FORECAST:
Friday (High 86, Low 67): Partly cloudy and breezy. Warm and muggy.
Saturday (High 85, Low 66): Partly cloudy, breezy, and muggy during the day. Rain and thunderstorms are likely at night, and some thunderstorms may become severe.
Sunday (High 72, Low 64): Rain likely - thunderstorms possible. A few thunderstorms may be severe, at least in the early morning hours.
EXTENDED OUTLOOK:
Monday (High 59, Low 44): Mostly sunny.
Tuesday (High 60, Low 35): Sunny.
Wednesday (High 66, Low 33): Mostly sunny with a 20% chance of a passing shower.
Thursday (High 69, Low 42): Mostly sunny with a 20% chance of a passing shower.
PRONÓSTICO:
Viernes (Máxima: 86, Mínima: 67): Parcialmente nublado y ventoso. Cálido y bochornoso.
Sábado (Máxima: 85, Mínima: 66): Parcialmente nublado, ventoso y bochornoso durante el día. Probabilidad de lluvia y tormentas eléctricas por la noche, y algunas tormentas eléctricas podrían volverse severas.
Domingo (Máxima: 72, Mínima: 64): Probabilidad de lluvia y tormentas eléctricas. Algunas tormentas eléctricas podrían ser severas, al menos en la madrugada.
PERSPECTIVA EXTENDIDA:
Lunes (Máxima: 59, Mínima: 44): Mayormente soleado.
Martes (Máxima: 60, Mínima: 35): Soleado.
Miércoles (Máxima: 66, Mínima: 33): Mayormente soleado con un 20% de probabilidad de algún lluvia pasajera.
Jueves (Máxima: 69, Mínima: 42): Mayormente soleado con un 20% de probabilidad de algún lluvia pasajera.
DISCUSSION:
Well let's see if we dare to try for a detailed forecast when the weather remains chaotic for part of the region around here.
Nashville and points North up to the state line are under Flash Flood Warnings.
There is a Severe Thunderstorm Warning for Lewis, Wayne, Perry, and Hickman Counties in Tennessee. There is weak rotation in that storm and a note that a tornado could quickly develop, though the warning was mainly issued for golfball-sized hail and 60 mph wind gusts.
A separate storm to the North is affecting Perry and Hickman Counties more directly.
Most of Tennessee, at least the Western 2/3, is under another Tornado Watch that runs until 10 PM. That watch also includes parts of Southern Kentucky and Northern Mississippi.
Anyway, to focus on current/local weather, at 3 PM skies are mostly cloudy in Cullman. The temperature is 84 degrees. The dewpoint is 66, making the relative humidity 55%. That's muggy, even for early April. Winds are from the South at 18 miles per hour with higher gusts up to 25 mph. The pressure is 30.02 inches and falling.
This morning's Low was 70. Yesterday's High was 84.
In Jasper, skies are partly cloudy. The temperatures and dewpoints are not currently available. But the system does show the winds from the South at 8 mph gusting to 17 mph. Pressure is 29.99 inches and falling.
It is mostly cloudy and 82 in Haleyville. The dewpoint is 66, making the relative humidity 58%. Winds are South at 18 mph with gusts to 28 mph. The pressure is 29.99 inches/991.5 millibars and falling.
It is mostly cloudy and 84 in Fort Payne. Mostly cloudy and 83 in Decatur, the winds there gusting all the way up to 30 mph. Mostly cloudy and 81 in Huntsville. Mostly cloudy, breezy, and 85 in Muscle Shoals, wind gusts up to 36 mph. Mostly sunny and 86 in Tupelo, wind gusts to 33 mph there. A thunderstorm is moving through Memphis, with some fog along with the rain. Visibility is cut down to a quarter-mile there, and the temperature has dropped to 60 degrees. It is overcast and 65 degrees in Nashville with a North wind sustained at 15 mph.
We certainly are in an odd pattern at the moment, with a quasi-stationary cold front boundary parked there in Tennessee through North MS and up through Kentucky and Ohio. This was the focus for many severe thunderstorms that trained over the same areas last night/early this morning. And today may be bringing more.
And yes, the fun continues in Middle Tennessee, an area that saw numerous Tornado Warnings overnight is now covered by a Severe Thunderstorm Warning for wind gusts up to 60 mph, half-dollar sized hail, and a low risk of a tornado developing out of the weak rotation in the storm. And as mentioned before, much of TN is under a Tornado Watch again this afternoon. It's exhausting to watch from a distance, so I can only imagine what it's like to be up there going through these relentless rounds of bad weather.
This morning's sounding at 7 AM from Birmingham showed marginal instability, about 500 joules of surface CAPE, ample wind shear, including turning of the winds at the lowest kilometer, over 200 units of Helicity. We were fortunate enough to have a capped atmosphere that kept us from seeing the kind of weather the Nashville area did last night and this morning.
And I note that there is no upper-air sounding data for Nashville from this morning. I wonder if their weather was still too rough to allow them to launch the radiosonde.
This morning's sounding from Jackson, Mississippi showed an atmosphere primed for severe weather, with strong instability, strong wind shear (including low-level helicity), a supercell composite of 16, a significant tornado parameter of 2-3.5 range. And I believe they did have some severe storms overnight. I know a lot of the stuff that affected Tennessee later initialized in Mississippi. But there was so much severe weather going on yesterday and overnight that it became an awful lot to try to keep up with and sort out. Just saying this morning's sounding showed an environment very favorable for severe thunderstorms capable of producing tornadoes at Jackson.
This front is going to stall out, shift more to the West tomorrow, and then start to make its way through our area (North Alabama) Saturday and Saturday night. There will be some risk for severe thunderstorms and flash flooding with it. Behind it will be a big pattern change, to clear and much cooler weather next week.
So let's look at the details day by day.
Tomorrow looks partly cloudy and breezy. Look for a High of about 85-86, a Low of about 66-67.
And it looks like the severe weather threat will stay to our West/Northwest. The tornado threat mainly looks like an issue for Arkansas, where unfortunately, they could see another round of organized tornado activity, significant damage possible. They certainly don't need any more of that, but they may get it tomorrow.
And you can see where the front is waffling back out that way and stalling.
Saturday also looks dry around here during the day. If we see any rain, it should be isolated. High should be mid-80's again, about 84-86 range, the Low near 65. And it'll be another breezy day, may not require a wind advisory, but we'll see as always about that.
The NAM is showing a squall line coming into Northwest Alabama/Middle Tennessee between 4-7 AM Sunday morning.
And in that time frame, it does look like we'll have enough unstable air and wind shear to support a risk for a few severe thunderstorms.
And here I'm showing the SREF at 4 AM, 7 AM, and then 1 PM Sunday. It is interesting because it has an even slower timing. Marginal instability starts to creep in here around daybreak and then ramps up to moderate instability by midday. Showing surface CAPE here, values getting up eventually to 750-1,000 j/kg.
The storm relative helicity at the lowest kilometer of the atmosphere looks strongest before the appreciable instability moves in here. But it's still sufficient to support rotating storms and even tornadoes by 1 PM when the unstable air looks to reach its peak if the SREF guidance is close to being right.
And you can see where significant tornado parameter values in the region get to a range of 1-2, mainly back in Mississippi at first, but then our broad area has a value of about 1 by midday/early afternoon.
So taking all this model guidance together, it's suggesting the severe weather comes in early Sunday morning and may last until about Noon or so. Severe thunderstorms will pose a threat for damaging winds, large hail, and isolated tornadoes. Most likely storm mode looks like a squall line. And it does feel a lot like the event we had last Sunday, except that one was Sunday night into the morning of Monday. So we could end up with another event where it's mostly just some strong thunderstorms staying under severe limits. But a few places could see storms become severe.
The Storm Prediction Center in Oklahoma has the main organized, significant severe weather threat (note the hatching) from about Memphis back through much of Arkansas, Louisiana, East Texas, and Western Mississippi.
And it looks like they expect us to get the leftovers in North Alabama up into Tennessee, mainly along and West of I-65. This is the outlook that runs from 7 AM Saturday to 7 AM Sunday.
And they are thinking our severe weather threat will be over in North Alabama after 7 AM Sunday.
Here's a zoomed-in look at our severe thunderstorm potential between Saturday and Sunday.
That slower timing from the SREF really is questionable, doesn't fit with the pattern and what models have shown for days. Just something to consider. More likely the NAM has a better handle on the timing, and we'll be out of the woods long before midday Sunday.
The GFS shows the rain pushing through the area still at 1 PM Sunday.
The ECMWF shows the rain starting to gradually clear the area by that time.
It can be tricky to nail down the exact timing with an oddball system like this that stays stalled and then is going to get moving in a hurry. But above you can see the basic idea between Saturday through Monday.
Rain is likely on Sunday, and again, the timing of storms is in question. Some time between late Saturday night and Sunday morning, looks like we'll start to see a line of thunderstorms, a squall line, some could be severe. Look for a High in the lower 70's Sunday, a Low in the lower 60's.
Then Monday looks mostly sunny behind this strong cold front. Look for a High of only about 60 degrees, a Low in the mid-40's.
High pressure in place Tuesday, looks sunny with a High near 60 again, Low down in the mid-30's with really dry air and great radiational cooling overnight.
There will be a Low pressure system passing through the Ohio Valley next Wednesday, and it might squeeze out some showers for Southern Middle Tennessee, doesn't look like they'll make it down to the Alabama side.
Here's how Tuesday through Thursday look on standard weather maps. Some rain chances may try to come back Wednesday and Thursday, though the ridge of High pressure may hold and mainly keep them out of North Alabama and only able to spread down to Southern Middle Tennessee.
For now I'm going to keep rain out of our local forecast for Wednesday, forecasting for Cullman, just looking for mostly sunny skies, a High rebounding into the mid-60's or so, the morning Low down in the lower-to-mid-30's.
And really doesn't look like much change Thursday. Or at least nothing major in the cards like another storm system.
This thing Wednesday/Thursday looks more like a quick little disturbance that might bring a few showers overnight between the two days. So will actually blanket a 20% chance of rain for Wednesday and Thursday mentioning mostly sunny skies. Looking for a High temperature Thursday of upper 60's, near 70, the Low in the lower 40's. So some moisture return, yes.
This forecast is quite a wild ride, as some places could easily see frost Tuesday or Wednesday morning.
As far as the flooding risk, here you have it day by day out of this real nuisance of a storm system we'll be dealing with through Sunday to some extent. Fortunately in Alabama, our rain probably holds off until Saturday night, and our severe weather risk looks fairly routine or even on the marginal end.
Most of us around here will see an average of up to two inches of total rainfall for this forecast period, with isolated amounts up to 3 inches possible. About the Western half of Tennessee has potential for 4-5 inches or greater over the next 7 days. And then as you get into Western Kentucky, the Missouri Bootheel, back into Arkansas, they could see amounts up to 7 inches or greater. So it's easy to see where flooding is a concern with this stalled-out but strong storm system.
Everybody stay safe while the weather is wacky. I think I'm going to confine my severe weather updates on here to when my weather radio goes off for local stuff in or around Cullman County. One person simply cannot cover all the mischief all over North Alabama and Southern/Middle Tennessee in a synoptic setup like this. So I'm saving my energy for Saturday night into Sunday, whatever we get locally then. Do know that more pleasant, tranquil weather is on the way, even if it comes with some cold mornings next week.
Before I forget it, history gets lost in the shuffle sometimes, today was the anniversary of the
April 3-4, 1974 tornado outbreak. In many ways it is still the worst tornado outbreak our region has experienced. And it was widespread. The magician
David Williamson credits the aftermath of the Xenia, Ohio tornado that day for helping him follow his interest and get into that career. In Alabama, the worst tornado was probably the one that hit Guin. But Jasper's F-4 tornado (and the F-scale had just come out) was plenty bad enough.
And there is a
SKYWARN class in Morgan County Thursday April 10th, so a week from today, 6 PM at the Hartselle/Oak Ridge Fire Department. I think that will wrap up the season for those except for a couple classes later in the month specifically for the deaf and hard-of-hearing, in Decatur and then another in Tuscumbia, which you can see on the schedule. And that does present a special challenge, doesn't it? We tell people to use weather radio to wake up for severe weather, but if somebody can't hear it . . . well, I'm glad the National Weather Service in Huntsville does those special classes for people who need some extra help getting timely weather information and staying safe from storms.
5:19 PM - Adding a note that the Lake City, AR and Selmer, TN tornadoes have been preliminary rated E/F-3 based on the damage that has been seen. But ongoing severe weather prevents staff from going out and surveying the damage safely. Those poor folks, they are going to be so busy next week. This is one of the most unusual severe weather setups I think I've ever seen. And I'll be glad when it's over with for everybody.
