TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
323 PM EDT THU JUL 11 2024

FORECAST BULLETIN 11 JUL 2024 AT 1930 UTC: A TROPICAL WAVE
PROPAGATING WESTWARD ACROSS THE THE EASTERN PACIFIC JUST OFF THE
COAST OF WESTERN MEXICO AND SOUTH OF BAJA CALIFORNIA. THIS WILL
CAUSE SOME SHOWERS AND THUNDERSTORMS ACROSS JALISCO AND
NAYARIT...WITH MAX RAINFALL VALUES BETWEEN 35-70MM TODAY. EVEN
THOUGH THIS TROPICAL WAVE WILL CONTINUE TO SLOWLY MOVE WEST AND
AWAY FROM LAND...THE SIERRA MADRE OCCIDENTAL WILL OBSERVE SOME
RAINFALL EACH DAY...WITH MAX TOTALS OF UP TO 30-60MM. THE HIGHEST
AMOUNTS ON FRIDAY BEING OBSERVED OVER DURANGO AND SINALOA...THEN
ON SATURDAY INTO SUNDAY OVER THE BOUNDARY BETWEEN CHIHUAHUA AND
SONORA.

ABOVE AVERAGE MOISTURE OVER THE BAHAMAS...ALONG WITH A WEAKENING
TUTT WILL CAUSE SOME SHOWER AND THUNDERSTORM ACTIVITY OVER THE
NEXT FEW DAYS. THE LATEST GUIDANCE IS VERY MODEST WITH ITS
RAINFALL TOTALS...SUGGESTING MAINLY MAX VALUES SOMEWHERE BETWEEN
15 AND 35MM EACH DAY. THE NORTHERN BAHAMAS WOULD BE RECEIVING THE
HIGHER AMOUNTS OF RAIN TODAY...BUT LESSER AMOUNTS ARE EXPECTED
FROM FRIDAY ONWARD FOR THE NORTHERN BAHAMAS...WHILE THE REST OF
THE BAHAMAS COULD BE OBSERVING MAX TOTALS OF LESS THAN 25MM EACH
DAY.

THE LESSER ANTILLES INTO PUERTO RICO AND HISPANIOLA WILL HAVE A
PLUME OF SAHARAN DUST MOVING IN TONIGHT...CAUSING MOISTURE TO
DECREASE. HOWEVER...AN APPROACHING TROPICAL WAVE LATE ON FRIDAY
WILL CAUSE MOISTURE TO INCREASE RAPIDLY INTO THE WEEKEND. THE MID
AND UPPER LEVELS WILL ALSO BECOME LESS FAVORABLE FOR STRONG
THUNDERSTORM DEVELOPMENT AS A MID AND UPPER LEVEL RIDGE DEVELOPS.
IT IS NOT UNTIL SUNDAY THAT A TUTT APPROACHES FROM THE EAST AND
IMPACTS THE LEEWARD ISLANDS AND PUERTO RICO. THAT BEING SAID...THE
INCREASE IN MOISTURE WILL HELP IN THE DEVELOPMENT OF LOCALIZED
SHOWERS AND THUNDERSTORMS OVER THE GREATER ANTILLES...WHILE THE
LESSER ANTILLES WILL OBSERVE BRIEF SHOWERS PASSING BY INTO THE
WEEKEND. IN TERMS OF RAINFALL AMOUNTS...THE LESSER AND GREATER
ANTILLES WILL OBSERVE MAX VALUES UNDER 25MM OF RAIN EACH DAY.
HOWEVER...GIVEN THE PERSISTENT EASTERLY WINDS AND INCREASE IN
MOISTURE...THE EASTERN THIRD OF PR COULD OBSERVE HIGHER AMOUNTS OF
RAIN ACROSS ISOLATED AREAS...UP TO 30MM THROUGH FRIDAY
MORNING...UP TO 45MM ON FRIDAY INTO SATURDAY...THEN UP TO 35MM ON
SATURDAY INTO SUNDAY. THOUGH...LOCAL EFFECTS AND SEA BREEZE
CONVERGENCE COULD CAUSE LOCALLY HIGHER AMOUNTS WITH THE LOCALLY
INDUCED THUNDERSTORMS OVER WESTERN PR AND PORTIONS OF HISPANIOLA.

ACROSS NORTHERN SOUTH AMERICA...THE MOST IMPACTFUL SITUATION IS
OVER NORTHERN PERU TO EASTERN ECUADOR...CONTINUING NORTH THROUGH
COLOMBIA AND WESTERN VENEZUELA. A SFC LOW PRESSURE OVER PANAMA IS
CAUSING ONSHORE FLOW INTO THE NORTHWESTERN SECTIONS OF SOUTH
AMERICA...AS WELL EASTERLY WINDS ACROSS THE NORTHERN PORTIONS OF
THE CONTINENT...CAUSING CONVERGENCE OF MOISTURE ON THE EASTERN
SIDE OF THE MOUNTAIN RANGE. FOR THAT REASON...SIGNIFICANT RAINFALL
IS FORECAST ACROSS THAT AREA. MAX RAINFALL VALUES UP TO 45MM ARE
FORECAST ACROSS CENTRAL COLOMBIA TODAY...BUT THE MOST SIGNIFICANT
RAIN IS FORECAST ON FRIDAY INTO SATURDAY...WHERE MAX RAINFALL
VALUES UP TO 100MM ARE FORECAST IN AND AROUND THE BOUNDARY OF
PERU...ECUADOR...AND COLOMBIA. NORTHERN COLOMBIA AND WESTERN
VENEZUELA ARE FORECAST AT LEAST UP TO 60MM ON FRIDAY INTO
SATURDAY...THOUGH ISOLATED HIGHER AMOUNTS ARE POSSIBLE. FOR
SATURDAY INTO SUNDAY...LOWER AMOUNTS OF RAIN ARE FORECAST...WITH
THE MODEL GUIDANCE SUGGESTING UP TO 45MM ALONG THE MOUNTAINS OF
ECUADOR AND ALSO OVER EAST CENTRAL COLOMBIA. ELSEWHERE ACROSS
NORTHWESTERN SOUTH AMERICA...MAX RAINFALL VALUES GENERALLY UP TO
25MM ARE FORECAST...THOUGH ISOLATED HIGHER OF UP TO 50MM COULD BE
OBSERVED OVER A SMALL PORTION OF CENTRAL AND WESTERN VENEZUELA.

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