010
FXCA20 KWBC 251914
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
314 PM EDT MON SEP 25 2023
FORECAST BULLETIN 25 SEP 2023 AT 1900 UTC: THE NATIONAL HURRICANE
CENTER IS MONITORING A FEW AREAS IN THE ATLANTIC BASIN THAT MAY
HAVE POTENTIAL FOR TROPICAL CYCLONE DEVELOPMENT. ACCORDING TO THE
NATIONAL HURRICANE CENTER...A TROUGH OF LOW PRESSURE NEAR THE
YUCATAN PENINSULA HAS NEAR ZERO PERCENT CHANCE OF TROPICAL CYCLONE
DEVELOPMENT. HOWEVER...IT HAS VERY DEEP MOISTURE AND COULD CAUSE
SIGNIFICANT SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE AREA OVER
THE NEXT FEW DAYS. ALSO...A TROPICAL WAVE CURRENTLY OVER LONGITUDE
32W AND KNOWN AS AL91...IS MOVING INTO A FAVORABLE ENVIRONMENT FOR
DEVELOPMENT...AND THE NATIONAL HURRICANE CENTER GIVES IT A 40
PERCENT CHANCE OF TROPICAL CYCLONE FORMATION IN THE NEXT 48
HOURS...AND AN 80 PERCENT CHANCE OF FORMATION THROUGH 7 DAYS. THE
LONG RANGE MODEL GUIDANCE SUGGESTS THAT THIS DISTURBANCE COULD
STAY IN THE OPEN ATLANTIC...CURVING NORTH WELL BEFORE REACHING THE
LEEWARD ISLANDS. THEN THERE IS TROPICAL STORM PHILIPPE...WHICH IS
ALSO FORECAST TO REMAIN IN THE OPEN ATLANTIC WELL EAST OF THE
LEEWARD ISLANDS AS IT MOVES WEST...THEN WEST-NORTHWEST OVER THE
NEXT FEW DAYS.
AT THE SURFACE...THERE IS A HIGH PRESSURE ACROSS THE EAST CENTRAL
ATLANTIC...WHICH WILL PREVAIL THROUGH THIS WEEK. THEN THERE IS THE
TROUGH OF LOW PRESSURE ACROSS THE SOUTHWESTERN GULF OF
MEXICO...NEAR THE YUCATAN PENINSULA...WHICH IS EXPECTED TO MEANDER
OVER THE SOUTHWEST GULF OF MEXICO FOR THE NEXT FEW DAYS. IN THE
MID LEVELS...A BROAD HIGH PRESSURE IS DOMINATING THE ATLANTIC WITH
ITS CENTER TO THE NORTHEAST OF THE LEEWARD ISLANDS. THERE IS ALSO
A MID LEVEL LOW PRESSURE OVER THE YUCATAN PENINSULA...WHICH IS
HELPING THE INSTABILITY IN THE AREA THAT WILL THEN CAUSE SHOWERS
AND THUNDERSTORMS TODAY AND TOMORROW AS THE LOW WEAKENS AND OPENS
INTO A TROUGH BY WEDNESDAY MORNING. UPPER LEVEL HIGH PRESSURES
ACROSS THE TROPICAL ATLANTIC AND THE CENTRAL CARIBBEAN IS HELPING
KEEP A SOMEWHAT STABLE ATMOSPHERE...THOUGH THE STRONG UPPER LEVEL
WINDS ASSOCIATED WITH THEM IS PROVIDING VENTILATION FOR THE
DEVELOPMENT OF SUSTAINED SHOWERS IN THE PERIPHERY OF THE HIGH
PRESSURE CIRCULATION. THERE IS A WEAK UPPER LEVEL LOW NEAR THE
YUCATAN PENINSULA AS WELL.
IN MEXICO...THE YUCATAN PENINSULA AND SOUTHERN MEXICO ARE EXPECTED
TO OBSERVE RAINFALL EACH DAY OVER THE FORECAST PERIOD...DUE TO THE
TROUGH OF LOW PRESSURE IN THE VICINITY BRINGING DEEP MOISTURE. THE
WEST COAST OF OF MEXICO IS ALSO EXPECTED TO OBSERVE SHOWERS AND
THUNDERSTORMS AT TIMES OVER THE NEXT SEVERAL DAYS...WHILE A
PORTIONS OF NORTHEAST MEXICO...NEAR COAHUILA AND CHIHUAHUA IS
FORECAST TO OBSERVE RAINFALL TODAY AND WEDNESDAY. THE RAINFALL
TOTALS ARE FORECAST TO BE GENERALLY IN THE ORDER OF 05-10MM/DAY
WITH MAX AMOUNTS UP TO 20MM...BUT A SMALL PORTION OF SOUTHERN
MEXICO AND THE YUCATAN COULD OBSERVE AS MUCH AS 45MM TODAY.
IN THE CARIBBEAN...MOSTLY EASTERLY TRADE WINDS WILL PREVAIL OVER
THE AREA...BUT DEEP MOISTURE FROM THE SOUTH IS MOVING NORTH
THROUGH THE WESTERN CARIBBEAN. IN TERMS OF RAINFALL...MOST OF THE
RAINFALL ACROSS THE LESSER ANTILLES WILL BE DUE TO BRIEF SHOWERS
AFFECTING THE AREA AS THE AVAILABLE MOISTURE REMAINS NEAR NORMAL.
LOCALLY INDUCED SHOWERS AND THUNDERSTORMS COULD AFFECT ISOLATED
AREAS OF PR AND HISPANIOLA IN THE AFTERNOON HOURS EACH
DAY...OTHERWISE BRIEF TRADE WIND SHOWERS WOULD AFFECT THE WINDWARD
SIDE OF THE GREATER ANTILLES. THEREFORE TOTALS OF UP TO 10MM WOULD
BE GENERALLY EXPECTED ACROSS HISPANIOLA...PUERTO RICO/USVI...AND
THE LESSER ANTILLES...THOUGH ISOLATED AMOUNTS UP TO 25MM OR EVEN
HIGHER COULD BE OBSERVED ACROSS HISPANIOLA AND PR EACH DAY THROUGH
WEDNESDAY. WESTERN CUBA HAS A CHANCE OF MORE SIGNIFICANT RAINFALL
TODAY AND TUESDAY...UP TO 45MM DUE TO THE SIGNIFICANT MOISTURE
THAT IS MOVING IN AND THE SOMEWHAT STRONG WINDS ALOFT.
IN CENTRAL AMERICA...THE AVAILABLE MOISTURE WILL BE ABOVE
NORMAL...WHICH WILL HELP IN THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS EVERY DAY. SOME AREAS OF COSTA RICA AND PANAMA WILL
OBSERVE UP TO 35MM TODAY...WHILE EL SALVADOR AND GUATEMALA COULD
OBSERVE UP TO 45MM. TUESDAY WILL BE A BIT DRIER...WITH RAINFALL
TOTALS FORECAST TO BE UP TO 35MM ONCE AGAIN ACROSS COSTA RICA AND
PANAMA...AND ALSO ACROSS EL SALVADOR AND GUATEMALA. RAIN INCREASES
ON WEDNESDAY ACROSS COSTA RICA AND PANAMA...WITH PORTIONS
OBSERVING MAX VALUES BETWEEN 40-80MM WITH STRONG STORMS...THEN EL
SALVADOR AND GUATEMALA OBSERVING UP TO 20-45MM. THROUGH THE 3-DAY
PERIOD...MOST OF HONDURAS AND NICARAGUA WILL OBSERVE MAX TOTALS
BETWEEN 15 AND 25MM.
IN NORTHERN SOUTH AMERICA...WESTERN COLOMBIA INTO WESTERN ECUADOR
ARE THE AREAS WITH THE MOST SIGNIFICANT RAINFALL WITH TOTALS UP TO
60 TO 70MM EXPECTED EACH DAY THROUGH WEDNESDAY. THE REST OF
COLOMBIA AND MOST OF VENEZUELA IS EXPECTED TO OBSERVE RAINFALL
EACH DAY BUT IN THE ORDER OF 05-10MM.DAY WITH MAX VALUES OF
15-25MM FOR THE MOST PART. NORTHERN PERU AND EASTERN ECUADOR IS
FORECAST TO OBSERVE SIMILAR AMOUNTS...GENERALLY 05-10MM AND UP TO
20MM EACH DAY. THAT BEING SAID...A PORTIONS OF SOUTH VENEZUELA AND
EASTERN COLOMBIA COULD OBSERVE MAX TOTALS OF 20-45MM TODAY. THE
GUIANAS ARE FORECAST TO OBSERVE MINIMAL RAINFALL TODAY...05-10MM
FOR THE MOST PART. ON TUESDAY...GUYANA IS FORECAST UP TO 20-35MM
BUT NO SIGNIFICANT RAIN IS FORECAST IN THE REST OF THE
GUIANAS...THEN UP TO 25-50MM IS FORECAST FOR NORTHWESTERN
GUYANA...WHILE THE REST OF THE GUIANAS ARE NOT FORECAST
SIGNIFICANT RAIN ONCE AGAIN.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 26/00 26/12 27/00 27/12 28/00 28/12 29/00 29/12
TW 20N 76W 81W 81W 85W 87W 88W ABSORBED
TW 15N 32W 34W 37W 39W 42W 44W 47W 50W 53W
A TROPICAL WAVE IS INITIALIZED AT 76W AND TO THE SOUTH OF 20N. IT
HAS ABUNDANT MOISTURE ASSOCIATED WITH IT AND WILL MOVE INTO
CENTRAL AMERICA BY TUESDAY. THIS TROPICAL WAVE WILL HELP IN THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS CENTRAL
AMERICA...DUE TO THE DEEP TROPICAL MOISTURE ASSOCIATED WITH IT. TE
TROPICAL WAVE IS EXPECTED TO BE ABSORBED OR BECOME A WEAK LOW BY
THURSDAY...CLOSE TO THE YUCATAN PENINSULA.
A TROPICAL WAVE IS INITIALIZED AT 32W AND TO THE SOUTH OF 15N. THE
NATIONAL HURRICANE CENTER LABELED THIS AS AL91. THIS WAVE COULD
DEVELOP INTO A TROPICAL CYCLONE WITH GRADUAL DEVELOPMENT OVER THE
NEXT SEVERAL DAYS. THE GLOBAL MODELS ARE SUGGESTING THIS SYSTEM
COULD DEVELOP INTO A TROPICAL CYCLONE BUT REMAIN IN THE ATLANTIC
OPEN WATERS. ONE SHOULD MONITOR THE LATEST BULLETINS BY THE
NATIONAL HURRICANE CENTER REGARDING THIS SYSTEM.
ALAMO...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page