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FXCA20 KWBC 291608
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1107 AM EST WED JAN 29 2025
FORECAST BULLETIN 29 JANUARY 2025 AT 15:00 UTC
..LARGE SCALE CONDITIONS
MJO:
THE MJO SIGNAL HAS STRENGTHENED CONSIDERABLY CURRENTLY APPROACHING
PHASE 4 THIS WEEK AND EARLY FEBRUARY. THIS MJO PHASE GENERALLY
FAVORS UPPER CONVERGENCE AND DRIER CONDITIONS IN THE CARIBBEAN
BASIN. HOWEVER AS THIS MJO REACHES PHASE 4 IS EXPECTED TO BE
SLIGHTLY LESS ORGANIZED. UNCERTAINTIES REMAINS IN THE MODELS ABOUT
THE ORGANIZATION OF THE MJO.
KELVIN WAVE:
NONE SIGNIFICANT KELVIN WAVE APPROACHING THE CARIBBEAN BASIN BY
THE END OF THE WEEK.
ENSO CONDITIONS:
LA NINA
..SYNOPTIC CONDITIONS CARIBBEAN BASIN
UPPER LEVELS:
AN UPPER LEVEL TROUGH CONTINUES MOVING OVER THE SOUTHWESTERN USA
PROPAGATING EASTWARD... THIS TROUGH WILL BE LOCATED NEAR THE
SOUTHEAST OF USA BY THURSDAY. THIS WILL ENHANCE RISK OF SEVERE
WEATHER IN THE SOUTHERN US. FOR MORE INFORMATION VISIT THE STORM
PREDICTION CENTER (HTTPS://WWW.SPC.NOAA.GOV/)
WHILE AN UPPER RIDGE WILL BUILD OVER THE WESTERN CARIBBEAN BY
THURSDAY...PROMOTING STABLE ATMOSPHERE AND LIMITING THE
DEVELOPMENT OF DEEP CONVENTION IN THE GREATER AND LESSER ANTILLES.
BY FRIDAY AN UPPER LEVEL TROUGH WILL AMPLIFY TO THE EAST OF THE
LESSER ANTILLES...WITH LIMITED IMPACT IN THE CARIBBEAN AND
TROPICAL SOUTH AMERICA.
LOWER LEVELS:
A COLD FRONT WILL CONTINUE PROPAGATING INTO THE NORTHERN CARIBBEAN
STARTING TODAY AND THROUGH FRIDAY.THE FRONT IS EXPECTED TO EXIT
INTO THE CENTRAL ATLANTIC BY FRIDAY. AN INDUCED TROUGH AND IN
COMBINATION WITH A SHALLOW MOISTURE PLUME THROUGH THE NEXT
FORECAST CYCLE WILL PROMOTE SOME SHALLOW CONVECTION OVER THE
GREATER ANTILLES FROM FRIDAY INTO SATURDAY.
..PRECIPITATION IN THE CARIBBEAN
AS MENTIONED BEFORE THE UPPER CONVERGENCE WILL LIMIT THE
DEVELOPMENT OF PRECIPITATION ACCUMULATIONS. HOWEVER SHALLOW MOIST
PLUMES ARE EXPECTED TO MOVE WESTWARD ACROSS THE GREATER AND LESSER
ANTILLES. THE MOIST PLUME WHEN INTERACTING WITH TERRAIN WILL
ENHANCE AND WILL FAVOR THE DEVELOPMENT OF THE FOLLOWING ISOLATED
MAXIMA.
LESSER ANTILLES: MAXIMA OF 10 - 15MM ON THURSDAY AND FRIDAY.
PUERTO RICO: MAXIMA OF 10MM ON THURSDAY AND FRIDAY.
DOMINICAN REPUBLIC: MAXIMA OF 10 -15MM ON THURSDAY AND FRIDAY.
EASTERN CUBA: MAXIMA OF 10 -15MM ON THURSDAY AND FRIDAY.
JAMAICA: MAXIMA OF 10 - 15MM FOR THE NEXT FORECAST CYCLE.
..PRECIPITATION IN MEXICO AND NORTHERN CENTRAL AMERICA
ANOTHER COLD FRONT EXTENDING INTO VERACRUZ AND AN INDUCED TROUGH
WILL FAVOR THE FOLLOWING MAXIMA:
SOME AREAS OF MEXICO...VERACRUZ...TABASCO...WEST OF CHIAPAS:
MAXIMA OF 20 - 35MM BY FRIDAY.
NORTHERN GUATEMALA AND WESTERN BELIZE: MAXIMA OF 20 - 35MM BY
FRIDAY.
..PRECIPITATION IN CENTRAL AMERICA
AS THE UPPER CONVERGENT MJO CONTINUES PROPAGATING EASTWARD...THE
CARIBBEAN LOW-LEVEL JET BECOMES MORE ACTIVE...LEADING TO INCREASED
PRECIPITATION OVER THE CARIBBEAN BASIN OF CENTRAL AMERICA. THE
TRADE WINDS STIMULATED BY THE CARIBBEAN LOW-LEVEL JET WILL ENHANCE
THE MOISTURE PLUME PROPAGATING ACROSS THE GULF OF
HONDURAS...NICARAGUA AND COSTA RICA. THIS IN COMBINATION WITH THE
INTERACTION WITH TOPOGRAPHY CAN FURTHER INFLUENCE PRECIPITATION
PATTERNS IN THE FOLLOWING AREAS:
BELIZE: MAXIMA OF 10 - 15MM ON WEDNESDAY AND THURSDAY.
SOUTHERN BELIZE: A MAXIMA OF 20 - 35MM ON FRIDAY.
COSTA RICA: MAXIMA OF 15 - 25MM ON WEDNESDAY AND THURSDAY...A
MAXIMA INCREASE OF 20 - 40MM ON FRIDAY.
EASTERN NICARAGUA AND EASTERN OF HONDURAS: MAXIMA OF 15-25MM FOR
THE NEXT FORECAST CYCLE.
..SYNOPTIC CONDITIONS OVER TROPICAL SOUTH AMERICA
UPPER SOUTHWESTERLY FLOW IS EXPECTED TO CONTINUE OVER
ECUADOR...COLOMBIA... AND VENEZUELA...WHICH TYPICALLY PROMOTES
ENHANCED UPPER DIVERGENCE. THIS WILL BE FOLLOWED BY THE
PROPAGATION OF THE SUBEQUATORIAL UPPER JET FROM THE WEST THROUGH
THE FORECAST CYCLE...WHICH WILL ALSO TRANSPORT A DRIER AIR MASS
FROM THE PACIFIC BASIN. THIS UPPER CONVERGENCE IS EXPECTED TO
RESTRICT FURTHER DEVELOPMENT OF PRECIPITATION AND ACCUMULATION.
PERPENDICULAR ONSHORE FLOW ALONG AND SOUTH OF THE PACIFIC ITCZ
WILL ENHANCE THE INCREASE IN MOISTURE FROM TUESDAY INTO WEDNESDAY
OVER ECUADOR AND SOUTHWEST OF COLOMBIA. IN THE FOLLOWING REGION A
MAXIMA OF IS EXPECTED:
CENTRAL COAST OF ECUADOR AND SOUTHWEST COLOMBIA: A MAXIMA OF 20 -
50MM FOR THE FORECAST CYCLE. HOWEVER... UNCERTAINTY REMAINS IN THE
FORECAST.
IN THE ATLANTIC BASIN...THE HEAVIEST PRECIPITATION IS ANTICIPATED
TO CONCENTRATE IN AREAS OF ENHANCED MOISTURE CONVERGENCE WITHIN
THE INTERTROPICAL CONVERGENCE ZONE (ITCZ). THE ITCZ WILL CONTINUE
MEANDER FROM THE GUIANAS ON WEDNESDAY AND THURSDAY TO AMAPA IN
BRASIL. AS THE ITCZ SHIFTS SOUTHWARD...DRIER CONDITIONS ARE
EXPECTED IN GUIANAS AND AMAPA BY FRIDAY. THE FOLLOWING MAXIMA ARE
EXPECTED:
GUIANAS AND AMAPA: MAXIMA 20 - 35MM ON WEDNESDAY......MAXIMA OF
15 - 25MM ON THURSDAY.
THE REST OF THE TROPICAL SOUTH AMERICA PRECIPITATION MAXIMA WILL
BE ALONG THE NET ITCZ...WITH MAXIMA OF 15-35MM FOR THE FORECAST
CYCLE.
LEDESMA...(WPC)
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