From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sat Nov 13 21:43:57 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 oADDhuL6022606 for ; Sat, 13 Nov 2010 21:43:57 +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 oAD35YUi006383; Sat, 13 Nov 2010 07:43:18 -0600 (CST) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4347397 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sat, 13 Nov 2010 07:43:18 -0600 Received: from relay10.cites.uiuc.edu (relay10.cites.uiuc.edu [128.174.196.10]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id oADDhIU2016739 for ; Sat, 13 Nov 2010 07:43:18 -0600 (CST) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay10.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id oADDhBAa016623 for ; Sat, 13 Nov 2010 07:43:17 -0600 (CST) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 8265B4050023; Sat, 13 Nov 2010 07:43:11 -0600 (CST) X-Proofpoint-Spam-Reason: safe Message-ID: <20101113134311.8265B4050023@weather3.admin.niu.edu> Date: Sat, 13 Nov 2010 07:43:11 -0600 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 18w Warning Nr 04// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN31 PGTW 131500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 18W WARNING NR 04// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 18W, LOCATED APPROXIMATELY 210NM SOUTHEAST OF HUE CITY, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 05 KNOTS DURING THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON A 131130Z PGTW SATELLITE FIX AND A 131110Z 37GHZ SSMIS MICROWAVE IMAGE. THE CURRENT INTENSITY ESTIMATE OF 25 KNOTS IS BASED ON A DVORAK ESTIMATE OF 20-25 KNOTS FROM PGTW. BOTH ANIMATED INFRARED IMAGERY AND MICROWAVE IMAGERY INDICATE CONVECTION IS WANING AND BECOMING MORE DISORGANIZED. THE LOW LEVEL CIRCULATION CENTER EXISTS UNDER 20-25 KNOTS OF VERTICAL WINDSHEAR (VWS) AND IS MOVING INTO AN AREA OF INCREASING VWS. ANIMATED WATER VAPOR IMAGERY INDICATES A VIGOROUS POLEWARD OUTFLOW CHANNEL REMAINS ON THE NORTHEAST SIDE OF THE SYSTEM, WHILE SUBSIDENCE AHEAD OF AN ENCROACHING SHORTWAVE IS SUPPRESSING OUTFLOW OVER THE NORTHWEST QUADRANT. 3. FORECAST REASONING: A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST REASONING FOR TD 18W. B. TD 18W IS TRACKING SLOWLY WEST-NORTHWESTWARD UNDER THE INFLUENCE OF THE LOW TO MID-LEVEL SUBTROPICAL RIDGE. DYNAMIC AIDS ARE IN GOOD AGREEMENT IN SUSTAINING THIS TRACK THROUGH TAU 12, WHEN TD 18 WILL MAKE LANDFALL OVER CENTRAL VIETNAM AND DISSIPATE OVER LAND. THE COMPETING INFLUENCES OF VIGOROUS POLEWARD OUTFLOW OVER THE NORTHEAST SIDE AND INCREASING VERTICAL WINDSHEAR ARE EXPECTED TO BALANCE OVER THE SHORT TERM, KEEPING THE SYSTEM AT ITS CURRENT INTENSITY THROUGH LANDFALL. AFTER TAU 12, THE CYCLONE WILL MOVE INLAND AND DISSIPATE. // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.