T.D. Harvey is starting to reorganize after crossing the Yucatan Peninsula.

The National Hurricane Center forecasts it to become a tropical storm, as it approaches the Texas Coast, moving slowly northwestward. Once it comes ashore, the steering currents are expected to become weaker and it may meander, creating a flooding threat from a long period of heavy rainfall.

Note the plume of tropical models, most of which take the storm to the Texas coast before slowing. Some move it northeastward or eastward or even loop it back over water.

WeatherBELL has been ahead of the forecast so far, and we continue to maintain it will be stronger, possibly a Category 2 Hurricane, prior to reaching the Texas Coast.

If we have to shift the forecast, it would be to slow it down a bit.

Most intensity models keep Harvey as a tropical storm. One model, the SHIPS, which is usually the most aggressive in increasing a storm's intensity, brings it into Category 1.

The hurricane HWRF model has winds above the surface reach hurricane force near the center close to landfall.

NHC has the probability high (70%+) for tropical storm winds to develop and believes the storm will reach hurricane intensity before landfall.

Of course should the stalling begin sooner, there would be more time for intensification. The greatest concern right now is for flooding from heavy rainfall. The Weather Prediction Center has an area exceeding 15 inches of rain near Galveston. it should be noted some models have peak local rainfall over 40 inches!

The HWRF model sequence shows the pressures, winds, precipitable water and simulated radar for Thursday night, Saturday night and Sunday night. Note the long period of heavy rainfall.

The American global model (GFS) has very heavy rain in southeastern Texas, with the peak over 40" to the west of Houston.

Other models, like the European, show over 30 inches of rain are possible.

Either way, heavy rains from stalling or slow moving Gulf Storms have brought the heaviest rainfall of all U.S. landfalling storms. Five of the top 10 heaviest rainfall events from tropical events have been in Texas. All were Gulf storms, although Camille, which came ashore in Mississippi, saved its peak rainfall for the mountains of western Virginia.