Tropical Depression 13 brewing in the Gulf of Mexico has the potential to create major flooding problems along the Gulf Coast and inland.
Opinions on where the developing tropical system will wander over
the next week vary from meteorologist to meteorologist. Most of them think this
system will become Tropical Storm Lee, and expect to see heavy rainfall and
flooding somewhere along the north-central Gulf Coast.
The developing consensus is that this will be an extensive,
slow-moving system, capable of affecting the same areas for days with downpours,
stormy seas and rough surf conditions. Rough seas alone have the potential to
shut down rigs in the Gulf for an extended period.
After meandering in the Gulf today, it is possible that the system
will gradually turn to the northeast, making landfall along the coast of
Louisiana Sunday evening. It is important to note, however, that the track is
uncertain and could vary widely over the next few days. The depression is
currently south of a high pressure ridge that is not giving much in the way of
steering currents. This is also the reason for its very slow movement.
At 6 a.m. Friday the Tropical Depression was centered about 240
miles southwest of the Mississippi River with highest winds of 35 mph. It was
crawling to the northwest at 2 mph.
Gov. Bobby Jindal said he was concerned about the serious threat of
flash flooding in his state. Craig Taffaro, president of coastal St. Bernard
Parish, said some flood gates were being closed along bayous and residents were
being warned to brace for heavy rain. Still, in a parish that was nearly wiped
out six years ago by Katrina, Taffaro wasn't expecting a major event.
Under the current scenario system will help to pull cooler air down
into Louisiana, Texas and Oklahoma over the Labor Day weekend, ending a
summer-long heat wave. Southern Louisiana through southern Alabama is set to
receive 10 to 15 inches of rain, while higher amounts near 20 inches are
possible in the hardest hit areas. This could lead to a precipitation pattern
much like Hurricane Danny in 1997, except peak areas would receive less rain.
Unfortunately for Texas, the major models are not currently producing any rain
in the drought-stricken state, aside from areas bordering Louisiana.
The system can move just about anywhere. That movement includes
zigzags, loops, a 180-degree change in direction, a stall, and perhaps a slow,
steady straight path inland. The Friday morning prediction by the National
Hurricane Center is for the depression to move slowly to the northwest or north
for the next 24 to 36 hours, followed by a gradual turn toward the northeast.
Small craft warnings were issued from northwest Florida to Texas as
seas of at least 1 to 2 feet above normal were in the forecasts. Winds are
likely to push tides up to three feet above normal.
Temperatures in the Gulf are near record warmth, 88°F , which will
provide plenty of moisture for heavy rains, and plenty of energy to help the
system strengthen into a tropical storm. Most of the models predict will have
some motion to the west by Saturday, which would bring rains to the Texas coast
near the Louisiana border.
One computer model is predicting, the storm could intensify into a
hurricane if it remains over water long enough. Most of the other models predict
will move ashore over Louisiana by Sunday, limiting the storm's development to
just tropical storm strength.
In very simple terms, a tropical disturbance is a blob of
thunderstorms gathered in a place and under conditions that could allow further
development. A tropical disturbance becomes a tropical depression when a
distinct pattern of circulation can be seen but sustained wind speeds are 38
miles per hour or less. Disturbances become tropical storms and are given names
when they reach a sustained wind speed of 39 mph. When a storm reaches sustained
wind speeds of 74 miles per hour, it officially becomes a hurricane.
The size of this depression will require significant time for it to
reach hurricane strength.
According to a hurricane center chart, maximum sustained winds could reach 60
mph by Saturday, lower than hurricane strength of 74 mph.