From the staff meteorologist (Jeff Lindner) for Harris County Flood Control District...
NWS has issued a Flash Flood Watch for areas along and S of I-10 for Friday.
Latest guidance has trended slower and wetter with this upcoming weather event while at the same time diverging on the exact track of the surface low. Regardless, QPF generated by the various guidance and the fact that KCRP is already showing numerous showers on their scope suggest that the higher amounts are more likely, but not as high as the GFS is suggesting.
Widespread rainfall of 2-4" with isolated amounts of 5-7" will be possible along and S of I-10 with amounts of 1-3" common N of I-10. Guidance has been pegging the coastal waters with 8-12" and this seems fairly aggressive given the fast nature of the event and about 18-28 hours of rainfall...not saying it won't happen. Rainfall predicted will likely exceed flash flood guidance and result in significant run-off especially in the coastal counties. The exact track of the surface low will determine where the axis of heaviest rains fall and it could be as far N as I-10 or 100 miles offshore.
Will also lean toward a slightly higher severe threat as a track of the surface low close enough to the coast could swing the warm front inland resulting in surface based rotating supercells. SPC has highlighted this in their outlook but currently is downplaying the threat to off the coast. It is a little too close of a call to not mention and any northward advance of the warm front inland would bring the threat of hail, wind, and tornadoes to that area south of the boundary.
No changes required on the marine side or with tides, but winds are already coming up and frequent gust at or over 40mph appear likely on Friday along the coast and offshore.
Rockport has had heavy rain for hours. I have not seen rain like this in 15 years here. We have some flooding according to the news here downtown.
The storm is headed North. Heavy lightning is on the way. We lost power 5 times in the last three hours.