From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Mon Oct 25 21:44:28 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 o9PDiQC5008137 for ; Mon, 25 Oct 2010 21:44:27 +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 o9P2muW5021767; Mon, 25 Oct 2010 08:44:12 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4036872 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Mon, 25 Oct 2010 08:44:11 -0500 Received: from relay05.cites.uiuc.edu (relay05.cites.uiuc.edu [128.174.4.40]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o9PDiBjs000385 for ; Mon, 25 Oct 2010 08:44:11 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay05.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o9PDi4ot028226 for ; Mon, 25 Oct 2010 08:44:11 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 23D8A4050022; Mon, 25 Oct 2010 08:44:03 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101025134404.23D8A4050022@weather3.admin.niu.edu> Date: Mon, 25 Oct 2010 08:44:03 -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 16w Warning Nr 17// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 251500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W WARNING NR 17// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 16W (CHABA), LOCATED APPROXIMATELY 525 NM SOUTH-SOUTHEAST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWEST- WARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED WATER VAPOR SATELLITE IMAGERY SHOWS DEEP CONVECTIVE BANDING ALONG THE SOUTHERN AND WESTERN PERIPHERY OF THE LOW LEVEL CIRCULATION CENTER (LLCC) HAS FURTHER CONSOLIDATED. ADDITIONALLY, A POLEWARD OUTFLOW CHANNEL HAS EMERGED AS A MID-LATITUDE TROUGH DIGGING IN FROM THE NORTHWEST CLOSES IN. THE INITIAL POSITION IS EXTRAPOLATED FROM 251032Z SSMI-S MICROWAVE IMAGE, WHICH DEPICTS A HOOK FEATURE TIGHTLY WRAPPED INTO THE LLCC. THE INITIAL INTENSITY IS BASED ON PGTW, KNES AND RJTD DVORAK ESTIMATES OF T3.5. TS 16W IS CURRENTLY TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL SUBTROPICAL STEERING RIDGE ANCHORED EAST OF JAPAN. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE TRACK FORECAST PHILOSOPHY, HOWEVER, THE FORECAST INTENSITIES ARE SLIGHTLY HIGHER. B. TS 16W WILL CONTINUE TO INTENSIFY AS VERTICAL WIND SHEAR DECREASES AND POLEWARD OUTFLOW IMPROVES AS IT ROUNDS THE WESTERN EDGE OF THE STEERING RIDGE. AFTER TAU 36, THE SYSTEM WILL VEER MORE TO THE RIGHT AS IT GETS ABSORBED INTO THE WESTERLIES AFTER THE PASSAGE OF THE AFOREMENTIONED MID-LATITUDE TROUGH. ITS INITIAL EXPOSURE TO THE STRONG WESTERLIES WILL FURTHER INCREASE POLEWARD OUTFLOW ALLOWING THE SYSTEM TO PEAK INTENSITY PRIOR TO TAU 72. C. AFTER TAU 72, TS CHABA IS EXPECTED TO RECURVE AND ACCELERATE TO THE NORTHEAST AND BEGIN EXTRATROPICAL TRANSITION. ITS PROLONGED EXPOSURE TO THE PREVAILING WESTERLIES AND DECREASING OCEAN HEAT CONTENT WILL GRADUALLY WEAKEN THE SYSTEM DURING THIS TRANSITION. WITH THE EXCEPTION OF GFDN, NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THIS TRACK FORECAST WHICH IS SLIGHTLY TO THE RIGHT OF CONSENSUS TO OFFSET THE UNREALISTICALLY ABRUPT WESTWARD GFDN SOLUTION.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.