Flash Flood Warning 1, NWS Guam

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
1055 PM CHST TUE JUL 29 2014

.MARIANAS SYNOPSIS...
PGUA WSR-88D SHOWS THAT TROPICAL STORM HALONG IS CENTERED NEAR
13.6 NORTH AND 147.0 DEGREES EAST. THIS IS ABOUT 150 MILES EAST OF
THE RADAR. THE VAD WIND PROFILE REVEALS 30 TO 40 KNOT NORTHWEST
WINDS THROUGH THE LOWEST 8 THOUSAND FEET OF THE AIR.

&&

.DISCUSSION...
24 HOUR PRESSURE FALLS OF 2.4 MB AT ROTA AND 2.1 MB AT ANDERSEN
SUGGEST THAT HALONG WILL END UP TRACKING THROUGH THE ROTA CHANNEL.
HALONG IS THE MAIN FORECAST PROBLEM TONIGHT. FOCUS WAS PLACED
ENTIRELY ON THE SHORT TERM FORECAST...ESPECIALLY WIND AND WAVES.

&&

.TROPICAL SYSTEMS...
HALONG CONTINUES TO INTENSIFY. AS HALONG PASSES THROUGH THE
MARIANAS WATERS...WIND AND WAVES WILL INCREASE MARKEDLY. THIS WILL
BE ESPECIALLY TRUE NEARER TO THE CENTER.

&&

.EASTERN MICRONESIA...
A SURFACE RIDGE SOUTH AND SOUTHEAST OF TROPICAL STORM HALONG
CENTERED EAST-SOUTHEAST OF THE MARIANAS NEAR 13N148E WILL SUSTAIN
FAIR WEATHER FOR CHUUK THRU THURSDAY NIGHT AND POHNPEI UNTIL
THURSDAY. FROM THE MARSHALL ISLANDS AND EASTWARD THRU THE DATE
LINE...THE EASTERN END OF THE MONSOON TROUGH IS INTERACTING WITH
MODERATE TO FRESH TRADE WINDS FILTERING WESTWARD TOWARD THE DATE
LINE. THIS WOULD CAUSE THE MONSOON TROUGH TO TRANSFORM INTO A
SURFACE TROUGH. INCREASING SURFACE CONVERGENCE NEAR THIS FEATURE IS
TRIGGERING SHOWERS AND A FEW THUNDERSTORMS NEAR KOSRAE AND MAJURO.
THIS TREND WILL CONTINUE FOR MAJURO THRU TONIGHT...AND ON KOSRAE FOR
THE NEXT COUPLE OF DAYS. THIS SAME FEATURE WILL GRADUALLY SHIFT
WESTWARD AND AFFECT POHNPEI AND CHUUK TOWARD THE WEEKEND. A SERIES
OF SURFACE IMPULSES EMBEDDED ALONG THIS FEATURE UPSTREAM EAST OF
THE DATE LINE COULD PROLONG WETNESS ACROSS THE WHOLE REGION THRU THE
WEEKEND.

&&

.WESTERN MICRONESIA...
REASONING FOR THE CHUUK FORECAST CAN BE FOUND ABOVE UNDER THE
EASTERN MICRONESIA SECTION DUE TO A SIMILAR SYNOPTIC PATTERN.

THE WESTERN HALF OF A SURFACE HIGH SOUTH OF TROPICAL STORM HALONG IS
GOING TO DOMINATE THE WEATHER NEAR KOROR AND YAP THRU MIDWEEK.
AFTERWARD...TROPICAL STORM HALONG PASSING THRU THE MARIANAS INTO THE
PHILIPPINE SEA WILL BEGIN TO STRENGTHEN THE MONSOON WINDS ACROSS
PALAU AND YAP ONCE AGAIN. THEREFORE EXPECT UNSTABLE WEATHER TO
RETURN TO BOTH LOCATIONS TOWARD THE WEEKEND.

LINGERING MONSOONAL SWELL WILL MAINTAIN HAZARDOUS SURF FOR THE
REPUBLIC OF PALAU AND YAP STATE THRU TONIGHT...AND COULD SUBSIDE
BELOW ADVISORY LEVELS WEDNESDAY EVENING.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...TROPICAL STORM WARNING FOR GUZ001-003-004.
     TYPHOON WATCH FOR GUZ001.
     FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR GUZ001>004.
     HIGH SURF ADVISORY UNTIL 6 AM CHST SUNDAY FOR GUZ001>004.
     TYPHOON WARNING FOR GUZ002.

MARIANAS WATERS...TROPICAL STORM WARNING FOR PMZ151-153-154.
     TYPHOON WARNING FOR PMZ152.

&&

STANKO/ZIOBRO/M. AYDLETT