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FXCA20 KWBC 171806
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
205 PM EDT MON JUN 17 2024

FORECAST BULLETIN 17 JUN 2024 AT 1800 UTC:

THE MAIN STORY CONTINUES TO BE THE CENTRAL AMERICAN GYRE (CAG)
THAT DEVELOPED...CAUSING EXCESSIVE AMOUNTS OF RAIN ACROSS CENTRAL
AMERICA INTO PORTIONS OF SOUTHERN AND EASTERN MEXICO. IT IS ALSO
WORTH MENTIONING...THAT AS OF THIS WRITING...THE NATIONAL
HURRICANE CENTER HAS DETERMINED THAT A LOW PRESSURE FORMING OVER
THE BAY OF CAMPECHE HAS A 70 PERCENT CHANCE OF TROPICAL CYCLONE
FORMATION IN 48 HOURS. AN AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM LATER TODAY.
HOWEVER...REGARDLESS OF THE DEVELOPMENT OF THIS SYSTEM...PORTIONS
OF CENTRAL AMERICA AND MEXICO WILL RECEIVE EXCESSIVE AND VERY
HAZARDOUS AMOUNTS OF RAIN THIS WEEK. ANOTHER FEATURE WORTH
MENTIONING IS THE TUTT LOCATED OVER THE WEST CENTRAL TROPICAL
ATLANTIC...WHICH IS SLOWLY MOVING WEST AND EXPECTED TO BE OVER THE
NORTHWESTERN CARIBBEAN TO THE SOUTHEASTERN GULF OF MEXICO BY LATE
WEDNESDAY INTO THURSDAY. THIS TUTT WILL PROVIDE INSTABILITY ACROSS
THE CARIBBEAN ISLANDS AND THE BAHAMAS...CAUSING A MARGINAL TO
SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREATER
ANTILLES INTO THE BAHAMAS ON TUESDAY AND WEDNESDAY.

STARTING WITH THE CAG...WHICH WILL PRODUCE EXCESSIVE AMOUNTS OF
RAIN ACROSS PORTIONS OF CENTRAL AMERICA THIS WEEK...EVEN BEYOND
OUR 3-DAY PERIOD. THE LATEST MODEL GUIDANCE SUGGESTED THAT THE
72-HR RAINFALL TOTAL WILL RANGE BETWEEN 8 AND 10 INCHES
(200-250MM) ON THE PACIFIC SIDE OF CENTRAL AMERICA...FROM THE
GOLFO DE FONSECA TO CHIAPAS OF MEXICO. OTHER SIGNIFICANT AMOUNTS
OF RAIN ARE FORECAST OVER OTHER PORTIONS OF MEXICO...SUCH AS
CHIAPAS...CAMPECHE...AND INTO THE NORTHEAST YUCATAN PENINSULA...AS
WELL AS NORTHEASTERN MEXICO IN AND AROUND TAMAULIPAS...WHERE 72-HR
MAX TOTALS OF 100-150MM ARE SUGGESTED BY THE MODEL GUIDANCE.  THE
PERSISTENT ONSHORE FLOW INTO THE PACIFIC CENTRAL AMERICAN
COAST...WITH THE ABOVE NORMAL MOISTURE...WILL PROVIDE A PERSISTENT
PATTERN FOR SHOWER DEVELOPMENT FOR THE AFOREMENTIONED AREAS.

THE CARIBBEAN REGION WILL BE UP AND DOWN EARLY THIS WEEK AS THERE
IS SOME SAHARAN DUST THAT COULD APPROACH THE LESSER ANTILLES THIS
AFTERNOON INTO TUESDAY. THIS PLUME OF SAHARAN DUST WILL SLOWLY
MOVE WEST...AND IT IS EXPECTED TO GET TO HISPANIOLA BY LATE
WEDNESDAY INTO THURSDAY. FOR THAT REASON...THE UPPER TROUGH WILL
HELP DEVELOP THUNDERSTORMS ON TUESDAY ACROSS THE EASTERN GREATER
ANTILLES ON TUESDAY INTO EARLY WEDNESDAY. THE UPPER TROUGH WILL
MOVE WEST AND PROVIDE INSTABILITY FOR STRONG THUNDERSTORM
DEVELOPMENT OVER PORTIONS HAITI INTO CUBA ON WEDNESDAY INTO
THURSDAY. AS THE SAHARAN DUST IS EXPECTED TO MOVE OVER PUERTO RICO
AND EASTERN HISPANIOLA ON WEDNESDAY INTO THURSDAY...THE
THUNDERSTORM ACTIVITY IS EXPECTED TO BECOME MORE ISOLATED...BUT
SOME OF THEM COULD BE STRONG FOR BRIEF PERIODS. THE OVERALL
EXPECTED RAINFALL OVER THE CARIBBEAN IS UNDER 50MM FOR THE 3-DAY
PERIOD...BUT ISOLATED SECTIONS COULD OBSERVE HIGHER AMOUNTS...SUCH
AS THE POSSIBLE STRONG THUNDERSTORMS THAT DO DEVELOP OVER
HISPANIOLA...WHICH CAUSE ISOLATED AMOUNTS TO 50MM ACROSS PORTIONS
OF HAITI ON TUESDAY INTO WEDNESDAY.

NORTHERN SOUTH AMERICA WILL HAVE A SERIES OF SFC TROUGHS IN THE
AREA EARLY THIS WEEK. THE 72-HR RAINFALL ACCUMULATION COULD HAVE
ISOLATED MAX VALUES OF 50-100MM ACROSS PORTIONS OF
VENEZUELA...COLOMBIA...AND ECUADOR. BUT OVERALL...MOST OF THE
RAINFALL EXPECTED OVER NORTHERN SOUTH AMERICA WILL BE
CONVECTIVE...AS THE DIURNAL HEATING INTERACTS WITH THE AVAILABLE
MOISTURE...AND WILL BE ENHANCED BY THE TROUGHS IN THE AREA. EACH
DAY WILL HAVE MAX TOTALS OF 25-45MM IN DIFFERENT SECTIONS.

IN SUMMARY...THE LATEST GUIDANCE CONTINUES TO SUGGEST THAT THE
POSITIONING OF THE MONSOON TROUGH IN THE PACIFIC...COMBINED WITH
THE CAG...WILL CONTINUE TO CAUSE A VERY MOIST ONSHORE FLOW INTO
CENTRAL AMERICA FOR THE NEXT SEVERAL DAYS. THIS WILL CAUSE A VERY
HAZARDOUS MULTI-DAY WET SPELL FOR PORTIONS OF CENTRAL AMERICA INTO
MEXICO. THE CARIBBEAN WILL HAVE SOME MOMENTS WITH STRONG
THUNDERSTORMS...PARTICULARLY ON TUESDAY AND WEDNESDAY...BUT MAY BE
LIMITED ACROSS THE NORTHEASTERN CARIBBEAN AS SAHARAN DUST MOVES
IN. NORTHERN SOUTH AMERICA WILL ALSO HAVE MOMENTS OF SHOWERS AND
THUNDERSTORMS AS THE SFC TROUGHS COMBINE WITH THE DIURNAL HEATING
AND AVAILABLE MOISTURE.



ALAMO (WPC)
CLARKE (CINWS)
FERNANDER (BDM)
























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