From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Thu Oct 28 21:43:30 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 o9SDhTQ5031720 for ; Thu, 28 Oct 2010 21:43:30 +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 o9S8U9AV021767; Thu, 28 Oct 2010 08:43:16 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4102346 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Thu, 28 Oct 2010 08:43:16 -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 o9SDhGmE017032 for ; Thu, 28 Oct 2010 08:43:16 -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 o9SDh9mG018580 for ; Thu, 28 Oct 2010 08:43:15 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 9C3DD405001F; Thu, 28 Oct 2010 08:43:09 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101028134309.9C3DD405001F@weather3.admin.niu.edu> Date: Thu, 28 Oct 2010 08:43:09 -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 29// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 281500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W WARNING NR 29// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TYPHOON (TY) 16W (CHABA), LOCATED APPROXIMATELY 130 NM EAST- SOUTHEAST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHEASTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED WATER VAPOR SATELLITE IMAGERY SHOWS THE SYSTEM REMAINED SYMMETRIC AS THE TIGHTLY-WRAPPED DEEP CONVECTIVE BANDS AROUND THE LOW LEVEL CIRCULATION CENTER CONSTRICTED. THE 10 NM EYE HAS BECOME CLOUD-FILLED OVER THE PAST THREE HOURS INDICATING AN INITIAL WEAKENING TREND. THE CURRENT POSITION WAS BASED ON THE 281130Z PGTW EYE FIX AND SUPPORTED BY KADENA RADAR FIXES. THE CURRENT INTENSITY IS AVERAGED FROM PGTW, KNES, AND RJTD DVORAK ESTIMATES RANGING FROM 102 TO 115 KNOTS. RADIAL OUTFLOW APPEARS TO BE DIMINISHING AS THE SYSTEM TRACKS 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 CHABA IS EXPECTED TO CONTINUE TRACKING NORTHEASTWARD, COMMENCE EXTRATROPICAL TRANSITION (ET) BY TAU 36 AND COMPLETE ET BY TAU 48. THE SYSTEM WILL START WEAKENING WITH INCREASING VERTICAL WIND SHEAR ASSOCIATED WITH A MIDLATITUDE UPPER LEVEL TROUGH TO THE NORTHWEST, AND DECREASING OCEAN HEAT CONTENT. AFTER TAU 24, TY 16W WILL START TO ACCELERATE NORTHEASTWARD AND BEGIN TO INTERACT WITH THE STRONG MID-LATITUDE WESTERLIES. MODEL GUIDANCE IS IN GOOD AGREEMENT, EXCEPT GFDN ACTING AS THE SOLE OUTLIER TO THE LEFT OF THE MODEL ENVELOPE. THIS FORECAST IS JUST TO THE RIGHT AND AHEAD OF MODEL CONSENSUS TO OFFSET GFDN'S UNLIKELY PULL TO THE LEFT AND 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.