623
FXCA20 KWBC 181848
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
247 PM EDT TUE JUN 18 2024

FORECAST BULLETIN 18 JUN 2024 AT 1845 UTC:

THE NATIONAL HURRICANE CENTER IS NOW ISSUING ADVISORIES ON WHAT IS
KNOWS AS POTENTIAL TROPICAL CYCLONE (PTC) ONE. THIS AREA OF LOW
PRESSURE KNOWN AS PTC ONE IS FORECAST...BY THE NATIONAL HURRICANE
CENTER...TO STRENGTHEN INTO A TROPICAL STORM ON WEDNESDAY...AND
MAKE LANDFALL IN SOUTHERN TAMAULIPAS BY WEDNESDAY EVENING AS A
TROPICAL STORM. THIS PTC ONE IS ASSOCIATED WITH A BROADER
CIRCULATION THAT IS CAUSING AND WILL CONTINUE TO CAUSE SIGNIFICANT
AMOUNTS OF RAIN ACROSS CENTRAL AMERICA AND MEXICO FOR AT LEAST THE
REST OF THE WORKWEEK. THEREFORE...REGARDLESS OF THE DEVELOPMENT OF
PTC ONE...PORTIONS OF CENTRAL AMERICA AND MEXICO WILL RECEIVE
EXCESSIVE AND VERY HAZARDOUS AMOUNTS FOR THE REST OF THIS WEEK.
ANOTHER FEATURE OF SIGNIFICANCE IS THE TUTT LOCATED OVER THE
WESTERN TROPICAL ATLANTIC...NEAR THE TURKS AND CAICOS...WHICH IS
DRIFTING WEST AND EXPECTED TO BE OVER THE NORTHWESTERN CARIBBEAN
TO THE SOUTHEASTERN GULF OF MEXICO BY LATE WEDNESDAY INTO
THURSDAY...THEN OVER THE NORTHWEST YUCATAN PENINSULA BY LATE
THURSDAY INTO FRIDAY. 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 LATER TODAY INTO LATE WEDNESDAY NIGHT.

EXCESSIVE AMOUNTS OF RAIN ARE EXPECTED ACROSS PORTIONS OF CENTRAL
AMERICA FOR THE REST OF THIS WEEK...EVEN BEYOND OUR 3-DAY PERIOD.
THE LATEST MODEL GUIDANCE SUGGESTED THAT THE 72-HR RAINFALL TOTAL
WILL RANGE BETWEEN 10 AND 16 INCHES (250-400MM)...WITH ISOLATED
HIGHER AMOUNTS ON THE PACIFIC SIDE OF CENTRAL AMERICA FROM THE
GOLFO DE FONSECA TO CHIAPAS OF MEXICO. ADDING TO THAT...SOME OF
THE MODEL GUIDANCE AVAILABLE SUGGESTED OVER 16 INCHES (400MM)
ACROSS ISOLATED SECTORS OF EL SALVADOR INTO HONDURAS AND EXTREME
SOUTHWEST NICARAGUA. OTHER SIGNIFICANT AMOUNTS OF RAIN ARE
FORECAST OVER CHIAPAS...CAMPECHE...AND INTO THE NORTHEAST YUCATAN
PENINSULA...AS WELL AS NORTHEASTERN MEXICO IN AND AROUND
TAMAULIPAS...WHERE 72-HR MAX TOTALS OF 8 TO 12 INCHES (200-300MM)
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 DURING THE MIDWEEK AS
THERE IS SOME SAHARAN DUST OVER THE LESSER ANTILLES THAT WILL
CONTINUE TO MOVE WEST. THE SAHARAN DUST IS EXPECTED TO GET TO
HISPANIOLA BY LATE WEDNESDAY INTO THURSDAY. FOR THAT REASON...THE
UPPER TROUGH WILL HELP DEVELOP THUNDERSTORMS TODAY ACROSS THE
EASTERN GREATER ANTILLES TODAY INTO EARLY WEDNESDAY. AS THE UPPER
TROUGH MOVES WEST...IT WILL PROVIDE INSTABILITY FOR STRONG
THUNDERSTORM DEVELOPMENT OVER PORTIONS HAITI INTO CUBA ON
WEDNESDAY INTO THURSDAY...WHILE THE DENSER SAHARAN DUST
CONCENTRATION LAGS BEHIND...BEING OVER PUERTO RICO AND EASTERN
HISPANIOLA WEDNESDAY INTO THURSDAY. 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 TODAY AND WEDNESDAY. CUBA AND THE BAHAMAS MAY ALSO
OBSERVE STRONG THUNDERSTORMS BUT THE TIMING FOR THE STRONGEST
STORMS WOULD BE LATE WEDNESDAY INTO THURSDAY.

THERE HAS BEEN VERY LITTLE TO NO CHANGE IN THE FORECAST FOR
NORTHERN SOUTH AMERICA. THE REGION WILL HAVE A SERIES OF SFC
TROUGHS IN THE AREA OVER THE NEXT FEW DAYS. THE 72-HR RAINFALL
ACCUMULATION COULD HAVE ISOLATED MAX VALUES OF 50-100MM ACROSS
PORTIONS OF COLOMBIA AND ECUADOR...WHILE VENEZUELA...NORTHWESTERN
BRAZIL AND THE GUIANAS WOULD HAVE 72-HR MAX TOTALS OF UP TO AROUND
50-75MM. BUT OVERALL...MOST OF THE RAINFALL EXPECTED OVER NORTHERN
SOUTH AMERICA WILL BE CONVECTIVE...AS THE DIURNAL HEATING
INTERACTS WITH THE AVAILABLE MOISTURE...AND MAY 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 BROAD CAG CIRCULATION WILL CONTINUE TO PROMOTE A VERY MOIST
ONSHORE FLOW INTO CENTRAL AMERICA FOR THE NEXT SEVERAL DAYS. THIS
WILL CONTINUE THE  VERY HAZARDOUS MULTI-DAY WET SPELL FOR PORTIONS
OF CENTRAL AMERICA INTO MEXICO. THE CARIBBEAN WILL HAVE SOME
MOMENTS WITH STRONG THUNDERSTORMS...PARTICULARLY LATE TODAY AND
WEDNESDAY...BUT SAHARAN DUST MAY LIMIT THE CONVECTION ACROSS THE
NORTHEASTERN CARIBBEAN AS IT MOVES IN. NORTHERN SOUTH AMERICA WILL
ALSO HAVE MOMENTS OF SHOWERS AND LOCALLY INDUCED THUNDERSTORMS AS
THE AVAILABLE MOISTURE COMBINES WITH THE DIURNAL HEATING.



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
























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