Flash Flood Warning 13, NWS Guam

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
1032 PM CHST THU OCT 15 2015

.SYNOPSIS...
TROPICAL STORM CHAMPI WAS NEAR LATITUDE 16.3 NORTH AND LONGITUDE
150.5 EAST AT 7 PM CHST. MOVEMENT IS TOWARD THE WEST-NORTHWEST AT
17 MPH. MAXIMUM SUSTAINED WINDS HAVE BEEN HOVERING NEAR 60 MPH
SINCE THIS MORNING. DENSE CLOUD COVER AND RAIN SHIELD OF CHAMPI
IS SPREADING OVER TINIAN AND SAIPAN.

&&

.DISCUSSION...
A TROPICAL STORM WARNING AND TYPHOON WATCH REMAIN IN EFFECT FOR
THE NORTHERN CNMI. A TROPICAL STORM WARNING REMAINS IN EFFECT FOR
THE ROTA...TINIAN AND SAIPAN ZONES. LATEST WARNING FROM JTWC TAKES
CHAMPI THROUGH THE MARIANAS NEAR ALAMAGAN...SO STRONGEST WINDS AND
HEAVIEST RAINS ASSOCIATED WITH CHAMPI ARE EXPECTED TO AFFECT THE
TINIAN AND SAIPAN ZONES FRIDAY AND FRIDAY NIGHT. CWFMY AND ZFPMY
ARE WORDED ACCORDINGLY. CONDITIONS ARE EXPECTED TO GRADUALLY
IMPROVE OVER THE WEEKEND AND EARLY NEXT WEEK...BUT MONSOONAL
WEATHER PATTERN WILL KEEP UNSETTLED WEATHER IN PLACE THROUGH DAY
7.

&&

.MARINE...
TROPICAL STORM WARNING REMAINS IN EFFECT FOR ROTA...TINIAN AND
SAIPAN ZONES. IF CHAMPI CONTINUES TO MOVE AND EVOLVE AS
EXPECTED...WATCHES AND WARNINGS SHOULD NO LONGER BE NECESSARY BY
SUNDAY EVENING. SMALL CRAFT AND HIGH SURF ADVISORIES REMAIN IN
EFFECT FOR GUAM ZONES. THESE MAY BE REQUIRED FOR SEVERAL DAYS
LONGER...AS MONSOONAL WINDS FROM THE SOUTHWEST COULD PROLONG
ADVERSE MARINE CONDITIONS WELL INTO NEXT WEEK.

&&

.TROPICAL SYSTEMS...
TROPICAL STORM CHAMPI CONTINUES TRACKING TOWARD THE WEST-
NORTHWEST AND IS EXPECTED TO PASS SOMEWHERE NEAR ANATAHAN IN THE
NORTHERN CNMI ON FRIDAY AFTERNOON. DEVELOPMENT OF CHAMPI CONTINUES
TO BE RETARDED BY STRONG VERTICAL WIND SHEAR. TOPS OF CONVECTION
CONTINUE TO BE ADVECTED TOWARD THE SOUTHWEST AWAY FROM THE CENTER.
QPF FORECAST IN THE HLSPQ2 TAKES THIS INTO ACCOUNT VIA HIGHEST
EXPECTED RAINFALL ACCUMULATIONS SOUTH OF THE CENTER NEAR TINIAN
AND SAIPAN. NIGHT SHIFT WILL NEED TO MONITOR RAINFALL
ACCUMULATIONS ON TINIAN AND SAIPAN FOR POSSIBLE FLOOD PRODUCT
ISSUANCE. LATEST WARNINGS FROM JTWC HAVE TRENDED NORTHWARD WITH
THE TRACK OF CHAMPI...SO LATEST WIND FORECASTS FOR GUAM...ROTA...
TINIAN AND SAIPAN ZONES HAVE BEEN TONED DOWN A BIT. CENTER OF
CHAMPI IS EXPECTED TO PASS THROUGH THE MARIANAS ON FRIDAY
AFTERNOON...AFTER THAT...CONDITIONS ARE EXPECTED TO IMPROVE.

&&

.EASTERN MICRONESIA...
TROPICAL STORM CHAMPI IS MOVING AWAY FROM EASTERN MICRONESIA AND
APPROACHING THE MARIANA ISLANDS. ASCAT ANALYSIS SHOWS SOUTHWEST TO
WEST WINDS PERSIST FROM CHUUK ACROSS POHNPEI TO KOSRAE WHERE THEY
TURN NORTHWEST ACROSS THE MARSHALL ISLANDS TOWARD A WEAK
CIRCULATION SOUTHEAST OF MAJURO NEAR 6N176E. THIS CIRCULATION IS
ASSOCIATED WITH JTWC INVEST AREA 93W. THE GFS MODEL INDICATES 93W
WILL MOVE TOWARD NORTHWEST AND SLOWLY DEVELOP DURING THE NEXT FEW
DAYS...MAINLY JUST AFFECTING THE MARSHALL ISLANDS AND KOSRAE
STATE. CHUUK AND POHNPEI SHOULD REMAIN IN A SLIGHTLY DRIER
SOUTHWEST WIND FLOW. IN THE LONGER TERM...A LITTLE DRIER WEATHER
IS EXPECTED FOR MAJURO AND KOSRAE BY EARLY NEXT WEEK AS INVEST
AREA 93W MOVES FARTHER AWAY THIS WEEKEND.

&&

.WESTERN MICRONESIA...
REASONING FOR CHUUK FORECAST IS INCLUDED IN THE EASTERN MICRONESIA
DISCUSSION DUE TO A SIMILAR MONSOON PATTERN.

TROPICAL STORM KOPPU IS CENTERED ALMOST 600 MILES NORTHWEST OF
KOROR AND MOVING TOWARD LUZON. GFS MODEL INDICATES FRESH TO STRONG
SOUTHWEST WINDS WILL CONTINUE ACROSS KOROR AND YAP THE NEXT COUPLE
OF DAYS. HIGH PRESSURE AND DRY WEATHER ARE CENTERED TO THE
SOUTHEAST OF YAP BUT MODELS STILL INDICATE A FEW SHOWERS FOR YAP
STATE DURING THE WEEKEND AS TROPICAL STORM CHAMPI MOVES WEST-
NORTHWEST THROUGH THE MARIANAS. DRIER CONDITIONS WILL RETURN TO
YAP SUNDAY...AND FAIR CONDITIONS AT KOROR ARE EXPECTED TO CONTINUE
INTO NEXT WEEK.

FRESH TO STRONG SOUTHWEST WINDS AND LARGE WAVES WILL CAUSE HAZARDOUS
SEA AND SURF CONDITIONS FOR YAP AND KOROR DURING THE NEXT FEW DAYS.
CONDITIONS SHOULD START IMPROVING BY SUNDAY OR MONDAY.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...HIGH SURF ADVISORY FROM 6 AM FRIDAY TO 6 PM CHST WEDNESDAY FOR
     GUZ001.

     TROPICAL STORM WARNING FOR GUZ002>004.

MARIANAS WATERS...TROPICAL STORM WARNING FOR PMZ152>154.

     SMALL CRAFT ADVISORY UNTIL 3 PM CHST SUNDAY FOR PMZ151.

&&

MCELROY/WILLIAMS/STANKO