From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Thu Oct 28 10:38:31 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 o9S2cUDD025434 for ; Thu, 28 Oct 2010 10:38:30 +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 o9RHpukw021767; Wed, 27 Oct 2010 21:38:14 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4096258 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Wed, 27 Oct 2010 21:38:14 -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 o9S2cE0A002261 for ; Wed, 27 Oct 2010 21:38:14 -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 o9S2c7X6014838 for ; Wed, 27 Oct 2010 21:38:13 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 74F414050024; Wed, 27 Oct 2010 21:38:06 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101028023807.74F414050024@weather3.admin.niu.edu> Date: Wed, 27 Oct 2010 21:38:06 -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 Typhoon 16w Warning Nr 27// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 280300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W WARNING NR 27// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TYPHOON (TY) 16W (CHABA), LOCATED APPROXIMATELY 140 NM SOUTH- SOUTHEAST OF KADENA AIR BASE, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. DESPITE COMPLETING AN EYEWALL REPLACEMENT CYCLE, TY CHABA HAS MANAGED TO INTENSIFY SLIGHTLY WITHIN THE LAST 12 HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS AN ENLARGED, SYMMETRIC 40 NM EYE. INITIAL POSITION WAS BASED ON THE PGTW FIX AND KADENA RADAR FIX. PGTW, KNES, AND RJTD DVORAK ESTIMATES ARE INDICATING INTENSITIES BETWEEN 102 TO 127 KNOTS. THE SYSTEM HAS INTENSIFIED DUE TO DUAL OUTFLOW CHANNELS, WITH AN ENHANCED POLEWARD OUTFLOW CHANNEL INTO AN UPPER LEVEL, MID-LATITUDE TROUGH TO THE NORTHEAST. TY 16W IS CURRENTLY TRACKING ALONG THE NORTHWESTERN PERIPHERY OF A MID-LEVEL SUBTROPICAL STEERING RIDGE TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 16W IS EXPECTED TO CONTINUE TRACKING ALONG THE NORTHWESTERN PERIPHERY OF THE SUBTROPICAL STEERING RIDGE AND CONTINUE TO ROUND THE RIDGE AXIS. WITHIN THE NEXT 12 HOURS THE SYSTEM SHOULD START WEAKENING WITH INCREASING VERTICAL WIND SHEAR, ASSOCIATED WITH A MID- LATITUDE UPPER LEVEL TROUGH TO THE NORTHWEST, AND DECREASING OCEAN HEAT CONTENT. AROUND TAU 24, TY CHABA SHOULD START TO ACCELERATE NORTHEASTWARD AND BEGIN TO INTERACT WITH THE STRONG MID-LATITUDE WESTERLIES. BY TAU 48, TY 16W SHOULD BECOME ABSORBED BY THE BAROCLINIC ZONE AND FULLY TRANSITION INTO AN EXTRATROPICAL LOW, WHCIH IS EVIDENT IN THE 500MB HEIGHT MODEL FIELDS. C. AFTER TAU 48, TY 16W WILL CONTINUE TO TRACK NORTHEASTWARD AS AN EXTRATROPICAL LOW. MODEL GUIDANCE IS IN GOOD AGREEMENT, HOWEVER THIS FORECAST IS JUST SOUTH AND AHEAD OF MODEL CONSENSUS TO ACCOUNT FOR THE TENDENCY OF THE CONSENSUS TO BE SLOW IN A RECURVATURE SCENARIO.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.