From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Thu Sep 23 22:31:27 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 o8NEVQVV003924 for ; Thu, 23 Sep 2010 22:31:26 +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 o8N3LhS6028356; Thu, 23 Sep 2010 09:31:12 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3552039 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Thu, 23 Sep 2010 09:31:12 -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 o8NEVB2j011289 for ; Thu, 23 Sep 2010 09:31:11 -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 o8NEV439008538 for ; Thu, 23 Sep 2010 09:31:11 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 5F3B2405001E; Thu, 23 Sep 2010 09:31:04 -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=2 classifier=spam adjust=0 reason=mlx engine=5.0.0-1005130000 definitions=main-1009230092 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: Message-ID: <20100923143104.5F3B2405001E@weather3.admin.niu.edu> Date: Thu, 23 Sep 2010 09:31:04 -0500 Reply-To: wxmaster@COX.NET Sender: WX-TROPL Tropical Storm and Hurricane WX products From: SIU Weather Processor Subject: Pacific-NW: Subj/prognostic Reasoning For Tropical Storm 13w Warning Nr 14// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 231500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W WARNING NR 14// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 13W (MALAKAS), LOCATED APPROXIMATELY 170 NM SOUTH OF IWO TO, JAPAN, HAS TRACKED NORTHWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS A BANDING EYE FEATURE WITH CONVECTION RE-BUILDING OVER THE SYSTEM CENTER. A 231021Z 37 GHZ SSMIS PASS AND A 231032Z 37 GHZ TRMM PASS DEPICT A FORMATIVE MICROWAVE EYE AND CONFIRM THE CURRENT POSITION WITH FAIR CONFIDENCE. THE CURRENT INTENSITY REMAINS AT 60 KNOTS BASED ON DVORAK ESTIMATES RANGING FROM 55 TO 65 KNOTS FROM PGTW, KNES, AND RJTD. UPPER LEVEL ANALYSIS INDICATES THE SUBSIDENCE PREVIOUSLY HINDERING CONVECTION ALONG THE WESTERN PERIPHERY OF THE SYSTEM HAS DECREASED ALLOWING FOR GOOD RADIAL OUTFLOW. TS 13W IS CURRENTLY TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL STEERING RIDGE ANCHORED OVER THE NORTHERN PACIFIC. 3. FORECAST REASONING. A. THE FORECAST REASONING HAS NOT CHANGED SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TS 13W IS FORECAST TO CONTINUE TRACKING POLEWARD AS IT ROUNDS THE RIDGE AXIS AND BEGINS TO INTERACT WITH THE STRONG BAROCLINIC ZONE TO THE NORTH. THE SYSTEM IS EXPECTED TO INTENSIFY THROUGH TAU 36 DUE TO ENHANCED POLEWARD OUTFLOW INTO THE MID-LATITUDE WESTERLIES. DURING EXTRA-TROPICAL TRANSITION (ET), TS 13W IS EXPECTED TO REMAIN INTENSE, AS STRONG UPPER LEVEL DIFFLUENCE AND A SHARP TEMPERATURE GRADIENT ASSOCIATED WITH THE APPROACHING UPPER LEVEL TROUGH PROVIDE A STRONG BAROCLINIC DEVELOPMENT MECHANISM. TS 13W IS EXPECTED TO COMPLETE ET BY TAU 72 AS AN INTENSE EXTRA- TROPICAL LOW. NUMERICAL MODEL GUIDANCE REMAINS IN STRONG AGREEMENT; THEREFORE THIS FORECAST IS CLOSE TO MODEL CONSENSUS.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.