Well some thunderstorms are forming ahead of schedule this morning. I think only the HRRR morning runs picked up on this trend at all out of any forecast models.
We've got a severe thunderstorm warning for McNairy, Hardin, and Decatur Counties in Southern Tennessee. Then in Middle Tennessee, another severe thunderstorm warning for Perry and Hickman counties. The latter storm is showing some weak rotation in addition to wind potential at 60 miles per hour.
So today/tonight's storm mode may be messy. These are two line segments of storms earlier than expected that are mainly affecting Tennessee, but the rain stretching down into Northern Mississippi and Alabama.
Everyone needs to be aware that all the NOAA Weather Radio transmitters for the Nashville and Birmingham NWS offices are down today through Thursday. It was a planned software upgrade that could not be changed.
All the weather radio transmitters for the Huntsville office will work fine. Fortunately that includes the one in Cullman, that covers Walker and Winston Counties as well.
People closer to Birmingham or Nashville may want to tune to the local NPR station or some reliable radio station that will definitely cut in for severe weather and also enable Wireless Emergency Alerts on a cell phone. If some of this ends up coming through later tonight. As it very well might.
Long-term consideration, a company called WeatherCall has been known to be a great backup when weather radio fails. I remember part of their advertising used to be how reliable they were during the April 27, 2011 super tornado outbreak. And they are available for old-fashioned land lines as well as cell phones.
And maybe an odd bit of advice: If all else fails, trust your instincts. One thing they used to run on NOAA Weather Radio back in the dark ages when there were real human voices was something along the lines of, "Be prepared to take steps to protect yourself if a warning is issued or if threatening weather approaches." If you ever don't feel right about the weather, even if you haven't heard a warning yet, it's okay to move to a safer spot in your home and continue to watch the weather from there. We live in very interesting times, and my gut feeling is that over the next few years, we may see several times that various systems fail.
Now this is just a planned software upgrade. I didn't realize Nashville was doing it as well as Birmingham. But sometimes you need to be prepared if something fails. Our time-honored tradition of always being able to buy toilet paper certainly failed in early 2020. And people got downright vicious about it. Apparently they forgot how to use old catalogs and corn cobs over the decades. But seriously, old-timers used to do a lot of watching the sky, listening, and trusting their instincts. There is still a lot to be said for that. As much as I love all the technology we have.
10:05 AM - And while I've been yacking here, a Severe Thunderstorm Warning has been extended to include Waynesboro, Wayne County there in Southern Middle Tennessee. We also have a Special Weather Statement including Florence for Lauderdale and Northern Colbert County in Northwest Alabama. The winds there are estimated at closer to 55 mph which is just under severe criteria.
10:13 - Random note while it's on my mind: Former President Joe Biden was diagnosed with prostate cancer. And as my Papaw would have said: "Don't look good at all!" I find it sad to get such news about even famous folks I don't know. I am pretty sure that's what Don Imus died from. And I loved that guy even when I disagreed with him. I forgot to make mention of that because of recent personal circumstances (including a relative hit by a pickup truck - technically minor injuries but still been rough stuff) and because of this severe weather threat coming up. So there we go. Now I've mentioned it.
And the SPC is thinking about issuing a Tornado Watch for us already. Will post the Mesoscale Discussion below.
Mesoscale Discussion 0902
NWS Storm Prediction Center Norman OK
1019 AM CDT Tue May 20 2025
Areas affected...parts of eastern Kentucky...middle/eastern
Tennessee,,,northern Alabama
Concerning...Severe potential...Watch possible
Valid 201519Z - 201745Z
Probability of Watch Issuance...60 percent
SUMMARY...An initially isolated severe wind threat will probably
gradually become more widespread, perhaps along with increasing
potential for tornadoes, as storms spread eastward into early/mid
afternoon.
DISCUSSION...Little in the way of notable surface pressures rises
have recently been evident within elongated, eastward advancing
(around 35 kt) conglomerate convective outflow. However, forcing
for ascent downstream of large-scale mid-level troughing slowly
pivoting into the lower Ohio Valley has been maintaining convective
development along its leading edge, with embedded cells occasionally
undergoing a period of intensification. The downstream
boundary-layer across eastern Tennessee into the vicinity of a
stalled frontal zone across Kentucky is seasonably moist, and
becoming characterized by CAPE in excess of 1000 J/kg, with
inhibition gradually weakening with insolation.
As daytime heating continues, a gradual intensification of storms is
likely to continue, with further organization probable as this
occurs, in the presence of strong deep-layer shear beneath 50+ kt
southwesterly 500 mb flow. It appears that the intersection of the
convective outflow and the surface frontal zone may become the focus
for a developing area of low pressure across south central through
southeastern Kentucky. As this occurs, hodographs might become
increasingly conducive to a risk for tornadoes, in addition to
increasing potential for strong to severe surface gusts associated
with the strengthening convective cold pool.
..Kerr/Hart.. 05/20/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...RLX...MRX...JKL...LMK...OHX...HUN...
LAT...LON 37708562 38428448 38278303 37078313 35698500 34588637
34558787 35158777 36098684 37708562
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
10:48 AM - All warnings have been let go. Still have a Special Weather Statement on that storm in Wayne County for wind gusts up to 50 mph.
The main event for severe weather is still expected to come later in the afternoon, evening, through the night hours.
If there is a clearly defined main event. The storm mode may end up being messy today despite some periods of daytime heating.
Logging off for a while.
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