8/19 - 6pm - Tranquil Weather for the Workweek

Mississippi State University

It's that time of year again when I switch over blog post content to cover Mississippi and West Tennessee in place of the Louisville area. I do this for two reasons: 1) It's difficult to write about the day-to-day goings on of weather back home in Louisville when I'm taking a full college course load at Mississippi State that requires me to keep up with and forecast weather for the Golden Triangle area here in Mississippi and 2) I'm convinced that it is better to forecast for the area which you are currently living in because you're always aware (sometimes painfully) of how accurate your forecast is. If anything significant happens back home in Louisville I'll be sure to include it in my posts here over the next few months, but for now I'll be covering weather down here.

While it was supposed to be a rainy day across the Golden Triangle today we actually saw quite a bit of sunshine and nice weather. A front that has become stationary over Central Mississippi put us in a much drier environment and this has cut off most of the needed moisture for showers and storms to fire up. There's still a chance that a few isolated showers and storms will get going around the region but that's a potential that will be highest during the early morning hours according to the latest short-range guidance.

The trough that's brought us the front and the cooler temperatures this weekend will continue to do so for most of the workweek as it slides slowly eastward. A lack of surface moisture and building surface high pressure will stave off rain chances and even clouds for the most part until we get close to the weekend. Temperatures this week will be gradually rising through the mid 80's for highs until we get to Thursday. By then stronger southerly flow will be bringing in warmer, moister air from the Gulf and get us back to around 90 for highs as we go through the late week and the weekend. Shower and storm chances will be returning by the weekend.

Click image to see a larger view

The tropics have been fairly quiet as of late near the US coastline but there's potential for that to change next week. A disturbed area of weather in the middle of the Atlantic Ocean is on a course that may take it toward the East Coast if the latest computer models are to be believed. It's way too early in the ballgame to discern whether or not this will be a threat to the US since it could curve back out to sea before hitting land or not strengthen into a tropical storm or hurricane. This will be something to keep a close eye on since it could become Tropical Storm Isaac.

8/9 - 2:15pm - Severe Storm Threat Tonight

Small storms are popping up around the Louisville area after a fairly calm night that featured a few storms in Southern Indiana. The same trough of low pressure over the eastern half of the nation that's generating today's storm activity will see a potent burst of energy round the base of it late this evening into tomorrow morning. This piece of energy, which is really a small trough within the main trough over the east right now, is called a shortwave trough. This shortwave will have some fast winds aloft as it treks through Kentuckiana late this evening and that will along with a cold front moving through early tomorrow morning will trigger a threat of severe storms.

While scattered storms will be possible for most of today, the best timing for severe storms in Kentuckiana looks to be from 10pm to 4am. The main threats from the storms that go severe will be damaging winds and hail but any of these storms can have heavy rain and lightning. Since these storms will be hitting during the overnight period they won't have the punch that they could've had during the daytime. The tornado threat looks very low right now but as with any line of storms moving through there's a possibility that a kink in the line could form a small spin-up. A Slight Risk of severe weather has been issued for this evening through early tomorrow morning for the entirety of Kentuckiana. The good news with all of this is that much cooler air will be filtering in behind the cold front for Friday and the weekend!

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.

7/26 - 1:55pm - Kentuckiana Severe Weather Update

Kentuckiana is right on the edge of what could be a significant severe weather outbreak this evening. Nothing demonstrates this better than the Storm Prediction Center's latest severe weather outlook, which puts us in a Slight Risk but has a 30% severe wind risk running right through the center of Louisville. The reason for this is that faster winds aloft are most prevalent to our north and east so more of a risk area (a Moderate Risk) is needed up there. These winds have the potential to power a large line or cluster of wind-driven storms that could possibly become a derecho just to our north if it sustains itself long enough.

A Severe Thunderstorm WATCH has gone up for areas northeast of Louisville but not including the city. This was needed because severe storms are already affecting areas near Cleveland right now and more will be forming in the near term across Ohio, West Virginia, and Pennsylvania. I suspect a Severe Thunderstorm Watch will be issued for the Louisville area at some point this evening since storms will come through a little later than areas to our north.

Storm timing in Kentuckiana should be after 5pm this evening. The latest High Resolution Rapid Refresh model has storms rolling through the Louisville Metro area at around 7pm but this may vary a bit because this will be highly dependant on where storms fire along outflow boundaries and other surface features. The HRRR suggests that these will be either a broken or continuous line of storms which makes sense given that winds both aloft and near the surface will be from a westerly direction. This also means this could be a wind-driven line of storms so wind damage potential is relatively high here if storms get severe enough. Large hail will be a threat from any of the strongest storms. There may be more than one round of storms this evening in the area through 2 or 3 am since the cold front will not be passing through until that time. This might be a good time to secure your trash cans or any loose articles you have outside your house so that they don't end up in your neighbor's yard...

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.

7/18 - 10:40pm - Storm Spotting in Your Own Front Yard

Most storms that erupted today across Kentuckiana and West Tennessee were pretty typical. For the most part they were disorganized and each individual storm didn't last very long but a few did get strong enough for some severe thunderstorm warnings. Unfortunately these storms did pack some nasty cloud-to-ground lightning in the city of Louisville and that sparked some structure fires. Later in the day around 7:30pm just after most storms had exited the city there was a spectacular collision of two outflow boundaries near the I-64/I-264 interchange in St. Matthews. These outflow boundaries, one from Clark County, IN and the other from Shelby County, KY in this case, are just rushes of cold air that come out of other storms and create something akin to a miniature cold front. When these two boundaries collided they created an incredible amount of convergence which birthed a complex of storms right over the city. We're talking about the radar being clear at 7:30pm and there being storms on radar in East Louisville at 7:36pm. This collision also created some weak rotation briefly and dropped quite a base cloud as the complex moved south. The cloud created quite a show in my front yard and I was quite surprised to see such a well-defined (and briefly rotating!) updraft base as I was driving down my driveway this afternoon!

Now that all that excitement is over, we're going to be in for more storms tomorrow and Friday. A cold front will be approaching Kentucky and Tennessee from the Upper Midwest that should create a focus for storm development or at least create storms that will send outflow boundaries toward the south to create more storms. These will largely be powered by the heat and humidity that we'll be seeing over the next couple of days but with the front coming into play there's a possibility that storms may form earlier in the day or even possibly in the morning tomorrow and Friday.

Strong winds will be possible with any storm that forms along with more of the same lightning that we've seen around the region today. Storms could reach severe limits thanks to all the moisture in the environment and the front moving closer so the Storm Prediction Center has issued a Slight Risk for severe weather tomorrow for all of Kentucky and some of Northwest Tennessee. Storms will again be possible on Friday as the front moves through, but we'll dry out behind the front for the weekend.

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!