665  
FXCA20 KWBC 071157  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
656 AM EST WED FEB 07 2018  
 
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM FEB 07/06  
UTC: A MID-LEVEL RIDGE EXTENDS ZONALLY FROM THE SOUTHERN GULF OF  
MEXICO/NORTHERN CENTRAL AMERICA INTO THE BAHAMAS...HISPANIOLA AND  
PUERTO RICO. THIS FEATURE IS SUSTAINING THE SUBSIDENCE CAP AS WELL  
AS VERY DRY CONDITIONS ABOVE 700 HPA. THESE FACTORS ARE LIMITING  
THE DEVELOPMENT OF DEEP CONVECTION. AT LOW-LEVELS...THE TRADES ARE  
FROM THE EAST-NORTHEAST AND HAVE SPEEDS OF 15-20KT AT 975 HPA AND  
ABOVE. THIS IS FAVORING THE CURRENT PATTERN OF RAPIDLY MOVING  
LIGHT AND ISOLATED TRADE WIND SHOWERS.  
 
A WEAK PERTURBATION EMBEDDED IN THE NORTHEASTERLY TRADES WILL  
ARRIVE IN THE ISLANDS ON WEDNESDAY EVENING. THIS WILL LEAD TO A  
TRANSIENT INCREASE IN ACCUMULATIONS STARTING WEDNESDAY EVENING  
THROUGH EARLY THURSDAY. LARGEST AMOUNTS ARE EXPECTED IN EXTREME  
NORTHEASTERN PUERTO RICO WHERE MAXIMA IN THE YUNQUE WILL APPROACH  
0.5 INCHES. ANOTHER ROUND OF ENHANCED TRADE WIND SHOWERS IS  
EXPECTED ON LATE THURSDAY-EARLY FRIDAY...IN ASSOCIATION WITH THE  
ARRIVAL OF A TRADE WIND SURGE FROM THE EAST. THIS WILL LEAD TO  
ACCUMULATIONS UNDER 0.25 INCHES.  
 
THE MOST SIGNIFICANT HAZARD FOR THE ISLANDS DURING THE WEEKEND  
WILL BE THE STRONG WINDS. A TRADE WIND SURGE IS FORECAST TO ARRIVE  
IN THE ISLANDS ON FRIDAY MORNING. MODELS ARE SHOWING SPEEDS OVER  
20-25KT DEVELOPING AT 900HPA...GRADUALLY INCREASING TO 30-35KT BY  
SATURDAY MORNING. VERTICAL MIXING WILL LEAD TO WIND GUSTS OF  
15-25KT CLOSE TO THE SURFACE DURING SATURDAY...STARTING TO  
DECREASE ON SUNDAY.  
 
GORDON...NMS (BELIZE)  
NIXON...BDM (THE BAHAMAS)  
DAVISON/GALVEZ...WPC (USA)  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page