From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Tue Oct 19 05:15:08 2010 Received: from vacuum.cso.uiuc.edu (vacuum.cso.uiuc.edu [128.174.5.113]) by cozumel.ust.hk (8.13.8/8.13.8) with ESMTP id o9ILF7KX007936 for ; Tue, 19 Oct 2010 05:15:08 +0800 Received: from vacuum.cso.uiuc.edu (vacuum.cso.uiuc.edu [128.174.5.113]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o9IGFWpA022864; Mon, 18 Oct 2010 16:14:51 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3942516 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Mon, 18 Oct 2010 16:14:51 -0500 Received: from relay04.cites.uiuc.edu (relay04.cites.uiuc.edu [128.174.196.5]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o9ILEpsK024097 for ; Mon, 18 Oct 2010 16:14:51 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay04.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o9ILEiML013542 for ; Mon, 18 Oct 2010 16:14:50 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 8C0F840501A6; Mon, 18 Oct 2010 16:14:44 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101018211444.8C0F840501A6@weather3.admin.niu.edu> Date: Mon, 18 Oct 2010 16:14:44 -0500 Reply-To: wxmaster@COX.NET Sender: WX-TROPL Tropical Storm and Hurricane WX products From: LDM Weather Subject: Western Pacific: Synoptic Discussion For The Marianas To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list 746 FXPQ60 PGUM 182114 AFDPQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TIYAN GU 714 AM CHST TUE OCT 19 2010 .SYNOPSIS...LIGHT WINDS AND ISOLATED SHOWERS ARE PRESENT ACROSS THE MARIANAS THIS MORNING. A SURFACE TROUGH OF LOW PRESSURE IS LOCATED JUST TO THE EAST OF THE ISLANDS WHILE AN UPPER-LEVEL TROUGH LIES JUST WEST OF THE LOCAL AREA. && .DISCUSSION... EXPECT LIGHT WINDS TO PREVAIL TODAY THROUGH WEDNESDAY AS A SURFACE TROUGH MOVES ACROSS THE MARIANAS. DIFFERENT MODELS HAVE VARIOUS VIEWS ON WHAT TO DO WITH THE SURFACE TROUGH JUST TO THE EAST OF THE MARIANAS. WHILE IT IS TRUE THAT THERE IS A CIRCULATION ON THE TROUGH...FIGURE THAT IT IS TOO FAR NORTH AND IF IT MOVES OVER THE AREA IT WILL BE NORTH OF SAIPAN. IN THE FORECAST TRIED TO DEPICT A SURFACE TROUGH MOVING ACROSS THE MARIANAS THROUGH WEDNESDAY. THIS WILL KEEP WINDS LIGHT TODAY AND TONIGHT. LIGHT WINDS AND DAYTIME HEATING COMBINED WITH THE UPPER-TROUGH OVER THE AREA WILL LEAD TO THE POSSIBILITY OF THUNDERSTORMS THIS AFTERNOON. THUNDERSTORMS MAY LINGER INTO TONIGHT. ONLY ISOLATED SHOWERS EXPECTED THROUGH THE FOR EAST. && .MARINE... EAST TRADE-WIND SWELL WILL PERSIST THROUGH THE FORECAST. THE SWELL BRIEFLY INCREASES TO FIVE FEET WEDNESDAY THROUGH THURSDAY. THIS WILL CAUSE A SHORT TIME PERIOD OF MODERATE RIP CURRENT RISK ON EAST FACING SHORES. AT THIS TIME IT IS BELIEVED THAT NO SIGNIFICANT SWELLS WILL ENTER THE AREA FROM TYPHOON MEGI. && .EASTERN MICRONESIA... WITH THE EXCEPTION OF SOME MINOR ADJUSTMENTS TO WINDS AND CLOUD COVER...NO CHANGES WERE MADE TO THE EXISTING FORECAST. MODELS PRETTY WELL AGREE THAT ALL THREE LOCATIONS WILL REMAIN FAIRLY DRY WITH SOUTHEAST FLOW SPREADING WESTWARD FROM MAJURO. WINDS AT POHNPEI WILL BE VARIABLE TODAY BEFORE TURNING SOUTHEAST...BUT EXACT TIMING DEPENDS ON HOW QUICKLY THE NEARLY-STATIONARY TROUGH AND WEAK CIRCULATION NORTH OF KWAJALEIN NEAR 12N169E...JTWC INVEST AREA 96W...PUSHES WEST-NORTHWESTWARD. A MID- AND UPPER-LEVEL LOW JUST SOUTH OF WAKE ISLAND HAS ALSO HELPED TO DEEPEN CONVECTION FROM KWAJALEIN NORTH...BUT CONVECTION SHOULD REMAIN NORTH OF POHNPEI AND MAJURO THROUGH THE WEEK. ANOTHER SURFACE TROUGH WILL APPROACH THE MARSHALLS AROUND THURSDAY LEADING TO INCREASED CLOUD COVER...BUT FOR NOW IS NOT EXPECTED TO SIGNIFICANTLY INCREASE THE CHANCE FOR SHOWERS. && .WESTERN MICRONESIA... A LINE OF SHOWERS SEEN IN SATELLITE IMAGERY JUST WEST OF KOROR PROMPTED THE ADDITION OF SCATTERED SHOWERS FOR TODAY. THE SHOWERS WILL LIKELY BE ACCOMPANIED BY WEAK WEST WINDS. ONLY GFS HINTS AT THE EXISTENCE OF THESE SHOWERS AND KEEPS THEM IN PLACE VERY BRIEFLY TODAY BEFORE ERODING THEM OUT OF THE PICTURE. A FEW CONVECTIVE CELLS HAVE RECENTLY DEVELOPED EAST OF YAP ALONG A TROUGH THAT STRETCHES NORTHEASTWARD TO A CIRCULATION EAST OF THE MARIANAS NEAR 17N154E. MODELS PROG THE CIRCULATION TO DROP WEST-SOUTHWESTWARD THE NEXT SEVERAL DAYS WHILE THE SOUTHERN END OF THE TROUGH MOVES VERY SLOWLY WESTWARD. FOR NOW...MODELS SUGGEST THE MAIN EFFECT THE TROUGH WILL HAVE ON YAP AND KOROR WILL BE LIGHT AND VARIABLE WINDS. LITTLE CHANGE IS EXPECTED AT CHUUK AS DRY SOUTHEAST WINDS PERSIST THROUGH THE REST OF THE WEEK. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && $$ ZIOBRO/W. AYDLETT +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from WX-TROPL send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with "unsub wx-tropl" in the body of your message. For help with WX-TROPL write to cnovy@cox.net. For more information on tropical weather products, see the NHC Homepage at http://www.nhc.noaa.gov.