Tropics: Invest 97L still spinning, but probably not bound for Texas

After Matt’s thorough tropical update on Saturday, and notably the area of interest known as Invest 97L, I thought I’d provide a shorter update today.

The system has now crossed over the Leeward Islands into the Caribbean Sea, and it continues to move westward, likely bringing winds and rains to Puerto Rico today. The National Hurricane Center continues to predict a 70 percent chance that this system develops into a tropical depression or storm within five days.

And after that? In the post Matt pointed toward two scenarios for what happens to 97L if it makes it into the Gulf of Mexico by around next Friday, or so. The first is that a fairly strong ridge over the southern United States keeps the tropical system to the south of Texas, confined to the Bay of Campeche. This solution was favored by the European model. The other possibility was that this ridge would shift east in about a week, allowing 97L to follow a more northwesterly track toward Texas. However the GFS model which had shown this weakness, appears to be trending toward a stronger ridge.

Models begin to align?

The image below shows the ensemble forecast from the GFS model this morning (06z run) which essentially means the model is run a number of different times, with slight different initial conditions. You can see that the majority of solutions now keep the storm well to the south of Texas.

GFS ensemble forecast for tropical low locations early Monday morning. (Weather Bell)
GFS ensemble forecast for tropical low locations early Monday morning. (Weather Bell)

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Drier, warmer pattern looms after a stormy week

Good morning. It’s been a mostly wet week to bring July to a close, and yesterday we saw some much needed rain just to the north of the city of Houston. As a result most of the area has seen 0.5 to 2.0 inches of rain during the last three days, a nice reprieve from what was otherwise a sweltering month. This rather wet interlude may soon draw to a close, however, as drier weather looms.

Fortunately that does not mean we are going to climb back toward the 100-degree temperatures we experienced last weekend. Houston continues to fall between two high pressure systems—one over the western United States and one along the east coast.

Texas lies between two high pressure systems at the moment. (Weather Bell)
Texas lies between two high pressure systems at the moment. (Weather Bell)

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It’s that time of year—slumbering tropics show signs of awakening

As we approach the beginning of August we’re about to begin the most active period of the Atlantic hurricane season. This is because low pressure systems start to move off the African coast and into the eastern Atlantic ocean, into what is known as the “main development region.”

And right on cue, the Atlantic is delivering, with a large low that has developed into a tropical wave just off the coast of Africa. According to the National Hurricane Center this system has a 40 percent chance of becoming a tropical depression or storm during the next five days.

The 1pm CT, Wednesday, advisory from the National Hurricane Center.
The 1pm CT, Wednesday, advisory from the National Hurricane Center.

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Moist environment expected again today for Houston

The last 48 hours have brought some welcome change to Houston’s hot and (mostly) rain free summer as Gulf of Mexico moisture has surged into the region amid a weakness in high pressure. Those conditions will more or less remain the same today, with one key difference.

So far the heaviest rains have been more clustered over the southern half of the metro area, in places like Fort Bend, Galveston and southern Harris counties. Although we’re likely to see some coastal rains again today, there’s a better chance of development further inland later this afternoon.

Accumulated rainfall for Houston from 5am Monday through 5am Wednesday. (NOAA)
Accumulated rainfall for Houston from 5am Monday through 5am Wednesday. (NOAA)

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