Aug 29, 2014 4:32 PM by Rob Perillo
Deep tropical moisture will advance northward from the Gulf of Mexico into Acadiana overnight through tomorrow with the threat of very heavy tropical rains and storms capable of producing 2-3" of rain...per hour.
Where storms repeat, or "train", rain totals will likely approach or exceed 5" with KATC RPM Model runs oscillating between 3-4" to 8-12" across potions of the area.
This tropical moisture is associated with a tropical wave in the Gulf of Mexico that is getting drawn northward by an upper level trough that will be sweeping through the Central U.S.
Pegging rainfall totals accurately will be nearly impossible until the heavier storms begin to show up inland as there will be no definitive focusing mechanisms.
This means that some areas may just see an inch of rain, especially the farther north and west you go from the coast, while others will likely see substantially more rainfall.
In general, expect 2-4" of rain through Saturday afternoon for most of Acadiana with isolated totals up to 4-8" or more possible.
Localized street flooding will be possible a few hours after the storms arrive.
With any luck, the heaviest rains...of up to a foot, may manifest offshore, but with such deep moisture across the area, heavy rainfall will likely occur in spots inland.
Prime-time for the heaviest rains to arrive should be after 10pm Friday night through mid-Saturday afternoon.
More stable, less moisture laden air will advance into the area for Sunday and Monday with rain chances decreasing accordingly.