From owner-wx-tropl@LISTSERV.ILLINOIS.EDU Sat Dec 18 20:32:17 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 oBICWFjX026913 for ; Sat, 18 Dec 2010 20:32:16 +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 oBI60DND027712; Sat, 18 Dec 2010 06:31:41 -0600 (CST) Received: by LISTSERV.ILLINOIS.EDU (LISTSERV-TCP/IP release 14.5) with spool id 4813627 for WX-TROPL@LISTSERV.ILLINOIS.EDU; Sat, 18 Dec 2010 06:31:41 -0600 Received: from relay04.cites.uiuc.edu (relay04.cites.uiuc.edu [128.174.196.5]) by vacuum.cso.uiuc.edu (8.14.2/8.14.2) with ESMTP id oBICVft0014360 for ; Sat, 18 Dec 2010 06:31:41 -0600 (CST) Received: from weather3.admin.niu.edu (weather3.admin.niu.edu [131.156.8.48]) by relay04.cites.uiuc.edu (8.14.4/8.14.2) with ESMTP id oBICVY8w000216 for ; Sat, 18 Dec 2010 06:31:40 -0600 (CST) Received: by weather3.admin.niu.edu (Postfix, from userid 501) id 3C2673FE0866; Sat, 18 Dec 2010 06:31:34 -0600 (CST) X-Proofpoint-Spam-Reason: safe Message-ID: <20101218123134.3C2673FE0866@weather3.admin.niu.edu> Date: Sat, 18 Dec 2010 06:31:34 -0600 Reply-To: wxmaster@COX.NET Sender: WX-TROPL Tropical Storm and Hurricane WX products From: LDM Weather Subject: Central Pacific: Satellite Interpretation Message To: WX-TROPL@LISTSERV.ILLINOIS.EDU Precedence: list 567 ATHW40 PHFO 181231 SIMHI HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI 1230 UTC SAT DEC 18 2010 BASED ON DATA THROUGH 1200 UTC DECEMBER 18 2010 THE WESTERN EDGE OF A WEAK WEST NORTHWEST TO EAST SOUTHEAST ORIENTED SURFACE RIDGE WAS LOCATED ABOUT 315 MILES NORTH OF HONOLULU. THE PRESSURE GRADIENT SOUTH OF THIS NEARLY STATIONARY FEATURE CONTINUED TO MAINTAIN RELATIVELY LIGHT SOUTHEASTERLY FLOW ACROSS THE STATE EARLY THIS MORNING. THERE WERE MAINLY SCATTERED LOW CLOUDS OVER THE HAWAIIAN COASTAL WATERS EAST OF KAUAI. THERE WERE ISOLATED LIGHT SHOWERS EMBEDDED WITHIN SOME OF THE LOW CLOUDS SOUTHEAST OF THE BIG ISLAND. THE INDIVIDUAL LOW CLOUD ELEMENTS WERE GENERALLY MOVING NORTHWESTWARD AT ABOUT 10 MPH OVER THE COASTAL WATERS FROM OAHU TO THE BIG ISLAND. THE HIGHEST TOPS OF THE LOW CLOUDS OVER THE OCEAN IN THE SAME AREA WERE ESTIMATED TO BE 5 TO 6 THOUSAND FEET. HOWEVER...BROKEN LAYERED CLOUDS AND ISOLATED SHOWERS WERE OVER THE WESTERN HAWAIIAN COASTAL WATERS JUST WEST OF KAUAI AND NIIHAU. SOME OF THIS PRECIPITATION APPEARED TO BE LOCALLY HEAVY...WITH A FEW OF THE ECHO TOPS ESTIMATED TO BE NEAR 20 THOUSAND FEET ACCORDING TO RADAR. THE INDIVIDUAL RAIN PRODUCING ELEMENTS WERE MOVING NORTHWARD AT 15 TO 20 MPH ACCORDING TO RADAR REFLECTIVITY DATA. IN ADDITION TO THE LOW CLOUDS OVER THE HAWAIIAN COASTAL WATERS...SCATTERED TO BROKEN CIRRUS CLOUDS WERE ALSO MOVING RAPIDLY EASTWARD HIGH ABOVE SKIES OVER THE ISLANDS. THE LAYERED CLOUDS AND PRECIPITATION JUST WEST OF KAUAI...AS WELL AS THE HIGH THIN CLOUDS MOVING ACROSS THE ALOHA STATE...WERE ALONG THE EXTREME EASTERN EDGE OF A LARGE COMPLEX WEATHER SYSTEM THAT EXTENDED ALMOST TO THE INTERNATIONAL DATE LINE. THE HIGH CLOUDS WERE MAKING TO DIFFICULT TO IDENTIFY LOW CLOUDS OVER THE ISLANDS ISLANDS USING INFRARED SATELLITE IMAGERY TONIGHT. ACCORDING TO LOOPS OF WATER VAPOR IMAGERY AND SATELLITE DERIVED UPPER LEVEL WINDS...AN UPPER TROPOSPHERIC LOW WAS CENTERED JUST EAST OF THE DATE LINE NEAR 22N 178.5W. THIS FEATURE HAS BEEN MOVING SOUTHWARD AT ALMOST 20 MPH DURING THE PAST 6 HOURS. EAST OF THIS UPPER LEVEL LOW...THE CORE OF A SUBTROPICAL JET EXTENDED FROM NEAR 15N 176W TO 22N 173W TO 30N 172W. A BROAD AREA OF OVERCAST LAYERED CLOUDS WITH RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH THE DIFFLUENCE ALOFT DUE TO THIS JET WAS SLIGHTLY LESS THAN 1000 MILES EAST OF A LINE FROM 13N 176W TO 24N 174W TO 30N 174.5W. A SURFACE LOW...WHICH WAS A REFLECTION OF THE UPPER LEVEL LOW ALOFT...WAS ALSO EVIDENT IN SATELLITE IMAGERY NEAR 23.8N 178.6W...OR ABOUT 310 MILES SOUTH SOUTHWEST OF MIDWAY ATOLL. SHOWERS AND NUMEROUS THUNDERSTORMS WERE WITHIN 140 MILES OF THIS LOW...WHICH HAS CHARACTERISTICS OF A SUBTROPICAL SYSTEM BASED ON EARLIER SCATTEROMETER PASSES AND ITS INFRARED SATELLITE SIGNATURE. THE HIGHEST TOPS OF THE THUNDERSTORMS WITHIN THE CORE OF THIS SYSTEM WERE ESTIMATED TO BE ABOUT 40 THOUSAND FEET. ELSEWHERE...THE AXIS OF AN UPPER TROPOSPHERIC TROUGH EXTENDED FROM NEAR 20N 145W TO 13.5N 147.5W TO 08.5N 147W...OR ABOUT 580 MILES SOUTHEAST OF HILO. THIS TROUGH ALOFT HAS BEEN PROPAGATING SLOWLY TOWARD THE EAST NORTHEAST DURING THE PAST 6 HOURS. ISOLATED THUNDERSTORMS ASSOCIATED WITH THIS FEATURE...WHICH HAVE DECREASED IN COVERAGE AND INTENSITY DURING THE PAST 6 HOURS...WERE IN THE AREA FROM 12N TO 15.5N BETWEEN 142.5W AND 147.5W. $$ HOUSTON +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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.