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FGCA72 TJSJ 110001
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PRC001-003-005-007-009-011-013-015-017-019-021-023-025-027-029-
031-033-035-037-039-041-043-045-047-049-051-053>055-057-059-061-
063-065-067-069-071-073-075-077-079-081-083-085-087-089-091-093-
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020-030-120000-

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE SAN JUAN PR
800 PM AST FRI OCT 10 2008

...A SLOW MOVING TROPICAL WAVE WILL BEGIN A WEEK LONG RAINY PERIOD
FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS...

AN UPPER LEVEL LOW HAS INDUCED AN AREA OF TROPICAL MOISTURE BETWEEN
50 AND 60 DEGREES WEST LONGITUDE EAST OF THE WINDWARD ISLANDS AND A
WAVE THAT IS NOW NEAR 60 DEGREES WEST THAT WILL CONTINUE TO MOVE AT
ABOUT 9 MPH TOWARD PUERTO RICO AND THE U.S. VIRGIN ISLANDS. THIS
WAVE WILL APPROACH THE U.S. VIRGIN ISLANDS AND PUERTO RICO DURING
THE DAY ON SATURDAY AND PASS THROUGH PUERTO RICO SATURDAY NIGHT.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL GRADUALLY INCREASE
IN COVERAGE AND INTENSITY OVER THE AREA SATURDAY NIGHT...SUNDAY AND
SUNDAY NIGHT AS MOISTURE IN CONVERGING FLOW OVER THE FORECAST AREA
BEHIND THE WAVE FORMS A WIDE BAND OF SHOWER AND THUNDERSTORM
ACTIVITY THAT FLOWS FROM THE SOUTHEAST OVER THE LOCAL AREA. BY
MONDAY THE WAVE WILL BE OVER THE DOMINICAN REPUBLIC.

THE AREAS MOST AFFECTED BY THESE SHOWERS WILL BE IN THE SOUTHEAST OF
PUERTO RICO...BUT RAINFALL WILL SPREAD ACROSS THE ISLAND DURING THE
PERIOD. MAXIMUM RAINFALL IN SOUTHEAST PUERTO RICO FROM SATURDAY
NIGHT THROUGH MONDAY COULD RANGE FROM 8 TO 15 INCHES AND WILL LIKELY
DIMINISH TO LESS THAN 1 INCH IN THE NORTHWEST PORTION OF THE ISLAND.
THE POTENTIAL EXISTS FOR MAJOR RIVER FLOODING IN THE SAME AREAS THAT
WERE HIT SO HARD DURING THE LATTER PART OF SEPTEMBER 2008 INCLUDING
THE COASTAL MUNICIPALITIES FROM NAGUABO TO JUANA DIAZ. MOST AREAS
THERE ARE STILL FAIRLY SATURATED AND AREAS OF STEEP TERRAIN WILL BE
SUBJECT MUDSLIDES AND DEBRIS FLOWS. DANGER EXISTS THAT DEBRIS IN
RIVER CHANNELS WILL CAUSE WIDER FLOODING WITH LESS WATER THAN WOULD
HAVE HAPPENED PREVIOUSLY.

LOW LEVEL LOW PRESSURE PERSISTS THROUGH THE WEEK FROM HISPANIOLA TO
PUERTO RICO AND THE U.S. VIRGIN ISLANDS AND WILL BE THE FOCUS ON
CONTINUING RAINS TUESDAY AND WEDNESDAY AS WELL. UNUSUAL
SOUTHWESTERLY WIND FLOW DURING THIS TIME PERIOD MAY BRING THE FOCUS
OF THE HEAVIEST RAINS TO THE SOUTHWEST WHERE 6 TO 12 INCHES OF RAIN
COULD ALSO FALL IN AREAS WHERE RAINS ARE THE HEAVIEST.

ALTHOUGH LESS CERTAIN...NATIONAL WEATHER SERVICE FORECAST MODELS
SHOW ABUNDANT MOISTURE AND FAVORABLE UPPER LEVEL
CONDITIONS...SOMETIMES WITH LOCAL LOW PRESSURE VORTICES FORMING...
THAT WILL PROLONG THIS EXTENDED WET PERIOD THROUGH THE WEEKEND OF
18-19 OCTOBER. AREAS WORST HIT RUN THE RISK OF 15 TO 40 INCHES OF
RAINFALL BETWEEN 10 OCTOBER AND 19 OCTOBER...NEVERTHELESS SOME AREAS
OF PUERTO RICO MAY RECEIVE LESS THAN 2 TO 3 INCHES DURING THE SAME
PERIOD. AREAS IN THE U.S. VIRGIN ISLANDS MAY SEE AS MUCH AS 6 TO 8
INCHES BY 19 OCTOBER.

LOCAL EMERGENCY MANAGERS SHOULD REVIEW STAFFING AND RESOURCE
REQUIREMENTS. CITIZENS SHOULD CHECK EMERGENCY SUPPLIES...AND FLOOD
PROCEDURES AND MAKE PRIOR ARRANGEMENTS TO LEAVE FLOOD PRONE AREAS
SHOULD RAINFALL DEVELOP AS EXPECTED. AREA RESIDENTS SHOULD LOOK FOR
ALTERNATE ROUTES IN CASE THEY ARE STRANDED BEHIND FLOODING IN LOW
LYING AREAS.  IT IS NEVER SAFE TO CROSS A FLOODED ROAD. EVERYONE
SHOULD REMAIN ABREAST OF THE DEVELOPMENT OF THIS SITUATION EITHER BY
NOAA WEATHER RADIO OR LOCAL MEDIA. ALTHOUGH CONVECTION IN THE AREA
OF INTEREST IS NOT AS DEEP OR AS STRONG AS LAST MONTH...FAVORABLE
CONDITIONS FOR HEAVY RAIN WILL LAST LONGER AND THE WEATHER-PRODUCING
TROUGH WILL MOVE AS SLOWLY AS THE WAVE IN THE PREVIOUS EVENT...WHICH
COULD PROLONG THE FLOODING FOR A LONGER PERIOD.


$$

SNELL







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