WTPA44 PHFO 150244

TCDCP4



TROPICAL DEPRESSION NORA DISCUSSION NUMBER  23

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP182015

500 PM HST WED OCT 14 2015



NORA CONTINUES TO WEAKEN...BUT VERY SLOWLY. THE LOW CLOUD LINES

AROUND THE CENTER OF NORA HAVE BECOME LESS TIGHTLY WRAPPED...MORE

SPIRAL SHAPED THAN CIRCULAR...OVER THE PAST 24 HOURS BUT

CUMULONIMBUS CLOUDS CONTINUE TO FORM NORTHEAST OF THE CENTER. THERE

HAVE BEEN NO RECENT SCATTEROMETER PASSES OVER THE SYSTEM.

SUBJECTIVE DVORAK INTENSITY ANALYSES WERE 1.5/25 KNOTS FROM HFO...

JTWC AND SAB...WHILE THE OBJECTIVE ANALYSIS FROM UW-CIMSS WAS

2.3/33 KNOTS. I HAVE KEPT THE INITIAL INTENSITY AT 25 KNOTS.



THE LOW LEVEL CIRCULATION CENTER HAS REMAINED EXPOSED MOST OF THE

DAY...ALLOWING HIGH CONFIDENCE IN THE FIX POSITIONS. THE FORWARD

MOTION HAS BEEN 325 DEGREES AT 5 KT FOR THE PAST SEVERAL HOURS. THE

FORECAST TRACK HAS BEEN SHIFTED TO THE RIGHT...FARTHER NORTH...THAN

THE PREVIOUS TRACK BASED ON THE RECENT MOTION.



NORA IS PART OF A TROUGH IN THE EASTERLY TRADE-WIND FLOW SOUTH OF

THE SUBTROPICAL RIDGE. OVER THE NEXT 36 HOURS OR SO THE TROUGH WILL

BULGE NORTH INTO A WEAKNESS IN THE RIDGE AND THE DEPRESSION WILL

CONTINUE MOVING SLOWLY NORTHWESTWARD IN THIS TROUGH. AFTER 36

HOURS THE SUBTROPICAL RIDGE WILL REBUILD AND NORA WILL MOVE OFF TO

THE WEST SOUTHWEST.



STRONG VERTICAL WIND SHEAR...VWS...CONTINUES OVER NORA WITH SHIPS

AND UW-CIMSS BOTH SHOWING ABOUT 36 KNOTS OF SHEAR FROM THE

SOUTHWEST. THE DEPRESSION HAS PROBABLY SURVIVED ONLY BECAUSE IT HAS

REMAINED OVER VERY WARM 28 DEGREE CELSIUS WATER. THE VWS IS

FORECAST TO REMAIN OVER 35 KNOTS OVERNIGHT. WE EXPECT THAT WILL BE

ENOUGH TO SHEAR AWAY THE REMAINING CONVECTION NEAR THE DEPRESSION

AND THAT NORA WILL WEAKEN TO A POST-TROPICAL/REMNANT LOW BY

TOMORROW.



THE WIND FIELD AROUND NORA IS FORECAST TO CONTINUE TO WEAKEN BUT

THE MOISTURE FIELD WILL LIKELY HELP BOOST RAINFALL OVER THE MAIN

HAWAIIAN ISLANDS THROUGH THE WEEKEND. SEE THE PUBLIC FORECASTS FROM

THE WEATHER FORECAST OFFICE IN HONOLULU FOR DETAILS.





FORECAST POSITIONS AND MAX WINDS



INIT  15/0300Z 15.5N 151.4W   25 KT  30 MPH

 12H  15/1200Z 16.0N 151.7W   25 KT  30 MPH

 24H  16/0000Z 16.6N 152.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

 36H  16/1200Z 16.8N 152.6W   20 KT  25 MPH...POST-TROP/REMNT LOW

 48H  17/0000Z 16.7N 154.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

 72H  18/0000Z 16.0N 156.9W   20 KT  25 MPH...POST-TROP/REMNT LOW

 96H  19/0000Z...DISSIPATED



$$

FORECASTER DONALDSON