Models shift back south

Discussion..

Well, the 18z suite of models has resulted in a major shift in the three models (GFS, CMC, and GFDL) that seemed to be the northern outliers but really got forecasters attention over the past couple of days. Now all of the major dynamic models with the exception of the HWRF are now predicting a landfall right around where the 4pm NHC track is currently positioned about 100 miles south of Brownsville, TX. It seems like as Alex has now moved into the gulf, the models are able to ingest better data and initialize better and have seemed to come into pretty good agreement with a ridge of high pressure forecast to build to the north of the storm and turn it more west-northwest, towards northern Mexico. It is still very possible due to the slow forward speed, that Alex could still move to the right of the current forecast and impact south Texas. Tomorrow is looking like the pivotal day in the track forecast because that is when Alex is currently forecast to make that more westward turn in response to the building ridge to its north-northeast. If that does not happen, then Alex could take more of a northerly track and head more towards the middle Texas coast.

Houston Impacts..

With the center of Alex currently forecast to remain well south of the area really strong winds do not look like an issue; however very deep tropical moisture with precip water values around 2 standard deviations above normal will continue to move into the region for the remainder of the week. This will likely produce periods of heavy showers and thunderstorms and the possibility of some localized flooding problems. The latest 5-day rainfall total forecast from HPC (Hydrometeorological Prediction Center) shows the potential for a widespread 1-3 inches with isolated 3-6 in totals if we see training setup. Depending on the future track of Alex, some outer rain bands may begin to affect areas south of I-10 as early as Wednesday afternoon or evening. Isolated tornadoes and gusty winds up to 40mph could be possible if we see some of the stronger squalls reach the coast later this week; however this will be highly dependent on the future track of Alex.

At this time I would expect to see winds at UH turn more east to northeast Wednesday and Thursday and increase into the 15-20mph range with gusts 25-30mph.

For UHCC, look for east winds increasing to the 20-25mph range with gusts 30-35mph Wednesday and Thursday.

4pm NHC Track


18z Tropical Models