Subject: Central Pacific: Satellite Interpretation Message

From: LDM Weather <[email-masked]>
Date: Fri, 17 Dec 2010 23:32:28 -0600

751 
ATHW40 PHFO 180532
SIMHI 

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0530 UTC SAT DEC 18 2010

BASED ON DATA THROUGH 0500 UTC DECEMBER 18 2010

THE WESTERN EDGE OF A WEAK WEST NORTHWEST TO EAST SOUTHEAST ORIENTED 
SURFACE RIDGE IS LOCATED ABOUT 315 MILES NORTH OF HONOLULU. THE 
PRESSURE GRADIENT SOUTH OF THIS NEARLY STATIONARY FEATURE WAS 
MAINTAINING RATHER LIGHT SOUTHEASTERLY FLOW ACROSS THE STATE EARLY 
THIS EVENING. THERE WERE MAINLY SCATTERED LOW CLOUDS OVER THE 
HAWAIIAN COASTAL WATERS EAST OF KAUAI. THE INDIVIDUAL LOW CLOUD 
ELEMENTS WERE GENERALLY MOVING TOWARD THE NORTHWEST AT 10 TO 15 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 AROUND 5 THOUSAND FEET.

HOWEVER...BROKEN LAYERED CLOUDS WITH EMBEDDED TOWERING CUMULUS 
CLOUDS AND RAIN WERE LOCATED NEAR THE EXTREME WESTERN HAWAIIAN 
COASTAL WATERS WEST OF KAUAI AND NIIHAU. SOME OF THIS PRECIPITATION 
APPEARED TO BE LOCALLY HEAVY...WITH A FEW OF THE ECHO TOPS ESTIMATED 
TO BE ABOVE 20 THOUSAND FEET ACCORDING RADAR ESTIMATES. THE 
INDIVIDUAL RAIN PRODUCING ELEMENTS WERE MOVING NORTHWARD AT ABOUT 15 
MPH ACCORDING TO RADAR REFLECTIVITY DATA. IN ADDITION TO THE LOW 
CLOUDS OVER THE HAWAIIAN COASTAL WATERS...STREAKS OF CIRRUS WERE 
ALSO MOVING 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 ALL THE WAY TO 
THE INTERNATIONAL DATE LINE.

AS OF 700 PM HST FRIDAY...WITH THE LIGHT WINDS ACROSS THE STATE... 
AFTERNOON CLOUD BUILD UPS OCCURRED AS LOCAL SEA BREEZE CIRCULATIONS 
CONVERGED OVER THE INTERIOR OF MOST ISLANDS EARLIER THIS EVENING. 
MOST OF THESE LOW CLOUDS WERE BEGINNING TO DISSIPATE AFTER DUSK THIS 
EVENING. SCATTERED LOW CLOUDS REMAINED OVER PARTS OF THE INTERIOR OF 
KAUAI. SCATTERED TO LOCALLY BROKEN LOW CLOUDS WERE ALONG THE KOOLAU 
AND WAIANAE MOUNTAIN RANGES ON OAHU. ONLY A FEW LOW CLOUDS LINGERED 
OVER PARTS OF MOLOKAI...WHILE SCATTERED TO LOCALLY BROKEN LOW CLOUDS 
WERE AFFECTING PORTIONS OF CENTRAL AND SOUTHWESTERN LANAI. ON 
MAUI...SCATTERED TO BROKEN LOW CLOUDS WERE OVER THE WESTERN 
MOUNTAINS AND ALONG PARTS OF THE LOWER SLOPES OF MOUNT HALEAKALA. 
BROKEN TO OVERCAST LOW CLOUDS WERE ALONG THE SOUTHEASTERN COASTAL 
SECTIONS OF THE BIG ISLAND. SCATTERED TO BROKEN LOW CLOUDS WERE 
ABOVE PARTS OF THE KONA COAST...WHILE MAINLY SCATTERED LOW CLOUDS 
WERE OVER SOME SECTIONS OF THE NORTHEASTERN BIG ISLAND.

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 24N 178.5W. THIS FEATURE HAS BEEN DRIFTING 
SLOWLY SOUTHWARD DURING THE PAST 6 HOURS. EAST OF THIS UPPER LEVEL 
LOW...THE CORE OF A SUBTROPICAL JET EXTENDED FROM NEAR 13N 176W TO 
20N 172W TO 30N 172W. A BROAD AREA OF LAYERED CLOUDS WITH SHOWERS 
AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH THE DIFFLUENCE ALOFT DUE 
TO THIS JET WAS IN THE AREA WITHIN 1000 MILES EAST OF A LINE FROM 
13N 176W TO 21N 174W TO 30N 174W. A SURFACE LOW...WHICH WAS A 
REFLECTION OF THE UPPER LEVEL LOW ALOFT WAS ALSO EVIDENT IN 
SATELLITE IMAGERY NEAR 24N 178.5W. SCATTERED THUNDERSTORMS WERE 
WITHIN 180 MILES OF THIS LOW...WHICH HAS CHARACTERISTICS OF A 
SUBTROPICAL SYSTEM BASED ON RECENT ASCAT PASSES AND ITS SATELLITE 
SIGNATURE. 

ELSEWHERE...ANOTHER UPPER TROPOSPHERIC LOW WAS SPINNING NEAR 16.5N 
147W...OR ABOUT 580 MILES SOUTHEAST OF HILO. THIS LOW ALOFT HAS BEEN 
DRIFTING TOWARD THE EAST NORTHEAST AT ABOUT 10 MPH DURING THE PAST 6 
HOURS. SCATTERED THUNDERSTORMS ASSOCIATED WITH THIS FEATURE WERE IN 
THE AREA FROM 07.5N TO 14.5N BETWEEN 140W AND 149W.

$$

HOUSTON

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