From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sat Sep 4 23:09:28 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 o84F9RsZ019830 for ; Sat, 4 Sep 2010 23:09:28 +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 o831TEkl007343; Sat, 4 Sep 2010 10:09:11 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3228555 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sat, 4 Sep 2010 10:09:11 -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 o84F9Bow013812 for ; Sat, 4 Sep 2010 10:09:11 -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 o84F94bc013516 for ; Sat, 4 Sep 2010 10:09:10 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 871A2405001F; Sat, 4 Sep 2010 10:09:04 -0500 (CDT) X-Spam-Score: 0 X-Spam-Details: rule=no-quarantine_notspam policy=no-quarantine score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=1 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-1005130000 definitions=main-1009040086 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: Message-ID: <20100904150904.871A2405001F@weather3.admin.niu.edu> Date: Sat, 4 Sep 2010 10:09:04 -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 10w Warning Nr 12// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN33 PGTW 041500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W WARNING NR 12// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 10W (MALOU), LOCATED APPROXIMATELY 35 NM NORTH-NORTHWEST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS DEVELOPING CENTRAL CONVECTION OVER A BROAD AREA OF CIRCULATION. THE MAJORITY OF THE DEEP CONVECTION IS ON THE EASTERN TO SOUTHEASTERN PERIPHERY OF THE LOW LEVEL CIRCULATION CENTER EMBEDDED WITHIN A MONSOON GYRE-LIKE PATTERN. TS 10W APPEARS TO HAVE MERGED WITH THE TROPICAL DISTURBANCE PREVIOUSLY LOCATED TO THE EAST. THE INITIAL POSITION IS BASED ON THE PGTW AND RJTD SATELLITE FIX ALONG WITH RADAR FROM JAPAN. THE INITIAL INTENSITY IS BASED ON THE PGTW, RJTD, AND KNES DVORAK ESTIMATES RANGING FROM 30 TO 35 KNOTS. TS 10W IS LOCATED IN AN AREA OF DIVERGENCE ALOFT, ALTHOUGH AN UPPER LEVEL MID-LATITUDE TROUGH APPEARS TO BE CAUSING SUBSIDENCE ALONG THE NORTHERN PERIPHERY OF THE SYSTEM, LIMITING POLEWARD OUTFLOW. HOWEVER, EQUATORWARD OUTFLOW REMAINS GOOD. 3. FORECAST REASONING. A. THE FORECAST HAS TRENDED EASTWARD BECAUSE TS 10W HAS TRACKED NORTHWARD WITH THE SUBTROPICAL STEERING RIDGE WEAKENING SOONER THAN EXPECTED. HOWEVER, THE FUNDAMENTAL PHILOSOPHY OF THE TRACK AND INTENSITY FORECASTS REMAINS THE SAME. B. TS 10W IS CURRENTLY TRACKING NORTHWARD ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE. AN UPPER AIR OBSERVATION FROM NAZE INDICATES MID-LEVEL SOUTHEASTERLY FLOW ALSO SHOWING THE STEERING RIDGE HAS WEAKENED. TS MALOU IS EXPECTED TO CONTINUE TRACKING NORTHEASTWARD. AROUND TAU 48, TS 10W WILL WEAKEN AS IT INTERACTS WITH THE MID-LATITUDE WESTERLIES AND TRACKS OVER COOLER SEA SURFACE TEMPERATURES IN THE YELLOW SEA. THE SYSTEM SHOULD REACH SOUTH KOREA AFTER TAU 72. C. AFTER TAU 72, TS MALOU IS EXPECTED TO CONTINUE WEAKENING AS IT TRACKS OVER LAND AND AS IT FURTHER INTERACTS WITH THE MID-LATITUDE WESTERLIES. THE NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT, BUT DEPICT VARYING RECURVATURE TIMING IN RESPONSE TO THE WEAKENING STEERING RIDGE. THIS FORECAST IS IN AGREEMENT WITH THE EGRR AND ECMWF MODELS, WHICH CURVE THE SYSTEM INTO THE WESTERLIES LATER THAN THE OTHER MODELS.// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.