From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Tue Oct 26 11:56:26 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 o9Q3uPf6027756 for ; Tue, 26 Oct 2010 11:56:26 +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 o9PHJNvw021767; Mon, 25 Oct 2010 22:56:15 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4052820 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Mon, 25 Oct 2010 22:56:14 -0500 Received: from relay08.cites.uiuc.edu (relay08.cites.uiuc.edu [128.174.196.9]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o9Q3uEOC022400 for ; Mon, 25 Oct 2010 22:56:14 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay08.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o9Q3u75v018626 for ; Mon, 25 Oct 2010 22:56:14 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id C08914050021; Mon, 25 Oct 2010 22:56:07 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101026035607.C08914050021@weather3.admin.niu.edu> Date: Mon, 25 Oct 2010 22:56:07 -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 Typhoon 16w Warning Nr 19 Corrected// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 260300 COR MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W WARNING NR 19 CORRECTED// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TYPHOON 16W (CHABA), LOCATED APPROXIMATELY 430 NM SOUTH- SOUTHEAST OF KADENA AIR BASE, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 5 KNOTS DURING THE PAST SIX HOURS. ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY SHOWS CONVECTION INTENSIFYING AND CONSOLIDATING OVER THE LOW LEVEL CIRCULATION CENTER (LLCC). MARKEDLY IMPROVED POLEWARD OUTFLOW DURING THE PAST SIX HOURS IS RESPONSIBLE FOR MUCH OF THE INTENSIFICATION. A 252132Z 37GHZ MICROWAVE PASS SHOWS A DEVELOPING MICROWAVE EYE AND INCREASINGLY WELL ORGANIZED CONVECTIVE BANDING. INFRARED ANIMATION SHOWS A SHARP INCREASE IN COLD TOPS OVER THE LLCC DURING THE PAST SIX HOURS. THE INTENSITY ESTIMATE IS BASED ON A COMBINATION OF DVORAK ESTIMATES OF 65 KNOTS FROM PGTW AND 77 KNOTS FROM RJTD. IN ADDITION TO THE IMPROVING POLEWARD OUTFLOW, WELL DEVELOPED EQUATORWARD OUTFLOW PERSISTS. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE TRACK FORECAST PHILOSOPHY. TRACK SPEEDS AFTER TAU 72 HAVE BEEN INCREASED. B. TYPHOON CHABA IS EXPECTED TO CONTINUE A STEADY POLEWARD TRACK AROUND THE PERIPHERY OF THE SUBTROPICAL RIDGE THROUGH TAU 48. THE STORM WILL SUSTAIN INTENSIFICATION AS A MID-LATITUDE TROUGH CURRENTLY MOVING OVER THE SEA OF JAPAN PROVIDES FURTHER ENHANCEMENT TO THE POLEWARD OUTFLOW CHANNEL. A MID-LATITUDE SHORT WAVE TROUGH CURRENTLY OVER THE SEA OF JAPAN WILL ACT TO SUSTAIN A VIGOROUS POLEWARD OUTFLOW CHANNEL UNTIL IT PASSES EAST OF THE STORM. THIS WILL INDUCE STEADY INTENSIFICATION AS TY 16W ROUNDS THE WESTERN EDGE OF THE SUBTROPICAL RIDGE. GFDN, FORMERLY AN OUTLIER TO THE EXTREME WEST, HAS NOW JOINED THE PACK AND IS TRACKING THE SYSTEM TO THE EAST OF OKINAWA. C. A RECENT COLD SURGE OVER WESTPAC HAS BROUGHT CONTINENTAL POLAR AIR DEEP INTO THE THEATER, THEREFORE EXTRATROPICAL TRANSISTION WILL BEGIN BEFORE THE STORM REACHES 30N. TYPHOON CHABA IS EXPECTED TO RECURVE AND TRACK ALONG THE EAST COAST OF HONSHU AFTER TAU 72 WHILE UNDERGOING A RAPID EXTRA-TROPICAL TRANSITION. THE RECURVATURE WILL NOT BE A DRAMATIC TURN AND ACCELERATION DUE TO A ZONAL ORIENTATION OF THE POLAR FRONT JET DURING THAT PERIOD. THE ZONAL JET, HOWEVER, WILL PRODUCE TREMENDOUS VERTICAL WINDSHEAR BETWEEN 30 AND 35 NORTH LATITUDE. THEREFORE TYPHOON CHABA IS EXPECTED TO UNDERGO RAPID DE-INTENSIFICATION DURING ITS PERIOD OF EXTRATROPICAL TRANSITION. DURING THE SAME PERIOD,THE STORM WILL BE RIDING OVER A REGION OF RAPIDLY DECREASING OCEAN HEAT CONTENT. NUMERICAL MODELS ARE COMING INTO BETTER AGREEMENT WITH THIS SCENARIO. NOGAPS AND EGRR BOTH STEER THE STORM OVER SHIKOKU AND INTO THE SEA OF JAPAN, PUNCHING IT THROUGH A 100 KNOT POLAR FRONT JET AND OVER THE JAPANESE ALPS. THIS SOLUTION IS INCOHERENT AND IS DISREGARDED. BECAUSE THE CONSENSUS INCLUDES BOTH NOGAPS AND EGRR, THE FORECAST IS TO THE RIGHT AND FASTER THAN CONSENSUS, WHICH IS SLIGHTLY SLIGHTLY SLOWER BUT VERY CLOSE TO ECMWF. ECMWF HAS SHOWN THE BEST HANDLING OF THE SYSTEM'S TRACK THUS FAR. 4. JUSTIFICATION FOR CORRECTION: CHANGED WEST OF TO EAST OF OKINAWA IN LAST SENTENCE OF PARA 3.B.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.