075
FXCA20 KWBC 081900
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
259 PM EDT THU AUG 08 2024
FORECAST BULLETIN 08 AUG 2024 AT 1900 UTC:
THE NATIONAL HURRICANE CENTER (NHC) IS ISSUING ADVISORIES ON
TROPICAL STORM DEBBY...WHICH IS AFFECTING PORTIONS OF THE
CAROLINAS INTO VIRGINIA AND WEST VIRGINIA. THE NATIONAL HURRICANE
CENTER IS ALSO MONITORING A
TROPICAL WAVE THAT LOCATED OVER THE EASTERN TROPICAL
ATLANTIC...AND HAS A NEAR ZERO CHANCE OF TROPICAL CYCLONE
FORMATION THROUGH 48 HOURS...AND A 40% CHANCE OF TROPICAL CYCLONE
FORMATION THROUGH 7 DAYS. THIS TROPICAL WAVE COULD APPROACH THE
LESSER ANTILLES BY TUESDAY AFTERNOON AND THEREFORE SHALL BE
MONITORED. THERE IS CURRENTLY TOO MUCH UNCERTAINTY ON THE
POTENTIAL DEVELOPMENT OF THIS SYSTEM...AS THE GLOBAL MODELS DIFFER
ON THEIR SOLUTIONS EVEN THOUGH THEY ARE CURRENTLY SUGGESTING SOME
DEVELOPMENT OF THIS SYSTEM. THERE WILL ALSO BE SOME SAHARAN DUST
PRESENT ACROSS THE ATLANTIC THIS WEEK...WHICH ADDS TO THE OVERALL
UNCERTAINTY. ACROSS THE EASTERN PACIFIC...TROPICAL STORM EMILIA IS
FORECAST TO CONTINUE MOVING TO THE WEST NORTHWEST AND ACROSS THE
OPEN WATERS. IN ADDITION...A TROPICAL WAVE MOVING ACROSS CENTRAL
AMERICA TODAY WILL CONTINUE MOVING WEST AND INTO EAST PACIFIC.
THIS TROPICAL WAVE HAS A 10% CHANCE OF TROPICAL CYCLONE FORMATION
THROUGH 48 HOURS AND 30% THROUGH 7 DAYS AS IT MOVES ACROSS THE
EASTERN PACIFIC CLOSE TO THE WESTERN COAST OF MEXICO. AT THIS
TIME...THIS SYSTEM IS FORECAST TO REMAIN OVER THE WATERS OFFSHORE
BUT PARALLEL TO THE COAST OF MEXICO...THOUGH SOME MOISTURE
ADVECTION INTO THE WESTERN COAST OF MEXICO WOULD BE POSSIBLE LATER
ON.
ACROSS THE ATLANTIC...A SIGNIFICANT PLUME OF SAHARAN DUST IS
PRESENT OVER THE LESSER ANTILLES EASTWARD THROUGH THE TROPICAL
ATLANTIC. THIS PLUME OF SAHARAN DUST WILL MOVE INTO THE CARIBBEAN
AND THROUGH THE LESSER AND GREATER ANTILLES FOR THE NEXT 3 DAYS.
BY SUNDAY...THE SAHARAN DUST COULD HAVE REACHED CUBA...THE
NORTHERN BAHAMAS AND THE WESTERN CARIBBEAN SEA INTO THE CARIBBEAN
COAST OF NICARAGUA AND HONDURAS.
AT THE SURFACE...THERE IS A BROAD HIGH PRESSURE ACROSS THE NORTH
CENTRAL ATLANTIC...WHICH WILL DOMINATE THE ATLANTIC FOR THE NEXT
SEVERAL DAYS...CAUSING GENERALLY EASTERLY WINDS ACROSS THE
CARIBBEAN AND SOUTHEASTERLY WINDS OVER THE BAHAMAS. THAT
SAID...TROPICAL STORM DEBBY IS CAUSING SOUTHERLY WINDS ACROSS
PORTIONS OF THE BAHAMAS AND CUBA TODAY. INTO THE EASTERN
PACIFIC...OTHER THAN THE AFOREMENTIONED TROPICAL WAVE...THERE IS
PLENTY OF MOISTURE ALONG THE MONSOON TROUGH...WHICH WILL BE
AFFECTING PORTIONS OF SOUTHERN CENTRAL AMERICA AND WESTERN
COLOMBIA OVER THE NEXT FEW DAYS. THIS MOISTURE ADVECTION INTO LAND
AREAS FROM THE MONSOON TROUGH WILL BE A DRIVER OF RAINFALL OVER
THE AREA OVER THE NEXT 3 DAYS.
THERE ARE A FEW TROPICAL WAVES IN THE AREA THAT COULD HAVE IMPACTS
OVER LAND. THE TROPICAL WAVE THAT WILL MOVE INTO THE EASTERN
PACIFIC IS CURRENTLY OVER SOUTHERN CENTRAL AMERICA WITH AXIS JUST
EAST OF NICARAGUA AND ACROSS COSTA RICA. THIS TROPICAL WAVE IS
INTERACTING WITH THE PANAMANIAN LOW...AND IS EXPECTED TO MOVE INTO
NICARAGUA LATER TODAY...CAUSING SHOWERS AND THUNDERSTORMS TO
AFFECT THE AREA. FURTHER EAST...THERE IS A TROPICAL WAVE NEAR 51W
AND IS FORECAST TO MOVE WEST THROUGH THE CARIBBEAN...WITH ITS AXIS
POSSIBLY EXTENDING FROM HISPANIOLA INTO NORTHERN COLOMBIA BY
SATURDAY NIGHT. THE TROPICAL WAVE WITH SOME POTENTIAL OF TROPICAL
CYCLONE DEVELOPMENT WOULD BE TOO FAR TO THE EAST OF OUR FORECAST
DOMAIN BY SATURDAY NIGHT...BUT IT MIGHT CROSS 50W BY SUNDAY NIGHT.
ACROSS THE CARIBBEAN...THE SAHARAN DUST EXPECTED TO MOVE THROUGH
THE CARIBBEAN WILL LIMIT THE POTENTIAL FOR CONVECTION AND THE
RAINFALL AMOUNTS ARE THUS EXPECTED TO BE MODEST INTO EARLY
SATURDAY. HOWEVER...THERE IS A RETROGRADING TUTT AND A MID LEVEL
TROUGH THAT WILL MOVE TO THE NORTHEAST OF THE LESSER ANTILLES BY
THIS WEEKEND...WHICH WILL INCREASE THE CHANCES OF SHOWERS AND
THUNDERSTORMS OVER THE NORTHEAST CARIBBEAN FROM LATE SATURDAY INTO
SUNDAY. THIS TUTT WILL ALSO INTERACT WITH A TROPICAL WAVE PASSING
THROUGH THE CARIBBEAN ON SATURDAY.
OVER THE NEXT 3 DAYS...CENTRAL AMERICA WILL OBSERVE A SIMILAR
RAINFALL PATTERN AS THE PAST FEW DAYS. HOWEVER THE AMOUNTS WOULD
BE DIFFERENT AS THE PANAMANIAN LOW IS EXPECTED TO MOVE INTO
NICARAGUA TODAY...THEN ANOTHER LOW WILL MOVE IN TO THE SOUTHERN
CARIBBEAN AND POSSIBLY MOVE SOUTH OF PANAMA. THIS WOULD THEN CAUSE
MOST OF THE SIGNIFICANT RAINFALL AFTER TODAY TO BE OVER THE
PACIFIC SIDE OF SOUTHERN CENTRAL AMERICA. THAT BEING
SAID...SIGNIFICANT AMOUNTS OF RAIN...WITH MAX VALUES NEAR 40-80MM
ARE FORECAST FOR PORTIONS OF EL SALVADOR.
ACROSS MEXICO...THE SIERRA MADRE OCCIDENTAL AND ALONG THE WEST
COAST IS EXPECTED TO RECEIVE THE MOST SIGNIFICANT RAIN OVER THE
NEXT 3 DAYS ONCE AGAIN. THIS IS BECAUSE OF DIURNAL ONSHORE FLOW
FROM THE EAST PACIFIC INTERACTING WITH THE LOCAL TERRAIN EFFECTS
AND SOME UPPER LEVEL SUPPORT. AN UPPER LEVEL TROUGH WILL
STRENGTHEN OVER NORTH CENTRAL TO NORTHEASTERN MEXICO TODAY...WHILE
AN UPPER RIDGE STRENGTHENS OVER THE BAJA PENINSULA...THIS WILL
CAUSE A LOCALIZED UPPER JET OVER WESTERN TO NORTHWESTERN MEXICO
AND ENHANCE SHOWER AND THUNDERSTORM POTENTIAL. THEREFORE...TODAY
IS EXPECTED TO BE THE WETTEST DAY OVER NORTHWESTERN MEXICO. THAT
BEING SAID...A LOW LEVEL LOW WILL BRING MOISTURE ACROSS THAT
WESTERN SECTIONS OF MEXICO...WHICH WILL INTERACT WITH THE LOCAL
TERRAIN. OVER THE 3-DAY PERIOD...TOTAL AMOUNTS OF RAIN ACROSS
WESTERN MEXICO COULD BE AS HIGH AS 75 TO 125MM OVER ISOLATED
AREAS.
NORTHERN SOUTH AMERICA WILL HAVE SOME RAINFALL EACH DAY...BUT THE
MOST SIGNIFICANT RAIN WILL OCCUR OVER WESTERN COLOMBIA DUE TO THE
AFOREMENTIONED LOW THAT COULD MOVE SOUTH OF PANAMA. THIS WILL
CAUSE DIRECT ONSHORE FLOW INTO COLOMBIA ON FRIDAY INTO SATURDAY.
THE 3-DAY RAINFALL FORECAST FOR NORTHERN SOUTH AMERICA IS UP TO
100MM OR SO FOR WESTERN COLOMBIA...AND ACROSS THE MOUNTAINOUS
SECTIONS OF VENEZUELA. OTHER AREAS FROM NORTHERN GUYANA AND ACROSS
OTHER PORTIONS OF VENEZUELA AND COLOMBIA ARE FORECAST MAX 3-DAY
TOTALS OF 25-50MM.
ALAMO...(WPC)
JACKMAN...(BMS)
MATHIAS...(CIAARA/MB)
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