164  
FXCA20 KWBC 101910  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
310 PM EDT TUE SEP 10 2024  
 
FORECAST BULLETIN 10 SEPT 2024 AT 1900 UTC:  
 
THE NATIONAL HURRICANE CENTER CONTINUES TO ISSUE ADVISORIES ON  
TROPICAL STORM FRANCINE...WHICH IS FORECAST TO BECOME A HURRICANE  
BY THIS EVENING. FRANCINE IS CURRENTLY LOCATED ON THE WESTERN GULF  
OF MEXICO...AT AROUND 210 KM ESE OF THE MOUTH OF THE RIO GRANDE.  
FRANCINE IS FORECAST TO MOVE NORTH NORTHEAST OVER THE NEXT DAY OR  
SO BEFORE MAKING LANDFALL IN THE STATE OF LOUISIANA ON WEDNESDAY  
EVENING. EVEN THOUGH FRANCINE IS FORECAST TO REMAIN OFFSHORE  
NORTHEASTERN MEXICO TODAY...THERE IS THE POTENTIAL OF SIGNIFICANT  
RAINFALL OVER NORTHEASTERN TIP OF TAMAULIPAS...CAUSING RAINFALL  
TOTALS RANGING FROM 25 TO 100MM. PLEASE SEE THE LATEST OFFICIAL  
ADVISORY BY THE NATIONAL HURRICANE CENTER.  
 
ACROSS THE ATLANTIC BASIN...THERE ARE A FEW LOW PRESSURES THAT  
HAVE DEVELOPED ALONG THE MONSOON TROUGH. ONE OF THE LOW PRESSURES  
IS LOCATED NEAR 13N/53W...15N/42W...AND 13N/34W. THE MODEL  
GUIDANCE IS CONSISTENT TO WHAT IT SUGGESTED YESTERDAY WITH REGARDS  
TO THESE LOW PRESSURES ALONG THE MONSOON TROUGH. THE LOW PRESSURES  
AT 53W AND 43W ARE NEARLY STATIONARY BUT WILL EVENTUALLY MOVE  
SLOWLY WEST. THE LATEST MODEL GUIDANCE HAS CHANGED FROM THE  
SOLUTION IT PRESENTED YESTERDAY. IT NOW SUGGESTS THAT THE LOW  
PRESSURES WILL MOVE WEST...REMAINING SEPARATE SYSTEMS AS THEY  
MOVE TO THE WEST TO WEST NORTHWEST...WEAKENING AS THEY APPROACH  
THE LESSER ANTILLES. THE LOW PRESSURE FURTHER EAST...NEAR 34W  
COULD MERGE WITH A SPEEDING AND DEVELOPING TROPICAL WAVE CURRENTLY  
NEAR THE CABO VERDE ISLANDS...THEN MOVE NORTH INTO THE OPEN  
ATLANTIC AS IT STRENGTHENS.  
 
A TROPICAL WAVE CURRENTLY NEAR 74W WILL CONTINUE TO MOVE WEST OVER  
THE NEXT FEW DAYS. THIS TROPICAL WAVE WILL MOVE INTO CENTRAL  
AMERICA BY WEDNESDAY EVENING. AS IT MOVES WEST...IT WILL INTERACT  
WITH THE PANAMANIAN LOW...ENHANCING THE AVAILABLE MOISTURE AND  
INCREASING THE CHANCES OF SHOWERS ACROSS PORTIONS OF SOUTHERN  
CENTRAL AMERICA...ESPECIALLY EASTERN NICARAGUA AND PORTIONS OF  
COSTA RICA AND PANAMA. ANOTHER TROPICAL WAVE...NEAR 99W IS  
EXPECTED TO MOVE WEST FOR THE NEXT FEW DAYS. AS THIS WAVE MOVES  
WEST IT WILL EVENTUALLY INTERACT WITH A BROADER AREA OF LOW  
PRESSURE LOCATED OFFSHORE OF WESTERN MEXICO. THIS WAVE AND LOW  
PRESSURE WILL CAUSE DEEP MOISTURE TO MOVE INTO THE WEST COAST OF  
MEXICO...CAUSING SIGNIFICANT RAIN OVER THE WEST COAST OF MEXICO  
OVER THE NEXT FEW DAYS. THE LATEST GFS MODEL GUIDANCE DOES DEVELOP  
A TROPICAL CYCLONE AND MOVES IT INTO THE BAJA PENINSULA.  
HOWEVER...THE GFS ENSEMBLES AS WELL AS THE ECMWF MODELS ARE MUCH  
LESS BULLISH WITH THE SYSTEM...DEVELOPING A WEAK LOW AND KEEPING  
IT OFFSHORE THE BAJA PENINSULA...THAT BEING SAID...PLEASE FOLLOW  
THE OFFICIAL TROPICAL CYCLONE FORECASTS AND OUTLOOKS ISSUED BY THE  
NATIONAL HURRICANE CENTER.  
 
IN THE MID LEVELS...THERE IS A LOW PRESSURE OVER THE CENTRAL  
ATLANTIC...THEN A WEAKER LOW PRESSURE OVER THE WEST TROPICAL  
ATLANTIC...JUST NORTH OF PUERTO RICO/USVI. A BROAD HIGH PRESSURE  
IS LOCATED OVER THE BAHAMAS INTO THE EASTERN GULF OF MEXICO. THE  
MID LEVEL HIGH PRESSURE WILL MOVE SOUTHWEST AND CENTER OVER  
WESTERN CUBA...MEANDERING THROUGH THE END OF THE WORKWEEK. THE MID  
LEVEL LOW NORTH OF PR/USVI WILL WEAKEN INTO AN OPEN TROUGH BY  
WEDNESDAY...WITH ITS AXIS OVER PUERTO RICO...THEN LIFT ON  
THURSDAY. THE MID LEVEL LOW OVER THE CENTRAL ATLANTIC WILL STAY  
MEANDERING OVER THE AREA FOR THE NEXT FEW DAYS...BUT WILL MOVE  
EAST BY THE END OF THE WORKWEEK.  
 
IN THE UPPER LEVELS... A TUTT OVER THE WESTERN TROPICAL  
ATLANTIC...NORTH OF PUERTO RICO/USVI IS CAUSING CONVECTIVE  
DEVELOPMENT ACROSS PORTIONS OF THE NORTHERN LEEWARDS AND THE  
EASTERN CARIBBEAN. THERE IS ALSO A HIGH PRESSURE TO THE EAST OF  
THE LESSER ANTILLES AND AN ELONGATED HIGH PRESSURE FROM THE GULF  
OF MEXICO ACROSS THE BAHAMAS...WHILE ANTHER HIGH PRESSURE IS  
LOCATED NORTHEAST OF BERMUDA. THERE IS ALSO AN UPPER TROUGH OVER  
NORTHERN MEXICO...WHICH IS EXPECTED TO REMAIN OVER THE COUNTRY FOR  
THE NEXT FEW DAYS...PROVIDING SOME DIVERGENCE ALOFT OVER CENTRAL  
TO EASTERN MEXICO. BY WEDNESDAY...THE TUTT OVER THE WESTERN  
TROPICAL ATLANTIC WILL WEAKEN INTO AN OPEN TROUGH WITH ITS AXIS  
NEAR PUERTO RICO...AND THE HIGH PRESSURE EAST OF THE LESSER  
ANTILLES WILL MOVE FURTHER EAST...INTO THE CENTRAL TROPICAL  
ATLANTIC.  
 
THE TROPICAL REGION OVERALL IS EXPECTED TO HAVE NEAR TO HIGHER  
THAN NORMAL MOISTURE FOR THE NEXT SEVERAL DAYS. WITH THE EXCEPTION  
OF A SMALL AREA OF BELOW NORMAL MOISTURE OVER THE CENTRAL  
CARIBBEAN...WHICH WILL REMAIN MOSTLY OVER THE WATERS...BUT THE DRY  
SLOT COULD APPROACH NICARAGUA ON FRIDAY. THE REST OF THE  
CARIBBEAN...CENTRAL MEXICO...CENTRAL AMERICA AND NORTHWEST SOUTH  
AMERICA WILL HAVE NEAR TO HIGHER THAN NORMAL MOISTURE.  
 
FOR TODAY INTO EARLY WEDNESDAY MORNING...THE AREAS WITH MOST  
SIGNIFICANT RAINFALL ARE EXPECTED TO BE ACROSS NORTHEASTERN  
TAMAULIPAS...WITH THE RAIN POSSIBLE ASSOCIATED WITH TS FRANCINE AS  
IT MOVES NNE AND AWAY FROM MEXICO. A SFC TROUGH WEST OF THE LESSER  
ANTILLES MAY CAUSE SOME RAINFALL OVER THE ISLANDS...OBSERVING NEAR  
25MM OR MORE ACROSS ISOLATED AREAS OVER THE LESSER  
ANTILLES...PUERTO RICO/USVI AND HISPANIOLA. THE INTERACTION OF AN  
APPROACHING TROPICAL WAVE AND THE PANAMANIAN LOW...COMBINED WITH  
THE LOCAL TERRAIN EFFECTS OVER SOUTHERN CENTRAL AMERICA...WILL  
CAUSE SIGNIFICANT RAIN OVER THE AREA FROM NICARAGUA SOUTH INTO  
PANAMA. THE REST OF CENTRAL AMERICA AND SOUTHERN MEXICO ARE  
FORECAST TO OBSERVE 10-20MM WITH ISOLATED AMOUNTS OF OVER 30MM.  
NORTHERN SOUTH AMERICA WILL HAVE 05-15 MM OF RAIN...WITH ISOLATED  
HIGHER AMOUNTS...ESPECIALLY IN AREAS OF MOUNTAINOUS TERRAIN.  
 
FOR WEDNESDAY AND THURSDAY...PORTIONS OF WESTERN AND CENTRAL  
MEXICO WILL OBSERVE ISOLATED AMOUNTS OF RAIN SURPASSING 30MM...AS  
THE MOISTURE INTERACTS WITH THE LOCAL TERRAIN AND THE UPPER  
TROUGH. HOWEVER...THE LATEST GUIDANCE IS NOW SUGGESTING MAX TOTALS  
UP TO AROUND 100MM OVER THE NORTHWEST COAST OF SINALOA...AS A LOW  
PRESSURE IS PRESENT OFFSHORE AND SOUTHWESTERLY WINDS BRINGS  
MOISTURE TO THE COAST OF SINALOA. OTHER AREAS OF THE SOUTHERN HALF  
OF MEXICO CAN EXPECT AMOUNTS OF 05-20MM...ISOLATED TO 30MM.  
PORTIONS OF CHIAPAS COULD OBSERVE UP TO 20MM ACROSS ISOLATED  
AREAS. CENTRAL AMERICA WILL OBSERVE AMOUNTS OF 05-15MM WITH  
ISOLATED AMOUNTS UP TO AROUND 30MM...MAINLY ACROSS PANAMA...COSTA  
RICA...AND THE PACIFIC SECTIONS OF  
HONDURAS...NICARAGUA...GUATEMALA AND OVER EL SALVADOR. THE  
CARIBBEAN ISLANDS WILL OBSERVE SCATTERED SHOWER ACTIVITY WITH  
ISOLATED THUNDERSTORMS...WITH RAIN TOTALS UP TO 10 MM IN MANY  
AREAS BUT ISOLATED TO 25-35 OVER THE HIGHER ELEVATIONS OF  
HISPANIOLA. THE BAHAMAS WILL BE SPLIT...NORTHERN BAHAMAS COULD  
OBSERVE AS MUCH AS 50MM OF RAIN ON WEDNESDAY AND UP TO 30MM ON  
THURSDAY. THE SOUTHERN BAHAMAS AND THE TURKS AND CAICOS WILL  
OBSERVE LITTLE TO NO RAIN ON WEDNESDAY AND THURSDAY. NORTHERN  
SOUTH AMERICA IS FORECAST NEAR 10-20MM WITH ISOLATED AMOUNTS NEAR  
50MM ON WEDNESDAY...WHILE 05-10MM ISOLATED TO 20 MM ARE EXPECTED  
FOR THURSDAY.  
 
ALAMO...(WPC)  
 

 
 
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