From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sat Sep 18 10:17:28 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 o8I2HRgp009083 for ; Sat, 18 Sep 2010 10:17:28 +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 o8HKE7lm023157; Fri, 17 Sep 2010 21:17:15 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3453847 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Fri, 17 Sep 2010 21:17:15 -0500 Received: from relay01.cites.uiuc.edu (relay01.cites.uiuc.edu [128.174.4.23]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o8I2HF0X028198 for ; Fri, 17 Sep 2010 21:17:15 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay01.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o8I2H8u8014368 for ; Fri, 17 Sep 2010 21:17:14 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id F3105108B0001; Fri, 17 Sep 2010 21:17:05 -0500 (CDT) X-Spam-Score: 11 X-Spam-Details: rule=no-quarantine_notspam policy=no-quarantine score=11 spamscore=11 ipscore=0 phishscore=0 bulkscore=69 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-1005130000 definitions=main-1009170187 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: ** Message-ID: <20100918021705.F3105108B0001@weather3.admin.niu.edu> Date: Fri, 17 Sep 2010 21:17:05 -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 Typhoon 12w Warning Nr 14// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN31 PGTW 180300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W WARNING NR 14// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TYPHOON (TY) 12W (FANAPI), LOCATED APPROXIMATELY 270 NM EAST- SOUTHEAST OF TAIPEI, TAIWAN, HAS TRACKED WESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL IMAGERY SHOWS A 20 NM EYE AND A 172216Z SSMIS MICROWAVE IMAGE DEPICTS MULTIPLE CONVECTIVE BANDS ALONG THE EASTERN PERIPHERY. THERE IS HIGH CONFIDENCE IN THE INITIAL POSITION BASED ON AN EYE FIX. THE INITIAL INTENSITY IS BASED ON THE 172301Z AND 180006Z VORTEX DATA MESSAGES INDICATING SURFACE WIND SPEED ESTIMATES OF 93 AND 95 KNOTS. THERE IS ALSO HIGH CONFIDENCE IN THE WIND RADII STRUCTURE, WHICH WAS BASED ON DOTSTAR DROPSONDE OBSERVATIONS. UPPER LEVEL ANALYSIS INDICATES INCREASED NORTHEASTERLY VERTICAL WIND SHEAR ALONG THE NORTHERN PERIPHERY OF THE SYSTEM. ADDITIONALLY, WATER VAPOR SATELLITE IMAGERY SHOWS EXCELLENT UPPER LEVEL EQUATORWARD OUTFLOW AND DECREASING POLEWARD OUTFLOW AS A MID-LATITUDE TROUGH MOVES FARTHER NORTHEASTWARD. TY 12W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE LOCATED TO THE NORTH. 3. FORECAST REASONING. A. NO CHANGE IN FORECAST PHILOSOPHY AND TRACK SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 12W IS FORECAST TO CONTINUE TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL STEERING RIDGE THROUGHOUT THE FORECAST PERIOD. ALTHOUGH POLEWARD OUTFLOW IS DECREASING, FAVORABLE EQUATORWARD OUTFLOW WILL ALLOW TY FANAPI TO SLIGHTLY INCREASE IN INTENSITY WITHIN THE NEXT 12 HOURS. AFTER TAU 24, TY FANAPI IS EXPECTED TO MAKE LANDFALL OVER TAIWAN, WHERE IT WILL WEAKEN SIGNIFICANTLY. THE SYSTEM SHOULD CONTINUE WESTWARD MAKING LANDFALL OVER CHINA BY TAU 48. NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT, THEREFORE THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST. C. IN THE EXTENDED PERIOD, TY 12W IS EXPECTED TO DISSIPATE BY TAU 96.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.