Invest 94L - On its potential development and track towards the Caribbean Sea

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My first blog post!

A strong tropical wave has emerged off the West African coast and has been designated as INVEST 94L...

The system looks to be of a potential long-track across the Caribbean Sea, typical for mid-August, a so-called "straight runner". 

NOAA/OPC 12Z Surface Analysis shows a 1011 mb surface Low pressure associated to this system. It is still interacting directly with the ITCZ and has a tropical wave associated to it. A 1027 mb High pressure system to its north will guarantee a general westward track throughout the next few days. 

   

Its structure is broad and disorganized, with convection occurring near the Cape Verde Islands, south of 10N in the ITCZ, and the African coast.  Source: NOAA

Easterly vertical wind shear of 10-20 kts is currently impinging on the low, which is quite normal in this location and time of the year. Source: CIMSS

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Saharan Air-Layer analysis from CIMSS shows lots of dry air surrounding 3 out of 4 quadrants of INVEST 94L. This dry air will be a limiting factor for early development into a tropical depression or tropical storm. Conditions should slowly improve as it moves away from Africa. Source: CIMSS

An ASCAT pass shows partially the circulation associated with the low, with winds that are generally of less than 20kts. Source: NOAA

Model guidance agrees on a westward track towards the Caribbean Sea. It is still very early to tell on track and intensity, but the potential of this system becoming a tropical cyclone is decent. 

The only global model picking up on its formation is the GFS, which hints at a W/WNW track through the Caribbean Sea and towards the Yucatan Peninsula by Friday (August 22). It is way too early but this type of track is within what can be expected from tropical cyclones in the Atlantic this time of the year. At this stage, we are merely speculating. 

A recent historical track is an extreme case, Hurricane Dean (2007), which became a Category 5 in the Caribbean Sea and is the last Category 5 landfall on record in the Atlantic Basin. This doesn't mean our storm will behave even similarly, but it shows what could happen in the Caribbean during this time of the year. 

Many days ahead, many days to track this system. Let the fun of tropical cyclogenesis, track, and intensity forecasting begin!

Greensboro, NC  (8/10/2014)  5:48pm