000 FXPQ60 PGUM 181956 AFDPQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TIYAN GU 556 AM CHST WED JUN 19 2013 .SYNOPSIS... A SMALL TUTT CELL IS CENTERED BETWEEN PAGAN AND SAIPAN. A FEW THUNDERSTORMS HAVE BEEN OBSERVED DURING THE OVERNIGHT HOURS NEAR THE CENTER OF THIS SYSTEM. AN INVERTED SURFACE TROUGH IS EVIDENT IN THE LATEST ASCAT IMAGERY IN THE VICINITY OF POHNPEI BETWEEN 5N AND 15N. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE ASSOCIATED WITH THIS FEATURE. && .DISCUSSION... THE WEAK BUT CONVECTIVELY ACTIVE TUTT HAS BEEN DROPPING SOUTHWARD TOWARD SAIPAN. BASED ON THIS ADDED SLIGHT CHANCE THUNDER TO THE FORECAST JUST FOR TODAY. NEXT WEATHER MAKER IN LINE APPEARS TO BE THE SYSTEM NEAR POHNPEI. MODEL GUIDANCE DIFFERS ON JUST HOW FAR NORTHWARD SCATTERED SHOWERS WILL REACH AS THIS SYSTEM PASSES BY. ALL THE MODELS AGREE THAT THE TROUGH WILL MOVE THROUGH ON THURSDAY NIGHT AND FRIDAY...SO HAVE ADDED MOSTLY CLOUDY SKIES TO THE FORECAST DURING THIS TIME FRAME FOR NOW. REMAINDER OF THE FORECAST LOOKS UNSETTLED AS DEEPER MOISTURE AND CONVERGENT TRADES ARRIVE FROM THE SOUTH. PERIODS OF SCATTERED SHOWERS WILL BE POSSIBLE DAYS 5 THROUGH 7...BUT IT IS TOO EARLY TO DETERMINE THE EXACT TIMING AND EXTENT OF THE RAINFALL. && .MARINE... ALTIMETRY AND BUOY READINGS INITIALIZE MARIANAS COMBINED SEAS IN THE 4 TO 5 FOOT RANGE. MODERATE RIP CURRENT RISK WILL CONTINUE TO PREVAIL ALONG EAST-FACING REEFS FOR THE REMAINDER OF THIS WEEK. A TRADE-WIND SURGE CURRENTLY ON THE EAST SIDE OF THE SURFACE TROUGH NEAR POHNPEI WILL ARRIVE JUST IN TIME FOR THE WEEKEND. SURF ALONG EAST FACING REEFS SHOULD BUILD A FOOT OR TWO...BUT REMAIN AT MODERATE RIP CURRENT RISK LEVELS. && .EASTERN MICRONESIA... SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE REGION NEAR ALL LOCALES THIS MORNING. IR SATELLITE SHOWS SCATTERED SHOWERS OVER KOSRAE AND POHNPEI THIS MORNING. THE LEADING EDGE OF A TRADE-WIND SURGE IS JUST EAST OF POHNPEI AND WILL REACH THE ISLAND BY MID- MORNING. SOMEWHAT DRIER WEATHER IS SEEN OVER MAJURO. HOWEVER... SATELLITE ANIMATION SUGGESTS CONVECTION IS FILLING IN ACROSS THE MARSHALLS THIS MORNING NEAR KWAJALEIN AND EVENTUALLY NEAR MAJURO. MODELS STILL SHOW THIS ACTIVE PATTERN PERSISTING A COUPLE MORE DAYS BEFORE GRADUALLY LIFTING NORTHWARD. DRIER WEATHER WILL BE IN PLACE WITH LIGHTER WINDS OVER ALL LOCATIONS BY THE WEEKEND. WIND FORECASTS FOR SPEED AND DIRECTION MAY BECOME VARIABLE ACROSS MOST OF THE REGION BY THE END OF THE WEEK. && .WESTERN MICRONESIA... WEATHER ON CHUUK WILL GRADUALLY DETERIORATE TODAY. SCATTERED SHOWERS WILL ARRIVE BY EVENING. WEATHER SCENARIO HERE WILL FOLLOW CLOSELY TO REASONING SEEN ABOVE FOR EASTERN MICRONESIA. CHUUK CURRENTLY LIES ON THE WESTERN EDGE OF THE SWATH OF SHOWERS AND THUNDERSTORMS THAT EXTENDS EASTWARD TOWARD THE MARSHALL ISLANDS. SHOWERS WILL GRADUALLY TAPER TOWARDS THE END OF THE WEEK. THE BAND OF SHOWERS CURRENTLY NEAR CHUUK WILL LIFT NORTHWARD...USHERING IN DRIER WEATHER AND LIGHTER WINDS. A WEAK DISTURBANCE WILL MAINTAIN CLOUDY SKIES AND A SLIGHT CHANCE OF THUNDERSTORMS OVER YAP AND KOROR TODAY. MODELS KEEP SOMEWHAT UNSETTLED WEATHER OVER BOTH LOCATIONS THROUGH THE WEEKEND...BUT WITH A LACK OF WELL DEFINED WEATHER FEATURES. FORECAST WILL FOLLOW PERSISTENCE FOR THE LONG TERM WITH MOSTLY CLOUDY SKIES... ISOLATED SHOWERS AND LIGHT SOUTHEAST WINDS PREVAILING. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && $$ MCELROY/M. AYDLETT