FXPQ60 PGUM 200828

AFDPQ 



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE TIYAN GU

628 PM CHST SAT MAR 20 2010



.SYNOPSIS...

RADAR INDICATES ISOLATED SHOWERS OVER THE FORECAST ZONES.

SATELLITE SHOWS MOSTLY CIRRUS CLOUDS WITH MAINLY PARTLY CLOUDY

SKIES IN THE VICINITY OF THE MARIANAS. A DEVELOPING CIRCULATION

SOUTHWEST OF CHUUK CONTINUES TO STRUGGLE TO MAINTAIN DEEP

CONVECTION. VERTICAL SHEAR IS HAMPERING DEVELOPMENT. WEAK AND

LIMITED BANDING IS POORLY WRAPPED INTO THE LOW LEVEL CIRCULATION

CENTER. THE JOINT TYPHOON WARNING CENTER (JTWC) HAS DESIGNATED

THIS SYSTEM AS 98W. DIFFLUENCE PERSISTS OVER 98W...SO JTWC IS

STILL CARRYING 98W AS A FAIR SUSPECT AREA.



&&



.DISCUSSION...

MODEL GUIDANCE SHOWS LOW CHANCES FOR PRECIP IN THE MARIANAS

DURING THE NEXT FEW DAYS. JTWC SUSPECT AREA 98W IS STILL EXPECTED

TO REMAIN WELL SOUTH OF THE MARIANAS AND MOVE IN THE GENERAL

DIRECTION OF YAP. MODEL FORECASTS FOR PRECIP SHOW SCATTERED

SHOWERS REACHING CLOSE TO SOUTHERN GUAM SUNDAY NIGHT. EXPECT

INCREASED LOW/MID LEVEL CLOUDS AND BREEZY CONDITIONS SUNDAY

THROUGH MONDAY...BUT GFS GUIDANCE HAS MEASURABLE RAIN CHANCES

APPROACHING 30 PERCENT IN THE MARINE ZONE SOUTH OF GUAM. FRESH

EAST-NORTHEAST TRADES WILL PREVAIL ACROSS THE REGION FOR THE NEXT

SEVERAL DAYS.



&&



.MARINE...

SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS AND A HIGH SURF ADVISORY

HAVE BEEN ISSUED. STRONG HIGH PRESSURE TO THE NORTH...A DEVELOPING

SYSTEM TO THE SOUTH...AND A RESULTANT TRADE-WIND SURGE HAVE

CAUSED SEAS AND SURF TO RISE JUST ABOVE THRESHOLD HEIGHTS.



&&



.EASTERN MICRONESIA...

LOW-LEVEL CONVERGENCE WILL CONTINUE TO COUPLE WITH UPPER-LEVEL

DIVERGENCE NEAR THE AXIS OF AN UPPER-LEVEL RIDGE TO PRODUCE

STRONG CONVECTION OVER KOSRAE TONIGHT AND POHNPEI INTO SUNDAY. AS

JTWC INVEST AREA 98W BEGINS TO PULL NORTHWESTWARD AWAY FROM

EASTERN MICRONESIA EARLY NEXT WEEK...DRIER TRADES ALONG WITH

SUBSIDENCE ALOFT WILL BRING GRADUAL IMPROVEMENT OVER BOTH

LOCATIONS. FOR THE MARSHALLS...A DRIER TRADE-WIND REGIME IS

EXPECTED TO LAST INTO MIDWEEK.



SURF ACROSS EASTERN MICRONESIA IS GRADUALLY SUBSIDING BUT WILL

REMAIN HAZARDOUS THRU THIS WEEKEND. BY MONDAY...SURF IS

ANTICIPATED TO DROP BELOW ADVISORY LEVELS FROM EAST TO WEST.



&&



.WESTERN MICRONESIA...

SATELLITE IMAGERY THIS AFTERNOON CONTINUES TO SHOW LITTLE IN THE

WAY OF CONSOLIDATION FOR 98W INVEST. DEEP CONVECTION IS STILL

CONCENTRATED ALONG THE NEAR-EQUATORIAL TROUGH AXIS BOTH WEST AND

SOUTHEAST OF THE SURFACE CIRCULATION CENTER. MAJOR

INTENSIFICATION PROBABLY WILL NOT OCCUR UNTIL ANTI-CYCLONIC

OUTFLOW HAS ESTABLISHED ABOVE THIS SYSTEM. AS 98W BECOMES BETTER

ORGANIZED AND BEGINS TO DRIFT TO THE NORTHWEST

TONIGHT...CONVECTION NEAR THE CENTER WILL SPREAD NORTHWARD OVER

CHUUK. ON SUNDAY...THE CONVERGENCE ZONE ALONG THE EAST SIDE OF

THE SYSTEM WILL MOVE OVER CHUUK AND PROLONG CONVECTIVE ACTIVITY.

LINGERING SHOWERS WILL BEGIN TO TAPER OFF TOWARD MIDWEEK AS DRIER

AIR SLOWLY FILTERS IN FROM THE EAST. IN RESPONSE TO 98W...THE

NEAR-EQUATORIAL TROUGH HAS LIFTED FARTHER NORTH IN THE

NEIGHBORHOOD OF PALAU AND YAP. THE LEADING EDGE OF THE TRADE

SURGE FLOWING ACROSS THE MARIANAS IS GOING TO CONCENTRATE

STRONGER CONVERGENCE NEAR THE TROUGH AXIS. AIDED BY DIVERGENT

WINDS ALOFT...SCATTERED SHOWERS AND A THUNDERSTORM OR TWO WILL

GRADUALLY MOVE OVER BOTH FORECAST POINTS SUNDAY INTO MONDAY. WENT

AHEAD AND PUT SCATTERED SHOWERS INTO THE YAP FORECAST ON MONDAY

AND MONDAY NIGHT.



HAZARDOUS SURF ACROSS CHUUK STATE WILL SUBSIDE AND MIGHT DROP

BELOW ADVISORY LEVELS ON MONDAY EVENING. 98W WILL PROBABLY CAUSE

COMBINED SEAS TO BE HIGHER NEAR CHUUK BUT NO SIGNIFICANT SWELLS

ARE EXPECTED AT THIS TIME.



&&



.GUM WATCHES/WARNINGS/ADVISORIES...

GU...NONE.

MARIANAS WATERS...NONE.

&&



$$



DEVITA/STANKO