625  
FXCA20 KWBC 171916  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
315 PM EDT FRI OCT 17 2025  
 
FORECAST BULLETIN 17 OCTOBER 2025 AT 1900 UTC:  
 
THE BAHAMAS AND CARIBBEAN:  
 
A DISSIPATING COLD FRONT EXTENDING OVER HISPANIOLA INTO THE  
YUCATAN PENINSULA WILL CONTINUE BRINGING SOME PRECIPITATION IN  
PORTIONS OF THE GREATER ANTILLES, INCLUDING JAMAICA, HISPANIOLA  
AND PUERTO RICO AND OVER THE LEEWARD ISLANDS FROM TODAY INTO  
SATURDAY AS DEEP MOISTURE INFLOW CONTINUES OVER LAND. IN ADDITION,  
ENHANCED UPPER-LEVEL DIVERGENCE WITH AN UPPER-LEVEL TROUGH WITH  
BASE OVER HISPANIOLA IS EXPECTED. PERIODS OF HEAVY RAINFALL ARE  
EXPECTED FOR PORTIONS OF THE LEEWARD ISLANDS WITH ENHANCED  
LOW-LEVEL MOISTURE CONVERGENCE, A SLIGHT RISK FOR SEVERE WEATHER  
EXISTS FOR THIS REGION. OVER JAMAICA A LOW-LEVEL TROUGH EXTENDING  
TO MID-LEVELS IS EXPECTED TO BRING HEAVY RAINFALL. IN HISPANIOLA  
THUNDERSTORMS ARE EXPECTED AS LOW- AND UPPER- LEVEL CONDITIONS ARE  
FAVORABLE FOR THE DEVELOPMENT OF CONVECTION.  
 
SOME PRECIPITATION IS ALSO EXPECTED OVER SOUTHERN BAHAMAS FROM  
TODAY THROUGH SATURDAY, WITH ANOTHER COLD FRONT EXTENDING INTO THE  
REGION. AS THE COLD FRONT MOVES SOUTH FROM SATURDAY TO SUNDAY,  
MORE PRECIPITATION IS EXPECTED OVER THE BAHAMAS AND THE GREATER  
ANTILLES, INCLUDING EASTERN CUBA AND HISPANIOLA. AS THE FRONT  
BECOMES STATIONARY, PRECIPITATION IS EXPECTED TO CONTINUE THROUGH  
MONDAY.  
 
A TROPICAL WAVE CURRENTLY LOCATED AROUND 55W IS EXPECTED TO BRING  
THUNDERSTORMS AND HEAVY RAINFALL OVER TRINIDAD Y TOBAGO AND THE  
NORTHEASTERN CARIBBEAN COAST OF VENEZUELA FROM SATURDAY TO SUNDAY.  
AS THE TROPICAL WAVE PROPAGATES WESTWARD OVER VENEZUELA  
PRECIPITATION WILL INCREASE IN THE REGION THROUGH MONDAY.  
 
ANOTHER TROPICAL WAVE OVER THE CENTRAL TROPICAL ATLANTIC,  
CURRENTLY BEING MONITORED BY THE NATIONAL HURRICANE CENTER (NHC)  
WITH A 30% CHANCE OF TROPICAL FORMATION IN THE NEXT SEVEN DAYS IS  
EXPECTED TO MOVE INTO THE REGION BY MONDAY, BRINGING RAINFALL AND  
THUNDERSTORMS, PARTICULARLY FOR THE WINDWARD ISLANDS FROM SUNDAY  
TO MONDAY.  
 
TROPICAL SOUTH AMERICA:  
 
ACROSS TROPICAL SOUTH AMERICA, SHOWERS AND THUNDERSTORMS WILL BE  
OBSERVED EACH DAY. THE PRIMARY DRIVERS WILL BE LOW-LEVEL MOISTURE  
CONVERGENCE, DIURNAL HEATING, AND LOCAL EFFECTS. MOST OF THE  
PRECIPITATION FROM TODAY THROUGH MONDAY WILL BE OVER THE PACIFIC  
COAST OF COLOMBIA ACROSS TROPICAL SOUTH AMERICA, SHOWERS AND  
THUNDERSTORMS WILL BE OBSERVED EACH DAY, AS LONG-FETCH PACIFIC  
MOISTURE FEEDS INTO THE REGION, RAINFALL TOTALS FROM 20-45MM ARE  
EXPECTED EACH DAY.  
 
THUNDERSTORMS AND PERIODS OF HEAVY RAINFALL ARE EXPECTED FROM  
TODAY THROUGH MONDAY OVER THE MARACAIBO REGION IN VENEZUELA AND  
THE NORTHEASTERN ANDES REGION IN COLOMBIA DUE TO THE PRESENCE OF  
LOW-LEVEL CONVECTIVE INDUCED TROUGHS, ENHANCED MOISTURE ADVECTION  
AND ADDITIONAL SUPPORT FROM MID-LEVEL TROUGHS.  
 
MEXICO AND CENTRAL AMERICA:  
 
A BROAD AREA OF LOW PRESSURE OFFSHORE OF SOUTHERN MEXICO,  
CURRENTLY BEING MONITORED BY NHC WITH A 40% CHANCE OF TROPICAL  
DEVELOPMENT IN THE NEXT SEVEN DAYS, WILL BRING SOME PRECIPITATION  
FROM THROUGH SUNDAY PARTICULARLY OVER PORTIONS OF OAXACA AND  
GUERRERO, HOWEVER THE HEAVIEST RAINFALL IS EXPECTED TO REMAIN  
OFFSHORE.  
 
ANOTHER AREA THAT SHOULD EXPECT SOME PRECIPITATION FROM TODAY  
THROUGH SUNDAY IS THE EASTERN COAST OF THE YUCATAN PENINSULA WITH  
ENHANCED LOW-LEVEL CONVERGENCE AND MOISTURE ADVECTION FROM THE  
CARIBBEAN.  
 
A LOW-LEVEL TROUGH IS EXPECTED TO MOVE INTO EASTERN MEXICO FROM  
SUNDAY TO MONDAY, INCREASING LOW-LEVEL MOISTURE CONVERGENCE OVER  
VERACRUZ. TOTAL ACCUMULATIONS ARE EXPECTED TO BE AROUND 20MM -  
45MM.  
 
RAINFALL IS EXPECTED ALONG THE PACIFIC COAST OF CENTRAL AMERICA,  
FROM TODAY THROUGH SUNDAY, DUE TO THE PRESENCE OF THE MONSOON  
TROUGH FROM GUATEMALA THROUGH NICARAGUA. THE MAIN DRIVER FOR  
PRECIPITATION IN THIS REGION IS THE ENHANCEMENT IN MOISTURE AND  
ONSHORE FLOW DUE TO THE MONSOON TROUGH, THE PRESENCE OF A BROAD  
LOW-PRESSURE WITHIN THE MONSOON TROUGH AND MID-LEVEL TROUGH  
PROPAGATING ALONG THE PACIFIC COAST OF CENTRAL AMERICA, STARTING  
OVER COSTA RICA TODAY AND MOVING NORTHWESTWARD TOWARDS EL SALVADOR  
THROUGH SUNDAY.  
 
OVER GUATEMALA, AND SOUTHERN MEXICO, AN ENHANCEMENT IN LOW-LEVEL  
MOISTURE CONVERGENCE IS EXPECTED TO CAUSE HEAVY RAINFALL WITH  
TOTAL ACCUMULATION REACHING 40-80MM.  
 
SOME PRECIPITATION IS EXPECTED OVER EASTERN HONDURAS AND NICARAGUA  
FROM TODAY THROUGH MONDAY DUE TO MOISTURE ADVECTION. MORE  
PRECIPITATION IS EXPECTED TOWARDS THE END OF THE FORECAST PERIOD,  
AS A LOW-LEVEL TROUGH APPROACHES NICARAGUA. ALTHOUGH THE HEAVIEST  
PRECIPITATION WILL REMAIN OFFSHORE FROM SUNDAY TO MONDAY, RAINFALL  
MAY INCREASE OVER LAND FROM MONDAY TO TUESDAY.  
 
OVER COSTA RICA AND PANAMA HEAVY RAINFALL IS EXPECTED FROM SUNDAY  
THROUGH MONDAY, WITH TOTAL ACCUMULATIONS AROUND 40MM-80MM AS A  
BROAD AREA OF LOW PRESSURE DEVELOPS AT LOWER LEVEL, AND UPPER  
LEVEL DIVERGENCE IS ENHANCED BY AN UPPER LEVEL TROUGH.  
 
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC  
TYP SOF INIT 18/00 18/12 19/00 19/12 20/00 20/12 21/00  
TW 14N 41W 44W 48W 53W 55W 57W 60W 65W  
TW 11N 55W 58W 61W 65W 68W 70W 72W 75W  
 
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