Rip Current in Guam, February 18, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
456 AM CHST MON FEB 18 2013

.SYNOPSIS...
NO RADAR. SATELLITE SHOWS A MODESTLY ORGANIZED DISTURBANCE MOVING
ACROSS 150E TO OUR EAST AND SOUTHEAST. DEEP CONVECTION REMAINS
SOUTH OF 10N ACROSS SOUTHERN MICRONESIA. BUOYS SHOW SIGNIFICANT
COMBINED SEAS IN THE RANGE OF 9 TO 11 FT WITH HIGHER MAX WAVES.
DIRECTIONS WERE MAINLY FROM NE AT SAIPAN AND IPAN...AND BOTH N AND
ENE AT RITIDIAN.

&&

.DISCUSSION...
HIGH SURF ADVISORY REMAINS IN EFFECT. SCATTERED SHOWERS WERE
INTRODUCED FOR TONIGHT THROUGH EARLY TUESDAY. ZONES MAYBE COULD
BE SEPARATED...BUT NOT ENOUGH CONFIDENCE TO DO THAT AT THIS TIME.
MODELS HAVE BEEN SHOWING THE DISTURBANCE TO OUR SE ARRIVING BY
TUESDAY FOR SEVERAL RUNS AND THIS MORNING IT ALL INITIALIZES
DECENTLY WITH SATELLITE LOOPS. NORTHEAST WINDS SHOULD PEAK OUT
TODAY AS THE DISTURBANCE APPROACHES...THEN WINDS WILL VEER EAST AS
THE DISTURBANCE PASSES AND SHOULD TAPER OFF BY WED OR THURSDAY SO
THAT RELATIVELY DRY TRADE-WIND CONDITIONS ARE EXPECTED THROUGH THE
LONGER TERM.

&&

.MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT. MODELS INDICATE WINDS AND
WAVES SHOULD PEAK TODAY...THEN GRADUALLY DIMINISH BELOW ADVISORY
CRITERIA LATE WED OR THU. WINDS WERE REFRESHED WITH LATEST GFS AND
ADJUSTMENTS WERE MADE TO WAVE GRIDS BASED ON AN EXCELLENT DIRECT
PASS OF ALTIMETRY DATA AND WW3 WAVE WATCH GUIDANCE.

&&

.EASTERN MICRONESIA...
ACTIVE WEATHER CONTINUES ACROSS THE REGION. A BAND OF SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS IS APPROACHING KOSRAE  WHILE
DEEP CONVECTION SIMMERS JUST SOUTH OF MAJURO. MODELS KEEP SHOWERS
JUST ON THE SOUTH SIDE OF MAJURO FOR THE NEXT SEVERAL DAYS SO HAVE
KEPT ONLY ISOLATED SHOWERS IN THE FORECAST. HOWEVER...WILL HAVE TO
KEEP AN EYE ON CONDITIONS THERE IN CASE SHOWERS SPREAD BACK NORTH.
FOR KOSRAE...SCATTERED SHOWERS WILL PERSIST TODAY AND GRADUALLY
DIMINISH THIS EVENING. MODELS SHOW CONVECTION ALONG THE TRADE-WIND
CONVERGENCE ZONE UNDULATING NORTH-AND-SOUTH DURING THE NEXT
COUPLE DAYS WHICH WILL LEAD TO ALTERNATING PERIODS OF SCATTERED
AND ISOLATED SHOWERS THROUGH WEDNESDAY. CONVECTION NEAR POHNPEI IS
DISSIPATING BUT POHNPEI COULD YET SEE A FEW SHOWERS...PERHAPS A
THUNDERSTORM...IN THE NEXT COUPLE DAYS...BUT THE OVERALL FORECAST
WILL BE ON THE DRIER SIDE.

HIGH SURF ADVISORIES CONTINUE FOR MAJURO AND KOSRAE AND WILL
CONTINUE THE NEXT SEVERAL DAYS AS FRESH TO STRONG TRADE WINDS AND
LARGE EAST SWELL PERSIST ACROSS THE AREA.

&&

.WESTERN MICRONESIA...
A LARGE CLUSTER OF CONVECTION THAT WAS NORTHEAST OF CHUUK HAS
QUICKLY WEAKENED AS INFRARED SATELLITE SHOWS WARMING CLOUD TOPS.
THE SURFACE TROUGH WILL PASS TO THE WEST LATER THIS MORNING WITH
DRIER CONDITIONS FOLLOWING BEHIND. MODELS SHOW ANOTHER SURFACE
TROUGH APPROACHING THE CHUUK AREA LATE TUESDAY AND THAT MAY BRING
ANOTHER ROUND OF SHOWERS TO THE AREA.

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE WEAK CIRCULATION SOUTH
OF KOROR DISSIPATED SOME OVERNIGHT BUT ARE BEGINNING TO REDEVELOP
ALONG A LINE FROM 5N130E TO 4N150E. KOROR WILL SEE SCATTERED SHOWERS
TODAY WITH SOME LOCALLY HEAVY DOWNPOURS...BUT AS THE CIRCULATION
CENTER HEADS FARTHER WEST...THE LIKELIHOOD OF DEEP CONVECTION WILL
DIMINISH. A SMALLER BAND OF SHOWERS HAS RECENTLY DEVELOPED NEAR YAP
BUT MODELS DO NOT SHOW MUCH DEVELOPMENT TODAY SO HAVE LEFT ONLY
ISOLATED SHOWERS AND THUNDERSTORMS. MORE SHOWERS ARE EXPECTED FOR
BOTH YAP AND KOROR MIDWEEK BEFORE DRIER WEATHER MOVES IN THURSDAY
AND FRIDAY.

ASCAT SHOWS 20 TO 25 KT WINDS ACROSS YAP AND PALAU WHILE ALTIMETRY
SHOWS SEAS IN THE 10 TO 12 FOOT RANGE. MODELS SHOW WINDS BEGINNING
TO DECREASE ACROSS THE REGION TONIGHT WITH EAST SWELL ALSO FALLING.
WW3 SHOWS THAT SEAS WILL DECREASE ENOUGH THAT SURF MAY FALL BELOW
HAZARDOUS LEVELS AS EARLY AS TUESDAY MORNING AT BOTH YAP AND PALAU.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...HIGH SURF ADVISORY UNTIL 6 PM CHST WEDNESDAY FOR GUZ001>004.

MARIANAS WATERS...SMALL CRAFT ADVISORY UNTIL 6 PM CHST WEDNESDAY
     FOR PMZ151>154.

&&

SIMPSON