WTPA31 PHFO 210249
TCPCP1

BULLETIN
TROPICAL DEPRESSION THREE-C ADVISORY NUMBER 2
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032015
500 PM HST THU AUG 20 2015

…TROPICAL DEPRESSION THREE-C MOVING WEST FAR SOUTHEAST OF THE
HAWAIIAN ISLANDS…

SUMMARY OF 500 PM HST…0300 UTC…INFORMATION
———————————————-
LOCATION…11.0N 151.5W
ABOUT 645 MI…1040 KM SSE OF HILO HAWAII
ABOUT 830 MI…1330 KM SSE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS…35 MPH…55 KM/H
PRESENT MOVEMENT…W OR 280 DEGREES AT 16 MPH…26 KM/H
MINIMUM CENTRAL PRESSURE…1005 MB…29.68 INCHES

WATCHES AND WARNINGS
——————–
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

DISCUSSION AND 48-HOUR OUTLOOK
——————————
AT 500 PM HST…0300 UTC…THE CENTER OF TROPICAL DEPRESSION THREE-C
WAS LOCATED NEAR LATITUDE 11.0 NORTH…LONGITUDE 151.5 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST NEAR 16 MPH…26 KM/H. A WEST
TO WEST-NORTHWEST MOTION IS EXPECTED OVER THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH…55 KM/H…WITH HIGHER
GUSTS. THREE-C IS EXPECTED TO STEADILY STRENGTHEN AND MAY BECOME A
HURRICANE WITHIN THE NEXT 48 HOURS.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB…29.68 INCHES.

HAZARDS AFFECTING LAND
———————-
NONE.

NEXT ADVISORY
————-
NEXT COMPLETE ADVISORY…1100 PM HST.

$$
FORECASTER KODAMA



WTPA41 PHFO 210250
TCDCP1

TROPICAL DEPRESSION THREE-C DISCUSSION NUMBER 2
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032015
500 PM HST THU AUG 20 2015

THE ORGANIZATION OF TROPICAL DEPRESSION THREE-C HAS NOT IMPROVED
THROUGH THE DAY AND THE CONFIDENCE IN THE CENTER POSITION REMAINS
POOR. AT AROUND 0000 UTC…AN APPARENT LOW LEVEL CLOUD SWIRL
APPEARED FROM BENEATH THE MAIN CLOUD MASS AND MOVED TOWARD THE
NORTHEAST. WHILE IT IS POSSIBLE THAT THIS IS THE LOW LEVEL CENTER
OF THE SYSTEM…LOW CLOUD LINE CURVATURE TO THE NORTHWEST OF THE
CIRRUS SHIELD AND THE CURVATURE OF THE WIND FIELD IN AN EARLIER
ASCAT PASS SUGGEST THAT A CENTER COULD BE SOUTH OF THE DEEPEST
CONVECTION. THIS WOULD BE CONSISTENT WITH THE CONTINUITY OF THE
PREVIOUSLY DERIVED MOTION. THE 0011 UTC AMSU PASS WAS NOT
CONSIDERED TO BE CONCLUSIVE IN DETERMINING THE CENTER POSITION.
DVORAK INTENSITY ESTIMATES CAME IN AT 35 KT FROM PHFO…30 KT FROM
SAB AND 25 KT FROM JTWC. THE INITIAL INTENSITY FOR THIS PACKAGE HAS
BEEN HELD AT 30 KT.

THE INITIAL MOVEMENT FOR THIS PACKAGE IS 280/14 KT. OBJECTIVE AIDS
REMAIN TIGHTLY LINED UP WITH A GENERAL WEST-NORTHWEST MOTION OVER
THE NEXT COUPLE OF DAYS AS THE SYSTEM MOVES SOUTH OF A MID-LEVEL
RIDGE BUILDING WESTWARD. A WEAKNESS IN THE RIDGE IS EXPECTED TO
DEVELOP WHICH WOULD RESULT IN A DECREASE IN FORWARD MOTION AND A
GRADUAL TURN TOWARD THE NORTH OR NORTH-NORTHEAST. THE MAIN DYNAMICAL
MODELS DIFFER ON THE LOCATION OF THE TURN WITH THE HWRF AND GFS
REMAINING ON THE EAST SIDE OF THE GUIDANCE ENVELOPE AND THE ECMWF ON
THE WEST SIDE. THE TIMING OF THE TURN WILL DEPEND ON WHEN THE
WEAKNESS IN THE MID-LEVEL RIDGE OCCURS. THE LONGER IT TAKES…THE
FARTHER WEST THE CYCLONE WILL MOVE BEFORE TURNING AND THIS ASPECT OF
THE FORECAST HAS THE MOST UNCERTAINTY. THIS FORECAST PACKAGE
HAS BEEN ADJUSTED SOUTH FROM THE PREVIOUS PACKAGE AND IS BETWEEN
THE DYNAMIC CONSENSUS AND HWRF THROUGH 36 HOURS THEN IS
EAST OF THE DYNAMICAL MODEL ENVELOPE THROUGH THE REMAINDER OF THE
FORECAST PERIOD. NOTE THAT IF THE LOW CENTER HAS INDEED SHIFTED TO
THE NORTHEAST AND DEEP CONVECTION REDEVELOPS NEAR IT…SUBSEQUENT
FORECASTS WILL HAVE TO BE ADJUSTED TO ACCOUNT FOR THIS CHANGE.

THREE-C IS MOVING OVER VERY WARM WATER…ABOVE 29C IN THE LATEST
ANALYSIS. EASTERLY SHEAR CONTINUES TO IMPACT THE SYSTEM BUT IS
EXPECTED TO STEADILY WEAKEN AT LEAST THROUGH 48 HOURS AND REMAIN
WEAK THROUGH 96 HOURS. THESE FACTORS SUGGEST THAT THE DEPRESSION
SHOULD CONTINUE TO STRENGTHEN…ASSUMING THAT THE LOW LEVEL CENTER
HAS NOT BEEN DECOUPLED FROM THE SYSTEM. THE CURRENT FORECAST
CONSERVATIVELY HOLDS THE COURSE WITH THE PREVIOUS FORECAST AND CALLS
FOR THREE-C TO BECOME A TROPICAL STORM WITHIN THE NEXT 24 HOURS AND
A HURRICANE IN ABOUT TWO DAYS. THIS IS IN LINE WITH THE INTENSITY
CONSENSUS GUIDANCE. AS WITH THE TRACK FORECAST…THE INTENSITY
FORECAST WILL NEED TO BE ADJUSTED IF THE LOW LEVEL CENTER HAS BECOME
SEPARATED FROM THE REST OF THE SYSTEM.

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. THIS WILL PROVIDE
VALUABLE DATA TO HELP BETTER DETERMINE THE LOCATION OF THE SYSTEM
CENTER AND THE DISTRIBUTION OF THE WIND FIELD.

FORECAST POSITIONS AND MAX WINDS

INIT 21/0300Z 11.0N 151.5W 30 KT 35 MPH
12H 21/1200Z 11.5N 153.6W 35 KT 40 MPH
24H 22/0000Z 12.3N 156.4W 45 KT 50 MPH
36H 22/1200Z 13.2N 159.3W 60 KT 70 MPH
48H 23/0000Z 14.7N 162.0W 70 KT 80 MPH
72H 24/0000Z 17.3N 163.7W 80 KT 90 MPH
96H 25/0000Z 19.5N 163.0W 85 KT 100 MPH
120H 26/0000Z 21.0N 162.0W 85 KT 100 MPH

$$
FORECASTER KODAMA