From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Wed Oct 20 05:28:11 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 o9JLSANw002580 for ; Wed, 20 Oct 2010 05:28:11 +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 o9JFe7Th019088; Tue, 19 Oct 2010 16:27:55 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3956925 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Tue, 19 Oct 2010 16:27:54 -0500 Received: from relay09.cites.uiuc.edu (relay09.cites.uiuc.edu [128.174.4.86]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o9JLRre1022841 for ; Tue, 19 Oct 2010 16:27:53 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay09.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o9JLRlwo027910 for ; Tue, 19 Oct 2010 16:27:53 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 7F166108B0002; Tue, 19 Oct 2010 16:27:45 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101019212746.7F166108B0002@weather3.admin.niu.edu> Date: Tue, 19 Oct 2010 16:27:45 -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 498 FXPQ60 PGUM 192127 AFDPQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TIYAN GU 727 AM CHST WED OCT 20 2010 .SYNOPSIS... PGUA WSR-88D SHOWS SCATTERED SHOWERS ASSOCIATED WITH A TROPICAL DISTURBANCE MOVING INTO THE MARIANAS FROM THE NORTHEAST. WINDS IN THE MARIANAS HAVE TURNED TO THE SOUTHWEST AND PRESSURES HAVE FALLEN AS THE WEAK CIRCULATION COMES NEAR. && .DISCUSSION... THIS WEAK CIRCULATION SHOULD BE AT ITS PEAK NOW...IT IS MOVING INTO A REGION OF INCREASED VERTICAL WIND SHEAR AND SUBSIDENCE. IT WOULD HAVE TO SIGNIFICANTLY MODIFY ITS ENVIRONMENT TO HAVE A GOOD SHOT AT DEVELOPING FURTHER. WHILE THIS IS POSSIBLE...IT IS NOT EXPECTED. NEVERTHELESS...ON RADAR AT 4 AM IT SEEMED LIKE A GOOD IDEA TO UPGRADE TINIAN AND SAIPAN TO SCATTERED SHOWERS. MOST LIKELY CAUSE FOR ANY UPDATES WOULD BE IF IT BECAME NECESSARY TO EXTEND THE SCATTERED SHOWERS TO GUAM AND ROTA. AT THE NEXT ISSUANCE IT MAY ALSO BE NECESSARY TO EXTEND THE SHOWERS IN TIME... DEPENDING ON HOW THE SITUATION DEVELOPS ON RADAR AND SATELLITE. THE SHEAR AND OTHER HAMPERING ENVIRONMENTAL FEATURES ARE WHY JTWC HAS LISTED THIS AS A POOR AREA FOR TROPICAL DEVELOPMENT VS A FAIR. && .EASTERN MICRONESIA... ONCE AGAIN...FEW CHANGES MADE TO THE FORECASTS AS PREVIOUS FORECASTS REMAIN WELL SUPPORTED BY CURRENT MODEL DATA AND SATELLITE IMAGERY. WITH THE UPPER LOW JUST SW OF WAKE ISLAND PUSHING WESTWARD AND SE WINDS AT THE SURFACE SPREADING FROM EAST TO WEST...NO MORE THAN ISOLATED SHOWERS ARE EXPECTED AT EACH LOCATION. GFS HAS REMAINED CONSISTENT DEPICTING A WEAK TROUGH MOVING THROUGH THE REGION IN A COUPLE OF DAYS. FOR NOW...THE TROUGH IS ONLY EXPECTED TO INCREASE CLOUD COVER AT MAJURO FOR LATE THU THROUGH SAT AND POHNPEI OVER THE WEEKEND. && .WESTERN MICRONESIA... LATEST ASCAT PASS SHOWS THE WEAK CIRCULATION NEAR YAP WITH LIGHT WEST WINDS NEAR KOROR. MOST CONVECTION HAS DISSIPATED NEAR YAP AND KOROR WITH A FEW SHOWERS AND THUNDERSTORMS CONTINUING ABOUT 300 MILES EAST OF YAP. ALTHOUGH MODELS DO NOT AGREE ON WHETHER THE CIRCULATION WILL LIFT NORTHWARD TOWARD GUAM OR PASS WESTWARD AS A TROUGH...THEY DO MELD TOGETHER BY PROGGING SHOWERS TO STAY IN THE AREA SOUTH OF GUAM...KEEPING KOROR...YAP AND CHUUK WITH JUST ISOLATED SHOWERS FOR THE REST OF THE WEEK. HOWEVER...LOW CONFIDENCE IN MODEL PERFORMANCE CONCERNING THE INTERACTION BETWEEN THE YAP CIRCULATION AND THE CIRCULATION EAST OF SAIPAN CREATES A FAIR AMOUNT OF UNCERTAINTY CONCERNING THE POSSIBLE DEVELOPMENT OF AND LOCATION OF SCATTERED SHOWERS DURING THE NEXT SEVERAL DAYS SO THE SITUATION WILL NEED TO BE WATCHED CLOSELY FOR ANY DEVELOPMENTAL CHANGES. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && $$ STANKO/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.