669
FXCA20 KWBC 121240
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
839 AM EDT TUE SEP 12 2023
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI SEP 12/12UTC:
HURRICANE LEE IS LOCATED OVER 350 NM NORTH OF PR/USVI AND IT IS
FORECAST TO CONTINUE MOVING FURTHER AWAY. HOWEVER...THE HURRICANE
WILL HAVE AN INFLUENCE IN THE LOCAL WINDS FOR THE NEXT SEVERAL
DAYS. THEREFORE THE LOCAL WINDS WILL BE GENERALLY SOUTHWESTERLY
TODAY...BECOMING SOUTHERLY FOR WEDNESDAY AND THURSDAY...THEN
SHIFTING SOUTHEAST BY FRIDAY AND EASTERLY ON SATURDAY. THE LATEST
GUIDANCE CONTINUES TO SUGGEST NEAR NORMAL MOISTURE FOR THE REST OF
THE WEEK...WITH PRECIPITABLE WATER VALUES RANGING FROM THE LOWER
END OF NORMAL TO THE UPPER END OF NORMAL...AROUND 1.7 TO 2 INCHES
RESPECTIVELY. THAT BEING SAID...THE RAINFALL TOTALS EACH DAY
THROUGH THE REST OF THE WEEK ARE FORECAST TO BE RELATIVELY
MODEST...WITH MAX VALUES GENERALLY UNDER A HALF AN INCH...ALTHOUGH
VERY ISOLATED HIGHER AMOUNTS WILL NOT BE RULED OUT DUE TO NORMAL
UNCERTAINTY.
THE LATEST MODEL GUIDANCE...BOTH GLOBAL AND HI-RES...INDICATE THAT
THE HIGHEST RAINFALL TOTALS TODAY WILL OCCUR ACROSS THE SOUTHERN
PORTIONS OF PR...WITH UNDER A HALF AN INCH OF RAIN...AND PERHAPS A
SMALL SECTION OF THE LUQUILLO MOUNTAIN RANGE HAVING A LOCAL MAX OF
RAIN OF UNDER A QUARTER OF AN INCH. CONSIDERING THE SOUTHWESTERLY
WIND FLOW AND NEAR NORMAL MOISTURE EXPECTED TODAY...NORMALLY THE
AFTERNOON CONVECTION WOULD OCCUR ACROSS THE NORTH AND EASTERN
SECTIONS OF PR DUE TO THE COMBINATION OF THE SEA BREEZE
CONVERGENCE AND THE DIURNAL HEATING...HOWEVER ALL OF THE GLOBAL
MODEL GUIDANCE AND THE HI-RES INCLUDING THE HRRR ARE IN AGREEMENT
THAT THE SEA BREEZE WOULD HAVE DIFFICULTY DEVELOPING...WHICH THEN
WOULD LOWER THE CHANCES FOR SEA BREEZE CONVERGENCE. CROSS SECTION
ANALYSIS IN THE GUIDANCE INDICATES THAT THERE MAY BE SOME
DIFFICULTY MIXING THE MOISTURE AND MOST OF IT WOULD REMAIN IN THE
LOWEST LEVELS...POSSIBLY DUE TO A WEAK INVERSION. SATELLITE
IMAGERY SHOWS SOME HIGH CLOUDS MOVING INTO THE LOCAL ISLANDS AND
THE FEEDER BANDS INTO HURRICANE LEE HAVE MOSTLY VERY SHALLOW
CONVECTION. IN ADDITION...THE GUIDANCE FOR THE LOCAL
AIRPORTS...INCLUDING THE GFS LAMP IS NOT INDICATING A STRONG SEA
BREEZE COMPONENT. THEREFORE...THE CURRENT FORECAST IS KEEPING THE
MAX RAINFALL ACROSS THE SOUTHERN SECTIONS OF PR...ALTHOUGH SOME
RAIN IS FORECAST ACROSS THE MOUNTAINS OF NORTHEAST PR...AND THE
USVI WILL OBSERVE ISOLATED BRIEF SHOWERS. OVER THE NEXT FEW
DAYS...A SOMEWHAT SIMILAR PATTERN WOULD BE EXPECTED...WITH SOME
RAIN EXPECTED ACROSS SOUTHERN PR...BUT THE MODEL GUIDANCE DOES
SHOW SOME MODEST AMOUNTS OF RAIN ACROSS PORTIONS OF NORTHERN PR IN
THE AFTERNOONS. THE USVI WOULD REMAIN MOSTLY WITH ISOLATED AND
BRIEF SHOWERS IN THE FORECAST.
THE 5-DAY RAINFALL TOTAL IS EXPECTED TO BE AROUND 0.75 TO 1 INCH
ACROSS SOUTHERN TO NORTHWESTERN PR...WHILE THE USVI AND
NORTHEASTERN PR IS FORECAST BETWEEN 0.25 AND 0.5 INCHES.
ALAMO...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page