From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Fri Sep 24 10:18:23 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 o8O2IMnv024309 for ; Fri, 24 Sep 2010 10:18:23 +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 o8N50q1U015719; Thu, 23 Sep 2010 21:18:12 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3562510 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Thu, 23 Sep 2010 21:18:12 -0500 Received: from relay01.cites.uiuc.edu (relay01.cites.uiuc.edu [128.174.4.23]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o8O2IBPb008270 for ; Thu, 23 Sep 2010 21:18:11 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay01.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o8O2I5s0016255 for ; Thu, 23 Sep 2010 21:18:11 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 07332405001E; Thu, 23 Sep 2010 21:18:04 -0500 (CDT) X-Spam-Score: 5 X-Spam-Details: rule=no-quarantine_notspam policy=no-quarantine score=5 spamscore=5 ipscore=0 phishscore=0 bulkscore=0 adultscore=3 classifier=spam adjust=0 reason=mlx engine=5.0.0-1005130000 definitions=main-1009230239 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: * Message-ID: <20100924021805.07332405001E@weather3.admin.niu.edu> Date: Thu, 23 Sep 2010 21:18:04 -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 16// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 240300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W WARNING NR 16// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TYPHOON (TY) 13W (MALAKAS), LOCATED APPROXIMATELY 40 NM WEST-SOUTHWEST OF IWO TO, JAPAN, HAS TRACKED NORTHWARD AT 16 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 232253Z SSMIS MICROWAVE IMAGE SHOW A LARGE RAGGED EYE WITH MULTIPLE CONVECTIVE BANDS WRAPPING AROUND THE SOUTHEASTERN TO NORTHERN PERIPHERY. THE INITIAL POSITION IS BASED ON A 232216Z ITOP VORTEX MESSAGE AS WELL AS A PGTW FIX. THE INITIAL INTENSITY IS BASED ON DVORAK ESTIMATES FROM PGTW AND RJTD RANGING FROM 77 TO 90 KNOTS. SURFACE LEVEL WIND OBSERVATIONS AT 240048Z FROM IWO JO ARE REPORTING 49 KNOT WINDS WITH 98 KNOT GUSTS. INCREASED POLEWARD OUTFLOW INTO A MID-LATITUDE UPPER LEVEL TROUGH TO THE NORTHWEST AND GOOD EQUATORWARD OUTFLOW HAS ALLOWED TY 13W TO INTENSIFY BY 10 KNOTS OVER THE PAST SIX HOURS. 3. FORECAST REASONING. A. THIS FORECAST PREDICTS A HIGHER MAXIMUM INTENSITY THAN THE PREVIOUS FORECAST BASED ON THE INTENSIFICATION TREND. B. TY 13W IS EXPECTED TO CONTINUE TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE AND INTENSIFY OVER THE NEXT 12 HOURS AS POLEWARD OUTFLOW INCREASES INTO THE APPROACHING UPPER LEVEL TROUGH. BY TAU 24, TY 13W SHOULD BEGIN TO ROUND THE RIDGE AXIS AND BEGIN TO INTERACT WITH THE MID-LATITUDE WESTERLIES. BY TAU 48, TY MALAKAS IS FORECAST TO BECOME ABSORBED BY THE STRONG BAROCLINIC ZONE TO THE NORTH. WITH THE UPPER LEVEL SUPPORT OF THE MID-LATITUDE TROUGH, TY 13W IS EXPECTED TO TRANSITION INTO AN INTENSE EXTRATROPICAL LOW. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT. THEREFORE, THIS FORECAST IS IN AGREEMENT WITH 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.