FXCA62 TJSJ 040847
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
447 AM AST SUN JUN 4 2006
.SYNOPSIS...AT UPPER LEVELS...A WEAK RIDGE HAS JUST PASSED OVER
THE LOCAL AREA FROM THE WEST. A STRONG TROUGH EXTENDS FROM A LOW
PRESSURE OVER OHIO TO THE EASTERN FLORIDA COAST AND SOUTH TO
EASTERN CUBA. THIS TROUGH WILL PASS NORTH OF THE AREA ON
MONDAY...THE LOW WILL CONTINUE TO DIG SOUTH UNTIL TUESDAY EVENING
WHEN IT REACHES THE EASTERN TIP OF SOUTH CAROLINA. AS IT DOES SO
HIGH PRESSURE WILL BUILD OVER THE LOCAL AREA AND REMAIN ACROSS THE
CARIBBEAN AND ADJACENT ATLANTIC WATERS THROUGH THE BEGINNING OF
THE FOLLOWING WEEK.
AT MID LEVELS...A RIDGE EXTENDS FROM THE NORTHERN WINDWARD ISLANDS
TO SOUTHERN MEXICO ACROSS THE CARIBBEAN SEA. IT WILL GRADUALLY SHIFT
NORTHWEST THROUGH THURSDAY WHEN IT WILL EXTEND FROM JUST NORTH OF
PUERTO RICO ACROSS JAMAICA AND INTO CENTRAL AMERICA. BY THE
BEGINNING OF NEXT WEEK THE HIGH WILL HAVE SHIFTED TO LOCAL WATERS
JUST NORTH OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS.
AT LOWER LEVELS...HIGH PRESSURE WILL DOMINATE THE CENTRAL ATLANTIC
THROUGH THE ENTIRE FORECAST PERIOD. A RIDGE WILL EXTEND SOUTHWEST
TOWARD PUERTO RICO AND THEN WEST ACROSS THE BAHAMAS AND CUBA.
ALTHOUGH THE RIDGE SHIFTS OVER PUERTO RICO BRIEFLY MID WEEK...IT
RETURNS TO A MORE NORTHERLY POSITION BY THURSDAY. A WEAK TROPICAL
WAVE PASSED SOUTH OF THE ISLANDS YESTERDAY. A SECOND WAVE IS
NEAR 55 WEST THIS MORNING AND IS EXPECTED TO TURN SOMEWHAT
NORTHWEST AND WEAKEN BEFORE IT PASSES OVER THE AREA ON MONDAY
AFTERNOON. A THIRD WAVE WILL PASS SOUTH OF THE AREA ON THURSDAY
MORNING...THOUGH MOISTURE MAY TRAIL IT FOR ANOTHER 24 HOURS.
&&
.DISCUSSION...MOISTURE CONTINUES TO STREAM ACROSS SOUTHEAST PUERTO
RICO FROM THE SOUTHEAST AND HAS LEFT MORE THAN 3 INCHES OF
RAINFALL IN SELECT SPOTS OF JUNCOS AND LAS PIEDRAS MUNICIPALITIES.
ALTHOUGH RAIN FELL IN SAN JUAN...RADAR INDICATED THAT THAT
MUNICIPALITY HAD HAD LESS THAN ONE HALF INCH AS OF 4 AM. THE URBAN
AND SMALL STREAM ADVISORY MAY HAVE TO BE CONTINUED FOR A FEW
MUNICIPALITIES IN SOUTHEAST PUERTO RICO. ALTHOUGH THE GFS SHOWED
THE MOISTURE CAUSING THE HEAVY SHOWERS IT TENDED TO DEPICT IT TOO
FAR NORTHWEST. THE MODEL THEN BRINGS SOMEWHAT DRIER AIR OVER THE
AREA THROUGH MONDAY MORNING. MOISTURE RETURNS LATE MONDAY BECOMES
LESS PRONOUNCED ON TUESDAY AND WEDNESDAY...AND THEN RETURNS
THURSDAY AND FRIDAY.
THE GFS ALSO APPEARS TO DEVELOP A WAVE...CURRENTLY NEAR 21 WEST...AND
BRINGS IT TO NEAR 45 WEST ON FRIDAY NIGHT. BY THE TIME THE MODEL
BRINGS IT TO 60 WEST ON MONDAY MORNING...THE GFS SHOWS 40 KNOT
WINDS OVER THE NORTH SIDE OF IT AT 850 MB AND INCREASING WINDS
OVER THE CARIBBEAN TO OUR SOUTH AT THE SURFACE. THE WAVE PASSES
SOUTH OF US ON MONDAY NIGHT...12 JUNE...AND MAY BRING INCREASED
SHOWERS TO THE AREA AS WELL. ALTHOUGH WINDS APPEAR TO BE
EXAGGERATED...THIS MAY BE THE BEST WAVE THIS SEASON TO PASS OVER
THE CARIBBEAN.
$$
SNELL
They are talking about the wave just off West Africa right now.Let's see if this GFS scenario verifies or not.We know that the GFS model likes to form many lows around the basin so I see this as suspisious.However next runs will tell how consistent the model will be with this feature.




East Atlantic Image
GFS Model