Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Fri, 29 Oct 2010 02:55:20 -0500

685 
FXPQ60 PGUM 290755
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
555 PM CHST FRI OCT 29 2010

.SYNOPSIS...LATE THIS AFTERNOON A THICK CIRROSTRATUS OVERCAST
PERSISTS OVER GUAM. VISIBLE AND IR SATELLITE IMAGERY SHOW THICK
CONVECTIVE CLOUD COVER SOUTH OF GUAM STRATIFYING OUT. GRADIENT
WIND ANALYSIS SHOWS TRADE-WIND CONVERGENCE SOUTH OF GUAM MOVING
WESTWARD. RADAR SHOWS ISOLATED SHOWERS IN THE GUAM AND ROTA MARINE
ZONES. UPSTREAM FARTHER EAST...SATELLITE IMAGERY INDICATES PARTLY
CLOUDY SKIES TO ABOUT 160E.

&&

.DISCUSSION...THE ABOVE MENTIONED CIRRUS DEBRIS SHOULD MOVE WEST
OF THE MARIANAS LATER THIS EVENING. HOWEVER...WATER VAPOR IMAGERY
NOW REVEALS THAT THE UPPER-LOW THAT WAS SOUTH OF GUAM AND MOVING
WESTWARD LAST NIGHT...IS NOW WEST OF GUAM AND MOVING NORTHWESTWARD.
THIS COULD PLACE THE MARIANAS SOUTHEAST OF THE UPPER LOW AND A
CHANCE OF THUNDERSTORMS MAY NEED TO BE ADDED TO THE FORECASTS.
OTHERWISE...MODEL GUIDANCE CONTINUES TO INDICATE LITTLE CHANGE IN
THE PREVIOUS BENIGN WEATHER PATTERN UNTIL ABOUT WEDNESDAY. SO
LIGHT TO MODERATE EAST WINDS...A SLIGHT INCREASE IN MOISTURE...AND
ONLY ISOLATED SHOWERS ARE EXPECTED THROUGH TUESDAY. FOR WEDNESDAY
THROUGH FRIDAY...IT IS TOO EARLY TO TELL IF WETTER CONDITIONS
MATERIALIZE.

&&

.MARINE...NORTHEAST TRADE-WIND SWELL WILL CONTINUE THROUGH THE
FORECAST. STILL EXPECT THE ARRIVAL OF THE NORTHWEST SWELL BY
SATURDAY. THIS SHOULD INCREASE SURF ON WEST FACING REEFS BY ABOUT
TWO FEET. THIS NORTHWEST SWELL WILL PERSIST THROUGH AT LEAST
TUESDAY.

&&

.EASTERN MICRONESIA...SATELLITE SHOWS SCATTERED TO ISOLATED SHOWERS 
BETWEEN 5N AND 8N FROM THE RMI EASTWARD ACROSS THE DATE LINE.
SCATTERED SHOWERS WILL MOVE TOWARD KOSRAE OVERNIGHT AND POHNPEI
SATURDAY. WATER VAPOR IMAGES SHOW A VIGOROUS TUTT CELL NW OF WAKE
ISLAND AND IT WAS TRIGGERING SCATTERED DEEP CONVECTION IN A LARGE
AREA. GFS AND NOGAPS INDICATE THE TUTT CELL WILL MOVE WESTWARD
WHILE MUCH CONVECTION OVER EASTERN MICRONESIA MOVES NORTHWESTWARD.
ITCZ WILL PERSIST ACROSS EASTERN MICRONESIA IN THE NEAR TERM...BUT
A RELATIVELY DRIER TRADE-WIND FLOW IS EXPECTED TO DEVELOP NEXT
WEEK.

MAJURO BUOY KALO SHOWS NNE WAVES OF 6 FT/12 SECOND PERIOD. WW3 MODEL 
INDICATES A LITTLE LARGER TRADE-WIND SEAS WILL DEVELOP THIS WEEKEND 
AND RECENT ALTIMETRY CONFIRMS AREAS OF 8 FT SEAS NE OF THE RMI.

&&

.WESTERN MICRONESIA...WEATHER WILL BE UNSTABLE ACROSS THIS AREA IN
THE NEAR-TERM. A TROUGH REMAINS OVER THE PHILIPPINE SEA AND LOW-
LEVEL CONVERGENCE PERSISTS ACROSS WESTERN MICRONESIA. ASCAT
ANALYSIS AND SATELLITE INDICATE SHARP TROUGHING SW OF PALAU. A
WEAK CIRCULATION MIGHT BE DEVELOPING NEAR 4N131E BUT NOTHING FOR
SURE AT THIS TIME. MODELS DIFFER AND SOLUTIONS ARE NOISY. CONT
PREV FORECAST TRENDS FOR LIGHT EAST TO SE WINDS AND ISOLATED
SHOWERS NEXT WEEK.

LONG-PERIOD SWELL GENERATED BY DISTANT TYPHOON CHABA WILL CAUSE 
HAZARDOUS SURF ALONG WEST AND NORTH FACING SHORES OF BOTH PALAU AND 
YAP THRU AT LEAST SUNDAY.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...NONE.
MARIANAS WATERS...NONE.
&&

$$

DEVITA/SIMPSON

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