From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sun Dec 12 21:38:34 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 oBCDcWcc012583 for ; Sun, 12 Dec 2010 21:38:33 +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 oBC6tjgw027712; Sun, 12 Dec 2010 07:38:19 -0600 (CST) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4737226 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sun, 12 Dec 2010 07:38:19 -0600 Received: from relay07.cites.uiuc.edu (relay07.cites.uiuc.edu [128.174.4.73]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id oBCDcI9q009849 for ; Sun, 12 Dec 2010 07:38:18 -0600 (CST) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay07.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id oBCDcCX2011385 for ; Sun, 12 Dec 2010 07:38:18 -0600 (CST) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 6DAC33FE0856; Sun, 12 Dec 2010 07:38:12 -0600 (CST) X-Proofpoint-Spam-Reason: safe Message-ID: <20101212133812.6DAC33FE0856@weather3.admin.niu.edu> Date: Sun, 12 Dec 2010 07:38:12 -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 19w To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN31 PGTW 121500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 19W /WARNING NR 01// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 19W, LOCATED APPROXIMATELY 325 NM EAST OF HO CHI MINH, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY INDICATES THAT TD 19W HAS CONSOLIDATED OVER THE PAST 06 HOURS WITH IMPROVED CONVECTIVE BANDING OVER THE SOUTHERN SEMI- CIRCLE WRAPPING INTO A DEFINED LOW-LEVEL CIRCULATION CENTER. THE IMPROVED ORGANIZATION IS CLEARLY EVIDENT IN A 120913Z SSMI IMAGE, WHICH SHOWS DEEP CONVECTIVE BANDING NORTHWEST WRAPPING INTO THE SOUTHEAST QUADRANT AND WELL-DEFINED LOW-LEVEL BANDING IN ALL OTHER QUADRANTS. TD 19W IS LOCATED SOUTH OF THE UPPER- LEVEL RIDGE AXIS AND IS UNDER LIGHT TO MODERATE, EASTERLY VERTICAL WIND SHEAR. SUBSEQUENTLY, OUTFLOW IS PREDOMINANTLY POLEWARD AND IS CONFINED TO THE WESTERN SEMI-CIRCLE. THERE IS FAIR CONFIDENCE IN THE CURRENT POSITION BASED ON THE 120913Z SSMI IMAGE. THE CURRENT INTENSITY OF 25 KNOTS IS BASED ON DVORAK ESTIMATES OF T1.5 (25 KNOTS) FROM BOTH PGTW AND KNES. 3. FORECAST REASONING. A. THIS IS THE FIRST PROGNOSTIC REASONING BULLETIN. B. TD 19W IS TRACKING WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE LOW-LEVEL (700 MB) SUBTROPICAL RIDGE (STR) POSITIONED NORTH OF THE SYSTEM. THE 12/00Z 700MB ANALYSIS SHOWS THE STR EXTENDING ACROSS THE NORTHERN SOUTH CHINA SEA INTO NORTHERN VIETNAM. AVAILABLE MODEL GUIDANCE (TO INCLUDE NOGAPS, ECMWF, GFS, JGSM AND UKMO) IS CONSISTENT IN MAINTAINING THE STR THROUGH THE FORECAST PERIOD, THEREFORE, TD 19W IS FORECAST TO CONTINUE TRACKING WESTWARD. THE SYSTEM SHOULD MAKE LANDFALL OVER VIETNAM NEAR TAU 36 AND IS EXPECTED TO DISSIPATE BY TAU 48.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.