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FXCA20 KWBC 291543

PMDCA 



TROPICAL DISCUSSION - INTERNATIONAL DESKS

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1142 AM EDT MON APR 29 2024



FORECAST BULLETIN 29 APR 2024 AT 1630 UTC: THE MJO IS EXPECTED TO

CONTINUE WEEKLY CONVERGENT IN THE UPPER LEVELS THROUGH THE

FORECAST CYCLE. UNDER THIS PATTERN...EXPECT AREAS OF POTENTIALLY

HEAVY PRECIPITATION TO REMAIN MOSTLY DISCRETE IN EXTENSION.



WEST IN THE DOMAIN...A CELL OF THE SUBEQUATORIAL RIDGE IS EXPECTED

TO PERSIST NEAR 10-13N AND 98-102W THROUGH THE CYCLE. THE RIDGE

WILL LIMIT THE PROGRESSION OF MID-UPPER TROUGHS IN

MEXICO...FAVORING THE PERSISTENCE OF A DIURNAL PATTERN IN TERMS OF

CONVECTIVE DEVELOPMENT. GIVEN CURRENT MOISTURE AVAILABILITY...THE

LARGEST ACCUMULATIONS ARE EXPECTED ALONG THE SIERRA MADRE

ORIENTAL...WHERE EXPECT AMOUNTS OF 05-10MM/DAY AND MAXIMA

GENERALLY IN THE 15MM/DAY RANGE. VENTILATION IN THE PERIPHERY OF

THE UPPER RIDGE WILL ALSO AID WITH THE DEVELOPMENT OF DIURNAL

CONVECTION IN PORTIONS OF NROTHERN CENTRAL AMERICA. ON MONDAY

EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM FROM WESTERN HONDURAS

INTO EAST CHIAPAS/SOUTHERN BELIZE. ON TUESDAY...EXPECT 10-15MM/DAY

AND VERY ISOLATED MAXIMA OF 20-40MM FROM SOUTHERN HONDURAS/EL

SALVADOR INTO SOUTHERN CHIAPAS. ON WEDNESDAY...EXPECT A DECREASE

TO 05-10MM/DAY AND ISOLATED MAXIMA OF 15-30MM.



THE PERSISTENCE OF THE UPPER RIDGE TO THE SOUTH OF MEXICO WILL

YIELD TO THE AMPLIFICATION OF AN UPPER TROUGH ACROSS THE NORTHWEST

CARIBBEAN. MODELS ARE RESOLVING THIS EVOLUTION BUT STRUGGLE IN THE

PRECISE LOCATION OF THE TROUGH AXIS AND SHAPE. THIS IS RELEVANT

FOR THE PRECIPITATION FORECAST IN JAMAICA...SOUTHEAST CUBA AND

HISPANIOLA...WHERE A MOIST PLUME IS BREWING.

FURTHERMORE...ENHANCEMENT BY A SURFACE FRONT WILL BE RELEVANT FOR

QPF. IN TERMS OF FRONTAL POSITIONS...BY MONDAY EVENING EXPECT A

BOUNDARY ALONG 20N 60W...NORTHERN PUERTO RICO...CENTRAL

HISPANIOLA...NORTHERN COAST OF CUBA. IT IS FORECAST TO REMAIN IN

THESE LOCATIONS THROUGH THE ENTIRE FORECAST CYCLE...WHILE SLOWLY

MEANDERING NORTHWARD AWAY FROM THE COASTS OF THE GREATER ANTILLES.

BY LATE WEDNESDAY...INTERACTIONS BETWEEN THE UPPER TROUGH AND THE

FRONT WILL LIKELY INDUCE A FRONTAL WAVE TO THE NORTH OF HISPANIOLA

WHILE THE FRONT LOSES DEFINITION IN AREAS TO THE WEST.



IN TERMS OF PRECIPITATION...ON MONDAY EXPECT MAXIMA OF 20-35MM IN

HISPANIOLA AND MAXIMA OF 15-20MM IN PUERTO RICO...VI AND LEEWARD

ISLANDS. IN PORTIONS OF CUBA EXPECT MAXIMA OF 15-25MM AND IN

JAMAICA MAXIMA OF 15MM. ON TUESDAY...AS THE UPPER TROUGH STARTS TO

ORGANIZE...EXPECT AN INCREASE IN ACCUMULATION. NOTE THAT A

MARGINAL RISK FOR SEVERE CONVECTION IS POSSIBLE IN PORTIONS OF

SOUTHEAST CUBA AND HAITI...WHERE INSTABILITY AND DIURNAL HEATING

MIGHT PLAY A ROLE. IN TERMS OF AMOUNTS...EXPECT MAXIMA OF 20-45MM

IN HAITI AND IN SOUTHEAST CUBA...WHILE IN PUERTO RICO...HISPANIOLA

AND JAMAICA EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM. IN CENTRAL

CUBA...EXPECT 05-10MM/DAY AND MAXIMA OF 15-25MM. BY

WEDNESDAY...EXPECT THE HEAVIEST PRECIPITATION IN HISPANIOLA DUE TO

INTERACTIONS BETWEEN THE UPPER TROUGH AND THE MOIST PLUME. EXPECT

ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 25-50MM WITH A SLIGHT

RISK OF SEVERE WEATHER. TO THE WEST OF THE MID/UPPER TROUGH

AXIS...EXPECT GENERALLY MAXIMA OF 15-20MM IN JAMAICA AND SOUTHEAST

CUBA. NOTE A SLIGHT RISK FOR SEVERITY IN SOUTHEAST CUBA. IN THE

CENTRAL/SOUTHEAST BAHAMAS AND THE TURKS AND CAICOS EXPECT ISOLATED

MAXIMA OF 15-25MM WITH A RISK FOR SQUALLY CONVECTION IN

ASSOCAITION WITH A MID-UPPER SHORT WAVE TROUGH.



SEASONAL CONVECTION IN NORTHERN SOUTH AMERICA IS CLUSTERING

GENERALLY ALONG THE ITCZ/NET AND TROUGHS PROPAGATING IN THE

TRADES. THE LARGEST ACCUMULATIONS ARE EXPECTED IN COLOMBIA...WHERE

ENHANCED MOISTURE CONVERGENCE IS EXPECTED THROUGH THE FORECAST

CYCLE. OF RELEVANCE...EXPECT AN INCREASING TREND IN WESTERN

COLOMBIA THROUGH WEDNESDAY/THURSDAY...GIVEN INCREASING

ONSHORE/WESTERLY WINDS.



GALVEZ/CLARKE/LEDESMA/ACOSTA...WPC (USA)





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