Caribbean disturbance to watch, and Rita moves out

Rita
Rita is moving quickly to the northeast at 20 mph, confounding the model predictions of a stall and serious rainwater flooding disaster. The maximum rainfall from Rita--a swath of 8 - 12 inches--fell along a narrow strip from Port Arthur to Shreveport. While some rivers in the area are in flood stage, only 1 - 3 more inches of rain are expected to fall over the area, alleviating concerns of a second major flooding disaster on top of the serious storm surge flooding that occurred. The remains of Rita are moving too quickly to present a serious flooding problem for any addional regions along its path. A few isolated areas of 3 or 4 inches are the maximum amounts expected.

Port Arthur got a direct hit by the eye or Rita, but escaped catastropic storm surge damage. This occurred because the east eyewall of Rita with its powerful southerly winds never blew over the bay Port Arthur lies on, but passed over land just to the east of the city. Thus, water from the open ocean was not forced up into the bay by the eyewall's winds. The maximum storm surge hit a very sparsely populated area of the Southwest Louisiana coast. The small town of Cameron (population 2000) was the largest town along this stretch of coast, and apparently suffered damage similar to what was seen in Mississippi from Hurricane Katrina. Damage estimates for Rita (insured plus uninsured property) range from $5 - $10 billion. These numbers would have been in the $20 - $40 billion range had Rita hit Galveston/Houston. So, while Rita was very bad for the regions it did hit, we were lucky it wasn't far worse.

Caribbean tropical disturbance
The main area of concern today is a tropical disturbance in the southeastern Caribbean sea, due south of Puerto Rico. This disturbance has a small but growing area of deep convection associated with it, and is in an area of 10 knots of shear. This shear is forecast to decrease the next 48 hours, possibly allowing more substantial development as the disturbance tracks westward at 15 mph.

African activity
A tropical disturbance about 800 miles west-southwest
of the Cape Verde Islands remains poorly organized, and is suffering from wind shear imparted by a large upper-level low pressure system to its west. This shear is expected to decrease over the next two days, which may allow some development to occur. The disturbance is moving west-northwest, and will probably recurve to the norhteast in the middle of the Atlantic Ocean.

Long range models show the possibility of more tropical development off the coast of Africa during the week, as well. However, keep in mind that we are now into the last week of September, and it is rare for tropical storms that form in the eastern Atlantic this late in the season to affect any land areas. These late September storms nearly always recurve out to sea before threatening any land areas. This occurs because the jet stream is getting more active as Fall begins to assert itself, driving strong troughs of low pressure futher south where they can more easily recurve tropical systems to the north.

The place to watch this week is the Caribbean.

Jeff Masters