Central Pacific: TS Kilo 720 Mile SE of Oahu

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The low level circulation appears to be tucking beneath the deeper convection.

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Tropical Depression 3 C forms in the Central Pacific approximately 900 miles SSE of Honolulu. The Central Pacific Hurricane Center will begin issuing Advisories shortly for this developing Tropical Cyclone.

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18Z Track and Intensity guidance.

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TROPICAL DEPRESSION THREE-C DISCUSSION NUMBER 1
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032015
1100 AM HST THU AUG 20 2015

SATELLITE IMAGERY SHOWED THAT A TROPICAL DISTURBANCE SOUTHEAST OF
THE MAIN HAWAIIAN ISLANDS HAS DEVELOPED SUFFICIENT PERSISTENT DEEP
CONVECTION AROUND A CLOSED CIRCULATION TO BE CONSIDERED A TROPICAL
DEPRESSION. THEREFORE...ADVISORIES ARE BEING INITIATED ON TROPICAL
DEPRESSION THREE-C. THIS IS THE SIXTH TROPICAL CYCLONE IN THE
CENTRAL NORTH PACIFIC BASIN FOR THE 2015 SEASON. DVORAK INTENSITY
ESTIMATES FROM THE FIX AGENCIES CAME IN AT 30 KT FROM PHFO AND
SAB...AND 25 KT FROM JTWC. THE INITIAL INTENSITY WILL BE 30 KT FOR
THIS FORECAST PACKAGE.

THE DEPRESSION IS MOVING AT 280/14 KT. THE LOW CONFIDENCE OF THE
CENTER POSITIONS OVER THE PAST 12 TO 24 HOURS MAKES THIS MOVEMENT
UNCERTAIN. OBJECTIVE AIDS ARE TIGHTLY LINED UP WITH A GENERAL
WEST TO WEST-NORTHWEST MOTION THROUGH TWO DAYS AS THREE-C MOVES
SOUTH OF A MID-LEVEL RIDGE BUILDING WESTWARD. IN ABOUT THREE DAYS...
A WEAKNESS IS FORECAST TO DEVELOP IN THE RIDGE WHICH WOULD RESULT IN
A SLOWING OF FORWARD MOTION AND A GRADUAL TURN TOWARD THE NORTH OR
NORTH-NORTHEAST. THE MAIN DYNAMICAL AIDS DIFFER ON THE LOCATION OF
THE TURN WITH THE HWRF AND GFS ON THE EAST SIDE OF THE ENVELOPE AND
THE ECMWF ON THE WEST SIDE. THE TIMING OF THE TURN WILL DEPEND
GREATLY ON WHEN THE WEAKNESS IN THE RIDGE OCCURS. THE LONGER IT
TAKES...THE FARTHER WEST THE CYCLONE WILL MOVE BEFORE MAKING THE
TURN AND THIS ASPECT OF THE FORECAST CONTAINS A HIGH AMOUNT OF
UNCERTAINTY. THE FORECAST CLOSELY FOLLOWS THE DYNAMIC CONSENSUS
THROUGH THE PACKAGE WITH THE TROPICAL CYCLONE APPROACHING
THE WEST SIDE OF THE MAIN HAWAIIAN ISLANDS IN FIVE DAYS.

TROPICAL DEPRESSION THREE-C IS MOVING OVER VERY WARM WATER...OVER
29C...BASED ON THE LATEST ANALYSIS. THERE APPEARS TO BE SOME
EASTERLY SHEAR IMPACTING THE SYSTEM BASED ON THE FLATTENING OF THE
HIGH LEVEL CLOUDS ON THE EAST SIDE AND THE CIMSS 1800 UTC SHEAR
ANALYSIS SHOWING MORE THAN 20 KT. THIS SHEAR IS FORECAST TO STEADILY
DECREASE OVER THE NEXT TWO TO THREE DAYS AS THE DEPRESSION MOVES
UNDERNEATH THE UPPER LEVEL RIDGE AXIS. THE WEAKENING SHEAR AND
THE VERY WARM WATERS SHOULD ALLOW FOR STEADY DEVELOPMENT. THE
SHIPS RAPID INTENSIFICATION PARAMETER ALSO SHOWS A 47 PERCENT
PROBABILITY FOR THE 25 KT THRESHOLD. THUS...THE FORECAST CALLS FOR
THREE-C TO BECOME A TROPICAL STORM WITHIN THE NEXT 24 HOURS AND A
HURRICANE IN ABOUT TWO DAYS SOUTH-SOUTHWEST OF THE MAIN HAWAIIAN
ISLANDS. THIS IS IN LINE WITH THE IVCN CONSENSUS.

U.S AIR FORCE RESERVE WEATHER RECONNAISSANCE ASSETS ARE IN THE
PROCESS OF DEPLOYING TO HAWAII AND A WC-130J IS SCHEDULED TO MAKE AN
INITIAL PASS THROUGH THREE-C FRIDAY EVENING.


FORECAST POSITIONS AND MAX WINDS

INIT 20/2100Z 11.0N 150.2W 30 KT 35 MPH
12H 21/0600Z 12.1N 152.0W 40 KT 45 MPH
24H 21/1800Z 12.9N 154.8W 45 KT 50 MPH
36H 22/0600Z 13.7N 158.0W 60 KT 70 MPH
48H 22/1800Z 14.9N 160.8W 70 KT 80 MPH
72H 23/1800Z 17.4N 163.4W 80 KT 90 MPH
96H 24/1800Z 19.6N 163.0W 85 KT 100 MPH
120H 25/1800Z 21.0N 162.0W 85 KT 100 MPH

$$
FORECASTER KODAMA

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Tropical Storm Kilo forms 720 miles SE of Honolulu. Tropical Storm conditions are expected to develop Monday across Honolulu and Waikiki Beach. Depending on the eventual track of Kilo, conditions may further deteriorate Monday night into Tuesday.

TROPICAL STORM KILO DISCUSSION NUMBER 4
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032015
500 AM HST FRI AUG 21 2015

AN AREA OF PERSISTENT DEEP CONVECTION ASSOCIATED WITH THE CYCLONE
HAS BEEN EXPANDING SINCE THE PREVIOUS ADVISORY...WHILE TRACKING
STEADILY TOWARD THE WEST-NORTHWEST. THE LOW-LEVEL CIRCULATION CENTER
/LLCC/ IS ESTIMATED TO BE ON SOUTHEAST EDGE OF THIS DEEP
CONVECTION...WITH BI-SPECTRAL IMAGERY HELPING TO HIGHLIGHT LOW CLOUD
MOTIONS ASSOCIATED WITH APPEARS TO BE A PARTIALLY EXPOSED LLCC. THIS
POSITION ESTIMATE CORRELATES WELL WITH SHEAR EVALUATIONS FROM
UW-CIMSS AND SHIPS GUIDANCE...WHICH INDICATE EASTERLY SHEAR ON THE
ORDER OF 15 TO 20 KT. DVORAK CURRENT INTENSITY ESTIMATES RANGE FROM
1.0/25 KT TO 3.0/45 KT...AND WITH THE LLCC ESTIMATED TO BE
RELATIVELY CLOSE TO THE DEEP CONVECTION...THE SYSTEM IS BEING
UPGRADED TO A 35 KT TROPICAL STORM WITH THIS ADVISORY...AND
HAS BEEN NAMED KILO.

THE INITIAL MOTION ESTIMATE FOR THIS ADVISORY IS 295/14 KT...WITH
THE STORM BEING DRIVEN WEST-NORTHWESTWARD BY A MID- AND UPPER-LEVEL
RIDGE CENTERED TO THE NORTH-NORTHEAST. THE CYCLONE IS FORECAST TO
MOVE ON THIS GENERAL TRAJECTORY THROUGH THE NEXT 36 TO 48 HOURS...
WITH A WEAKNESS IN THE RIDGE FORECAST TO DEVELOP THEREAFTER. AFTER
THIS TIME...THE FORWARD SPEED OF THE CYCLONE IS FORECAST TO DIMINISH
SIGNIFICANTLY AS IT MOVES INTO THIS WEAKNESS...WITH A GRADUAL TURN
TOWARD THE NORTH-NORTHEAST. THE DYNAMICAL MODELS DIFFER ON THE
TIMING AND LOCATION OF THIS TURN DUE TO DIFFERENCES IN THE
STRENGTH OF THE RIDGE...WITH THE HWRF REMAINING ON THE EAST SIDE OF
THE GUIDANCE ENVELOPE AND THE TVCN CONSENSUS ON THE WEST SIDE...DUE
TO THE ECMWF...WHICH REMAINS ON THE WESTERN SIDE OF THE ENVELOPE. THE
UPDATED TRACK FORECAST HAS BEEN NUDGED TO THE LEFT...IS NEAR THE
MIDDLE OF A WELL CLUSTERED GUIDANCE ENVELOPE THROUGH DAY 3...AND
LIES CLOSE TO A BLEND OF THE HWRF...GFS AND GFDL ON DAYS 4 AND 5.

KILO IS MOVING OVER VERY WARM WATER...ABOVE 29C IN THE LATEST
ANALYSIS...AND THE OCEAN HEAT CONTENT ANALYSIS FROM RAMMB-CIRA
INDICATES INCREASING VALUES ALONG THE FORECAST TRACK. EASTERLY SHEAR
IS EXPECTED TO SLOWLY WEAKEN LATER TODAY...AND THEN REMAIN RATHER
WEAK THROUGH DAY 3. THESE FACTORS SUGGEST THAT THE STORM WILL
STRENGTHEN...AND THE LATEST DYNAMICAL AND STATISTICAL MODELS AGREE.
WHILE THE UPDATED INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS...
THE RATE OF INTENSIFICATION HAS BEEN SLOWED...AND REPRESENTS A BLEND
OF THE PREVIOUS FORECAST AND THE ICON INTENSITY CONSENSUS.

THE U.S. 53RD WEATHER RECONNAISSANCE SQUADRON /WRS/ WILL BEGIN
FLIGHTS INTO KILO THIS EVENING...AND WILL CONTINUE TO DO SO AT 12
HOURLY INTERVALS UNTIL FURTHER NOTICE...PROVIDING CRITICAL INSIGHT
INTO KILO/S STRUCTURE AND INTENSITY. WITH THE G-IV AIRCRAFT TASKED
IN THE ATLANTIC...THE 53RD WRS IS ALSO SCHEDULED TO DO A SYNOPTIC
SURVEILLANCE MISSION ON SATURDAY MORNING IN ORDER TO SAMPLE THE
STRENGTH OF RIDGE TO THE NORTH OF KILO.


FORECAST POSITIONS AND MAX WINDS

INIT 21/1500Z 12.7N 151.7W 35 KT 40 MPH
12H 22/0000Z 13.5N 154.0W 40 KT 45 MPH
24H 22/1200Z 14.2N 157.2W 40 KT 45 MPH
36H 23/0000Z 15.2N 160.0W 45 KT 50 MPH
48H 23/1200Z 16.3N 162.0W 50 KT 60 MPH
72H 24/1200Z 18.4N 162.3W 65 KT 75 MPH
96H 25/1200Z 20.0N 162.0W 75 KT 85 MPH
120H 26/1200Z 21.5N 161.5W 85 KT 100 MPH

$$

FORECASTER BIRCHARD