9/25/05 REPORT: MS/AL

Tony Cook

EF2
Joined
Apr 26, 2005
Messages
157
Location
Austin, Texas
My chase partner and I got a late start (~3:45CDT) out of West Huntsville, AL. Caught a rotating wall cloud with a couple of transient funnels just south of the city of Madison, AL. It persisted for less than ten minutes.

Caught two other cells with suspicious wall clouds over the next 3 hours. As the sun went down, the activity in N AL calmed down, with more discrete convection still occuring south of us near Birmingham.

Tuscaloosa County, AL was hit by several tornadoes. Some of the local media showed video of an impressive, strong-looking tornado. Seems to me that Tuscaloosa County, AL is the epicenter of tornadoes for our region over the last few years. We always joke that we should just head towards Tuscaloosa whenever there's a slight risk around here. Cuts out the headache of preparing a forecast.

TonyC
 
There was an unmistakable RFD slot in the towercam video that ABC 33/40 in BHM had yesterday for the Tuscaloosa County tornado. Still kinda hard to believe they caught the sucker live.....
 
Excerpt from the latest public info. statement from Birmingham about the Tuscaloosa county tornadoes...


AFTER EXTENSIVE AERIAL AND GROUND SURVEYS ACROSS WESTERN TUSCALOOSA
COUNTY...AT LEAST 8 SEPARATE TORNADO TRACKS WERE DISCOVERED.
PRELIMINARY DATA SUGGEST THAT 2 F1`S AND 6 F0`S OCCURRED. FURTHER
REVIEW OF SURVEY PHOTOS AND RADAR DATA IS ONGOING AND A LIST OF THE
TRACK LOCATIONS AND FINAL RATINGS WILL BE MADE AVAILABLE TUESDAY
MORNING. AT THIS TIME...ONLY TWO INJURIES WERE REPORTED WITH THE
TORNADOES IN TUSCALOOSA COUNTY. ..

8 separate reports now. I am surprised the Towercam tornado only did F1 damage. It looked like a monster. I believe it traversed mainly unpopulated areas, with the exception of Lake Lurleen.

TonyC
 
Wow, Really? Geez, it looked like something much greater than an F1. I am surprised about this, Like I said, I thought it would have been a higher end F2. It was pretty wide, and looked pretty powerful.
 
The problem with this tornado was that it wasn't rotating rapidly at the SFC. The highest winds were indicated just above the SFC by radar estimates and VWP's. A mesoscale boundary setup just west of downtown Tuscaloosa, AL and made for a rocky afternoon Satruday as supercell after supercell rode across it. I have a few pictures here that are of the torando taken by the ABC33/40 towercam. This tornado was some 18 miles away from that towercam site.







I also have a few shots from my Spectrum Width and Storm Relative Velocity from my LIVE Level II radar. In this shot of spectrum width, the tornado is idicated and is currently on the ground right between these two intense spikes NW of Coker.



Also, the couplet is currently maxed out, outbound and inbound.

 
This is a perfect example of why the size of a tornado cannot become equal to an F-rating, like we were discussing several months ago.

Jason
 
Are there many known cases of F-4 and above tornadoes spawned by hurricanes? In my few experiences with them, it seems that large visible funnels are not unusual, but F-0/F-1 damage reports are the most common.

I accidentally drove under a wall cloud late at night during Hurricane Danny's trip through South Carolina that caused one or two fatalities a few miles further north. The structure visible due to elevated billboard lighting in North Augusta, SC, was formidable.

Dave Gallaher
Huntsville, AL
 
Hi Brett,

Just to clarify, your screencaps there aren't from the towercam video. They are much closer to the tornado than the towercam was. Those screencaps look like they came from the vantage point of the video shot by Alex Cody, located here:

http://www.tuscaloosanews.com/apps/pbcs.dl...WVUA01/50925006

He was supposedly shooting NW towards Lake Lurleen. Some of the treeline features look the same as those in the screencaps you posted. Nice shot of the velocity couplet, btw.

TonyC
 
Thanks, Tony for clearing that up. I have some wall cloud and funnel pictures to post up. This was the largest outbreak that I can ever remember Alabama experiencing enduced from a tropical cyclone. :shock:
 
Originally posted by Jason Toft
This is a perfect example of why the size of a tornado cannot become equal to an F-rating, like we were discussing several months ago.

Jason

I do not know if I participated in that discussion, but the Fujita scale has some Major flaws, and inconsistencies. I mean as you know if depends on how well each building was built, and if the tornado occurs in the city orr in a rural area. I mean an actual F5 tornado could occur in a field in some rural countryside, and be rated at F0, because it caused no damage. Now, and F1 could happen in a city and be named an F4-F5. IT's just too flawed, and it's not just measured by wind-speed but as you know, the damage it did.
 
Originally posted by Andrew Khan+--><div class='quotetop'>QUOTE(Andrew Khan)</div>
<!--QuoteBegin-Jason Toft
This is a perfect example of why the size of a tornado cannot become equal to an F-rating, like we were discussing several months ago.

Jason

I do not know if I participated in that discussion, but the Fujita scale has some Major flaws, and inconsistencies. I mean as you know if depends on how well each building was built, and if the tornado occurs in the city orr in a rural area. I mean an actual F5 tornado could occur in a field in some rural countryside, and be rated at F0, because it caused no damage. Now, and F1 could happen in a city and be named an F4-F5. IT's just too flawed, and it's not just measured by wind-speed but as you know, the damage it did.[/b]

That is just how the F-scale was designed...

When a tornado moves through a city, it's gonna recieve an honest rating - Since the actual windspeed of the tornado will make itself more clear. You cannot make a rating scale that is based upon the actual windspeeds, as there is no way of determining that by looking at fields where a tornado hits. It's all about the damage the tornado produces...
 
This is in response to Dave's question earlier about F4/F5 tornadoes in Hurricanes. I took this from here:
http://www.srh.noaa.gov/jax/ghls/ghlstornadofaq.shtml


Q. Is it true that only weak tornadoes occur in association with hurricanes?
A. While most hurricane tornadoes are weak, strong tornadoes do occur and can result in fatalities. In fact, an F3 tornado (158-206 mph) occurred during Hurricane Andrew (1992) at La Place, LA and killed 2 people and an F4 tornado (207-260 mph) touched down in Galveston, TX during Hurricane Carla (1961) and resulted in 8 deaths. Hurricane Agnes (1972) produced 28 tornadoes within Florida, with 11 of F2 or greater strength, resulting in 7 deaths.

So there's at least one instance of an F4 on record from a Hurricane Tornado.

TonyC
 
I am wondering why it is so rare to get a major tornado from a Hurricane (Bands). I would take a guess that, the storm-scale rotation doesn't have time to mature enough, because in Hurricanes, the rotations/meso's quickly dissipate and initiate.
 
Bingo. These storms are usually mini-supercells that spawn for the most part, short lived tornadoes. The fast movement of the parent storms and the moist environment (lack of dry air) all play some role. The bottom line is that the storms are not able to develop a sustained, persistent updraft rotation.
 
Originally posted by HAltschule
Bingo. These storms are usually mini-supercells that spawn for the most part, short lived tornadoes. The fast movement of the parent storms and the moist environment (lack of dry air) all play some role. The bottom line is that the storms are not able to develop a sustained, persistent updraft rotation.

So, if they obtained dry air into their inflow, then they would get a sustained rotating updraft, which would allow longer lived tornadoes.
 
I'd have to say strong/violent tornadoes are very much possible from some hurricanes (depending on all the dynamics/instability). For instance, there was some very sustained and discrete supercells in southern MS the other day (associated with Rita) - Some of them lasted a solid hour or so, which is more then ample time to drop a F3-F4 tornado.
 
Thanks, TonyC, and everyone.

Wow--Hurricane Carla. I rode that one out with my family in SW Houston and that was a lo-ong night. I remember Dan Rather (local in those days) broadcasting from Galveston until power was gone.

We had a hurricane-spawned tornado that crossed Redstone Arsenal in this area in (I think) 1985 that had an impressive upper structure (which was all I could see from my vantage point as it translated very rapidy) that I reported on in the old print version of ST. If I recall, damage was spotty and F-1...

Dave Gallaher
Huntsville, AL
 
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