From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sun Oct 24 10:40:50 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 o9O2ensw019392 for ; Sun, 24 Oct 2010 10:40:49 +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 o9N518Zx021767; Sat, 23 Oct 2010 21:40:15 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4015578 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sat, 23 Oct 2010 21:40:15 -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 o9O2eF0j017652 for ; Sat, 23 Oct 2010 21:40:15 -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 o9O2e8Tv001738 for ; Sat, 23 Oct 2010 21:40:15 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 5C5AC405001E; Sat, 23 Oct 2010 21:40:06 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101024024008.5C5AC405001E@weather3.admin.niu.edu> Date: Sat, 23 Oct 2010 21:40:06 -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 Depression 16w Warning Nr 11// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN32 PGTW 240300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W WARNING NR 11// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 16W (SIXTEEN), LOCATED APPROXIMATELY 700 NM SOUTH-SOUTHEAST OF OKINAWA, JAPAN, HAS REMAINED QUASI- STATIONARY OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS IMPROVED CONVECTIVE LOW LEVEL BANDING AROUND A PARTIALLY EXPOSED, BROAD LOW LEVEL CIRCULATION (LLCC). ANIMATED INFRARED SATELLITE IMAGERY DEPICTS FLARING DEEP CONVECTION ALONG THE SOUTHERN PERIPHERY OF THE LOW LEVEL CIRCULATION CENTER (LLCC). THERE IS UNCERTAINTLY IN THE INITIAL POSITION BASED ON THE PARTIALLY EXPOSED LLCC IN A 232025Z TRMM MICROWAVE IMAGE AND MSI. THE INITIAL INTENSITY IS SLIGHTLY HIGHER THAN THE PGTW AND RJTD DVORAK ESTIMATES OF 25 KNOTS DUE TO AN EARLIER 231248Z ASCAT PASS DEPICTING 30 KNOT WINDS ALONG THE SOUTHERN PERIPHERY. ENVIRONMENTAL ANALYSIS INDICATES AN UPPER TROPOSPHERIC TROUGH TO THE NORTH IS INDUCING SUBSIDENCE ALONG THE NORTHERN PERIPHERY OF THE LLCC, HINDERING POLEWARD OUTFLOW, AND CAUSING INCREASED VERTICAL WIND SHEAR. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE IN FORECAST PHILOSOPHY SINCE THE PREVIOUS BULLETIN. B. TD 16W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF A LOW- TO MID-LEVEL SUBTROPICAL STEERING RIDGE. AN UPPER LEVEL, MID- LATITUDE TROUGH CURRENTLY TRACKING OVER CHINA IS EXPECTED TO CONTINUE TO DIG SOUTHWARD CAUSING THE STEERING RIDGE TO WEAKEN AND REORIENT. THIS WILL ALLOW TD 16W TO TURN POLEWARD AROUND TAU 24. ADDITIONALLY, POLEWARD OUTFLOW IS EXPECTED TO INCREASE INTO THE UPPER LEVEL TROUGH AND SUPPORT CONSISTENT INTENSIFICATION. C. AFTER TAU 72, TD 16W IS FORECAST TO CONTINUE TRACKING NORTHWARD ALONG A MID-LEVEL STEERING RIDGE. AROUND TAU 72, THE INTENSIFICATION RATE SHOULD SLOW IN RESPONSE TO AN INCREASE IN VERTICAL WIND SHEAR CAUSED BY A STRONG COLD SURGE ORIGINATING OVER NORTHERN CHINA. THE AVAILABLE NUMERIC GUIDANCE IS SPREAD IN THE POLEWARD TURN WITH NOGAPS, WBAR, UKMO FAVORING AN EARLIER POLEWARD TURN, ALTHOUGH NOGAPS IMMEDIATELY PULLS THE SYSTEM NORTHWARD INTO THE SUBTROPICAL RIDGE. ECMWF TURNS THE SYSTEM NORTHWARD TOWARD OKINAWA, JAPAN. GFDN AND GFS ARE TRACKING TD 16W POLEWARD INITIALLY AND THEN WESTWARD AFTER THE PASSAGE OF THE UPPER LEVEL TROUGH. JGSM ERRONEOUSLY TRACKS IT CONSISTENTLY WESTWARD. THIS FORECAST IS IN AGREEMENT WITH THE MODELS TRACKING MORE POLEWARD IN ANTICIPATION OF AN APPROACHING MID-LATITUDE TROUGH DEEPENING AND REORIENTING THE STEERING RIDGE.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.