923  
FXCA20 KWBC 021907  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
306 PM EDT FRI OCT 02 2026  
 
FORECAST BULLETIN 02 OCTOBER 2026 AT 1900 UTC:  
 
TODAY (FRIDAY), LOCALLY HEAVY RAINFALL WILL REMAIN A CONCERN  
ACROSS SOUTHERN MEXICO AND PACIFIC CENTRAL AMERICA. OVER THE  
WEEKEND, HEAVY RAIN AND A FEW STRONG THUNDERSTORMS ARE EXPECTED  
OVER HISPANIOLA, WHILE MOISTURE SHIFTING TOWARD THE WESTERN GULF  
WILL INCREASE THE RAINFALL THREAT ALONG EASTERN MEXICO BY SUNDAY.  
 
AN UPPER-LEVEL LOW NEAR THE SOUTHERN BAY OF CAMPECHE WILL DRIFT  
WEST TO NORTHWEST THROUGH SUNDAY. RAINFALL WILL FAVOR ITS MOIST  
PERIPHERY, WITH CONVERGENCE AND TERRAIN HELPING FOCUS CONVECTION  
ACROSS SOUTHERN MEXICO. DEEP MOISTURE EXTENDING FROM THE WESTERN  
CARIBBEAN INTO THE GULF WILL GRADUALLY SHIFT WESTWARD. BY SUNDAY,  
SOUTHEASTERLY FLOW WILL TRANSPORT THIS MOISTURE TOWARD TAMAULIPAS  
AND VERACRUZ, INCREASING THE POTENTIAL FOR HEAVY RAINFALL WHERE  
COASTAL CONVERGENCE AND LIFTING ALONG THE EASTERN SLOPES OVERLAP.  
FARTHER WEST, AFTERNOON CONVECTION WILL FAVOR THE SIERRA MADRE  
OCCIDENTAL AND ADJACENT INTERIOR AREAS, WHILE MOISTURE AND TERRAIN  
CONTINUE TO SUPPORT LOCALLY HEAVY STORMS OVER OAXACA AND CHIAPAS.  
 
OVER HISPANIOLA, A MID- TO UPPER-LEVEL TROUGH WILL DEEPEN TOWARD  
THE ISLAND AND DEVELOP A CLOSED CIRCULATION NEARBY BY SUNDAY.  
RELATIVELY COOL AIR ALOFT ABOVE A WARM, MOIST BOUNDARY LAYER WILL  
SUPPORT INCREASING INSTABILITY. DAYTIME HEATING, MOUNTAIN  
CIRCULATIONS, AND SEA-BREEZE CONVERGENCE WILL FAVOR THUNDERSTORMS,  
WITH THE GREATEST COVERAGE EXPECTED SATURDAY AFTERNOON AND EVENING  
OVER HAITI AND THE WESTERN TO CENTRAL DOMINICAN REPUBLIC. LOCALLY  
HEAVY RAINFALL MAY CONTINUE INTO THE NIGHT. ADDITIONAL STORMS ARE  
POSSIBLE SUNDAY, ALTHOUGH DECREASING MOISTURE ACROSS EASTERN  
HISPANIOLA SHOULD REDUCE OVERALL COVERAGE.  
 
FORECAST SOUNDINGS SUPPORT VIGOROUS AFTERNOON UPDRAFTS,  
PARTICULARLY OVER HAITI. POCKETS OF DRIER AIR ABOVE THE MOIST  
LOWER LEVELS COULD STRENGTHEN DOWNDRAFTS, WHICH COULD ALLOW A FEW  
STORMS TO PRODUCE STRONG WINDS. BRIEF SMALL HAIL IS POSSIBLE IN  
THE STRONGEST CELLS, ALTHOUGH CONFIDENCE IS LOWER THAN FOR STRONG  
GUSTS. THE EXPECTED PROFILE FAVOR LOCALIZED EPISODES OF STRONG  
CONVECTION.  
 
FOR THE 48-HOUR PERIOD FROM 12Z SATURDAY, OCTOBER 3, THROUGH 12Z  
MONDAY, OCTOBER 5, RAINFALL TOTALS OF 50-100 MM ARE POSSIBLE IN  
THE WETTER PORTIONS OF CENTRAL AND NORTHERN HAITI AND THE WESTERN  
TO CENTRAL DOMINICAN REPUBLIC, WITH LOCALIZED MAXIMA THAT COULD  
SURPASS 100 MM. MOIST EASTERLY FLOW OVER EXPOSED SLOPES AND  
REPEATED DEVELOPMENT ALONG TERRAIN AND CONVERGENCE BOUNDARIES  
COULD CONCENTRATE THESE HIGHER TOTALS. THE PLACEMENT AND  
PERSISTENCE OF THE HEAVIEST CELLS REMAIN UNCERTAIN. HEAVY RAINFALL  
COULD PRODUCE FLOODING AND LOCALIZED LANDSLIDES IN STEEP TERRAIN,  
WITH RUNOFF AFFECTING DOWNSTREAM VALLEYS EVEN WHERE LOCAL RAINFALL  
IS LOWER. SATURDAY SHOULD CONTRIBUTE MOST OF THE WEEKEND  
ACCUMULATION.  
 
ELSEWHERE IN THE GREATER ANTILLES, DAYTIME HEATING AND LOCAL  
CONVERGENCE WILL SUSTAIN SHOWERS AND THUNDERSTORMS OVER CUBA,  
JAMAICA, AND PUERTO RICO. THE NEARBY TROUGH WILL SUPPORT  
INSTABILITY OVER PUERTO RICO THROUGH SATURDAY, WHILE MOISTURE  
BECOMES LESS CONSISTENT SUNDAY. LINGERING MOISTURE OVER EASTERN  
CUBA AND JAMAICA WILL SUPPORT LOCALLY HEAVY CONVECTION. ACROSS THE  
LESSER ANTILLES, PASSING TRADE-WIND SHOWERS WILL PREVAIL, WITH  
INCREASING MOISTURE FAVORING THE SOUTHERN WINDWARD ISLANDS LATER  
IN THE PERIOD.  
 
THE MONSOON TROUGH AND MOIST PACIFIC INFLOW WILL CONTINUE TO  
SUPPORT CONVECTION ALONG PACIFIC CENTRAL AMERICA. UPSLOPE FLOW  
WILL FAVOR LOCALLY HEAVY RAINFALL OVER COSTA RICA AND PANAMA TODAY  
AND SATURDAY. FARTHER NORTHWEST, LOW-LEVEL CONVERGENCE AND  
DEVELOPING CYCLONIC FLOW OFFSHORE WILL FAVOR RENEWED CONVECTION  
FROM PACIFIC NICARAGUA TOWARD EL SALVADOR AND GUATEMALA DURING THE  
WEEKEND, WITH TERRAIN AND REPEATED STORMS DETERMINING THE HEAVIEST  
ACCUMULATIONS.  
 
ACROSS NORTHWESTERN SOUTH AMERICA, MOIST PACIFIC FLOW CONVERGING  
ALONG WESTERN COLOMBIA AND RISING OVER THE COASTAL TERRAIN WILL  
SUSTAIN LOCALLY HEAVY SHOWERS AND THUNDERSTORMS, PARTICULARLY  
TODAY AND SATURDAY. OVER NORTHERN COLOMBIA AND VENEZUELA,  
AFTERNOON HEATING AND LOCAL CONVERGENCE WILL REMAIN THE MAIN  
TRIGGERS FOR CONVECTION, WITH AVAILABLE MOISTURE CONTROLLING ITS  
COVERAGE.  
 
TROPICAL WAVES INITIALIZED AT 12 UTC:  
TYPE SOF INIT 03/00 03/12 04/00 04/12 05/00 05/12 06/00 06/12  
TW 15N 38W 41W 44W 48W 52W 55W 57W 60W 62W  
TW 17N 69W 71W 74W 77W 79W 81W 83W 85W 87W  
 
ALAMO...(WPC)  
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HPC Page
Main Text Page