From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sun Sep 19 15:58:35 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 o8J7wXw3022778 for ; Sun, 19 Sep 2010 15:58:34 +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 o8J2ZJhw023157; Sun, 19 Sep 2010 02:58:10 -0500 (CDT) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 3467571 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sun, 19 Sep 2010 02:58:10 -0500 Received: from relay02.cites.uiuc.edu (relay02.cites.uiuc.edu [128.174.196.4]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id o8J7wAHu025011 for ; Sun, 19 Sep 2010 02:58:10 -0500 (CDT) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay02.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id o8J7w36Q015797 for ; Sun, 19 Sep 2010 02:58:09 -0500 (CDT) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 50F43108B0001; Sun, 19 Sep 2010 02:58:03 -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=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-1005130000 definitions=main-1009190004 X-Spam-OrigSender: ldm@weather3.admin.niu.edu X-Spam-Bar: Message-ID: <20100919075803.50F43108B0001@weather3.admin.niu.edu> Date: Sun, 19 Sep 2010 02:58:03 -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 037 FXPQ60 PGUM 190757 AFDPQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TIYAN GU 557 PM CHST SUN SEP 19 2010 .SYNOPSIS... PGUA WSR-88D SHOWS ISOLATED SHOWERS IN THE MARIANAS WATERS... WITH SCATTERED SHOWERS DEVELOPING JUST TO THE SOUTHEAST. THESE SHOWERS ARE ASSOCIATED WITH A DEVELOPING TROPICAL DISTURBANCE ABOUT 400 MILES EAST OF GUAM. THE MAIN AREA OF SHOWERS WITH THIS DISTURBANCE IS BETWEEN 10N AND 20N FROM 150E TO 160E. ELSEWHERE A TRADE- WIND TROUGH IS CREATING SCATTERED SHOWERS JUST EAST AND NORTH OF YAP. TRADE-WIND CONVERGENCE IS GENERATING SCATTERED SHOWERS WITHIN 100 MILES OF A LINE FROM 1.5N 137E TO 10N 157E. && .DISCUSSION... DEVELOPING TROPICAL DISTURBANCE EAST OF THE MARIANAS IS DEFINITELY THE 800 POUND GORILLA IN THE FORECAST ROOM TONIGHT. IT IS NOW THE SUBJECT OF A TROPICAL CYCLONE FORMATION ALERT FROM THE JOINT TYPHOON WARNING CENTER. SINCE IT IS JUST BEGINNING TO PULL ITSELF TOGETHER...WINDS WILL REMAIN FAIRLY LOW...WITH RAIN BEING THE BIG STORY. THE NEXT FEW HOURS DO NOT LOOK SO BAD...SO WENT WITH SCATTERED LOCALLY HEAVY SHOWERS AFTER MIDNIGHT AND MONDAY. THE CONVECTION WITH THE DISTURBANCE IS WEAKENING AT THE MOMENT BUT WILL ATTRIBUTE THAT TO CYCLING...A COMMON PHENOMENON WITH NASCENT TROPICAL CYCLONES. EXPECT IT TO PICK UP AGAIN IN A FEW HOURS. THIS ALSO AGREES WELL WITH THE GENERAL DIURNAL CYCLE SO FOR ALL THOSE REASONS AFTER MIDNIGHT SEEMED TO BE THE BEST BET. JUST COULD NOT FIND ANY WIND GRIDS THAT DEFINITELY SEEMED BETTER THAN THE CURRENT GRIDS SO DID NOT CHANGE THE WINDS AT ALL. IN FACT...LIGHT AND VARIABLE SEEMS GOOD BASED ON THE ASCAT OF 10 KNOTS OR LESS THROUGHOUT THE LATITUDES OF THE MARIANAS WATERS. TWEAKED TEMPERATURES TONIGHT AND MONDAY DOWN BASED ON EXPECTED RAINFALL. AS HAS BEEN THE PATTERN THIS YEAR...VIRTUALLY ALL TROPICAL CYCLONE ACTIVITY IS DEVELOPING AT THE UPPER-LEVEL ANTICYCLONIC AREAS BETWEEN THE CELLS OF THE TROPICAL UPPER TROPOSPHERIC TROUGH. && .EASTERN MICRONESIA... SHOWERS ASSOCIATED WITH A WEAK TRADE WIND CONVERGENCE ZONE WILL AFFECT MAJURO THIS EVENING AND POSSIBLY KOSRAE LATER TONIGHT. FAIRLY QUIET CONDITIONS ARE EXPECTED THROUGH THE NEXT FEW DAYS AS MODELS INDICATE A NORTHWARD PROGRESSION OF DRIER ESE TO SE TRADE FLOW OVER THE REGION. CONVERGING SOUTHEAST FLOW INTO TROPICAL DISTURBANCE 90W WELL TO THE NORTH OF CHUUK IS GENERATING SCATTERED CONVECTION JUST TO THE NORTH OF POHNPEI WITH CONVECTION ASSOCIATED WITH TRADE-WIND CONVERGENCE MOVING INTO THE AREA MONDAY. OTHERWISE...MODELS SHOW NO MAJOR WEATHER FEATURES AFFECTING ANY OF THE FORECAST LOCATIONS IN THE LONG-TERM. && .WESTERN MICRONESIA... LATEST SATELLITE IMAGERY AND 00Z SOUNDING DATA SHOW TRADE-WIND CONVERGENCE ZONE AND ASSOCIATED CONVECTION HAVE MOVED TO THE NORTHWEST OF CHUUK...WITH ONLY ISOLATED SHOWERS APPARENT BEHIND THIS BOUNDARY. GFS IN PARTICULAR INITIALIZED WELL IN THIS AREA SO WEIGHTED SHORT TERM FORECAST ACCORDINGLY...WITH ONLY ISOLATED SHOWERS EXPECTED THROUGH TUESDAY. A SURFACE TROUGH EVIDENT IN ASCAT AND SATELLITE DATA IS PROGRESSING WESTWARD OVER YAP THIS EVENING THAT WILL BRING A PERIOD OF SCATTERED SHOWERS OVER THE AREA FOR TONIGHT. SHOWERS ASSOCIATED WITH THIS FEATURE ARE EXPECTED TO PASS TO THE NORTH OF KOROR MONDAY. HOWEVER...A BROAD AREA OF CONVECTION ALONG A TRADE-WIND CONVERGENCE ZONE WILL GRADUALLY PUSH NORTHWEST ALLOWING INCREASED SHOWERS COVERAGE TUESDAY AND POSSIBLY TUESDAY NIGHT FOR KOROR. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && $$ STANKO/WILLIAMS +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.