TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
359 PM EDT TUE OCT 01 2024

FORECAST BULLETIN 01 OCT 2024 AT 2000 UTC:

THE NATIONAL HURRICANE CENTER (NHC) IS MONITORING TROPICAL STORM
KIRK IN THE ATLANTIC WATERS...AS WELL AS AN AREA OF POSSIBLE
TROPICAL CYCLONE FORMATION JUST SOUTH OF THE CABO VERDE ISLANDS.
THERE ARE ALSO TWO AREAS OF POSSIBLE TROPICAL CYCLONE FORMATION
ACROSS THE EASTERN PACIFIC...BOTH OF WHICH ARE SOUTH OF SOUTHERN
MEXICO. AS OF THIS WRITING...AN AREA OF LOW PRESSURE SOUTH OF THE
GULF OF TEHUANTEPEC HAS A HIGH CHANCE OF TROPICAL CYCLONE
FORMATION...AND ACCORDING TO THE LATEST OUTLOOK BY NHC...A
TROPICAL DEPRESSION COULD DEVELOP LATER THIS AFTERNOON. PLEASE
MONITOR THE LATEST AND OFFICIAL OUTLOOKS AND ADVISORIES ISSUED BY
THE NATIONAL HURRICANE CENTER.

OVER THE NEXT FEW DAYS...THE GENERAL PATTERN AND FORECAST ACROSS
CENTRAL AMERICA AND SOUTHERN MEXICO WILL BE COMPLEX...THERE WILL
BE ABOVE NORMAL MOISTURE ACROSS THE EASTERN PACIFIC INTO THE
CARIBBEAN AND THE GULF OF MEXICO. THE DEEP MOISTURE WILL PREVAIL
OVER ALL AREAS MENTIONED EXCEPT THE CARIBBEAN WHERE THE DEEP
MOISTURE IS EXPECTED TO MOVE WEST WITH EACH PASSING DAY. GIVEN THE
COMPLEX PATTERN...THERE IS CONSIDERABLE UNCERTAINTY WITH THE
FORECAST...AND THE DIFFERENT MODEL GUIDANCE IS IN SOME
DISAGREEMENT EVEN IN THE SHORT TERM. THAT BEING SAID...SIGNIFICANT
RAINFALL IS EXPECTED OVER SOUTHERN MEXICO INTO CENTRAL AMERICA
OVER THE NEXT FEW DAYS.

ACROSS SOUTHERN MEXICO...RAINFALL TOTALS COULD REACH VALUES NEAR
40-80MM ON WEDNESDAY AND 50-100MM ON THURSDAY NEAR THE BOUNDARY
BETWEEN CHIAPAS...OAXACA...TABASCO...AND VERACRUZ. THIS IS DUE TO
THE AFOREMENTIONED COMBINATION OF FACTORS THAT COULD INTERACT OVER
THE AREA...MEANING THE TROPICAL WAVE THAT WILL STALL OVER THE
AREA...NEAR 95W...AND THE DEEP MOISTURE CONVERGENCE. A LONG FETCH
NORTHWESTERLY WIND FROM THE GULF OF MEXICO WILL THEN CONVERGE WITH
THE SOUTHERLY WINDS ACROSS THE EASTERN PACIFIC ON WEDNESDAY AND
THURSDAY. THERE IS ALSO A MID LEVEL VORTICITY MAXIMA THAT IS
FORECAST TO BE NORTH OF SOUTHERN MEXICO BY WEDNESDAY. THERE IS
HOWEVER...NOTHING IN PARTICULAR IN THE UPPER LEVELS THAT WOULD
PROMOTE OR ENHANCE DEEP CONVECTION OVER THE AREA...THOUGH THERE IS
NOTHING PROMOTING SUBSIDENCE EITHER...HOWEVER. THEREFORE...ONCE
AGAIN...SIGNIFICANT RAINFALL IS EXPECTED OVER THE NEXT THREE DAYS
ACROSS PORTIONS OF SOUTHERN MEXICO...BUT THERE IS CONSIDERABLE
UNCERTAINTY AS THERE ARE SEVERAL FACTORS INTERACTING THAT WOULD
PLAY A ROLE IN THE EXACT LOCATION AND AMOUNTS OF RAIN...THOUGH
PERIODS OF HEAVY AND PERSISTENT RAIN ARE EXPECTED
REGARDLESS...ESPECIALLY ON WEDNESDAY AND THURSDAY.

MOST OF CENTRAL AMERICA IS EXPECTED TO OBSERVE SIGNIFICANT
RAINFALL EACH DAY...TODAY INTO TONIGHT BEING THE WETTEST
PERIOD...GIVEN THE INTERACTION BETWEEN A UPPER TROUGH ACROSS THE
CENTRAL TO WESTERN CARIBBEAN...COMBINED WITH DEEP MOISTURE
CONVERGING FROM THE MONSOON TROUGH AND A SFC TROUGH ACROSS THE
CARIBBEAN. THIS MOISTURE CONVERGENCE WITH THE UPPER TROUGH WILL
PROVIDE A GOOD ENVIRONMENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT
PARTICULARLY OVER COSTA RICA TO NICARAGUA FOR THE REST OF TODAY
INTO VERY EARLY WEDNESDAY MORNING...AND MAX RAINFALL TOTALS NEAR
35-70MM ARE FORECAST FOR PORTIONS OF NICARAGUA AND COSTA RICA.
FURTHER NORTH IN CENTRAL AMERICA...THE DAILY RAINFALL IS EXPECTED
TO BE IN THE ORDER OF 10-15MM/DAY WITH MAX VALUES NEAR 20-45MM.

MOST OF THE CARIBBEAN ISLANDS ARE EXPECTED TO OBSERVE MODEST
AMOUNTS OF RAIN OVER THE NEXT FEW DAYS. HOWEVER...WESTERN CUBA
DOES HAVE A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS ON WEDNESDAY
AND THURSDAY...AS A LOW LEVEL LOW MOVES NORTH OVER THE WESTERN
CARIBBEAN AND OVER CUBA. THE REST OF THE GREATER ANTILLES AS WELL
AS THE LESSER ANTILLES WILL OBSERVE MAINLY ISOLATED TO SCATTERED
SHOWERS...WITH LOCALLY INDUCED DIURNAL CONVECTION EXPECTED IN THE
AFTERNOON HOURS EACH DAY ACROSS THE GREATER ANTILLES. THE AMOUNTS
OF RAIN FORECAST WILL BE GENERALLY UNDER 25MM EACH DAY ACROSS THE
LESSER ANTILLES...PUERTO RICO AND MOST OF HISPANIOLA...WHILE CUBA
IS FORECAST 25MM OR LESS FOR THE REST OF TODAY THROUGH EARLY
THURSDAY MORNING...BUT AS MUCH AS 30-60MM IS FORECAST ON THURSDAY
ACROSS WESTERN CUBA.

NORTHERN SOUTH AMERICA WILL HAVE A SIMILAR RAINFALL PATTERN TO
THAT IS HAS OBSERVED OVER THE PAST FEW DAYS. ONSHORE FLOW IN THE
LOW LEVELS ACROSS WESTERN COLOMBIA WILL HELP IN THE DEVELOPMENT OF
SHOWERS AND THUNDERSTORMS ALONG THE WESTERN COAST...WITH RAINFALL
TOTALS LIKELY REACHING MAX TOTALS NEAR 20-45MM EACH DAY. THE REST
OF THE NORTHERN PORTIONS OF SOUTH AMERICA WILL OBSERVE SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY...STRONGLY INFLUENCE BY THE
DIURNAL HEATING. FOR THAT REASON...WIDESPREAD AREAS WITH DAILY MAX
TOTALS BETWEEN 15-25MM ARE FORECAST ACROSS NORTHERN BRAZIL INTO
VENEZUELA AND THE GUIANAS. HOWEVER...THE LATEST MODEL GUIDANCE
DOES SHOW AN AREA OF LOCALLY HIGHER RAINFALL ACROSS THE WESTERN
BRAZIL ON THURSDAY INTO FRIDAY...WITH MAX RAINFALL NEAR 20-45MM.  



EASTERLY/TROPICAL WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 02/00 02/12 03/00 03/12 04/00 04/12 05/00
TW   23N  90W  91W   93W   94W   95W   95W   DISS  ---

ALAMO...(WPC)
TINOCO-MORALES...(WPC)