From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Mon Sep 20 15:46:14 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 o8K7kDKC002647 for ; Mon, 20 Sep 2010 15:46:13 +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 o8K50F8i028356; Mon, 20 Sep 2010 02:45:50 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3482577 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Mon, 20 Sep 2010 02:45:49 -0500 Received: from relay10.cites.uiuc.edu (relay10.cites.uiuc.edu [128.174.196.10]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o8K7jmFp009785 for ; Mon, 20 Sep 2010 02:45:48 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay10.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o8K7jfGI024326 for ; Mon, 20 Sep 2010 02:45:47 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 46F2B405001E; Mon, 20 Sep 2010 02:45:41 -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-1009200006 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: Message-ID: <20100920074541.46F2B405001E@weather3.admin.niu.edu> Date: Mon, 20 Sep 2010 02:45:41 -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 689 FXPQ60 PGUM 200745 AFDPQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TIYAN GU 545 PM CHST MON SEP 20 2010 .SYNOPSIS... PGUA WSR-88D SHOWS SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS SOUTH OF A TROPICAL DISTURBANCE MOVING THROUGH THE MARIANAS WATERS. THE TROPICAL DISTURBANCE IS CENTERED NEAR 19N AND 146E...AND REMAINS THE SUBJECT OF A TROPICAL CYCLONE FORMATION ALERT RECENTLY RENEWED BY THE JOINT TYPHOON WARNING CENTER. ELSEWHERE...TRADE-WIND CONVERGENCE IS COMBINING WITH UPPER-LEVEL DIVERGENCE SOUTH OF THE TROPICAL UPPER TROPOSPHERIC TROUGH /TUTT/ TO CREATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NEAR YAP AND PALAU BETWEEN 3N AND 17N FROM 130E TO 143E AND NEAR KOSRAE AND THE MARSHALL ISLANDS BETWEEN 5N AND 11N FROM 159E TO 171E. && .DISCUSSION... INVEST AREA 90W HAD ITS TROPICAL CYCLONE FORMATION ALERT RENEWED. IF IT MAINTAINS THE DEEP CONVECTION IT HAS HELD ON TO FOR A GOOD 12 HOURS NOW IT WILL COOK OFF AND BECOME A TROPICAL CYCLONE. BY THE TIME IT ACHIEVED GALE FORCE WINDS IT SHOULD BE WEST OF THE MARIANAS THOUGH...SO STILL NO WATCHES OR WARNINGS ARE EXPECTED. GFS40 MODEL SHOWS THAT 90W WAS UNDER 15 TO 20 KNOTS OF VERTICAL SHEAR THIS MORNING. THAT SHEAR HAS SINCE RELAXED A BIT WHICH HAS ALLOWED THE CONVECTION TO REMAIN MORE STABLE AND NEARER TO THE CIRCULATION CENTER. THE SHEAR IS EXPECTED TO RELAX EVEN FURTHER THIS EVENING SO WOULD NOT BE SURPRISED TO SEE IT WARNED ON WITHIN THE NEXT 18 TO 21 HOURS. THE HEAVY RAIN IS NOW POISED TO PASS NORTH OF SAIPAN INTO THE FAR NORTHERN MARIANAS. WENT AHEAD AND REFRESHED THE SPECIAL WEATHER STATEMENT TO EMPHASIZE THIS. NOW THAT THE SYSTEM IS MOVING AND THE WORST SHOWERS WILL MISS THE PUBLIC AND COASTAL FORECAST ZONES SHORTENED THE SCATTERED SHOWERS TO NOON TUESDAY INSTEAD OF TUESDAY EVENING. AFTER THE SYSTEM PASSES BY SOME CLOUDS WILL REMAIN FOR A DAY OR TWO...THEN A RETURN TO THE RATHER LACKLUSTER WET SEASON WE HAVE ALREADY BEEN EXPERIENCING. NO OTHER CHANGES WERE NECESSARY AS THE PREVIOUS GRID PACKAGE HAD A SIMILAR PHILOSOPHY. && .EASTERN MICRONESIA... EXTENSIVE CLOUDINESS AND SOME SHOWERS BETWEEN KWAJALEIN AND POHNPEI IS ALL THAT REMAINS FROM THE BELT OF CONVECTION EARLIER TODAY. SCATTERED SHOWERS ACROSS KOSRAE AND POHNPEI HAVE ENDED WITH DRIER CONDITIONS EXPECTED THROUGH THE WEEKEND. GFS BUILDS SOUTHEASTERLY FLOW ACROSS THE REGION WITH THE BULK OF CONVECTION NORTH OF ALL LOCATIONS THROUGH SATURDAY. && .WESTERN MICRONESIA... SCATTERED SHOWERS FOR CHUUK WERE REDUCED TO ISOLATED TONIGHT AS DEEP CONVECTION DISSOLVES ACROSS THE AREA TOWARDS POHNPEI. SCATTERED SHOWERS COULD RETURN TOMORROW AS EASTERLY FLOW BUILDS AND CONVERGES WITH THE SOUTHEAST FLOW NORTH AND WEST OF CHUUK. SCATTERED SHOWERS AND THUNDERSTORMS EXIST WEST OF CHUUK IN RELATION TO JTWC INVEST AREA 90W...WITH ITS CENTER NEAR PAGAN. SHOWERS AND STORMS WEST OF CHUUK WILL MOVE OUT AS THE SYSTEM MOVES NORTHWEST. A NORTH-SOUTH ORIENTED TROUGH BETWEEN YAP AND PALAU HAS KEPT SHOWERS AND THUNDERSTORMS IN PLACE ACROSS THE REGION TODAY. SOUTHERLY FLOW AND SHOWERS WILL GRADUALLY GIVE WAY TO EASTERLY FLOW AND DRIER CONDITIONS BY TUESDAY NIGHT. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && $$ STANKO/M. 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.