Wednesday, January 30, 2013

The Tornado Chronicles: Adairsville, GA Tornado of 1-30-13...


An isolated supercell thunderstorm formed out ahead of a line of thunderstorms over northwest Georgia on Wednesday morning, January 30, 2013, producing a tornado that has caused significant damage and injuries in the Adairsville area. 

One person was killed (reportedly the occupant of a mobile home), and numerous persons have been injured.  Our thoughts and prayers are with all of the victims and those attempting to help them.

The above screen grab came from the following YouTube video, which shows the actual tornado as it moved into Adairsville:



Another video shows the same tornado from a different vantage point (likely the opposite side and obviously further away than the one above):



A few still photos have also come about, the first one relatively close to the location of the 2nd video (note the sign belonging to the shopping center that appears to be just to the right of the tornado):



Here is another photo of the tornado, taken from an unspecified location but obviously some distance away.  The identity of the photographer was not provided:



Damage photos are also flowing in, and I will be sure to credit the images when the original person is known.  The first two via twitter from Megan Jamison:



...and the next two are via WSB-TV:



I believe the photo of the overturned vehicle shows one of "numerous" vehicles, including semi's, that were overturned on I-75.

Numerous people were reportedly trapped in both vehicles and buildings throughout the area and had to be rescued.  Efforts were hampered in some cases by trees and power lines blocking several major roadways.

It's difficult to accurately gauge the intensity of the tornado thus far with limited details on the types of structures that were impacted.  The picture below shows a fence laying down on top of a brick base, but is unclear what may or may not have been sitting above that brick in the first place:




The following video has been posted to YouTube and gives us some very revealing insights into the intensity of the tornado.  I'll post the video first, and then point out a few things immediately following it:



At about 0:36 into the video, note what appears to be a frame home with only a bathroom and part of an interior wall standing.  Unless the construction of the home was below average, that type of damage is generally consistent with an EF-3 intensity tornado:


Another sign that the Adairsville tornado was strong and/or violent is the small debris that you can see sticking straight up vertically in the ground at about 1 minute into the video:


...and as if that weren't enough evidence, take a look at this final screen grab from the damage video, which shows a "missile" that has been shot into the side of a vehicle:


I have just come across the following photo that shows the first possible hint of EF-4 intensity damage:


Depending on what type of construction was in place (i.e., how much of the exterior was covered by the masonry block, etc.), this could be EF-4 damage.  Otherwise, all of the damage photos that I've seen so far mostly depict a maximum of high-end EF-3 damage.  I'll continue looking at new photos and video and post any revelations as they come forward...

Indeed, a very strong circulation was noted on radar as the parent thunderstorm moved through the area at about 11:20 a.m. EST / 10:20 a.m. CST this morning:


An image put together by the National Severe Storms Laboratory (NSSL) shows the progression of the "mesocyclone" (or radar indicated tornado signature like the one above) associated with the parent thunderstorm as it tracked from east-central Alabama into northwestern Georgia:


The National Weather Service (NWS) has just released their preliminary assessment of the damage in Adairsville, and have rated the tornado "high end" EF-3 intensity, with maximum winds estimated at 160 mph.

The tornado was on the ground for 24.5 miles and had a width of 400 yards (nearly 1/4 mile) at its maximum:



Please check back to this post for updates as new information, photos and videos are received.

For more information from 'The Original Weather Blog', including shorter, more frequent posts during rapidly changing weather events, please be sure to follow me on facebook and twitter:
 

Coming March 2013:  The Tornado Chronicles full website!
• Interactive tornado database back to 1950 (earlier years coming soon)
• Interactive radar with live warnings and street-level zoom
• Tornado safety, preparedness and education
• Daily tornado outlooks/threat index
• Photos, videos & more!

Please show your support and follow The Tornado Chronicles on twitter and on facebook for the latest updates on tornadoes and the upcoming website!

Severe Weather Continues; Shifting into Southeast/Mid-Atlantic...

Strong to severe thunderstorms continue this morning along a strong cold front that currently stretches from near Buffalo, NY to New Orleans:


The front will continue Eastward during the day, with widespread wind damage a continued threat, especially over the southeast U.S. and mid-Atlantic regions, as shown by the red shaded and black hatched area on the image below:


Within this region, which includes the cities of Columbus, Atlanta, Columbia, Charlotte, Raleigh and Roanoke, damaging wind gusts may exceed 70 mph in some areas.  Such intense winds can cause just as many (or even more) problems as your "average" tornado, so please take the threat seriously if you live in this region.

Like yesterday, a few isolated tornadoes cannot be ruled out, however the primary threat will be wind damage, some of which could be significant.

Any tornado threat would primarily come in the form of brief spin-ups in rotating comma heads or "dog leg" signatures on radar.  Any isolated storms that are able to become well organized out ahead of the main line would have a locally higher potential for a tornado, but this would be a relatively isolated threat.

Elsewhere, strong to at times severe storms will be possible across a broad swath of the eastern U.S. today (as indicated by the yellow and brown shaded areas on the above image).  Here again, wind damage will be the primary threat.

If you live across the severe weather threat areas for today, please pay attention to the weather.  Review your severe weather safety and preparedness tips and be ready to seek shelter quickly if threatening weather is observed or a warning is issued for your area.

For more information from 'The Original Weather Blog', including shorter, more frequent posts during rapidly changing weather events, please be sure to follow me on facebook and twitter:
 

Coming March 2013:  The Tornado Chronicles full website!
• Interactive tornado database back to 1950 (earlier years coming soon)
• Interactive radar with live warnings and street-level zoom
• Tornado safety, preparedness and education
• Daily tornado outlooks/threat index
• Photos, videos & more!

Please show your support and follow The Tornado Chronicles on twitter and on facebook for the latest updates on tornadoes and the upcoming website!

Tuesday, January 29, 2013

Severe Weather Update for the Deep South / Lower MS Valley Region...


An area of shower and thunderstorm activity is developing over central and northern Louisiana at this hour, well ahead of a line of thunderstorms along the cold front further to the West and Northwest.

If this activity is able to organize and intensify this evening, a locally higher risk of tornadoes may result across northern Louisiana, southern and eastern Arkansas, western Mississippi and western Tennessee - as compared to what we've seen so far today.  This would especially be the case with any storms that are able to remain relatively isolated and become well organized.

Otherwise, a line of severe storms will move West to East across the region later this evening, as the cold front approaches from the West. The activity currently extending from Ft. Smith, AR to Dallas to Waco will intensify and become better organized as it moves East into the region this evening...


The primary threats with the line of activity will be intense wind damage, with possible brief tornado spin-ups, much like we've seen throughout the day today, though on a larger scale as the upper-level storm system to the West moves over the region and enhances lift.

If you live across the aforementioned areas of Louisiana, Arkansas, Mississippi and Tennessee, please remain alert this evening.  Make sure that you have a way to receive severe weather warnings, and be prepared to seek shelter immediately if threatening weather is observed or a warning is issued for your area.

Regardless of any specific tornado threat across the region, due to the strength of the jet stream winds that will be flowing across this region this evening and early tonight, wind damage could be particularly intense and widespread.  I strongly suggest taking the same precautions with a severe thunderstorm warning as you would with a tornado warning this evening, just to be safe.  Wind gusts well in excess of 70 or 80 mph will be possible with the strongest storms, regardless as to whether or not any specific tornado threat materializes.

For more information from 'The Original Weather Blog', including shorter, more frequent posts during rapidly changing weather events, please be sure to follow me on facebook and twitter:
 

Coming March 2013:  The Tornado Chronicles full website!
• Interactive tornado database back to 1950 (earlier years coming soon)
• Interactive radar with live warnings and street-level zoom
• Tornado safety, preparedness and education
• Daily tornado outlooks/threat index
• Photos, videos & more!

Please show your support and follow The Tornado Chronicles on twitter and on facebook for the latest updates on tornadoes and the upcoming website!

Early Afternoon Severe Weather Update...


At 1:30 p.m. CST, a line of strong thunderstorms extended from northeast Missouri back to the southwest into western Texas.  The activity continues to develop along and ahead of a surface cold front (northern and central portions) and dryline (southern portion).

Individual thunderstorms are racing Northeast at 55-60 mph, while the line itself is moving East at about 25 mph on the southern end, and 45-50 mph on the northern end.
Tornado Watches continue this afternoon and evening in the areas shaded in lavender, with a Severe Thunderstorm watch shown in red over Texas:


The main energy associated with a strong middle and upper-level weather disturbance (currently centered over New Mexico) remains to the West of the thunderstorm line at this time, but is starting to approach the line in Texas:


As stronger middle and upper-level winds and other energy continue to advance toward and overspread the thunderstorm line later this afternoon, the activity will become more intense and will likely generate widespread wind damage at times, particularly in a region extending from northeast Texas into much of Arkansas, as shown within the lavender shaded and black hatched area on the image below:


This threat will shift East and Northeast into the Mississippi Valley region later this evening and into tonight.

Some of the winds could be particularly intense, in excess of 70 or 80 mph, due to the strong jet stream forcing that will come into play later today.  That type of wind can cause extensive damage, injuries and even death if you are in the wrong place at the wrong time, so please take the situation seriously.

A few tornadoes also cannot be ruled out, particularly in association with any storms that are able to form out ahead of the main line, and within circulations embedded within the line itself.  These types of circulations tend to be smaller, weaker and shorter lived than their supercell counterparts, which can make radar detection difficult - leading to little or no advanced warning.

With the potential for extreme winds rather high, I would strongly suggest treating a severe thunderstorm warning in the aforementioned areas today as you would a tornado warning.  In the least, move to the center most portion of your home or business and stay away from outside windows and doors until the storm passes your location.

Much of the severe weather threat for roughly the Eastern (and especially the southeastern) half of the outlook area will take place after dark or even overnight tonight.  Please make sure that you have a way to receive weather warnings at night if you live in these areas.

For more information from 'The Original Weather Blog', including shorter, more frequent posts during rapidly changing weather events, please be sure to follow me on facebook and twitter:
 

Coming March 2013:  The Tornado Chronicles full website!
• Interactive tornado database back to 1950 (earlier years coming soon)
• Interactive radar with live warnings and street-level zoom
• Tornado safety, preparedness and education
• Daily tornado outlooks/threat index
• Photos, videos & more!

Please show your support and follow The Tornado Chronicles on twitter and on facebook for the latest updates on tornadoes and the upcoming website!

Severe Weather Update for Texas...

Thunderstorms are developing southward into extreme northwest Texas along the cold front at this hour:


...and I expect them to increase in coverage and intensity and sweep through most of northcentral and northeast Texas this afternoon...including the DFW Metroplex region.  Damaging wind gusts and hail will be the primary threats, although an isolated tornado spin-up cannot be ruled out.

If any isolated storms are able to develop and become organized ahead of this line, the localized tornado threat would increase with such cells.

Further South, including the Austin-San Antonio corridor along I-35, its coming down to a battle of the atmosphere.  The low levels are very moist and will become increasingly unstable throughout the day, however a relatively strong "capping inversion" (also known as a "lid" - see the oldie but goodie link for details) is in place across the region.

Strong instability and increasing support from the upper level storm approaching from the West is likely to be able to overcome the cap and allow for thunderstorm development down at least part of the I-35 corridor later this afternoon... but the question is how far South?

One way to measure how unstable it is in the lower atmosphere is to look at an index called CAPE (convective available potential energy).  The current CAPE analysis shows high values starting to "pool" along the dryline in west-central and southwest Texas, as indicated by the green shaded area on the image below:


This pocket of instability is forecast to move Eastward into the Austin-San Antonio corridor and become even more unstable later this afternoon, as indicated by the brighter yellow shaded area on the forecast image below (valid at 3pm):


This could indeed be enough of a "push" to allow for thunderstorm development as far South as the Austin-San Antonio area late this afternoon.

As I've been saying for a few days now... this is one of those "all or nothing" situations.  If a storm is able to break through the cap and form in this region, it will tap that high instability and could become severe quickly, with large hail, damaging winds and an isolated tornado possible.

I would place the chance of a thunderstorm at 30-40% in Austin, 20-30% in the Kyle/Buda areas, and 20% in San Antonio.  If a storm is able to form in any of those areas, the chance of severe weather would be relatively high, so stay alert!

For more information from 'The Original Weather Blog', including shorter, more frequent posts during rapidly changing weather events, please be sure to follow me on facebook and twitter:
 

Coming March 2013:  The Tornado Chronicles full website!
• Interactive tornado database back to 1950 (earlier years coming soon)
• Interactive radar with live warnings and street-level zoom
• Tornado safety, preparedness and education
• Daily tornado outlooks/threat index
• Photos, videos & more!

Please show your support and follow The Tornado Chronicles on twitter and on facebook for the latest updates on tornadoes and the upcoming website!

Severe Weather Event Getting Underway...

As expected, thunderstorms formed during the pre-dawn hours from western Oklahoma into southeast Kansas and west-central Missouri.  The activity is racing toward the North/Northeast, while gradually shifting Eastward over time:


There have been isolated reports of hail and/or wind gusts near severe limits thus far in west-central Oklahoma, but nothing widespread or major through the time of this writing.

The development thus far has taken place ahead of a strong middle and upper level weather disturbance that is currently centered over the southern Rockies:


This disturbance will lift out to the Northeast during the day today, resulting in an increasing threat of severe weather (with respect to both coverage and intensity) across the southern and central Plains, Deep South and Mississippi Valley regions.

The latest severe weather outlook from the Storm Prediction Center is shown below, valid for today and tonight:


This particular graphic is focused on the wind damage threat, which I continue to believe will be the primary severe weather mode today and tonight.  The red and lavender shaded and black hatched areas are where intense, very damaging winds are possible over a fairly widespread area.  The jet stream will be blowing overhead of this region at speeds well in excess of 100 mph later today and tonight, and some of those intense winds are likely to "mix down" to the surface in association with some of the most severe storms.

While wind damage will be the primary severe weather mode today and tonight, there is still a risk of tornado development in two primary ways:

(1).  In association with any isolated storms that are able to form out ahead of the developing line or lines of storms

(2).  In association with any rotating "comma heads" or "dog legs" that form along the lines of storms

I took a screen shot of a "dog leg" on a small line in Oklahoma earlier this morning (circled in white on the following image):


The trick with the linear severe storm tornado situations is that the tornadoes tend to be very brief, making radar detection difficult.  As in the example above, on the next radar scan about 4 minutes later, the "dog leg" rotational signature was gone.

The best chance of tornado spin-ups today will be within the red and lavender shaded areas on the outlook image above.  Keep in mind that part of this risk (the Eastern portions of the risk area) will take place after dark and into tonight.

If any isolated storms are able to form ahead of the main line or lines, they could potentially produce a stronger or longer track tornado, but I do not expect this to be a general rule today.  Therefore, I believe using the term "tornado outbreak" does not apply to the situation today.  A severe weather outbreak is certainly possible, with wind damage being the primary feature.

Hail up to around 1 inch in diameter is also possible with the stronger storms.  A more vigorous storm or two could produce locally larger hail, but the overall scenario does not favor widespread large hail production today.

If you live in or near the severe weather threat areas for today and tonight, please remain alert.  Make sure that you have a way to receive severe weather warnings, including overnight tonight in the Deep South and Mississippi Valley region.

Please review your severe weather safety and sheltering tips this morning, that way you're ready to seek shelter at a moments notice later today if threatening weather approaches your area.

The best way to receive "live" updates from me today will be to follow on the twitter and/or facebook links below.  Radar and watch links will also be updated here on the blog homepage throughout the day, along the right hand side of the page.

For more information from 'The Original Weather Blog', including shorter, more frequent posts during rapidly changing weather events, please be sure to follow me on facebook and twitter:
 

Coming March 2013:  The Tornado Chronicles full website!
• Interactive tornado database back to 1950 (earlier years coming soon)
• Interactive radar with live warnings and street-level zoom
• Tornado safety, preparedness and education
• Daily tornado outlooks/threat index
• Photos, videos & more!

Please show your support and follow The Tornado Chronicles on twitter and on facebook for the latest updates on tornadoes and the upcoming website!