TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
256 PM EDT WED MAY 01 2024

FORECAST BULLETIN 01 MAY 2024 AT 1900 UTC: THE MJO CONTINUES TO
FAVOR CONVERGENCE IN THE UPPER LEVELS THROUGH THE FORECAST CYCLE.
UNDER THIS PATTERN...EXPECT AREAS OF POTENTIALLY HEAVY
PRECIPITATION TO REMAIN MOSTLY DISCRETE IN EXTENSION.

A CELL OF THE SUBEQUATORIAL RIDGE CONTINUES TO LIMIT THE
PROGRESSION OF MID TO UPPER LEVEL TROUGHS IN MEXICO. FURTHER
EAST... THE PERSISTENCE OF THE RIDGE WILL SUPPORT THE
AMPLIFICATION OF A MID-UPPER TROUGH OVER THE CARIBBEAN BASIN AND
EXTENDS INTO CENTRAL COLOMBIA. A WEAK MID-UPPER SHORTWAVE TROUGH
IS EMBEDDED WITHIN THE MAIN TROUGH AND MOVES OVER SE
BAHAMAS...TURKS AND CAICOS...EASTERN CUBA...AND INTO HISPANIOLA.
THERE REMAINS SOME DISAGREEMENT WITH THE EVOLUTION OF THE UPPER
LEVEL TROUGH BETWEEN MODELS FROM THURSDAY THROUGH FRIDAY. AS A
RESULT THE EXACT LOCATION OF THE BASE OF THE UPPER LEVEL TROUGH
AND THE AXIS IS UNCERTAIN. A FRONTAL BOUNDARY IS LOCATED OVER THE
CENTRAL ATLANTIC AND EXTENDS JUST OF PUERTO
RICO...HISPANIOLA...AND INTO TURKS AND CAICOS ON WEDNESDAY. THE
APPROACHING UPPER LEVEL TROUGH IS EXPECTED TO ENHANCE THE
DEVELOPMENT OF UNDULATION OF THE EXISTING FRONTAL
BOUNDARY...HOWEVER IT IS NOT SUSTAINED THROUGHOUT THE CYCLE.
HEAVIEST PRECIPITATION IS EXPECTED FROM WEDNESDAY INTO
THURSDAY...AND DECREASES BY FRIDAY.

ON WEDNESDAY...ENHANCED CONVECTIVE ACTIVITY OVER SOUTH
BAHAMAS...TURKS AND CAICOS...AND NORTHERN HISPANIOLA...WILL FAVOR
MAXIMA OF 30-60MM WITH MODERATE RISK OF SQUALLY/SEVERE WEATHER.
WHILE NORTHEAST CUBA AND JAMAICA CAN EXPECT A MAXIMA OF 20-35MM.
THE EASTERN PORTION OF CUBA CAN EXPECT SLIGHT RISK OF SEVERE
WEATHER. CENTRAL BAHAMAS...CENTRAL CUBA...PUERTO RICO...SOUTHERN
HISPANIOLA...AND HAITI CAN EXPECT GENERAL MAXIMA OF 15-25MM. ON
THURSDAY...THE UPPER LEVEL TROUGH PROPAGATES TO THE EAST...AND ITS
CONVERGENT SIDE IS LOCATED OVER THE NORTHERN CARIBBEAN...AS SUCH A
DECREASE IN PRECIPITATION TOTALS IS FORECAST. IN NORTHERN
DOMINICAN REPUBLIC...EASTERN CUBA...AND JAMAICA...CAN EXPECT
GENERAL MAXIMA OF 20-45MM. PUERTO RICO CAN EXPECT MAXIMA OF
20-35MM WITH A MARGINAL RISK OF SEVERE WEATHER. ELSEWHERE IN
CENTRAL CUBA...AND THE NORTHERN LESSER ANTILLES...EXPECT
GENERALIZED MAXIMA OF 15-25MM. ON FRIDAY...A DECREASE IN
PRECIPITATION THE CARIBBEAN IS EXPECTED..AS THE UPPER TROUGH
CONTINUES PROPAGATING EAST. THE DOMINICAN REPUBLIC...PUERTO
RICO...AND THE NORTHERN LESSER ANTILLES CAN EXPECT MAXIMUM OF
20-45MM. MAXIMA OF 10-20MM ARE FORECAST FOR HAITI...JAMAICA...AND
LESSER ANTILLES.

ELSEWHERE IN CENTRAL AMERICA...AND MEXICO...SEASONAL PRECIPITATION
IS EXPECTED THROUGH THE FORECAST CYCLE. THIS WILL BE INHIBITED BY
THE CONVERGENT MJO PATTERN THAT PERSISTS IN THE UPPER LEVELS.
EXPECT ISOLATED MAXIMA TO REMAIN BELOW THE 20-25MM RANGE IN
PORTIONS OF EASTERN MEXICO...SOUTHERN GUATEMALA...THE GOLF OF
FONSECA REGION...COSTA RICA...AND PANAMA.

IN NORTHERN SOUTH AMERICA...EASTERLY WAVES ARE EXPECTED TO
INTERACT WITH THE ITCZ/NET AS THEY PROPAGATE TO THE WEST...DIURNAL
CONVECTION IS EXPECTED TO FAVOR MAXIMA OF 20-35MM IN
AMAPA-BRASIL...AND INTO PARA. SIMILAR AMOUNTS ARE EXPECTED IN
CENTRAL COLOMBIA...NORTHEAST PERU...AND WESTERN ECUADOR. MAXIMA OF
30-60MM ARE EXPECTED IN THE LAKE MARACAIBO REGION AND INTO NORTH
COLOMBIA. IN WESTERN COLOMBIA AND WESTERN ECUADOR...FAVORABLE
ONSHORE FLOW WILL FAVOR MAXIMA OF 30-60MM IN WESTERN
COLOMBIA...AND 20-35MM IN NORTHWEST ECUADOR. ON THURSDAY...A
DECREASE IN VALUES IS EXPECTED...AS CONDITIONS LESS CONDUCIVE FOR
SUSTAIN DEEP CONVECTION. EXPECT GENERALIZED MAXIMA OF 20-45MM FROM
THE LAKE MARACAIBO REGION...ALONG WEST COLOMBIA...AND INTO WEST
ECUADOR. THE EASTERLY WAVES WILL FAVOR MAXIMA OF ISOLATED 20-35MM
FROM EASTERN COLOMBIA...INTO VENEZUELA...GUYANA...AND NORTHERN
BRASIL. ON FRIDAY...THE POSSIBLE ENHANCEMENT OF DEEP CONVECTION
OVER NORTHERN COLOMBIA IS LIKELY UNDER THE INFLUENCE OF THE BASE
OF THE UPPER LEVEL TROUGH. IN WESTERN COLOMBIA...ONSHORE FLOW
FAVORS DEEP CONVECTION IN THE REGION. COLOMBIA CAN EXPECT MAXIMA
OF 30-60MM. TO THE EAST...EASTERLY WAVE PROPAGATION WILL FAVOR
ISOLATED CONVECTION...AND MAXIMA OF 20-35MM IN SOUTHEAST
COLOMBIA...INTO SOUTHERN VENEZUELA...AND RORAIMA-BRASIL.

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