Flash Flood Warning 3, NWS Guam

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
447 PM CHST FRI MAY 15 2015

.SYNOPSIS...
PGUA RADAR SHOWS HEAVY RAIN WITH SOME EMBEDDED THUNDERSTORMS OVER
MOST OF THE COVERAGE AREA. TYPHOON DOLPHIN IS MOVING MORE WESTWARD
RECENTLY...PERHAPS TOWARD THE ROTA CHANNEL OR ACROSS FAR NORTHERN
GUAM. VAD GRAPHIC SHOWS NORTH-NORTHWEST WINDS 65 TO 70 KNOTS ABOVE
THE RADAR. IPAN BUOY SHOWS COMBINED SEAS FROM THE EAST AT 22 FEET.

&&

.DISCUSSION...
ORECAST GRIDS WERE ADJUSTED FOR A TRACK OF TYPHOON DOLPHIN SLIGHTLY
MORE SOUTH THAN PREVIOUS FORECAST. THE MAIN THREAT OF TYPHOON FORCE
WINDS WILL BE TO NORTHERN GUAM AND ROTA THIS EVENING...WHILE TINIAN
AND SAIPAN WILL RECEIVE TROPICAL STORM FORCE WINDS. THE WORST WIND
AND SEA CONDITIONS WILL BE THIS EVENING...BUT DOLPHIN SHOULD BE
MOVING WEST OF THE MARIANAS BY ABOUT MIDNIGHT AND WEATHER WILL VERY
SLOWLY IMPROVE DURING THE MORNING HOURS SATURDAY. MUCH MORE PLEASANT
WEATHER IS EXPECTED NEXT WEEK.

&&

.MARINE...
TYPHOON AND TROPICAL STORM FORCE CONDITIONS WILL PERSIST OVERNIGHT
FOR THE MARIANA WATERS WITH COMBINED SEAS PEAKING AT 25 TO 30 FEET
THIS EVENING. IT WILL TAKE MOST OF SATURDAY AND EARLY SUNDAY FOR
CONDITIONS TO SUBSIDE BUT PLEASANT MARINE WEATHER IS EXPECTED BY
MONDAY.

&&

.TROPICAL SYSTEMS...
A TYPHOON WARNING REMAINS IN EFFECT FOR GUAM...ROTA...TINIAN AND
SAIPAN. TYPHOON CONDITIONS...INCLUDING WINDS OF 74 MPH OR MORE...
ARE EXPECTED THIS AFTERNOON AND EVENING. A FLASH FLOOD WATCH IS ALSO
IN EFFECT FOR GUAM AND THE NORTHERN MARIANAS. TYPHOON DOLPHIN HAS
VEERED TO THE WEST AND APPEARS LIKELY TO PASS OVER NORTHERN GUAM OR
JUST NORTH OF GUAM DURING THE NEXT FEW HOURS. LATEST RADAR IMAGERY
SHOWS TYPHOON DOLPHIN VEERING MORE TO THE WEST ON A HEADING THAT
WOULD BRING THE EYE TO NORTHERN GUAM OR JUST NORTH OF GUAM AROUND
500 OR 600 PM. SEAS HAVE REACHED 22 FEET AT THE IPAN BUOY JUST EAST
OF GUAM...AND WINDS AND SEAS WILL INCREASE THROUGH THIS EVENING AS
DOLPHIN DRAWS NEAR AND PASSES THROUGH THE MARIANAS.

&&

.EASTERN MICRONESIA...
A TROPICAL DISTURBANCE OVER EASTERN MICRONESIA CENTERED ROUGHLY NEAR
4N170E WILL TRIGGER SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FOR
THE MAJURO AREA TONIGHT THROUGH SATURDAY NIGHT. SATELLITE SHOWS AN
AREA OF SHOWERS AND THUNDERSTORMS ALSO DEVELOPED JUST NORTH AND EAST
OF KOSRAE DURING THE DAY...WHILE FAIR WEATHER PREVAILS FOR POHNPEI.
MODELS STILL INDICATE THE CENTER OF THE DISTURBANCE WILL MOVE TOWARD
THE NORTHWEST. MOST OF THE RAINFALL IS EXPECTED TO STAY CLOSE TO THE
DISTURBANCE AND SHOULD REMAIN NORTH OF POHNPEI AND KOSRAE. THE WINDS
WILL BECOME SOUTHERLY AT KOSRAE BY MONDAY AND AT POHNPEI BY TUESDAY
AS THE DISTURBANCE MOVES NORTH OF THESE LOCATIONS.

&&

.WESTERN MICRONESIA...
TYPHOON DOLPHIN IS MOVING ACROSS THE SOUTHERN MARIANAS THIS
AFTERNOON AND ALSO AFFECTING THE WIND PATTERN ACROSS MOST OF WESTERN
MICRONESIA. SATELLITE SHOWS WIDELY SCATTERED SHOWERS NEAR YAP AND
NORTH OF CHUUK THAT ARE ASSOCIATED WITH A SPIRAL BAND WRAPPING INTO
DOLPHIN. THIS BAND OF CONVERGENCE ALONG THE SOUTHERN EDGE OF THE
MONSOON TROUGH WILL CAUSE SOME CLOUDS AND A FEW SHOWERS FOR YAP AND
POSSIBLY KOROR FOR THE NEXT COUPLE OF DAYS. NORTHWEST WINDS AT YAP
AND KOROR WILL BACK WESTERLY WHILE DOLPHIN MOVES NORTHWEST THEN
NORTHWARD BY ABOUT MONDAY. MAINLY FAIR WEATHER IS EXPECTED AT CHUUK
EXCEPT A DISTURBANCE MOVING NORTHWEST FROM EASTERN MICRONESIA MAY
TRIGGER A FEW SHOWERS OVER NORTHERN CHUUK STATE BY NEXT TUESDAY OR
WEDNESDAY.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...TYPHOON WARNING FOR GUZ001>004.

     FLASH FLOOD WATCH THROUGH LATE SATURDAY NIGHT FOR GUZ001>004.

MARIANAS WATERS...TYPHOON WARNING FOR PMZ151>154.

&&

CHAN/SIMPSON/MIDDLEBROOKE