FIRST ALERT FORECAST: Tropical Depression #19 forms, could threaten La. next week

FIRST ALERT FORECAST: Friday, Sept. 11-Tropical Depression #19 forms, could threaten La. next week

BATON ROUGE, La. (WAFB) - The area of disturbed weather located between the northern Bahamas and south Florida was officially upgraded to Tropical Depression #19 at 4 p.m. Friday.

Enhanced infrared (IR) satellite loop showing Tropical Depression #19 gathering steam between the northern Bahamas and south Florida. T.D. #19 is forecast to strengthen as it moves into the Gulf of Mexico this weekend.
Enhanced infrared (IR) satellite loop showing Tropical Depression #19 gathering steam between the northern Bahamas and south Florida. T.D. #19 is forecast to strengthen as it moves into the Gulf of Mexico this weekend. (Source: WAFB)

The forecast indicates that T.D. #19 is likely to become a tropical storm over the weekend as it moves into the Gulf. The name would either be Sally or Teddy, depending on how quickly a system located off the west coast of Africa develops.

Upper-level steering shown by the European model as of Friday afternoon. High pressure centered north of T.D. #19 should keep it moving to the west-northwest for the next day or so
Upper-level steering shown by the European model as of Friday afternoon. High pressure centered north of T.D. #19 should keep it moving to the west-northwest for the next day or so (Source: WAFB)

High pressure centered over the southeast U.S. should keep T.D. #19 moving west-northwest for the next day or so, but a trough of low pressure moving across the U.S. is expected to weaken the high over the weekend.

Upper-level steering forecast by the European model valid for Sunday morning. Note that high pressure over the eastern states has weakened, leaving a path for T.D. #19 to potentially turn more northward. However, that high may build again by early next week, turning the storm westward near the northern Gulf Coast.
Upper-level steering forecast by the European model valid for Sunday morning. Note that high pressure over the eastern states has weakened, leaving a path for T.D. #19 to potentially turn more northward. However, that high may build again by early next week, turning the storm westward near the northern Gulf Coast. (Source: WAFB)

That would allow T.D. #19 to turn more northwest with time, but the steering gets rather complex by late in the weekend and into early next week. As the trough of low pressure exits to the northeast, high pressure once again builds over the southern U.S. and may cause the storm to turn westward just offshore of the northern Gulf Coast. The National Hurricane Center (NHC) made a point of addressing the high uncertainty in their 4 p.m. discussion:

“The uncertainty in the track forecast is much larger than normal after 48 hours, as small changes in the forecast steering flow could result in this system moving over the northern Gulf Coast faster and to the northeast of what is shown here.”

The intensity forecast also features some typical uncertainty, but for now the NHC is showing a strong tropical storm near the northern Gulf Coast by early next week and indicating it is possible the forecast could trend a little stronger.

For the next 2 to 3 days at least, there aren’t any obvious hinderances to intensification, but it’s possible there could be some wind shear in play as it gets closer to a potential landfall.

It is too soon to outline specific local impacts given the high uncertainty on the exact track and intensity, but as you probably know, a track east of our area would keep us out of the worst.

Regardless of the exact track, we are expected to be in a rainy pattern beginning this weekend and continuing through much of next week. The 7-day rainfall outlook suggests 2″ to 4″ of rain on average, but amounts could trend higher, possibly considerably, if we had a tropical system threatening our local area.

Rainfall forecast from NOAA's Weather Prediction Center valid through 7 p.m. Friday, Sept. 18. Rain totals of 2" to 5" are forecast for our area over the next week, with locally higher possible. Totals will be highly dependent on the eventual track of T.D. #19.
Rainfall forecast from NOAA's Weather Prediction Center valid through 7 p.m. Friday, Sept. 18. Rain totals of 2" to 5" are forecast for our area over the next week, with locally higher possible. Totals will be highly dependent on the eventual track of T.D. #19. (Source: WAFB)

Take the time this weekend to sure up your hurricane plan and get anything done you made need to get accomplished in the yard. And make sure you keep up with the latest in our First Alert Weather App.

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