Area Forecast Discussion
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000
FXPQ60 PGUM 021038 RRB
AFDPQ

AREA FORECAST DISCUSSION...RESEND
NATIONAL WEATHER SERVICE TIYAN GU
630 PM CHST THU JUL 2 2015

UPDATED TO ADD MICRONESIAN SECTION

.SYNOPSIS...
A TYPHOON WATCH REMAINS IN EFFECT FOR THE MARIANAS. MODERATE NORTH
TO NORTHEAST WINDS AND ISOLATED SHOWERS ARE PRESENT ACROSS THE
MARIANAS THIS AFTERNOON. BUT THE NORTHWEST FRINGE OF CHAN-HOM`S MAIN
CONVECTIVE MASS IS NOW BECOMING VISIBLE ON RADAR ABOUT 200 MILES ESE
OF GUAM.

&&

.DISCUSSION... AT 4 PM THE CENTER OF TS CHAN-HOM WAS LOCATED BY
SATELLITE ABOUT 415 MILES EAST-SOUTHEAST OF GUAM NEAR 10.9N AND
150.3E...MOVING WEST AT 18 MPH. CHAN-HOM IS STILL BEING
SHEARED...WITH MOST OF THE CLOUDS AND RAIN OVER THE WESTERN HALF OF
THE CIRCULATION. THE CURRENT VISIBLE SATELLITE LOOP SHOWS CHAN-HOM
MOVING WESTWARD AT A BRISK 18 MPH...BUT MODEL GUIDANCE SHOWS A
DRASTIC SLOW-DOWN OVERNIGHT AS CHAN-HOM VIRTUALLY STALLS A COUPLE OF
HUNDRED MILES SOUTHEAST OF GUAM FRIDAY BEFORE TURNING NORTHWEST
SATURDAY AND MOVING THROUGH THE MARIANAS SATURDAY NIGHT. THE JTWC
FORECAST TRACK IS A GOOD REPRESENTATION OF THIS GENERAL
SCENARIO...BUT THERE IS MUCH UNCERTAINY REGARDING THE TIMING OF THE
ANTICIPATED TRACK CHANGE...AND JUST HOW MUCH THE DIRECTION OF MOTION
WILL CHANGE. IF CHAN-HOM IS INDEED GOING TO SLOW DOWN IT SHOULD
BECOME EVIDENT TONIGHT.

NOT ONLY THE WIND FORECAST...BUT ALSO THE RAIN FORECAST HINGES ON
CHAN-HOM`S TRACK. THE CURRENT FORECAST HOLDS OFF HEAVY RAIN UNTIL
SATURDAY...BUT THAT IS BASED ON THE STORM HAVING STALLED MOST OF
FRIDAY. IF THE ANTICIPATED STALL FAILS TO MATERIALIZE OR IF IT TAKES
PLACE LATER THAN EXPECTED...WIND AND HEAVY RAIN COULD ARRIVE SOONER
THAN FORECAST. THOSE PREPARING FOR THE STORM`S ARRIVAL SHOULD BEAR
ALL THIS IN MIND...AND PREPARE EARLY.

&&

.EASTERN MICRONESIA... SATELLITE IMAGERY HAS VERIFIED MUCH OF THE
PRIOR FORECAST...SO LITTLE CHANGE TO INHERITED FORECASTS AND
MICRONESIAN AREA FORECAST DISCUSSION A MONSOON TROUGH RUNS EASTWARD
FROM TROPICAL STORM CHAN-HOM CENTERED NORTH-NORTHWEST OF CHUUK NEAR
11N150E TO ANOTHER CIRCULATION...JTWC INVEST 97W CENTERED NEAR
MAJURO NEAR 7N171E TO BEYOND 180 AT 7N. CONVERGING FRESH TO STRONG
SOUTHWEST WINDS FEEDING TOWARD CHAN-HOM AND THE MONSOON TROUGH WILL
MAINTAIN SHOWERY WEATHER NEAR CHUUK AND POHNPEI THRU FRIDAY. FARTHER
EAST...MONSOONAL WEST TO SOUTHWEST WINDS ASSOCIATED WITH 97W WILL
ALSO SUSTAIN SIMILAR CONDITIONS NEAR KOSRAE AND MAJURO THRU FRIDAY.
ENHANCED BY AN UPPER-LEVEL TROUGH IN THE VICINITY...DEEP CONVECTION
IS OCCURRING NEAR MAJURO TONIGHT AND IS POSSIBLE NEAR KOSRAE TONIGHT
AND FRIDAY.

TROPICAL STORM CHAN-HOM IS PASSING WEST-NORTHWESTWARD OF CHUUK AND
IS ABSORBING 94W AND CAUSING ITS WIND FIELD TO EXPAND. THESE
CONVERGENT SOUTHWEST WINDS WILL CONTINUE OVER CHUUK THRU SATURDAY
CONTINUING SCATTERED SHOWERS THROUGH SATURDAY. THE MONSOON TROUGH IS
ALSO EXPECTED TO LIFT SLOWLY WEST-NORTHWESTWARD OVER THE NEXT COUPLE
OF DAYS. THIS SHOULD ALLOW WEAKER MONSOONAL WINDS FARTHER SOUTH TO
SHIFT OVER POHNPEI...KOSRAE AND MAJURO BY THIS WEEKEND. UNDER THIS
SCENARIO...SHOWER COVERAGE SHOULD BEGIN TO DECREASE OVER THESE THREE
LOCATIONS. BY EARLY NEXT WEEK...GENTLE SOUTH TO SOUTHEAST TRADES
MIGHT RETURN TO KOSRAE AND MAJURO WITH FAIR WEATHER. HOWEVER
...LINGERING MONSOONAL WINDS CAN STILL TRIGGER ISOLATED CONVECTION
FOR POHNPEI AND CHUUK THRU MONDAY.

SOUTHWEST SWELL AND WIND WAVES PRODUCED BY FRESH MONSOONAL WINDS
WILL PROLONG HAZARDOUS SURF ACROSS CHUUK...POHNPEI AND KOSRAE STATES
THRU THIS WEEKEND. THESE ELEMENTS WILL ALSO CAUSE SEA CONDITIONS
HAZARDOUS FOR SMALL CRAFT ACROSS THE MARSHALL ISLANDS...KOSRAE UNTIL
FRIDAY AFTERNOON AND POHNPEI...CHUUK THRU SATURDAY AFTERNOON. A
PEAKING SPRING TIDE CYCLE AND THE SOUTHWEST SWELL MAKE MINOR COASTAL
INUNDATIONS  POSSIBLE ALONG SOUTH AND WEST FACING SHORES NEAR MAJURO.


&&

.WESTERN MICRONESIA...
DISCUSSION FOR THE CHUUK FORECAST IS INCLUDED IN THE EASTERN
MICRONESIA SECTION ABOVE DUE TO A SIMILAR WEATHER PATTERN.

A STRONG MONSOON TROUGH EXTENDS EAST-SOUTHEASTWARD FROM A WEAK
CIRCULATION WEST OF 13N130E PASSING NORTH OF KOROR AND YAP NEAR 12N
TO TROPICAL STORM CHAN-HOM CENTERED NORTH-NORTHEAST OF CHUUK NEAR
11N150E. MONSOONAL WINDS SOUTH OF THE TROUGH WILL CONTINUE TO
GENERATE SPORADIC CONVECTION NEAR KOROR AND YAP THRU FRIDAY. AS CHAN-
HOM HOM GRADUALLY TRACKS WEST-NORTHWESTWARD TOWARD THE MARIANA
ISLANDS FRIDAY NIGHT AND SATURDAY...IT WILL REINFORCE ANOTHER
MONSOONAL WIND SURGE ACROSS KOROR AND YAP. THEREFORE ANTICIPATE EVEN
WETTER WEATHER FOR BOTH LOCALES THRU SATURDAY. DEPENDS ON THE
INTENSITY OF CHAN-HOM AFTER IT HAS MOVED OVER THE PHILIPPINE SEA
NORTH OF PALAU AND YAP EARLY NEXT WEEK...IT MIGHT STILL MAINTAIN A
WET MONSOONAL REGIME OVER THE AREA.

EXPECT THE TREND OF RISING SEA HEIGHTS TO CONTINUE THRU THIS WEEKEND
PROLONGING HAZARDOUS SURF AND SEA CONDITIONS HAZARDOUS TO SMALL CRAFT
ACROSS THE REPUBLIC OF PALAU AND YAP STATE INTO NEXT WEEK.

&&

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

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

&&

$$

MIDDLEBROOKE/DEVITA



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