From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Mon Oct 18 16:47:42 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 o9I8lfEU008935 for ; Mon, 18 Oct 2010 16:47:42 +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 o9I0xeT0021853; Mon, 18 Oct 2010 03:47:26 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3930033 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Mon, 18 Oct 2010 03:47:26 -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 o9I8lQ7V025951 for ; Mon, 18 Oct 2010 03:47:26 -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 o9I8lJKV020390 for ; Mon, 18 Oct 2010 03:47:26 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id CB5C140501A6; Mon, 18 Oct 2010 03:47:19 -0500 (CDT) X-Proofpoint-Spam-Reason: safe Message-ID: <20101018084719.CB5C140501A6@weather3.admin.niu.edu> Date: Mon, 18 Oct 2010 03:47:19 -0500 Reply-To: wxmaster@COX.NET Sender: WX-TROPL Tropical Storm and Hurricane WX products From: LDM Weather Subject: Western Pacific: Synoptic Discussion For The Marianas To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list 065 FXPQ60 PGUM 180846 AFDPQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TIYAN GU 646 PM CHST MON OCT 18 2010 .SYNOPSIS... AN ELONGATED N-S UPPER LOW IS LOCATED JUST WEST OF THE MARIANA ISLANDS...AS BRISK SOUTH WINDS SPREAD IN ALOFT FROM THE EAST. THIS SHOULD PRODUCE CONDITIONS FAVORABLE FOR ISOLATED THUNDERSTORMS DURING THE NEXT 36 HOURS OR SO. RADAR SHOWS INCREASING SHOWERS DEVELOPING EAST AND SOUTH OF GUAM...BUT ALSO STARTING TO POP EAST OF SAIPAN AND TINIAN AS WELL. && .DISCUSSION... NONE OF THE MODELS ARE INDICATING MUCH IN THE WAY OF SHOWERS TONIGHT...ESPECIALLY THE UKMET. BUT IN LIGHT OF THE SHOWERS DEVELOPING ON RADAR NOW...HAVE GONE WITH SCATTERED SHOWERS FOR THIS EVENING...THEN WINDING DOWN TO ISOLATED BY MIDNIGHT. WITH THE TUTT LOW JUST WEST...DIVERGENT SOUTH WINDS AT 30-40 KT ABOVE 30K FT SHOULD ENHANCE THUNDERSTORM POTENTIAL A BIT THROUGH TUE NIGHT. BEYOND THAT GFS WANTS TO DEVELOP A WEAK CIRCULATION NW OF THE ISLANDS WED/THU...GIVING THE MARIANAS SOUTHWEST WINDS...BUT THE EUROPEAN MODELS ARE NOT SHOWING THAT. FOR NOW...WILL STAY WITH PREVIOUS FORECAST WED AND BEYOND UNTIL MODELS COME INTO BETTER AGREEMENT. && .EASTERN MICRONESIA... MOSTLY SUNNY SKIES AND ISOLATED SHOWERS HAVE PREVAILED ACROSS THE REGION AS CLOUDS AND SHOWERS REMAIN NORTH OF ALL THE FORECAST LOCALES EXCEPT FOR KWAJALEIN. A LARGE AREA OF CLOUDS AND SHOWERS IS FOUND EAST OF 158E BETWEEN 10N AND 20N. WITHIN THIS AREA OF CONVECTION...A SURFACE TROUGH EXTENDS NORTHEASTWARD FROM 10N163E THROUGH JTWC INVEST AREA 96W AT 14N171E TO 14N172E. OBSERVATIONS FROM THE MARSHALL ISLANDS SUPPORT MODEL ANALYSIS OF A WEAK CIRCULATION IN CONJUNCTION WITH 96W JUST NORTHEAST OF KWAJALEIN. GFS CONSISTENTLY CARRIES THIS FEATURE AS A WEAK CIRCULATION... MAINTAINS IT AND EVENTUALLY MOVES IT NORTHWEST...WHILE OTHER MODELS MERELY PROG AN OPEN TROUGH. FORECAST WIND DIRECTIONS REMAIN DEPENDENT ON THE FUTURE EVOLUTION AND MOTION OF 96W. FOR THE REST OF THE WEEK...SOUTHEAST TO EAST FLOW WILL RESUME WITH MOSTLY CLOUDY CONDITIONS TRICKLING WESTWARD FROM MAJURO TO POHNPEI THURSDAY THROUGH SATURDAY AS A WEAK SURFACE TROUGH PUSHES THROUGH. && .WESTERN MICRONESIA... A TRICKY FORECAST IS IN STORE FOR THE REGION THE NEXT COUPLE OF DAYS. SHOWERS ALONG THE EASTERN SIDE OF SUPER TYPHOON MEGI HAVE RECEDED WESTWARD AWAY FROM KOROR AND THUS ISOLATED SHOWERS REMAIN IN THE FORECAST. SATELLITE HAS SHOWN MOSTLY SUNNY CONDITIONS ALL DAY. HOWEVER...SLIGHT CHANCE THUNDER WAS ADDED TO YAP FOR TONIGHT AS SHOWERS AND A FEW THUNDERSTORMS APPROACH FROM THE SOUTHEAST. A POSSIBLE WEAK CIRCULATION...JTWC INVEST AREA 97W...IS EMBEDDED IN THIS CONVECTIVE CLUSTER AS IT DRIFTS TOWARD YAP. VISIBLE IMAGERY SHOWS CBS JUST EAST OF YAP BUT THEY ARE ENCOUNTERING CONSIDERABLE SHEARING ALOFT. IF THIS AREA OVERSPREADS YAP...THE YAP FORECAST MAY REQUIRE AN UPDATE. ECMWF INITIALIZES RATHER POORLY BUT EVENTUALLY JOINS IN WITH THE OTHER MODELS BY DAYS 2 AND 3 WITH A WEAK CIRCULATION SEEMINGLY MEANDERING BETWEEN YAP...CHUUK AND GUAM...WITH NO IMPRESSIVE RAIN EVENTS FOR ANY LOCATION. BY THE END OF THE WEEK...THIS PATTERN IS PROGGED TO LIFT NORTHWARD AS SOUTHEAST TO EAST FLOW RETURNS ACROSS THE REGION. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && $$ MIDDLEBROOKE/M. AYDLETT +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.