874  
FXCA20 KWBC 051822  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
121 PM EST FRI DEC 05 2025  
 
FORECAST BULLETIN 05 DECEMBER 2025 AT 1820 UTC:  
 
MEXICO AND CENTRAL AMERICA:  
 
A POSITIVELY TILTED UPPER- TO MID-LEVEL TROUGH IS CURRENTLY  
LOCATED OVER THE SOUTHWEST UNITED STATES AND NORTHWEST MEXICO,  
INCLUDING THE BAJA PENINSULA AND THE REGION OF SONORA. AS THE  
TROUGH PROGRESSES EASTWARD INTO THE WEEKEND, A REMNANT TROUGH,  
POTENTIALLY IN THE FORM OF A CUTOFF LOW PER THE GFS, WILL REMAIN  
IN PLACE OVER THE WEEKEND AND EARLY NEXT WEEK. THIS SETUP WILL  
SUPPORT STRONG UPPER-LEVEL DIVERGENCE TODAY INTO EARLY IN THE  
MORNING ON SATURDAY. STEEP LAPSE RATES WILL ALSO BE PRESENT, WITH  
MID-LEVEL TEMPERATURES TO REACH AS LOW AS -12 DEGREES CELSIUS,  
WHICH WILL BE CONDUCIVE FOR THE GENERATION OF STRONG AND  
POTENTIALLY SEVERE THUNDERSTORMS IN BAJA CALIFORNIA SUR. AS SUCH,  
THERE IS A MARGINAL RISK FOR SEVERE WEATHER FOR BAJA CALIFORNIA  
SUR, AND PRECIPITATION IS EXPECTED TO PEAK AT AROUND 20-35MM  
TODAY. AFTER SATURDAY, A LOW-LEVEL RIDGE WILL ENTER FROM THE  
PACIFIC AND IS EXPECTED TO STABILIZE THE ENVIRONMENT IN THE BAJA  
PENINSULA AND SONORA.  
 
ON THE EAST COAST OF MEXICO, A COLD FRONT IS EXPECTED TO MOVE INTO  
THE GULF FROM THE SOUTHERN UNITED STATES EARLY NEXT WEEK. AS THE  
FRONT BEGINS TO ENTER, THE LOW-LEVEL FLOW AT THE TAIL END OF THE  
FRONT WILL CHANGE FROM A WESTERLY REGIME TO A NORTHEASTERLY FLOW,  
WHICH WILL ALLOW FOR THE TRANSPORT OF MOISTURE TO FLOW ONSHORE  
INTO VERACRUZ BEGINNING ON MONDAY MORNING. THE LOW-LEVEL FLOW WILL  
BE STRONG AT THIS POINT, POTENTIALLY EXCEEDING 30KTS, AND IS  
EXPECTED TO STRONGLY ENHANCE OROGRAPHIC EFFECTS. THE HEAVIEST  
PRECIPITATION IS EXPECTED EARLY NEXT WEEK, PAST THE FORECAST  
PERIOD, HOWEVER, MODERATE TO POTENTIALLY HEAVY PRECIPITATION WILL  
BEGIN FOR THIS REGION ON SUNDAY, WITH 20-35MM EXPECTED.  
 
IN HONDURAS AND NICARAGUA, A PLUME OF MOISTURE ASSOCIATED WITH A  
LOW-LEVEL TROUGH, CURRENTLY LOCATED IN THE CENTRAL CARIBBEAN, WILL  
PROPAGATE WESTWARD BEFORE REACHING THE EASTERN COASTS OF HONDURAS  
AND NICARAGUA ON SATURDAY MORNING. THE PRESENCE OF AN UPPER-LEVEL  
RIDGE WILL BE LOCATED OVER THE CARIBBEAN SEA, AND THE WESTERN  
PERIPHERY OF THE RIDGE WILL BE LOCATED OVER MUCH OF CENTRAL  
AMERICA, PARTICULARLY HONDURAS AND NICARAGUA. THIS WILL ENHANCE  
UPPER-LEVEL DIVERGENCE, AND ADDITIONAL LOW-LEVEL MOISTURE  
CONVERGENCE IS EXPECTED AS THE TROUGH MOVES INLAND INTO NICARAGUA.  
THE HEAVIEST PRECIPITATION IS EXPECTED TO OCCUR BEGINNING ON  
SATURDAY MORNING, WITH A MAXIMUM OF 20-35MM EXPECTED IN NICARAGUA  
AND PARTS OF EASTERN HONDURAS.  
 
THE CARIBBEAN AND BAHAMAS:  
 
IN THE LESSER ANTILLES, A WESTWARD PROPAGATING LOW-LEVEL TROUGH  
WITH AN ASSOCIATED PLUME OF MOISTURE ORIGINATING FROM THE ITCZ  
WILL BRING PRECIPITATION TO THE WINDWARD ISLANDS ON SATURDAY.  
INSTABILITY WILL BE SLIGHTLY ENHANCED DURING THIS TIME DUE TO THE  
PRESENCE OF AN UPPER-LEVEL TROUGH, AND WITH THE ADDITION OF  
LOW-LEVEL MOISTURE CONVERGENCE, MODERATE PRECIPITATION IS  
ANTICIPATED. EXPECT A PRECIPITATION MAXIMUM OF AROUND 20-35 ON  
SATURDAY IN THE WINDWARD ISLANDS.  
 
MUCH OF THE REST OF THE CARIBBEAN WILL EXPERIENCE CALM AND DRIER  
CONDITIONS DUE TO THE PRESENCE OF AN UPPER-LEVEL RIDGE PROMOTING  
ANTI-CYCLONE CIRCULATION AND OVERALL SUBSIDENCE. ANY PRECIPITATION  
WILL BE IN THE FORM OF LOCALLY INDUCED SHOWERS.  
 
TROPICAL SOUTH AMERICA:  
 
THE AFOREMENTIONED LOW-LEVEL TROUGH FROM THE EASTERN CARIBBEAN  
WILL MOVE MOISTURE INTO TRINIDAD AND TOBAGO AND PARTS OF THE  
GUIANAS OVER THE NEXT THREE DAYS. MOISTURE FLOW INTO THE REGION  
WILL BE PERSISTENT, AND HEAVY PRECIPITATION SHOULD BE EXPECTED FOR  
THIS REGION, WITH DAILY PRECIPITATION MAXIMA OF AROUND 20-45MM. IN  
THE INTERIOR REGIONS OF TROPICAL SOUTH AMERICA, MOISTURE WILL  
CONTINUE TO MOVE FROM THE EASTERN PORTIONS OF THE AMAZON AND WILL  
PROVIDE FUEL FOR CONVECTION DUE TO LOCALIZED, DIURNAL, AND  
OROGRAPHIC EFFECTS, WITH DAILY HEAVY PRECIPITATION EXPECTED,  
PARTICULARLY IN SOUTHERN VENEZUELA AND NORTHWEST BRAZIL. IN  
WESTERN COLOMBIA, WEAK WESTERLY FLOW ONSHORE WILL AID IN BRINGING  
PRECIPITATION, WHICH WITH OROGRAPHIC ENHANCEMENT, WILL RESULT IN  
LOCALIZED HIGH PRECIPITATION TOTALS. THE HEAVIEST PRECIPITATION IS  
EXPECTED TODAY, WITH A MAXIMUM OF 25-50MM POSSIBLE IN LOCALIZED  
AREAS OF WESTERN COLOMBIA.  
 
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC  
TYP SOF INIT 06/00 06/12 07/00 07/12 08/00 08/12 09/00  
-- -- -- --- --- --- --- --- --- ---  
 
FOR THE LATEST AVAILABLE CHARTS PLEASE VISIT:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/INTERNATIONAL/CRB_DAY1-3.SHTML  
 
BLANCO-ALCALA...(WPC)  

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page