Tropical Formation Chances Increased Again Overnight, But Track Still Likely East of Houston

A tropical disturbance located over the extreme SW Gulf of Mexico now has a 50% chance of developing into a tropical cyclone over the next 5 days. At this time there is, still no threat to the Texas coast. 

A trough of low pressure that was in Central America yesterday, moved across the Yucatan overnight as predicated. It now is just offshore of the coast of southern Mexico, in the Bay of Campeche and producing disorganized showers and thunderstorms.

Guidance from National Hurricane Center

The National Hurricane Center predicts possible gradual development. They say that a tropical or subtropical cyclone could form late this week over the western or central Gulf of Mexico while the system moves generally northeastward. An Air Force reconnaissance aircraft will investigate the system this afternoon, if necessary.

Formation chance through 48 hours…low…30 percent. Formation chance through 5 days…medium…50 percent.

24 hours ago, the comparable numbers were 0 and 10.

Disturbance in Bay of Campeche now has a 5-day 50% chance of tropical formation.

The Story Behind the Storm

Conditions appear favorable for slow development of this system because of upper level wind patterns and warm sea surface temperatures. An area of high pressure over the SE Gulf of Mexico will direct this feature toward the N and then NNE by late this week.

At the same time an approaching trough from the SW US will move toward west Texas by late in the weekend should force any tropical system to turn NE/ENE. Global model guidance supports a track of any tropical system toward the central or eastern Gulf of Mexico this weekend. Here’s a map that shows the expected location of the front two days from now. Note how the front pushes that orange line toward the NE.

Expected frontal location two days from now should push any tropical disturbance toward the NE.

Given the expected upper level shear across the northern Gulf of Mexico this weekend any system will likely have the majority of the weather near and far to the east of any actual surface circulation. That means people in Louisiana and east of there should get out their umbrellas. Houston will likely be on the dry side of the storm.

Keep your eyes on the Gulf any time a storm forms. Remember that Harvey originated in this same general area and forecasters predicted it to move inland over Mexico. It did…for a while.

Posted by Bob Rehak on 10/16/2019, with help from the National Hurricane Center and Harris County Flood Control

778 Days since Hurricane Harvey and 27 since Imelda