From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Wed Oct 13 11:03:31 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 o9D33TY3011848 for ; Wed, 13 Oct 2010 11:03:30 +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 o9CKppCM017124; Tue, 12 Oct 2010 22:03:18 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3861990 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Tue, 12 Oct 2010 22:03:17 -0500 Received: from relay07.cites.uiuc.edu (relay07.cites.uiuc.edu [128.174.4.73]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o9D33HIk010996 for ; Tue, 12 Oct 2010 22:03:17 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay07.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o9D33Bmd016080 for ; Tue, 12 Oct 2010 22:03:17 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 0315F40501E6; Tue, 12 Oct 2010 22:03:10 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101013030311.0315F40501E6@weather3.admin.niu.edu> Date: Tue, 12 Oct 2010 22:03:10 -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 15w Warning Nr 01// To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list WDPN31 PGTW 130300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 15W WARNING NR 01// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 15W (FIFTEEN), LOCATED APPROXIMATELY 260 NM WEST-SOUTHWEST OF GUAM, HAS TRACKED WEST-SOUTHWEST AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 122231Z SSMIS MICROWAVE IMAGE SHOW IMPROVED CONVECTIVE BANDING WRAPPING INTO A LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS BASED ON ITOP C-130 OBSERVATIONS AND THE AFOREMENTIONED SSMIS IMAGE. THE INITIAL INTENSITY IS BASED ON PGTW AND KNES DVORAK ESTIMATES RANGING FROM 25 TO 30 KNOTS. UPPER LEVEL ANALYSIS INDICATES THE LLCC IS LOCATED BENEATH THE SUBTROPICAL RIDGE AXIS IN AN AREA OF DIVERGENCE AND LOW VERTICAL WIND SHEAR, FAVORABLE FOR CONTINUED DEVELOPMENT. ADDITIONALLY, WATER VAPOR IMAGERY DEPICTS GOOD EQUATORWARD OUTFLOW AND ENHANCED POLEWARD OUTFLOW INTO A TUTT CELL LOCATED TO THE NORTHEAST. 3. FORECAST REASONING. A. THIS IS THE FIRST ISSUANCE OF THE PROGNOSTIC REASONING MESSAGE. B. TD 15W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF A LOW- TO MID- LEVEL STEERING RIDGE AND IS FORECAST TO CONTINUE THROUGH TAU 36. AFTER TAU 36, AN UPPER LEVEL, MID-LATITUDE TROUGH IS EXPECTED TO WEAKEN THE STEERING RIDGE AND ALLOW THE SYSTEM TO TURN NORTHWESTWARD. TD 15W IS FORECAST TO STEADILY INTENSIFY THROUGH TAU 48, AS POLEWARD OUTFLOW INCREASES INTO THE MID-LATITUDE TROUGH. C. AFTER TAU 72, TD 15W IS FORECAST TO CONTINUE TRACKING NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE STEERING RIDGE. POLEWARD OUTFLOW SHOULD CONTINUE TO ENHANCE INTO THE MID- LATITUDE TROUGH AND ALLOW FOR FURTHER INTENSIFICATION. IN THE LATER TAUS, THE RIDGE IS EXPECTED TO RE-BUILD TO THE NORTH, FOLLOWING THE PASSING MID-LATITUDE TROUGH AND ALLOW TD 15W TO TURN MORE WESTWARD. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT, HOWEVER, GFDN ERRONEOUSLY TURNS THE SYSTEM IMMEDIATELY NORTHWARD. THIS FORECAST IS IN GOOD AGREEMENT WITH THE GFS AND NOGAPS 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.