From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sat Oct 23 22:17:33 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 o9NEHW2h022876 for ; Sat, 23 Oct 2010 22:17:32 +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 o9MGVYlw001368; Sat, 23 Oct 2010 09:17:20 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4010038 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sat, 23 Oct 2010 09:17:19 -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 o9NEHJSA000511 for ; Sat, 23 Oct 2010 09:17:19 -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 o9NEHCS3006892 for ; Sat, 23 Oct 2010 09:17:18 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 9E85A108B0002; Sat, 23 Oct 2010 09:17:12 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101023141712.9E85A108B0002@weather3.admin.niu.edu> Date: Sat, 23 Oct 2010 09:17:12 -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 Depression 16w Warning Nr 09// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 231500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W WARNING NR 09// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 16W (SIXTEEN), LOCATED APPROXIMATELY 640 NM SOUTH-SOUTHEAST OF OKINAWA, JAPAN, HAS TRACKED WEST-NORTHWEST- WARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED WATER VAPOR SATELLITE IMAGERY SHOWS THE SYSTEM HAS STRUGGLED TO MAINTAIN DEEP CONVECTION DUE TO MODERATE VERTICAL WIND SHEAR (VWS) AND SUBSIDENT FLOW FROM THE NORTH INDUCED BY A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT). THE INITIAL POSITION IS BASED ON ANIMATED SATELLITE IMAGERY AND ON A 231105Z SSMI-S MICROWAVE PASS WITH POOR CONFIDENCE. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE IN FORECAST PHILOSOPHY SINCE THE PREVIOUS BULLETIN. B. TD 16W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF A LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR) TO THE NORTH AND IS EXPECTED TO TRACK MORE POLEWARD BY TAU 36 AS IT BEGINS TO ROUND THE STR TOWARDS RECURVATURE IN RESPONSE TO AN APPROACHING MID-LATITUDE TROUGH. AS THE TUTT MENTIONED IN PARA 2.A. MOVES WESTWARD, THE VWS AND SUBSIDENCE WILL DECREASE, ALLOWING THE SYSTEM TO STEADILY INTENSIFY. C. BEYOND TAU 72, TD 16W WILL CONTINUE TO TRACK POLEWARD ALONG THE WESTERN PERIPHERY OF THE STEERING RIDGE. THE SYSTEM WILL FURTHER INTENSIFY AS POLEWARD OUTFLOW INITIALLY IMPROVES WITH THE SYSTEM'S EXPOSURE TO THE UPPER LEVEL WESTERLIES. THE AVAILABLE NUMERIC GUIDANCE IS SPLIT WITH NOGAPS, GFS, UKMO, AND ECMWF FAVORING A POLEWARD TURN WHILE GFDN AND JGSM ARE TRACKING THE SYSTEM STRAIGHT TOWARDS THE WEST ALONG A PRESUMABLY STRONGER STR. THIS FORECAST IS IN AGREEMENT WITH THE MODELS TRACKING MORE POLEWARD IN ANTICIPATION OF THE MID-LATITUDE TROUGH THAT IS CURRENTLY MOVING ACROSS SOUTHEAST CHINA.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.