From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sat Sep 25 16:29:41 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 o8P8TdDh013831 for ; Sat, 25 Sep 2010 16:29:40 +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 o8P50RDO019148; Sat, 25 Sep 2010 03:29:25 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3583332 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sat, 25 Sep 2010 03:29:25 -0500 Received: from relay02.cites.uiuc.edu (relay02.cites.uiuc.edu [128.174.196.4]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o8P8TPlx004596 for ; Sat, 25 Sep 2010 03:29:25 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay02.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o8P8TI9R008788 for ; Sat, 25 Sep 2010 03:29:24 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 6E6874050022; Sat, 25 Sep 2010 03:29:18 -0500 (CDT) X-Spam-Score: 0 X-Spam-Details: rule=no-quarantine_notspam policy=no-quarantine score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-1005130000 definitions=main-1009250013 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: Message-ID: <20100925082918.6E6874050022@weather3.admin.niu.edu> Date: Sat, 25 Sep 2010 03:29:18 -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 118 FXPQ60 PGUM 250829 AFDPQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TIYAN GU 629 PM CHST SAT SEP 25 2010 .SYNOPSIS... RADAR AND SATELLITE SHOW SCATTERED SHOWERS MAINLY JUST SOUTH OF GUAM...BUT WITH A FEW OF THE SHOWERS MOVING THROUGH THE GUAM/ROTA WATERS. THE BIG FEATURE ON SATELLITE IS THE E-W BAND OF CLOUDS AND SHOWERS EXTENDING FROM SW OF GUAM EASTWARD TO NORTH OF POHNPEI. THIS IS A RESULT OF LOW-LEVEL CONVERGENCE BETWEEN 10-15 KT EASTERLIES NORTH OF THE BAND AND LIGHT SOUTHEAST WINDS SOUTH OF IT. && .DISCUSSION... LATEST GFS IS BIG A DEPARTURE FROM PREVIOUS RUNS...BRINGING QUITE A BIT MORE RAINFALL TO GUAM THAN PREVIOUS VERSIONS...MAINLY FROM THE NORTHERN FRINGES OF THE CONVERGENCE ZONE DESCRIBED ABOVE. IF GFS IS RIGHT...GUAM COULD SEE SCATTERED SHOWERS THE NEXT FEW DAYS WHILE TINIAN AND SAIPAN GET ONLY ISOLATED. HOWEVER...NOGAPS AND UKMET KEEP MOST OF THE SHOWERS SOUTH OF GUAM...CONSISTENT WITH PREVIOUS RUNS. FOR NOW...NOT ENOUGH CONFIDENCE IN GFS TO GO WITH SCATTERED...BUT WITH THE CONVERGENCE ZONE SO CLOSE TO THE SOUTH...HAVE OPTED FOR MOSTLY CLOUDY WITH ISOLATED SHOWERS AND THUNDERSTORMS. WITH WEATHER VERY DEPENDENT ON THE EXACT PLACEMENT OF THE CONVERGENCE ZONE...UNCERTAINTY IS RATHER HIGH FOR THIS FORECAST. BUT IN ANY CASE...GUAM WILL PROBABLY SEE SOMEWHAT MORE RAINFALL THAN ISLANDS TO THE NORTH THE NEXT FEW DAYS. && .MARINE... NORTH SWELL STILL EXPECTED TO ARRIVE IN FORCE LATE SUNDAY NIGHT OR MONDAY...WHICH SHOULD KEEP THE RIP RISK MODERATE ON NORTH FACING REEFS FOR A FEW DAYS. INCREASING TRADE SWELL WILL ALSO KEEP THE RISK MODERATE ON EAST FACING REEFS. && .EASTERN MICRONESIA... AN ITCZ IS STRETCHING ACROSS THE REGION ALONG 9N FROM NORTH OF CHUUK EASTWARD TO THE MARSHALL ISLANDS. SURFACE TROUGHS MIGRATING ALONG THE CONVERGENCE ZONE ARE EXPECTED TO CAUSE PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS FOR MAJURO AND POHNPEI THRU THIS WEEKEND... AND EVENTUALLY OVER CHUUK BY EARLY NEXT WEEK. BEING FARTHER SOUTH OF THE CONVERGENCE ZONE...KOSRAE SHOULD ONLY RECEIVE A PERIOD OF WIDELY SCATTERED SHOWERS SUNDAY EVENING INTO MONDAY. TOWARD MIDWEEK... SLIGHTLY WEAKER TRADES CAN EASE CONVERGENCE-INDUCED SHOWER ACTIVITY FROM EAST TO WEST. && .WESTERN MICRONESIA... WITH TYPHOON MALAKAS MOVED AS FAR NORTH AS EAST OF JAPAN...THE SURFACE RIDGE SOUTH OF IT IS WEAKENING OVER THE PHILIPPINE SEA THIS EVENING. THIS IS ALLOWING TRADE WINDS TO INFILTRATE WESTWARD INTO WESTERN MICRONESIA. CONVERGENCE IN THE VICINITY OF A SURFACE WAVE TRACKING WESTWARD SOUTH OF GUAM WILL COMBINE WITH DIVERGENT WINDS ALOFT TO FIRE UP ISOLATED CONVECTION OVER BOTH YAP AND PALAU FOR THE REST OF THE WEEKEND. AFTERWARD...AN UPPER-LEVEL TROUGH PASSING OVER IS GOING TO MAINTAIN THE CHANCE FOR MORE SHOWERS INTO MIDWEEK. A NORTH SWELL FROM TYPHOON MALAKAS HAS ALREADY REACHED THE MARIANAS AND WILL ALSO ARRIVE AT YAP AND PALAU BY MONDAY. IT IS ANTICIPATED TO CREATE HIGHER SURF ALONG NORTH FACING SHORES BUT SHOULD REMAIN BELOW ADVISORY LEVELS. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && $$ MIDDLEBROOKE/CHAN +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.