WTPA43 PHFO 231459 RRA

TCDCP3



TROPICAL STORM DARBY DISCUSSION NUMBER  48

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP052016

500 AM HST SAT JUL 23 2016



DEEP CONVECTION ASSOCIATED WITH DARBY HAS INCREASED ONCE AGAIN THIS

MORNING, WITH THE BULK OF THIS ACTIVITY NOW ACROSS THE SYSTEM'S

SOUTHEAST SEMICIRCLE. OUTFLOW REMAINS BEST WITHIN THE NORTHEAST

QUADRANT, BUT IS RESTRICTED THROUGHOUT THE SOUTH SEMICIRCLE, THANKS

TO CONTINUED 7 TO 10 KT SOUTHWEST SHEAR. LOW CLOUD SWIRLS EAST OF

THE LLCC ADD CONFIDENCE TO THE INITIAL POSITION BASED HEAVILY ON

SATELLITE FIXES. HOWEVER, DARBY CONTINUES TO DEFY PREDICTIONS TO

GAIN LATITUDE. GIVEN THE CONTINUED MESSY SATELLITE PRESENTATION AND

THE LACK OF AIRCRAFT DATA FOR THIS PACKAGE, IT'S POSSIBLE THAT THIS

SYSTEM IS A TENTH OF A DEGREE OR TWO FARTHER SOUTH. THE NEXT

FORECAST PACKAGE MAY BENEFIT FROM LAND-BASED WEATHER RADAR POSITION

ESTIMATES. INITIAL INTENSITY IS DECREASED TO 45 KT AS A COMPROMISE

BETWEEN CONTINUED 35 KT OBJECTIVE DVORAK SATELLITE INTENSITY

ESTIMATES AND EARLIER SFMR INTENSITY FROM RECONNAISSANCE AIRCRAFT.

THE NEXT AIRCRAFT RECONNAISSANCE MISSION WILL BE LATER THIS MORNING.



INITIAL MOTION IS 275/08 KT, REPRESENTING A GRADUAL SLOWING OVER

THE PAST 12 HOURS. HOWEVER, THIS IS A 12 HOUR MOTION. DARBY HAS NOT

GAINED LATITUDE OVER THE PAST 6 HOURS AND WE MAY FIND OUT LATER

THAT A SMALL SOUTHWARD COMPONENT EXISTS WHEN RADAR ESTIMATES BECOME

AVAILABLE. DARBY IS MOVING WESTWARD ALONG THE SOUTHERN FLANK OF THE

SUBTROPICAL RIDGE. GLOBAL MODELS CONTINUE TO DEPICT A WEAKNESS IN

THIS RIDGE BETWEEN 150W AND 160W DUE TO LOW PRESSURE DIGGING IN FROM

THE NORTH. ALL MODELS CONTINUE TO SHOW DARBY SLOWING AND=