Monday, January 25, 2010

A Look Back at Wednesday's Tornadoes

Funnel Cloud in Flint

It was a very busy night Wednesday evening as severe weather struck East Texas producing at least 9 tornadoes and numerous reports of large hail. I thought I would take you through the event by looking at each storm that produced a tornado and show you what we see on radar to determine if a storm could produce a tornado.

The Waskom Tornado

The 1st tornado we will look at is the Waskom Tornado. The storm that produced this tornado developed over southeastern Smith CO in the early afternoon and produced up to Golfball size hail near Arp. The three images below are of the velocity data, showing you the tornado circulation, the reflectivity, and the volumetric data. As the storm crossed the interstate and produced most of its damage, it looks as though the radar is picking up a debris ball, an area of enhanced reflectivity on the tip of the hook. The radar beam was hitting this part of the storm at 950’ so it is very possible we are seeing rooftops and trees swirling around this storm. In the volumetric scan you see a large area of deep purple indicating this storm had intense updrafts able to produce large hail and ultimately, a ¾ mile wide EF-3 tornado.







Below is from the National Weather Service :

THE NATIONAL WEATHER SERVICE COMPLETED A DAMAGE SURVEY IN HARRISON
COUNTY TEXAS...AND CADDO PARISH LOUISIANA. AN EF3 TORNADO FIRST
TOUCHED DOWN NEAR WASKOM...TEXAS IN A WOODED AREA WEST OF IRELAND
WILLIAMS ROAD. THE TORNADO QUICKLY INTENSIFIED AS IT APPROACHED
INTERSTATE 20 NEAR MILE MARKER 628 WHERE 2 BUSINESSES WERE DESTROYED
ON BOTH THE SOUTH AND NORTH SERVICES ROADS. ONE OF THE BUSINESSES
WAS A METAL BUILDING AND THE OTHER WAS A MOBILE HOME. ONE HOME WAS
COMPLETELY DESTROYED WITH ONLY A FEW INTERIOR WALLS REMAINING. A
SECOND HOME SUSTAINED MAJOR DAMAGE TO THE ROOF AND CARPORT. DEBRIS
WAS SCATTERED ACROSS INTERSTATE 20 AND HWY 80. SEVERAL OTHER HOMES
WERE DAMAGED FURTHER EAST ALONG BOTH SIDES OF THE SERVICE ROAD. MANY
TREES WERE SNAPPED AND UPROOTED IN THE AREA...SOME WERE SNAPPED DOWN
CLOSE TO THE BASE. THE TORNADO CONTINUED NORTHEAST...CROSSING
BELLVIEW ROAD INTO JONESVILLE...TEXAS WHERE A GROCERY STORE ROOF WAS
PEELED BACK AND WALLS WERE BLOWN OUT OF A LARGE WAREHOUSE. THE
TORNADO ALSO DAMAGED SOME METAL BUILDINGS NORTH OF JONESVILLE ALONG
FM 134. THE TORNADO TRACKED EAST ACROSS A WOODED AREA...SNAPPING AND
UPROOTING TREES CROSSING FM 9...AND THEN HEADED EAST INTO CADDO PARISH
IN LOUISIANA. A WEAKENED TORNADO CONTINUED EAST...CROSSING GREENWOOD
MOORINGSPORT ROAD WHERE SEVERAL TREES WERE UPROOTED AND CONTINUED
EAST OVER PORTIONS OF WESTERN CROSS LAKE BEFORE LIFTING SOUTHWEST OF
BLANCHARD...LOUISIANA. MAXIMUM WINDS WERE ESTIMATED BETWEEN 150-160
MPH WITH A PATH LENGTH OF 15.6 MILES AND A PATH WIDTH OF 0.75 MILES.


The Canton Tornado


The 2nd tornado was the EF-2 tornado that struck Canton in Van Zandt CO. Originally there was some confusion on whether this was one tornado or was the damage path two tornadoes. The final survey report indicates that this was only one tornado. Again below are three images showing velocity, reflectivity, and volumetric views. This storm had a nice velocity couplet as the tornado was crossing the hwy 19, I-20 intersection. Also you will notice a very strong hook echo with this storm. Again the volumetric image shows deep purple indicating a very strong updraft. This storm at one point was showing 3”+ hail on radar. I think the largest reported hail with this storm was golfball.







Below is from the National Weather Service :
...PRELIMINARY INFORMATION ON VAN ZANDT COUNTY DAMAGE SURVEY...

INFORMATION IN THIS MESSAGE SHOULD BE CONSIDERED PRELIMINARY AND
WILL BE SUBJECT TO CHANGE AS ADDITIONAL INFORMATION IS RECEIVED.
AN NWS STORM SURVEY TEAM SURVEYED DAMAGE ACROSS VAN ZANDT COUNTY ON
THURSDAY JANUARY 21 2010. THE DAMAGE OCCURRED ON WEDNESDAY JANUARY
20. THE DAMAGE PATH STARTED ON THE NORTHWEST SIDE OF CANTON NORTH OF
HIGHWAY 64 AND JUST WEST OF FM859. THE DAMAGE PATH ENDS IN THE
SILVER LAKE AREA IN THE EXTREME NORTHEAST CORNER OF VAN ZANDT
COUNTY.
IT IS NOT KNOWN AT THIS TIME IF THERE IS A SINGLE CONTINUOUS DAMAGE
PATH OR IF THERE ARE TWO OR MORE SHORTER PATHS ACROSS VAN ZANDT
COUNTY.
ALONG THE DAMAGE PATH...A SINGLE FAMILY HOME LOST ITS ENTIRE ROOF
AND PART OF ITS EXTERIOR WALLS. A NUMBER OF LARGE TREES WERE
UPROOTED...AND SEVERAL SHEDS AND OUTBUILDINGS WERE DAMAGED TO
VARIOUS DEGREES. A CHURCH WAS DESTROYED IN THE COMMUNITY OF STARR.
EYEWITNESS REPORTS...RADAR INFORMATION...AND DAMAGE PATTERNS SUGGEST
THAT A TORNADO WAS RESPONSIBLE FOR THE SIGNIFICANT DAMAGE. BASED ON
THE SURVEY...THE TORNADO HAS BEEN ASSIGNED AN EF2 ON THE ENHANCED
FUJITA SCALE WITH PEAK WINDS IN THE 110 TO 120 MPH RANGE.


The Henderson CO. Tornadoes

The next 2 tornadoes were spawned from a supercell thunderstorm over southeast Henderson counties in the communities of Larue, Poynor, and Coffee City. Again the three images below show the storm as it was producing tornadoes.








Below is from the National Weather Service :

PRELIMINARY INFORMATION ON HENDERSON COUNTY DAMAGE SURVEY...

INFORMATION IN THIS MESSAGE SHOULD BE CONSIDERED PRELIMINARY AND
WILL BE SUBJECT TO CHANGE AS ADDITIONAL INFORMATION IS RECEIVED.
AN NWS STORM SURVEY TEAM SURVEYED DAMAGE ACROSS HENDERSON COUNTY ON
THURSDAY JANUARY 21 2010. THE DAMAGE OCCURRED ON WEDNESDAY JANUARY
20. THE SURVEY FOUND A DISCONTINUOUS DAMAGE PATH FOR A TOTAL OF
SEVEN MILES ACROSS SOUTHERN HENDERSON COUNTY.
TWO TORNADO TRACKS WERE OBSERVED. THE FIRST TORNADO STARTED SOUTH OF
THE CITY OF LARUE AND TRACKED EAST NORTHEAST. EXTERIOR WALLS
COLLAPSED ON SOME STRUCTURES. THIS TORNADO WAS RATED EF2 ON THE
ENHANCED FUJITA SCALE WITH ESTIMATED MAXIMUM WINDS AROUND 130 MPH.
ESTIMATED PATH WIDTH WAS 200 YARDS.

THE SECOND TORNADO STARTED NEAR POYNOR AND TRACKED NORTHEAST TOWARD
COFFEE CITY. A MOBILE HOME WAS DISLODGED AND A WOOD FRAMED HOME HAD
SIGNIFICANT DAMAGE. TREE DAMAGE WAS NOTED ALONG A THREE MILE PATH
WITH AN AVERAGE WIDTH OF ABOUT 100 YARDS. THIS TORNADO WAS RATED EF1
ON THE ENHANCED FUJITA SCALE WITH ESTIMATED PEAK WINDS IN THE 90 TO
100 MPH RANGE.


The Smith CO. Tornadoes

The same storm that produced two tornadoes in Henderson CO moved into Smith CO and produced an additional two tornadoes, an EF-0 in Flint and an EF-1 near Whitehouse. As this storm moved through southern Smith CO, it was showing very strong rotation on both the National Weather Service NEXRAD and our own Stormtraker Live Doppler Network. The communities of Noonday, Gresham, Flint, and Whitehouse are very lucky. With this type of circulation we would normally have seen a long track tornado. However the circulation stayed off the ground for most of its time in Smith CO. The rotation was much stronger over Smith CO than when this storm produced an EF-2 tornado in Henderson CO.







Below is from the National Weather Service:

THE NATIONAL WEATHER SERVICE COMPLETED A DAMAGE SURVEY IN SMITH
COUNTY...TEXAS...NEAR NOONDAY. A WEAK EF0 TORNADO FIRST TOUCHED DOWN
IN A SUBDIVISION ALONG SOUTHERN TRACE CIRCLE WHERE SHINGLES WERE
PEELED OFF SEVERAL HOMES AND A TRAMPOLINE WAS THROWN UP ONTO A HOME.
SEVERAL FENCES WERE ALSO BLOWN DOWN. THE TORNADO CONTINUED EAST ONTO
WALNUT HILL DRIVE WHERE SPORADIC TREE DAMAGE WAS OBSERVED AS WELL AS
MINOR DAMAGE TO SEVERAL HOMES ALONG THE STREET. MAXIMUM WINDS WERE
65-70 MPH. PATH LENGTH WAS 1.5 MILES WITH A PATH WIDTH OF 75 YARDS.
THE NATIONAL WEATHER SERVICE COMPLETED A SECOND DAMAGE SURVEY IN
SMITH COUNTY...TEXAS...NEAR WHITEHOUSE.

AN EF1 TORNADO BRIEFLY TOUCHED DOWN NEAR THE INTERSECTIONS OF OSCAR BURKETT ROAD AND JOYE LANE (CR 2192). A SMALL METAL GARAGE WAS DAMAGED WHERE A COUPLE OF
THE WALLS WERE BLOWN OUT. A LARGE PINE TREE WAS SNAPPED ALONG CR
2192 CLOSE TO THE GROUND. SEVERAL LARGE LIMBS WERE SNAPPED OUT OF A
CEDAR TREE AS WELL AS OTHER TREES ALONG THE PATH. FURTHER NORTHEAST
ON THE NORTH SIDE OF CR 2192...A SMALL BARD WAS DESTROYED AND TIN
ROOF PANELS WERE PEELED FROM ANOTHER BUILDING. MAXIMUM WINDS ARE
ESTIMATED AT 80-85 MPH. THE PATH WAS 0.5 MILES LONG AND 75 YARDS
WIDE.



The Harleton Tornado

The next tornado was a surprise, the Harleton tornado. The storm that produced this tornado started in Gregg CO and actually showed good signs of rotation on our Stormtracker Live Doppler Radar but was not as great on the National Weather Service NEXRAD. Since the national Weather Service does not have access to our radar, there was only a severe thunderstorm warning issued on this storm. As this storm moved into Harrison CO, the rotation on our radar weakened significantly. The actual storm itself was showing a weakening sign as well. Looking at the radar grabs you will notice the cell over Harleton is very small. Also notice the rotation on the velocity image is weak and broad. The volumetric scan shows deep convection, but no large areas of deep purple so the updraft was not as strong as with previous storms. This storm showed very little evidence of a tornado but it did produce. An EF-1.







Below is from the National Weather Service:
THE NATIONAL WEATHER SERVICE COMPLETED A DAMAGE SURVEY IN HARRISON
COUNTY TEXAS NEAR HARLETON...TEXAS. AN EF1 TORNADO TOUCHED DOWN
ALONG CENTRAL AVENUE...UPROOTING TREES AND CAUSING MINOR DAMAGE TO
AWNINGS ON HOMES ALONG THE STREET. THE TORNADO TRAVELED NORTHEAST
AND UPROOTED MORE TREES AND CAUSED MINOR ROOF AND STRUCTURAL DAMAGE
TO 2 BRICK BUILDINGS AND ONE METAL BUILDING ALONG HWY 154. THE TORNADO
LIFTED JUST ACROSS HWY 154. WINDS WERE ESTIMATED AT 95 TO 105 MPH. THE PATH LENGTH WAS 0.5 MI...AND THE WIDTH WAS 50 YARDS.


The Sulphur Springs Tornadoes

The next two tornadoes were produced near Sulphur Springs Hopkins CO. Both of these tornadoes were rated EF-0. The images below show the storm as it produced its first tornado along HWY 19 south on I-20.




Below is from the National Weather Service:
INFORMATION IN THIS MESSAGE SHOULD BE CONSIDERED PRELIMINARY AND
WILL BE SUBJECT TO CHANGE AS ADDITIONAL INFORMATION IS RECEIVED.

AN NWS STORM SURVEY TEAM SURVEYED DAMAGE IN HOPKINS COUNTY ON
THURSDAY JANUARY 21 2010. THE DAMAGE OCCURRED ON WEDNESDAY JANUARY
20. THE SURVEY FOUND TWO PATHS OF DAMAGE INDICATIVE OF A
DISCONTINUOUS TORNADO TRACK. BECAUSE OF THE LACK OF COHERENT DAMAGE
BETWEEN THE PATHS...THE PRELIMINARY FINDINGS WILL LIST THE PATHS AS
SEPARATE TORNADOES.

THE FIRST TORNADO TOUCHED DOWN AROUND 615 PM APPROXIMATELY 4 MILES
SOUTHWEST OF SULPHUR SPRINGS. THE TORNADO TRACKED TO THE EAST-
NORTHEAST FOR 1.5 MILES. ONE MOBILE HOME WAS DESTROYED...RESULTING IN
INJURIES TO TWO OF ITS OCCUPANTS. IN ADDITION...A PRE-FABRICATED
METAL BUILDING ON STATE HIGHWAY 19 (JUST SOUTH OF COUNTY ROAD 174)
SUSTAINED CONSIDERABLE DAMAGE. THE DAMAGE WAS CONSISTENT WITH THE
UPPER END OF THE EF0 RATING ON THE ENHANCED FUJITA SCALE...WITH WIND
SPEEDS ESTIMATED AT NEAR 80 MPH.

THE SECOND TORNADO PATH BEGAN ONE MILE SOUTH OF THE CENTRAL BUSINESS
DISTRICT OF SULPHUR SPRINGS AROUND 630 PM...AND CONTINUED 1.5 MILES
TO THE NORTHEAST. DURING THE 10 MINUTES THE TORNADO WAS ON THE
GROUND...AROUND 50 HOMES SUFFERED SOME DEGREE OF ROOF DAMAGE...TWO
OF WHICH SUSTAINED MORE SEVERE DAMAGE AFTER BEING IMPALED BY LARGE
TREE BRANCHES. THIS DAMAGE WAS CONSISTENT WITH SPEEDS OF 80 TO 85
MPH...ALSO ON THE UPPER END OF THE EF0 RATING.




The Geneva Tornado

The 10th final tornado I will discuss was near Geneva in Sabine CO. This was the first tornado warning issued in Texas on this day. A strong area of rotation is shown on the velocity data below. Also you will see on the reflectivity a doughnut hole where a red circle surrounds an area of yellow. This indicates the rotation was wrapped in precipitation.




Below is from the National Weather Service:
THE NATIONAL WEATHER SERVICE COMPLETED A DAMAGE SURVEY IN SABINE
COUNTY...TEXAS...NEAR GENEVA. AN EF1 TORNADO TOUCHED DOWN ALONG FM
330 TOPPLING AND UPROOTING SEVERAL LARGE TREES. ONE HOME HAD MINOR
ROOF DAMAGE ALONG WITH MOST OF ITS SHINGLES STRIPPED OFF...WHILE
ANOTHER HAD ITS OUTSIDE STORAGE SHED DESTROYED. WINDS WERE
ESTIMATED TO BE FROM 95 TO 105 MPH. THE PATH LENGTH WAS 500
YARDS...AND THE WIDTH WAS 150 YARDS.

1 comment:

Joey said...

Thanks for the info, Grant. Much appreciated.