Tropical System Better Organized Gulf Coast Threat Increases

Satellite loops this afternoon along with surface observations indicate that the broad low pressure center in the Northwest Caribbean is becoming better organized. The National Hurricane Center has increased the chances of development to 70 percent in the next 2 days and 90 percent over the next 5 days. This is all happening as the holiday weekend approaches and the threat to the US Gulf Coast is increasing for Sunday into Monday.

All the weather models this afternoon show a developing storm in the Gulf of Mexico over the weekend. Models are grappling with the upper low and trough in the Central Gulf and how this system reacts to it. It appears it will be slow moving and the biggest threat is going to be heavy rains from Florida westward to Louisiana.

NAM MODEL FORECAST SUNDAY AFTERNOON MAY 27, 2018

Some models slow this system down to a crawl Sunday night and Monday just offshore. The outer bands of heavy rains will likely be over Florida as well bringing more heavy rains to that state. An Air Force plane is scheduled to investigate this on Friday.

A broad surface low drifting slowly northward over the eastern
Yucatan Peninsula continues to become better defined. Although
showers and thunderstorms, along with strong gusty winds, remain
primarily over the adjacent waters of the northwestern Caribbean
Sea, environmental conditions are forecast to become more conducive
for development through early next week, and a subtropical or
tropical depression is likely to form by late Saturday over the
southeastern Gulf of Mexico. An Air Force Reserve reconnaissance
aircraft is scheduled to investigate the disturbance Friday
afternoon, if necessary. Locally heavy rainfall is forecast across
western Cuba and over much of Florida and the northern Gulf Coast
into early next week. In addition, the threat of rip currents will
steadily increase along the Gulf coast from Florida westward to
Louisiana over the Memorial Day weekend. For more information on
these threats, please see products issued by your local weather
office. The next Special Tropical Weather Outlook on this system
will be issued by 800 PM EDT this evening.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...90 percent.