1/13/06 NOW: AL/GA/FL

[Andy Wehrle]

Strong semi-discrete supercell currently located in Henry County, AL soon to cross the AL/GA border. At times it has varied back and forth from classic to HP. Sometimes the forward flank develops a shear zone and appears to want to bow out but as of 1852Z it has reverted to a more classic supercell signature with the dominant rotating updraft in the back right corner.

It shows a moderately strong couplet on both base velocity and storm-relative velocity, and a hint of an appendange on reflectivity. It has not been tornado-warned.

Everything seems go for this cell producing at least some form of significant severe weather, only impediment for a tornado would appear to be less-than-ideal placement of surrounding showers/storms relative to its inflow.

Edit: Reference SPC MCD # 53 which specifically mentions this storm:

http://www.spc.noaa.gov/products/md/md0053.html

 

[Mike Johnston]

Prelim storm reports show one unconfirmed fatality Belleville, AL and a school complex damaged at Baker, FL with minor injuries 10 to 15 students.

As instability now starting to build over the Carolina coastal plain, and RUC shows surface low deepening to 996mb by 00z, along with impressive mid-level dynamics and steepening lapse rates, looks like may be setting up for an event later this afternoon over the Carolina Piedmont, and then coastal plain this evening, perhaps even up to Tidewater Virginia.

 

[Jeff Snyder]

Geez, the activity in Georgia looks like an reverse squall line -- leading stratiform, trailing convection. This is leading to reduced instability available to the more vigorous convection on the western side of the line. Storm mode currently doesn't look like it'll be favorable strong tornadoes, which is partly why I'm a little surprised that the new Day 1 has a hatched tornado risk. I guess the low-level shear is strong enough to support a significant tornado, but instability is marginal and the surface flow ahead of the convection is mainly out of the southwest. Models suggest stronger flow will overspread the area through the afternoon, and some insolation should help increase CAPE ahead of the activity for the next couple of hours. I guess I'd focus the threat across far southern GA and the northern FL panhandle.

 

[Andy Wehrle]

I noticed that too earlier Jeff, which is why I was somewhat skeptical that supercell I was talking about could produce a tornado, although there is a report of one in Henry County, AL right around the time I posted.

Now, even the entire system seems to have undergone "reverse evolution"-the squall line has broken up into more discrete cells. Darned if there isn't a hook echo in Colquitt County, GA. 52 dbz and a POSH (1.50") hail indicator on that cell. No warnings of any kind on it though.

EDIT: DUH...the image I was looking at from KVAX (Moody AFB, GA) hadn't updated in almost an hour (was showing 2138Z) which explains why there was no warning marker on such an impressive looking cell.

EDIT #2: Turns out the storm was tornado-warned during that time, and did produce.

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM EST FOR SOUTHERN TIFT...NORTHERN COOK AND NORTHEASTERN COLQUITT COUNTIES...

AT 430 PM EST...TRAINED WEATHER SPOTTERS REPORTED A TORNADO. THIS TORNADO WAS LOCATED NEAR CROSLAND ON LIVINGSTON BRIDGE ROAD...OR ABOUT 12 MILES NORTHEAST OF MOULTRIE...MOVING EAST AT 50 MPH.

 

[Dan Robinson]

I think the stratiform area is outrunning the frontal forcing, which is strong enough to re-initiate storms.

The 11/15/05 outbreak also featured a thick stratiform precip region on the leading side of the convection later in the evening in IN, KY and TN. Very unusal to see that on radar and in the field.

 

[Mike Johnston]

New WW issued for the central Carolinas, as I suspected might be tonight. RUC showing strengthening LLJ through the evening hours and surface obs hinting at winds starting to back a little. Meanwhile, upper trough showing some negative tilt. Reflectivities out of Columbia radar site keep showing shear markers on and off, with 0-3km helicity maxing at 500-600 m2s2 over the area. Although instability barely detectable, never discount strong dynamics over the south at night - especially this winter season!

 

[mikegeukes]

Some TV Links to the tornadoes from today:

Birmingham AL:
http://www.wbrc.com/news/news1.html
http://www.wbrc.com/news/news2.html

Mobile AL
http://www.wkrg.com/servlet/Satellite?page...d=1128769307278
http://www.wpmi.com/news/local/story.aspx?...14-753AF66DC2B9

Montgomery AL:
http://www.waka.com/
http://www.wsfa.com/Global/story.asp?S=4360059

Panama City FL
http://www.wjhg.com/home/headlines/2198422.html

Mike

 

[Scott Olson]

That Camden storm is isolated and showing 90kts rotational velocity at 1700ft. A very strong low level mesocyclone present on that cell.

In addition to the fatality from the tornado today there was also one reported from lightning.

 

[Bob Schafer]

USA Today article, and there are some cool general-tornado-info links from there, too

http://www.usatoday.com/weather/stormcente...do_x.htm?csp=34

Bob

 

[Bob Schafer]

<deleted due to duplication>

Geez, soon as I rave about Firefox, I get a dup of my post...

Bill Gates is monitoring me, I guess.

 

[Dan Robinson]

This is a little odd - The 0600Z SWODY1 (graphic and discussion) just came out and the severe risk is gone from the outlook. It is the correct outlook for Saturday, except right now, severe storms are still ongoing across the Carolinas and the southeast, and will be for several more hours. Watches are in effect for eastern NC, one until 7AM well into the Day 1 period.

I've never seen a new Day 1 that looked past current ongoing severe weather.

 

[Jeff Snyder]

Originally posted by Dan Robinson
This is a little odd - The 0600Z SWODY1 (graphic and discussion) just came out and the severe risk is gone from the outlook. It is the correct outlook for Saturday, except right now, severe storms are still ongoing across the Carolinas and the southeast, and will be for several more hours. Watches are in effect for eastern NC, one until 7AM well into the Day 1 period.

I've never seen a new Day 1 that looked past current ongoing severe weather.

Dan,

The 6z SWODY1 outlines the risk starting at 12z; the SWODY1 0600z outlook is valid from 12z to 12z the following day. So, it does not address the 6z-12z period, though ongoing severe threats are usually at least mentioned in the 6z SWODY1.

 

[Mike Johnston]

Wow, woke up to some thunder a few moments ago and see that 4 counties just to the E of Richmond are tornado warned now at 2:00am! Surface low just to the N has deepened to 992mb and LLJ looks to have kicked up as expected. Shear and TVS markers look to be just on the nose of a vigorous bowed line moving across New Kent towards Riverview Landing. Given the hour of the day, really hope that these aren't producing as many residents in that area would most likely be underprepared and unaware.