From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Tue Oct 5 11:11:53 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 o953Bpwe011257 for ; Tue, 5 Oct 2010 11:11:52 +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 o949qPQL006168; Mon, 4 Oct 2010 22:07:13 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3743666 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Mon, 4 Oct 2010 22:07:12 -0500 Received: from relay10.cites.uiuc.edu (relay10.cites.uiuc.edu [128.174.196.10]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o9537Cdl016593 for ; Mon, 4 Oct 2010 22:07:12 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay10.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o95376Sv002890 for ; Mon, 4 Oct 2010 22:07:12 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id F137D405016A; Mon, 4 Oct 2010 22:07:05 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101005030705.F137D405016A@weather3.admin.niu.edu> Date: Mon, 4 Oct 2010 22:07:05 -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 14w Warning Nr 01// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN31 PGTW 050300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 14W WARNING NR 01// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 14W (FOURTEEN), LOCATED APPROXIMATELY 40 NM SOUTH OF HAINAN, HAS TRACKED NORTHWARD AT 06 KNOTS DURING THE PAST SIX HOURS. ANIMATEDINFRARED SATELLITE IMAGERY INDICATES THAT CONVECTION HAS CONSOLIDATED AND INCREASED DRAMATICALLY DURING THE PAST SIX HOURS. A 041857Z AMSU-B MICROWAVE IMAGE SHOWS A COMMA-SHAPED CONVECTIVE BAND FEEDING INTO THE LOW LEVEL CIRCULATION CENTER (LLCC). AN EARLIER ASCAT IMAGE CONFIRMS A LARGE CYCLONIC WIND FIELD WITH NEAR GALE FORCE WINDS WITHIN THE NORTHEASTERN QUADRANT. A VIGOROUS POLEWARD OUTFLOW CHANNEL HAS DEVELOPED AND IS BEING ENHANCED BY AN UPPER LEVEL ANTICYCLONE JUST SOUTH OF HAINAN ISLAND. THIS CHANNEL IS AIDING DEEP CONVECTION NEAR THE SYSTEM CENTER. DESPITE THE COMMA PATTERN INDICATED ON A 042346Z 91 GHZ SSMIS, CONFIDENCE IN THE EXACT POSITION OF THE LLCC IS ONLY FAIR AS THE CIRCULATION IS EMBEDDED WITHIN THE MONSOON TROUGH. INTENSITY ESTIMATES ARE BASED ON A COMBINATION OF SURFACE AND SHIP OBSERVATIONS AND A PGTW DVORAK ESTIMATE OF 2.0. 3. FORECAST REASONING. A. THIS MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY FOR TD 14W. B. TD 14W IS FORECAST TO DRIFT NORTHWARD OVER HAINAN ISLAND AND WEAKEN, THEN RE-INTENSIFY AS IT TRACKS INTO THE EASTERN GULF OF TONKIN AT TAU 24. SUSTAINED FAVORABLE OUTFLOW CONDITIONS COUPLED WITH WARM SEA SUFACE TEMPERATURES ARE EXPECTED TO MITIGATE THE EFFECTS OF LAND INTERACTION AND ENABLE THE SYSTEM TO INTENSIFY TO LOW TROPICAL STORM STRENGTH BEFORE IT MAKES LANDFALL OVER SOUTHERN CHINA. WEAK STEERING FLOW IN THE MID-LEVELS INDICATE THAT THE SYSTEM WILL LIKELY DRIFT NORTHWARD TOWARDS THE WEAKEST PART OF THE SUBTROPICAL RIDGE, INTENSIFY TO THE EXTENT THAT IT REMAINS OVER WATER, AND THEN DISIPATE OVER LAND. DUE TO A LACK OF AVAILABILITY OF MANY OF THE MOST RELIABLE DYNAMIC AIDS AND EXTREMELY POOR AGREEMENT OF THOSE AVAILABLE, THE SHORT-TERM FORECAST IS BASED ON A CONSTANT RATE OF MOVEMENT. THE LONG TERM FORECAST IS BASED ON THE 1200Z ECMWF MODEL RUN.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.