Watching the Skies » Hillsborough County FL

Multiple waterspout sightings around Tampa Bay

Sean Toner — Mon, 27 Jul 2009 19:44:36 +0000

Several reports of waterspouts have been submitted to the National Weather Service in Ruskin today, including one in Old Tampa Bay. The waterspout in Old Tampa Bay is the storm that prompted the tornado warning earlier, no damage has been reported at this time.

I have included some pictures of today’s waterspouts, courtesy of Bay News 9.

[nggallery id=76]

Tornado Warning for Hillsborough County

Sean Toner — Mon, 27 Jul 2009 15:32:21 +0000

A waterspout moving ashore from upper Tampa Bay prompted a tornado warning for west Hillsborough County. The tornado is near Courtney Campbell Causeway, Town N Country and Tampa Intl Airport.

BULLETIN – EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TAMPA BAY AREA – RUSKIN FL
1123 AM EDT MON JUL 27 2009

THE NATIONAL WEATHER SERVICE IN RUSKIN HAS ISSUED A

* TORNADO WARNING FOR…
WESTERN HILLSBOROUGH COUNTY IN FLORIDA.

* UNTIL 1145 AM EDT

* AT 1121 AM EDT…A WATERSPOUT MOVING TOWARD SHORE WAS SIGHTED NEAR
TOWN ‘N’ COUNTRY…OR 8 MILES WEST OF TAMPA…MOVING EAST AT 10
MPH.

* THE WATERSPOUT WILL BE NEAR…
COURTNEY CAMPBELL CAUSEWAY.
TOWN ‘N’ COUNTRY.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

REMEMBER…AS WATERSPOUTS MOVE ASHORE THEY BECOME TORNADOES AND
SHOULD BE CONSIDERED EXTREMELY DANGEROUS!

IF YOU ARE IN THE PATH OF THE TORNADO GO TO A SMALL INTERIOR ROOM IN
A STRONG AND WELL CONSTRUCTED BUILDING. CARS AND MOBILE HOMES ARE NOT
SAFE! IF NO SHELTER IS AVAILABLE…LIE FLAT IN A DITCH OR CULVERT AND
COVER YOUR HEAD WITH YOUR HANDS.

TO REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE PLEASE CALL
813-645-2323.

Edit: How fitting that my 400th blog post is a tornado warning. That makes me happy.

Tornado damage confirmed in Carrollwood Village!

Sean Toner — Tue, 30 Jun 2009 21:01:34 +0000

Looks like the NWS is confirming tornado damage in Carrollwood Village from a tornado earlier this afternoon. Usually it takes the weather service a day or two to perform damage surveys so this is extremely fast. They rated this as an eF-0 tornado which toppled pine trees and telephone poles in Carrollwood Village along Golf Crest Circle. The trees that fell hit a house and broke some shingles. No other damage reports have come in at this time.

Threat has ended – Tornado warning for Hillsborough County!

Sean Toner — Tue, 30 Jun 2009 19:38:38 +0000

The tornado warning has ended for Hillsborough County. The storm that produced the warning weakened and rotation completely stopped. The rotation spun up over Carrollwood Village at Fletcher & Dale Mabry, continued east twards I-275 and Fowler, and occluded near Busch and 30th.

No tornado or wind damage reports have come in at this time, but if any do then I will post updates. Below is screenshot from 3:18pm of reflectivity (left) and velocity (right).

Tornado warning for Hillsborough County!

Sean Toner — Tue, 30 Jun 2009 19:14:43 +0000

The center of circulation is over the Lake Magdalene area, moving ESE! This will affect Temple Terrace as well!

The National Weather Service in Ruskin has issued a

* Tornado Warning for…
northwestern Hillsborough County in Florida.

* Until 345 PM EDT

* at 309 PM EDT…National Weather Service Doppler radar indicated a
tornado near Carrollwood…or 6 miles southwest of Lutz…moving
southeast at 10 mph.

* The tornado will be near…
Carrollwood.
Tampa International Airport.
Temple Terrace.

Precautionary/preparedness actions…

If you are in the path of the tornado go to a small interior room in
a strong and well constructed building. Cars and Mobile homes are not
safe! If no shelter is available…lie flat in a ditch or culvert and
cover your head with your hands.

To report severe weather to the National Weather Service please call
813-645-2323.

Storm damage in Riverview from Thursday

Sean Toner — Fri, 19 Jun 2009 18:55:40 +0000

Looks like a microburst occurred in Riverview yesterday as a very strong outflow boundary collided with another developing severe storm. I actually watched this as it occurred, for a brief moment it looked as if a brief tornado could have developed as there was a small compact area of rotation along the outflow boundary. Turns out it was just a small microburst that damaged roofs and uprooted trees. The statement from the weather service in Ruskin is below:

During the afternoon of June 18, 2009, a line of strong thunderstorms moved south colliding with other thunderstorms developing along the west coast sea breeze (see radar loop below). When this collision occurred the storms became severe over Riverview producing a downburst. Downbursts are generated when rain-cooled, dense air sinks inside a thunderstorm. Also, some of the strong winds aloft are carried down with the downburst by a process called “momentum transfer”. As precipitation begins to fall, it drags some of the air with it. This “precipitation drag” initiates a downburst. The downburst is intensified by evaporative cooling as drier air from the edges of the storm mix with the moist air within the storm. Downbursts are divided into two categories, macrobursts and microbursts. A macroburst is more than 2.5 miles (4 km) in diameter while microbursts are smaller. Based on the NWS survey this event would be defined as a microburst.

A link to the weather service website, including pictures of storm damage:

http://www.srh.noaa.gov/images/tbw/TopNews/NWSDamageSurveyinRiverview.htm

Severe Thunderstorm Watch for Tampa Bay

Sean Toner — Thu, 18 Jun 2009 16:22:29 +0000

Looks like the SPC in Norman Oklahoma has issued a Severe Thunderstorm Watch for a majority of the Florida peninsula. This will be mainly due to large hail and damaging straight line winds. Tornado threat is low, but still possible in areas with multiple strong boundary collisions . Mid-level lapse rates are very steep which suggests storms that develop will have larger than normal hail risks for today. Lapse rates are the rate of temperature decrease as you increase in altitude. Again, the watch was issued because the risk of large hail and damaging winds is higher than normal today, thus warranting the severe storm watch.

URGENT – IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 463
NWS STORM PREDICTION CENTER NORMAN OK
1150 AM EDT THU JUN 18 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

MUCH OF THE FLORIDA PENINSULA

EFFECTIVE THIS THURSDAY MORNING AND EVENING FROM 1150 AM UNTIL
700 PM EDT.

HAIL TO 2 INCHES IN DIAMETER…THUNDERSTORM WIND GUSTS TO 70
MPH…AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70
STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES WEST
NORTHWEST OF JACKSONVILLE FLORIDA TO 25 MILES SOUTHEAST OF NAPLES
FLORIDA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).

REMEMBER…A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION…CONTINUE…WW 459…WW 460…WW
461…WW 462…

DISCUSSION…THUNDERSTORMS WILL INCREASE IN NUMBER AND INTENSITY
THRU THE AFTERNOON AS THE AIR MASS MDTLY UNSTABLE WITH STEEP MID
LEVEL LAPSE RATES. SEVERE THUNDERSTORMS EXPECTED…PARTICULARLY
ASSOCIATED WITH LOW LEVEL CONVERGENCE ALONG SEA BREEZE FRONTS AS
THEY MOVE INLAND.

AVIATION…A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 36015.

Tornado damage survey in Temple Terrace and Lakeland FL

Sean Toner — Fri, 15 May 2009 17:01:59 +0000

This is going out to both my Florida and Texas lists. Two tornadoes have been reported in the Tampa Bay area so far this week, the most note worthy one being in southern Temple Terrace.

The NWS office in Ruskin dispatched meteorologists to conduct storm damage surveys in both Lakeland FL and Temple Terrace FL, and concluded both tornados were of eF-0 strength. The most severe damage occured in Temple Terrace from falling trees hitting houses.

May 13 – Temple Terrace FL – http://www.srh.noaa.gov/images/tbw/TopNews/PDF/HillsTORMay13.pdf

May 12 – Lakeland FL – http://www.srh.noaa.gov/images/tbw/TopNews/PDF/May12th2009LakelandTornadoDamageSurveyReport.pdf

Keep in mind while these storms were occurring I was actively watching the radar. These tornadoes correspond with areas of multiple fast moving outflow boundaries colliding with each other at the same time. Outflow boundaries are like mini cold fronts generated by thunderstorms, when the cold air from aloft rushes down, hits the ground and spreads out. These boundary collisions are just enough to start storm initiation, and when there are enough boundaries colliding, the brief intense updraft can compact into a small funnel. These tornadoes tend to be relatively weak and short lived.

More storms are expected to occur the next several days as atmospheric conditions are very favorable for strong to severe short lived storms. Friday’s storm coverage may be slightly limited compared to the past three days as mid-level moisture is not as high.

Tornado Warning for Hillsborough County!

Sean Toner — Wed, 13 May 2009 22:35:51 +0000

This is for the core of Tampa too, I see no strong rotation on radar but it is still entirely possible a small scale funnel formed.

BULLETIN – EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TAMPA BAY AREA – RUSKIN FL
628 PM EDT WED MAY 13 2009

THE NATIONAL WEATHER SERVICE IN RUSKIN HAS ISSUED A

* TORNADO WARNING FOR…
CENTRAL HILLSBOROUGH COUNTY IN FLORIDA.

* UNTIL 645 PM EDT

* AT 628 PM EDT…NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
TORNADO NEAR EAST LAKE-ORIENT PARK…OR NEAR TEMPLE TERRACE.
NEARLY STATIONARY.

* THE TORNADO WILL BE NEAR…
TEMPLE TERRACE.
EAST LAKE-ORIENT PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

IF YOU ARE IN THE PATH OF THE TORNADO GO TO A SMALL INTERIOR ROOM IN
A STRONG AND WELL CONSTRUCTED BUILDING. CARS AND MOBILE HOMES ARE NOT
SAFE! IF NO SHELTER IS AVAILABLE…LIE FLAT IN A DITCH OR CULVERT AND
COVER YOUR HEAD WITH YOUR HANDS.

TO REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE PLEASE CALL
813-645-2323.