CARIBBEAN SYSTEM HAS MEDIUM POTENTIAL FOR FURTHER DEVELOPMENT.

TWO LEFT CLICKS WILL ENLARGE IMAGES A GREAT DEAL

According to the National Hurricane Center, the tropical wave in the Caribbean has a medium potential for tropical cyclone development.  For those of you who don’t understand that here is a brief explanation.

In order for a system to be cyclonic there must be a rotation of the wind around a low pressure center.  Presently there is no indication of a closed rotation in this otherwise impressive system.  A tropical wave (also called a tropical disturbance) becomes a tropical depression if rotation begins.  Ordinarily the rotation itself signals a maturing (growth) of the system.  Once rotation begins, the conservation of angular momentum kicks in such that as the wind spirals closer and closer to the center its velocity increases.  Tropical depressions can intensify into tropical storms (39-73 mph) and the latter can intensify into hurricanes (74 or more mph).  Here is the formal statement from the Hurricane Center:

================================================

TROPICAL WEATHER OUTLOOK

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

800 PM EDT SAT SEP 20 2008

FOR THE NORTH ATLANTIC…CARIBBEAN SEA AND THE GULF OF MEXICO…

1. A TROPICAL WAVE…ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM OVER THE NORTHEASTERN CARIBBEAN SEA…IS PRODUCING WIDESPREAD CLOUDINESS AND SHOWERS OVER THE LESSER ANTILLES…AND ADJACENT CARIBBEAN AND ATLANTIC WATERS.  THIS SYSTEM IS SHOWING SIGNS OF ORGANIZATION…AND UPPER-LEVEL WINDS ARE EXPECTED TO BECOME A LITTLE MORE FAVORABLE

FOR DEVELOPMENT OVER THE NEXT COUPLE OF DAYS.  A TROPICAL

DEPRESSION COULD FORM DURING THIS TIME AS THE SYSTEM MOVES SLOWLY NORTHWESTWARD.  AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM ON SUNDAY…IF NECESSARY.  REGARDLESS OF DEVELOPMENT…LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS WILL AFFECT MUCH OF THE LESSER ANTILLES…THE VIRGIN ISLANDS AND PUERTO RICO THROUGH SUNDAY.

================================================

On the infrared satellite image above from the U.S. Naval Research Lab, I have marked two islands that don’t need any more precipitation for a while due to recent tropical systems having dumped heavy (and deadly) loads upon them.  Flooding and mudslides are likely if this disturbance moves as expected, over the islands.  For the same reasons, Cuba also stands a risk of increased problems.

Please visit the rest of this web-log at http://cloudman23.wordpress.com/.  If you are interested in weather, there are some tutorials scattered about and more will be added in time.