TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
938 AM EDT THU OCT 03 2024

WEEKLY DISCUSSION FOR PUERTO RICO AND THE USVI OCT 03/12UTC:

THERE ARE SEVERAL FEATURES IN THE REGION TO CONSIDER FOR THE
RAINFALL PATTERN OVER PR/USVI OVER THE NEXT FEW DAYS. THAT BEING
SAID...WE CAN EXPECT A CHANCE OF BRIEF SHOWERS EACH MORNING ON THE
WINDWARD SIDE OF PR...AND ACROSS THE USVI...WHILE AFTERNOON
CONVECTION WITH ISOLATED THUNDERSTORMS ARE FORECAST EACH DAY
ACROSS AREAS OF SEA BREEZE CONVERGENCE IN PR. THE LOCATION OF
THESE AFTERNOON ISOLATED THUNDERSTORMS WILL VARY DEPENDING ON THE
OVERALL WIND DIRECTION AND SPEED AND ITS INTERACTIONS WITH THE
LOCAL OROGRAPHY. THE TOTAL 5-DAY RAINFALL FORECAST OVER PR COULD
BE AS MUCH AS 3-5 INCHES OR SO ACROSS PORTIONS OF EASTERN
PR...WITH THE HIGHEST ACCUMULATIONS EXPECTED ACROSS THE CAYEY
MOUNTAIN RANGE INTO SOUTH CENTRAL PR...WITH 1-2 INCHES OF RAIN
FORECAST ACROSS THE NORTHWESTERN QUADRANT OF PR. THE USVI ARE
FORECAST A 5-DAY TOTAL IN THE ORDER OF 1-2 INCHES AS WELL...MOSTLY
DUE TO ISOLATED TO SCATTERED SHOWER ACTIVITY EACH DAY.

OVER THE NEXT FEW DAYS...THERE WILL BE A PERSISTENT NORTHEASTERLY
WIND FLOW AS A SFC LOW PRESSURE ACROSS THE WESTERN ATLANTIC
MEANDERS OVER THE AREA. THE WINDS WILL REMAIN GENERALLY
NORTHEASTERLY THROUGH EARLY SATURDAY...BUT WILL WEAKEN AND BECOME
VERY LIGHT THIS WEEKEND AS THE AFOREMENTIONED SFC LOW STARTS
INTERACTING WITH THE CURRENT HURRICANE KIRK. THIS INTERACTION WILL
CAUSE A COL OVER THE LOCAL ISLANDS BY SUNDAY. WITH THIS COL
DEVELOPING ON SUNDAY...THE WINDS WILL BE LIGHT AND VARIABLE INTO
THE NEXT WORKWEEK. THAT BEING SAID...THE LATEST MODEL GUIDANCE
SUGGESTS LIGHT SOUTHERLY WINDS ACROSS THE AREA ON SUNDAY...BUT THE
WINDS ARE EXPECTED TO BE LIGHT ENOUGH THAT A STRONG SEA BREEZE
INFLUENCE MAY OCCUR ACROSS NORTHERN INTO CENTRAL PR...CAUSING
CONVERGENCE OVER THE AREA IN THE LOW LEVELS.

IN THE MID LEVELS...A TROUGH WITH ITS ASSOCIATED LOW IS LOCATED TO
THE NORTH OF PR/USVI...AND IS EXPECTED TO DRIFT
SOUTHEASTWARD...POSITIONING ITSELF AROUND 32N/62W BY SATURDAY
MORNING...THEN FLATTENING AS IT INTERACTS WITH KIRK...THOUGH A MID
LEVEL TROUGH COULD DEVELOP WITH ITS AXIS JUST WEST OF HISPANIOLA
ON SUNDAY...LIFTING BY SUNDAY NIGHT. THERE IS ALSO A MID LEVEL
HIGH PRESSURE RIDGE OVER THE WESTERN GREATER ANTILLES...EXTENDING
TO THE LOCAL ISLANDS BY EARLY FRIDAY. ALTHOUGH THE LOCAL ISLANDS
WILL BE INFLUENCED BY THE MID LEVEL TROUGH THIS WEEKEND...A MID
LEVEL HIGH PRESSURE WILL MOVE INTO THE CARIBBEAN EARLY IN THE
WORKWEEK. THE UPPER LEVELS WILL BEHAVE SIMILARLY...THERE IS AN
UPPER LOW AND ASSOCIATED TROUGH ACROSS THE WESTERN ATLANTIC...THAT
IS EXPECTED TO MOVE EAST AND WEAKEN...BUT A TROUGH WILL DIG INTO
HISPANIOLA THIS WEEKEND. HOWEVER...FOR THE UPCOMING WORKWEEK...THE
HIGH PRESSURE CURRENTLY ACROSS THE WESTERN GREATER ANTILLES WILL
STRENGTHEN AND EXTEND EAST AND OVER THE LOCAL ISLANDS. THE OVERALL
MOISTURE IS EXPECTED TO BE NEAR NORMAL OVER THE NEXT SEVERAL
DAYS...BUT THERE WILL BE BRIEF PATCHES OF HIGHER AND LOWER
MOISTURE MOVING THROUGH.

THIS GENERAL SYNOPTIC PATTERN...AND AVAILABLE MOISTURE...WILL BE
CONDUCIVE FOR THE LOCAL EFFECTS TO HAVE A STRONG INFLUENCE ON THE
LOCATION OF THE AFTERNOON CONVECTION. THE TEMPERATURE IN THE MID
LEVELS ARE WARMER THAN NORMAL...THE MID TO UPPER LEVELS ARE NOT
PARTICULARLY FAVORABLE FOR STRONG CONVECTIVE SUPPORT...AND THE
RELATIVE HUMIDITY IN THE LOW TO MID LEVELS WILL BE NEAR NORMAL
OVER THE NEXT SEVERAL DAYS. CONSIDERING THIS PATTERN...AND THE
OUTPUT FROM THE EGDI ALGORITHM...THE THUNDERSTORMS THAT DO OCCUR
IN THE AFTERNOONS ARE EXPECTED TO BE ISOLATED...AND THE GR02T
SEVERITY ALGORITHM DOES NOT SHOW AREAS AT RISK FOR SEVERE
THUNDERSTORMS. 

ALAMO...WPC (USA)