From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Fri Sep 3 22:13:29 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 o83EDSQW020322 for ; Fri, 3 Sep 2010 22:13:29 +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 o8350MMo019570; Fri, 3 Sep 2010 09:13:17 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3214125 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Fri, 3 Sep 2010 09:13:17 -0500 Received: from relay04.cites.uiuc.edu (relay04.cites.uiuc.edu [128.174.196.5]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o83EDH1F004439 for ; Fri, 3 Sep 2010 09:13:17 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay04.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o83ED9iE023562 for ; Fri, 3 Sep 2010 09:13:16 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 4252C4050021; Fri, 3 Sep 2010 09:13:08 -0500 (CDT) X-Spam-Score: 0 X-Spam-Details: rule=no-quarantine_notspam policy=no-quarantine score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-1005130000 definitions=main-1009030069 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: Message-ID: <20100903141309.4252C4050021@weather3.admin.niu.edu> Date: Fri, 3 Sep 2010 09:13:08 -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 Storm 10w Warning Nr 08// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN33 PGTW 031500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W WARNING NR 08// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 10W (MALOU), LOCATED APPROXIMATELY 130 NM SOUTHEAST OF KADENA AB, OKINAWA JAPAN, HAS TRACKED WEST-NORTHWEST- WARD AT 20 KNOTS OVER THE PAST SIX HOURS. ANIMATED WATER VAPOR IMAGERY SHOWS MODERATE OUTFLOW ON THE NORTHEAST QUADRANT WITH SUSTAINED DEEP CONVECTION THAT IS MOSTLY TO THE SOUTHEAST OF THE LOW LEVEL CIRCULATION CENTER (LLCC). THE SAME ANIMATION ALSO SHOWS A TUTT CELL TO THE WEST THAT IS IMPINGING THE OUTFLOW ALONG THE WESTERN FLANK OF THE SYSTEM. THE CURRENT POSITION IS BASED ON ANIMATED MULTISPECTRAL IMAGERY AND EXTRAPOLATED FROM A 031059Z SSMI-S MICROWAVE IMAGE SHOWING A DETACHED LLCC FROM THE MAIN CONVECTION. CONFIDENCE IN THIS POSITION IS POOR. THE CURRENT INTENSITY IS AVERAGED FROM DVORAK ESTIMATES OF 35 KNOTS FROM PGTW, KNES, AND RJTD. THE RECENT STORM MOTION IS MORE WESTWARD THAN THE PREVIOUS TRACK WHICH MAY BE AN INDICATION OF DIRECT CYCLONE INTERACTION (DCI) WITH A DEVELOPING TROPICAL DISTURBANCE (TD) TO THE SOUTH. 3. FORECAST REASONING. A. THE INITIAL PORTION OF THE FORECAST IS NOW ON A MORE WEST- WARD TRAJECTORY THAN THE PREVIOUS FORECAST AND THE EXTENDED FORECAST IS MORE TO THE RIGHT. HOWEVER, THE FUNDAMENTAL PHILOSOPHY OF THE TRACK AND INTENSITY FORECASTS REMAINS THE SAME. B. TS 10W WILL CONTINUE TO TRACK GENERALLY NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP SUBTROPICAL RIDGE ENTRENCHED JUST SOUTH OF MAINLAND JAPAN THROUGH TAU 72. OVER THIS PERIOD, THE SYSTEM WILL INTENSIFY SLIGHTLY, PEAKING AT 60 KTS. THE INITIAL STORM MOTION MAY BE SLOWED DOWN SLIGHTLY DUE TO DCI MENTIONED IN PARA 2.A. C. AFTER TAU 72, TS MALOU IS EXPECTED TO DRIFT INTO A WEAK STEERING FLOW IN THE YELLOW SEA AS THE WESTERN EXTENT OF THE RIDGE BREAKS DOWN IN RESPONSE TO A PASSING MID-LATITUDE TROUGH. IT WILL THEN WEAKEN DUE TO THE COOLER WATERS OF THE NORTHERN YELLOW SEA AND EXPOSURE TO WESTERLY VERTICAL WIND SHEAR ASSOCIATED WITH THE BAROCLINIC ZONE. NUMERICAL MODEL GUIDANCE ARE IN FAIR AGREEMENT UP TO TAU 24 THEN OFFER VARIOUS SOLUTIONS. GFS IS LEFT OF THE MODEL ENVELOPE AND DEPICTS A LOOPING MOTION AFTER TAU 24, PRESUMABLY DUE TO A MERGER BETWEEN THE SYSTEM AND THE AFOREMENTIONED TD. DUE TO THE WEAK STEERING ENVIRONMENT IN THE YELLOW SEA, THE MODELS DIVERGE SIGNIFICANTLY. ECMWF OPTS FOR AN ACCELERATED RECURVE ACROSS THE KOREAN PENINSULA, NOGAPS BRINGS THE SYSTEM STRAIGHT INTO CHINA, AND WBAR OFFERS AN ABBREVIATED RECURVE TOWARDS THE KOREAN STRAIT. NEEDLESS TO SAY, ERRATIC STORM MOTION AFTER TAU 72 IS A DISTINCT POSSIBILITY.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.