer to Cincinnati are in a Moderate Risk. Expect to see Winter Weather Advisories being issued tomorrow for portions of Kentuckiana. There may also be a few Winter Storm Watches issued as well depending on if forecast amounts of 4" or more look to be more widespread. You can keep up with the latest on this storm tomorrow by following me on Twitter and Facebook. Good luck, snow lovers!

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!

11/5 - 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.

8/4 - 2:30pm - Waking Up to Storms Tomorrow

Scattered storms are firing between Evansville and Louisville right now and are slowly trekking eastward. These aren't expected to become severe but some downpours and lightning are certainly a possibility in Louisville as they continue to develop. The chance for storms in the area should remain with us in Kentuckiana through the early evening.

More storms forming in Illinois and Missouri will be our next focus as they move into Kentuckiana during the early morning hours tomorrow. Some of these could be strong to severe since a trough moving through to our north will be bringing faster winds aloft to the area. This means that damaging winds will be the primary threat from these storms should they hold together for us during the early morning. The 6z NAM model run (right) was pretty bullish on these morning storms but the 12z that just came in was more subdued with their intensity. In either case it looks likely that a lot of folks will wake up to storms early tomorrow morning.

Storms could fire up during the afternoon tomorrow if the morning's storms clear out in time for instability to recover during the afternoon. Another limiting factor for this will be the cold front that will be moving through during the day tomorrow. Storms will fire along and in front of that boundary so its speed will determine who gets storms during the afternoon. Right now it looks like Louisville and areas to the south and east will be in the zone for storms tomorrow afternoon and it's worth noting that their coverage won't be anywhere near this afternoon's and tomorrow morning's storms. Both Kentuckiana and West Tennessee are under a Slight Risk for severe weather tomorrow afternoon as these storms fire up in the heating of the day with the cold front in play. Strong winds will again be the main threat here.

After the front moves through on Sunday temperatures will be in the upper 80's to near 90 for the start of the workweek in Kentuckiana and storm chances will be nonexistent until Thursday.

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!

 

7/12 - 11:45pm - A Festive Forecast

Tomorrow is the beginning of the Forecastle Festival at Waterfront Park in Louisville. Unfortunately rainfall could be an issue as a stationary boundary begins to move northward from North Mississippi overnight. This boundary will bring even more moisture into the area and a source of lift, the boundary itself, which should bring in some ongoing showers and storms tomorrow morning. The short-range models right now are suggesting that there may be a break in the action after 2pm, which you'll see in the NAM simulated radar image on the right. Disagreement among the models exists over whether the storms will re-fire and make an impact in the area later on in the afternoon. My thoughts on this are that storms may have trouble getting going again in the late afternoon since the morning's activity will be hanging around well into the early afternoon, but that the presence of the frontal boundary will compensate quite a bit for this. Expect then for storms to possibly re-fire and move into the area sometime after 5pm. The good news here for festival goers is that I don't think storm coverage will be quite as high during this second round, so there's a good chance the Waterfront may be able to dodge storms if they remain scattered.

Daily storm chances will continue on Saturday and Sunday as the moisture from the current system sticks around and a bit of upper-level support kicks in thanks to a trough passing through the Great Lakes region. These storm chances will be a bit lower than tomorrow's though because there won't be much of anything to trigger them, like a front, aside from daytime heating in the afternoon. Long story short, bring a rain jacket or poncho if you're going downtown for Forecastle this weekend. Temperatures will top out near 80 tomorrow as the clouds and rain move through, but it will warm into the mid 80's for the weekend in Louisville.

Speaking of this weekend, I'm going to be a busy guy! On Saturday I'm heading down to Jackson, Tennessee to do the Saturday and Sunday evening shifts of weather at WBBJ-TV. This means you'll see me on the 6pm and 10pm newscasts this weekend if you're in the viewing area. It's been almost three months since I've done weather on TV, but I'm very excited to be getting back into it this coming weekend and again on Saturday night next weekend. Be sure to tune in!

7/7 - 10:30pm - Massive Heat Wave Ends with Storms

Today capped off the longest, hottest stretch of weather in Louisville that most people can remember. Today's 106° high at Louisville International Airport was the hottest it's been since July 14th, 1936 when it got to 107°. That temperature is Louisville's all-time record high and if we didn't have as many clouds as we did this afternoon in the city we would have met or broken it. This ends nine days of 100°+ weather, which is the third-longest stretch of triple digits ever recorded according to NWS Louisville.

Storms that will develop tomorrow will be ushering in cooler temperatures, which is welcome news! The bad part is that some of these storms may be severe due to the incredible amount of energy they'll have at their disposal from all the heat. Temperatures in the mid 90's tomorrow with sunshine and high humidity will power an awful lot of instability, or the tendency for air parcels to rise and create thunderstorms. A cold front sinking down from the north that will be stalling out once it passes just to our south will be the focus for storm chances starting tomorrow in the early afternoon in Louisville and lasting through Monday morning.

The main threats from these storms will be wind and hail, but there could also be a threat for some rotating storms too. While winds don't look favorable for any sort of big tornado problems tomorrow, a couple of these rotating storms may get just enough juice to put down a brief spin-up. EHI values in the adjacent image take into account both instability and helicity, which is a product of wind shear. The elevated values you see are powered mostly by instability and just a little bit of helicity, so again, winds aren't that favorable here. The Louisville area is no stranger to summertime tornadoes as you may remember a series of four of them that touched down in late June of last year.

Given the chances for some severe wind and hail tomorrow, the Storm Prediction Center has issued a 15% Slight Risk area for Kentucky. A better chance for severe weather (30%) exists closer to the East Coast where upper-level winds will be stronger as a trough digs down a bit into that area.

6/23 - 11:30pm MDT - Who's Ready to Go North?

Our tour guests have been through orientation and now we're ready to set off for our northward journey tomorrow from Denver to the region where Wyoming, Nebraska, and South Dakota meet. This area will be on the northwestern side of the large ridge in the middle of the country and on the eastern side of the trough coming onshore from the Pacific. This means there will be southwesterly winds aloft, at 500 mb or 18,000 feet, to hopefully bring in some drier air so that instability will increase when it contrasts with the warm, moist air at the surface that will be rising into it. While weak in speed, the winds up there will also increase wind shear because they will be at odds with the easterly and southeasterly winds at the surface. This will increase helicity a little bit, which is a corkscrew-like rotation in the atmosphere that is good for fueling rotating thunderstorms.

Moisture shouldn't be too big of a deal since dewpoints will be in the 60's, but we'll be eying the potential for issues with the the cap, which is a warm layer of air above the surface that inhibits thunderstorm development. All the warm air in place over the central part of the country breeds strong capping since the warm air is in place at the mid levels, but the models are suggesting that this cap may be overcome tomorrow afternoon and lead to some isolated storms. At this point there is nothing that suggests any storm that forms will be anything past marginally severe, but the helicity that the NAM model is picking up on above is certainly worth keeping an eye on.

The Storm Prediction Center has a general thunderstorm risk out for our target area tomorrow with no chance for severe weather. Since storms will be pretty isolated and in a fairly unpopulated area, it may not be worth it for them to issue any sort of severe risk with a setup this marginal. We'll see how things have developed overnight when we set out in the morning though. A secondary low may try to form in western South Dakota tomorrow according to the NAM and that may influence our decision on where to go if it forms since the best winds will be just to the north of the low center. Hopefully we'll see some storms!

Follow me on Twitter and Facebook for the latest tomorrow!

4/18 - 9pm - Rainy End to the Week?

Low off the Gulf Coast on Saturday

After seeing well over three inches of rain yesterday in Starkville we're enjoying much more pleasant weather that's going to continue over the next few days. Southerly winds will be bringing moisture and temperatures near 80 for both Thursday and Friday, but the weekend is a question mark at the moment. Our next system tracking to our south will be sending up rain our way for a good portion of the day on Saturday, but the most recent computer forecast model runs suggest this may be less of an issue than previously thought. Should that system stay well enough south and not send as much moisture our way, Saturday may be showery but not a washout. Sunday should be much cooler regardless but at least the sunshine will return! Your full forecast is available in the video below:

3/22 - 4:30pm - Heavy Rain is Gone, but Warm Temps Remain!

Heavy Rain

Did you get drenched? I think we all did. The rain over the past 24 hours has been tremendous, especially across Mississippi as inches and inches have fallen from the pesky system that has been slowly churning through the Plains and now the South. Check out the estimated rainfall map from today below to see what I mean (the totals for West Tennessee are underdone but you get the picture of who saw some tremendous rainfall earlier today!) Most of the rain is now east of West Tennessee and North Mississippi, but a few showers remain and will continue this evening.

More rain will fall tomorrow afternoon as another piece of energy from the same system rotates around the Mid-South. The area in red with the directional arrow coming from it is called a vorticity max. Usually the area where rain and storms develop is east of the vort max as it moves along. Tomorrow's rain won't be as heavy as today's by any stretch of the imagination and it will be more of a scattered nature than today's washout. Once this rain is all said and done by Saturday morning we should be left with a very nice weekend and temperatures warming back up through the upper 70's across West Tennessee and North Mississippi.

The Big Picture

Let's zoom out more and look at the system that's been causing all of this rain as a whole. What we have is an upper-level low in the Plains that is slowly moving eastward. An upper-level low like this one is basically a ball of cold-air that gets cut off from its northerly source because the jet stream kicks north leaves whatever is in the base of the former trough behind. It moves slowly because the jet stream, which usually drives big weather features, is absent from the process after the low gets cut-off. The satellite and radar images coming in from area where the low is are striking... you can see very well the rotation of the low pressure center, which makes it look like a land-based hurricane.

The jet stream being way up north is also why it's been so warm lately. In the winter the jet stream usually dips down from Canada and brings cold air to the USA. Areas north of the jet stream remain cold due to the influence of an arctic air mass while to the south of it there is usually a warm, moist air mass. This winter and now into this spring the jet stream has not really come down from Canada to the eastern half of the nation. The West has had it come down a few times though, which meant snow and cold temperatures for the Pacific Northwest and even down through California. The reason the jet stream stayed so far north is that La Nina (colder than usual ocean temperatures off the coast of Peru) remained pretty consistent throughout the season. In an El Nino pattern, the jet stream comes down to the US with a vengeance.

Record Warmth

The above-average temperatures from this pattern will persist for quite a while it looks like. A cursory glance at some of the long-range models shows that the jet stream will remain somewhere close to this northerly position for the foreseeable future. With that said, comparing this year and month to years past is incredible. This March so far has been the warmest on record in Jackson, TN and Tupelo, MS and the second warmest in Memphis. Jackson is running 10.6 degrees above average for this March. Comparing the year so far to years past, this is the warmest year so far in Memphis and Tupelo, and the second warmest so far in Jackson. These are remarkable numbers and we'll likely see more of these records flash by as the warmth continues. A running list of how this year's heat compares to previous records is available from NWS Memphis.

3/14 - 11:55pm EDT - Record-Breaking Warmth

The warm weather we've been seeing across the region hit record-breaking levels this afternoon. Here is a list of some broken temperature records today:

Jackson, TN: High 84° | Previous Record 80°

Memphis, TN: High 82° | Previous Record 80°

Chattanooga, TN: High 83° | Previous Record 81°

Louisville, KY: High 82° | Previous Record 80°

Paducah, KY: High 82° | Previous Record 78°
Evansville, IN: High 82° | Previous Record 77°

Indianapolis, IN: High 81° | Previous Record 79°

Many other cities in came close to breaking records, especially in Alabama and Middle Tennessee. The ridge over the Eastern US that's funneling all the remarkably unseasonable temperatures into the area will stay put through the weekend, but a few shortwave disturbances aloft will bring storm chances to much of West Tennessee, North Mississippi, and even into Central Kentucky tomorrow and Friday. These storms will be more organized than the spotty ones that developed in eastern portions of West Tennessee and even up through Western Kentucky this afternoon. The crazy-warm temperatures are going to last at least another full week as this strong ridge stays put, so I think to say that spring (or even summer) has sprung before winter officially ended!

3/2 - 12:30am - Severe Weather Outbreak Likely

A potent severe weather setup looks likely this afternoon and evening for Tennessee, Kentucky, Alabama, Mississippi, and even parts of Indiana and Ohio. All the ingredients are coming together for what could be a sizable tornado outbreak in these areas, especially around Middle Tennessee and Central Kentucky, maybe extending into Indiana too. We've had severe weather in some of these places just earlier this week, but this setup looks to be even more potent than that. Cities like Louisville, Lexington, Cincinnati, Nashville, Bowling Green, KY, Huntsville, Jackson, TN, Tupelo, MS, Starkville, MS, and Birmingham need to be on the lookout today.

Risks and Timing

The Storm Prediction Center has outlined a Moderate Risk area for severe weather tomorrow in an expansive area of the South. This includes a 15% tornado risk. Storms will likely erupt early this morning as a warm front surges northward and bring a hail risk to West Tennessee while not-as-strong storms will affect the most of the remainder of Kentucky, Tennessee, and Mississippi. These storms shouldn't be a huge deal, but a few might reach severe limits.

A brief break in the action throughout the mid and late morning hours should provide enough recovery time for the atmosphere to recharge and re-fire storms around noon. These storms will try to get going in West Tennessee and Northeast Arkansas, but will gain strength as they hit areas of greater surface heating to the east. These are the storms that could be very bad in a lot of areas. The worst tornado threat throughout the afternoon will be in Central Kentucky and Middle Tennessee, but there's a secondary area that could have tornado problems in Northeast Mississippi into North Alabama if a little more low-level wind shear comes into play. The Storm Prediction Center's latest severe weather outlook seems to pick up on that secondary tornado risk area by extending the Moderate Risk down to East Mississippi and Alabama. Straight-line wind damage and hail will be possible throughout the South tomorrow, so even if you're not in an area where tornadoes will be likely you need to be on the lookout for severe storms. The storms should move out quickly tomorrow evening once the cold front accelerates southeastward through the region.

Details

The reason why Central Kentucky to Middle Tennessee will be the area for maximum tornado potential tomorrow is because of an alignment of a few factors. For one, the fastest upper-level winds will be centered right over this area tomorrow afternoon. When you couple that with almost southerly winds (may be a bit southwesterly at times), you get not only a high difference between wind speed aloft and at the surface, but also a difference in direction. This is called wind shear and it's crucial to sustaining a thunderstorm and allowing it to become strong enough for tornado development. The southerly winds at the surface will help what's called low-level wind shear, and that's usually a pretty big factor in who gets tornadoes.

These southerly winds will also be bringing in moist air from the Gulf, which is the fuel for these storms as they develop. While the best moisture will be over Mississippi, Alabama, and Tennessee tomorrow, it will still be ample for serious severe weather in Kentucky. This moisture will bring some serious atmospheric instability to the region. When you couple this instability with helicity (the tendency for the atmosphere to rotate), you get what's called the Energy Helicity Index (EHI). This is a decent indicator of where the best tornado ingredients will be, and as you can see on the left, the values are particularly high tomorrow across a pretty vast area from Mississippi through Kentucky. Supercells appear likely in Tennessee and Kentucky, but Northeast Mississippi may have more of a mixed supercell/squall line of storms scenario due to less wind shear. This could be an entirely linear squall line event across Northeast Mississippi/North Alabama tomorrow if wind shear under performs. While squall lines don't harbor as many strong tornadoes, it is still a very real threat that needs to be monitored.

Safety

Before severe weather

• Make sure your cell phone is charged in case you lose power
• Have flashlights with fresh batteries ready to go. Your cell phone should NOT be your primary flashlight
• Your NOAA Weather Radio/Cell phone alert app should be ready to alert you
• Make a central meeting location for family members should you lose communications after the severe weather passes

I've said before that I like iMapWeather Radio on the iPhone for weather alerts. This is not any sort of endorsement, but it is an app that I use and it just works.

When a Tornado Warning is issued for your area

• Get to the lowest level of your home, apartment, or office
• Stay away from windows and try to get to the center of the structure you're in
• Evacuate mobile homes and get to a safe, sturdy building immediately
• Make sure you are wearing sturdy shoes
• If you have time (have these ready to go before a warning is issued), put bicycle helmets on the kids and yourself. Quite a few deaths were caused by head trauma in last year's tornadoes.

Please heed ALL warnings. This is a dangerous severe weather setup that needs no playing around with.