Tropical Depression Four Forms in the Atlantic, Tropical Storm Warning In Effect for the Bahamas

August 23, 2014

Tropical Depression Four has formed in the tropical Atlantic Ocean, about 255 miles east-southeast of the Central Bahamas.

Tropical Depression Four is pushing its way from the Caribbean into the Atlantic, and it is still being closely monitored for potential development into a tropical storm.

With that said, the Government of the Bahamas has issued a tropical storm warning for the central and southeastern portion of the Bahamas, as well as the Turks and Caicos. A tropical storm warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next 24 hours.

Here is the latest information on this system.

Projected Path

The latest forecast path and wind speeds from the National Hurricane Center.


Current Information

So, where exactly is the cyclone's center located now? If you're plotting the storm along with us, the information depicted in the map above provides the latitude/longitude coordinates, distance away from the nearest land location, maximum sustained winds and central pressure (measured in millibars).  


Tropical Storm/Hurricane Watches/Warnings

A tropical storm or hurricane watch is issued when those conditions are possible within the area. Watches are typically posted 48 hours in advance of the onset of tropical storm-force conditions, since preparing for the storm becomes difficult once tropical storm-force winds begin. A tropical storm or hurricane warning means those conditions are expected in the area. Warnings are typically issued 36 hours in advance of the onset of tropical storm-force winds. When a warning is issued, you should complete all storm preparations and, if directed by local officials, evacuate the area immediately.


Infrared Satellite

This infrared satellite image shows how cold (and therefore how high) the cloud tops are. Brighter orange and red shadings concentrated near the center of circulation signify a healthy tropical cyclone.


Caribbean Impact

Rain and gusty winds will continue to spread through the Caribbean through the weekend, regardless of what the system is called.

Mudslides and flash flooding have already been reported throughout the island of Puerto Rico on Friday and Saturday afternoons.

Through Sunday, locally heavy rain will fall over parts of the Virgin Islands, Puerto Rico, Haiti, the Dominican Republic and the Turks and Caicos.

(FORECASTS: St. Thomas | St. Croix | San Juan | Punta Cana)

This weekend, bands of rain will spread into the southeast Bahamas, Jamaica, Cuba and possibly the Cayman Islands.

(FORECASTS: Ocho Rios | Grand Cayman | Nassau)

Local flash flooding is a possibility, particularly over mountainous terrain of Puerto Rico, Haiti, the Dominican Republic, Jamaica and eastern Cuba. Flood watches have been posted for Puerto Rico and the U.S. Virgin Islands.

Given the close proximity to the eastern U.S. coast, especially leading up to the Labor Day Holiday weekend, it is wise to consider the tropical depression's potential impacts to the Atlantic coast.

U.S. Threat?

To be clear, it is still too soon to determine with certainty if this system will have any direct impacts on the mainland U.S.

(MORE: Why Long-Range Model Forecasts in the Tropics Can't Often Be Trusted)

A crucial player in determining if the U.S. will be impacted appears to be a southward dip in the jet stream expected to carve out over the western Atlantic Ocean. There appear to still be three scenarios at this time:

1) Avoiding the U.S.: If the system tracks farther north in the Caribbean, and the jet stream dip is sufficiently strong and penetrates far enough south, the system may turn sharply north, then northeast after leaving the southeast Bahamas. In this scenario, the U.S. coast would be missed -- except for perhaps some high surf next week. 

2) East Coast threat: If the system either isn't pulled far enough north by the jet stream dip or the jet stream dip passes by into the north Atlantic, it may track much closer to at least part of the East Coast next week.

3) Gulf of Mexico:  The system may continue toward the west-northwest, then head into the eastern Gulf of Mexico where it would strengthen. For now, this scenario appears to have a low, but not zero probability.

Forecast uncertainty is typically very high several days out even in cases of a well-defined tropical cyclone. Therefore, we cannot take either of these scenarios completely off the table yet. 

All interests along the East Coast should closely monitor the progress of this system. Check back with us at The Weather Channel and for the latest on this potential threat. 

(EXPERT ANALYSIS: The Weather Channel | Dr. Jeff Masters from Weather Underground)

In the meantime, now is an excellent time to make sure you're hurricane ready.

Brief History

After a few days moving through the Caribbean as an unorganized cluster of storms, Air Force Hurricane Hunters flew into the disturbance on August 23 to determine whether a surface low pressure circulation -- which requires not only the east or northeast winds typically found in the Northern Hemisphere tropics, but also a westerly wind -- was present.

The Hurricane Hunters found that as of August 23, environmental conditions were favorable for development into a tropical depression and they detected a closed center of circulation. Within the next 48 hours, it is possible that Tropical Depression Four could strengthen even further and become Tropical Storm Cristobal.

(MORE: Hurricane Central)

MORE: Hurricanes From Space

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