WTPA44 PHFO 120240

TCDCP4



TROPICAL STORM NORA DISCUSSION NUMBER  11

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP182015

500 PM HST SUN OCT 11 2015



NORA IS A COMPACT TROPICAL SYSTEM...AND THE CENTRAL DENSE OVERCAST

AREA HAS BECOME SMALLER THIS AFTERNOON. LOW CLOUD LINES APPEAR TO

PLACE THE LOW LEVEL CIRCULATION CENTER...LLCC...BENEATH THE EASTERN

EDGE OF DEEPEST CONVECTION. A 2339 UTC SSMI MICROWAVE PASS...WHILE

NOT CONCLUSIVE...MARGINALLY SUPPORTS THE INITIAL POSITION...BUT

CONFIDENCE IS NOT VERY HIGH WITHOUT AN INFRARED WARM SPOT OR A

VISIBLE EYE. THIS SAME SSMI PASS SHOWED A LACK OF AN EYEWALL ACROSS

THE EASTERN SEMICIRCLE. SUBJECTIVE DVORAK SATELLITE INTENSITY

ESTIMATES RANGED FROM 3.5...55 KT...FROM JTWC TO 4.0...65 KT...FROM

PHFO AND SAB. UW-CIMSS ADT REMAINED 3.9...63 KT. NORA LOOKS NO

BETTER ORGANIZED THAN IT DID THIS MORNING AND...WITH NO

COMPLETE EYEWALL DEPICTED IN MICROWAVE IMAGERY...WE WILL HOLD THE

INITIAL INTENSITY AT 60 KT FOR THIS ADVISORY.



ANIMATION AND SUCCESSIVE SSMI PASSES SEEM TO SHOW THAT NORA IS

MAINTAINING A MORE NORTHERLY TRACK THIS AFTERNOON THAN IT WAS

OVERNIGHT. INITIAL MOTION IS SET AT 300/08 KT...NOTICEABLY SLOWER

THAN BEFORE. TRACK GUIDANCE CONTINUES TO DEPICT NORA MOVING

WEST NORTHWESTWARD THROUGH 36 HOURS...ALONG THE SOUTHWEST FLANK OF

MID-LEVEL RIDGING TO THE NORTHEAST OF THIS SYSTEM. GUIDANCE THEN

RECURVES NORA NORTHWARD ON DAYS TWO AND THREE...THEN NORTHEASTWARD

ON DAYS FOUR AND FIVE AS A DEEP TROUGH NORTH OF HAWAII MOVES

EAST...WEAKENS THE RIDGE...AND SCOOPS NORA OUT OF THE DEEP TROPICS.

THE SPREAD IN TRACK GUIDANCE IS DUE TO DIFFERENCES IN INITIAL

MOTION AND FORWARD SPEED DURING RECURVATURE. IN SPITE OF THIS

UNCERTAINTY...ALL OF THE GUIDANCE EITHER RECURVES NORA NORTHEASTWARD

FAR FROM HAWAII...OR DECAPITATES NORA AND SHOVES THE REMNANTS WEST

SOUTHWESTWARD WITHIN THE TRADES.



INTENSITY GUIDANCE SHOWS THE WINDOW FOR STRENGTHENING WILL LIKELY

SLAM SHUT IN 12 HOURS. SHEAR ACROSS NORA HAS INCREASED INTO THE 15

TO 20 KT RANGE THIS AFTERNOON BUT...WITH SEA SURFACE TEMPERATURES

NEAR 29C...SHIPS AND LGEM ALLOW FOR A SMALL INTENSITY INCREASE

THROUGH TONIGHT. GUIDANCE THEN AGREES ON STEADY WEAKENING THROUGH

120 HOURS...WITH SHIPS DISSIPATING NORA AT 96 HOURS. WE WILL

CONTINUE TO PEAK NORA AT 65 KT...AS A HURRICANE...IN 12 HOURS.

HOWEVER...WE NOW FORECAST CONTINUED WEAKENING THEREAFTER.





FORECAST POSITIONS AND MAX WINDS



INIT  12/0300Z 13.5N 143.8W   60 KT  70 MPH

 12H  12/1200Z 14.0N 144.9W   65 KT  75 MPH

 24H  13/0000Z 14.7N 146.1W   60 KT  70 MPH

 36H  13/1200Z 15.4N 146.9W   60 KT  70 MPH

 48H  14/0000Z 16.1N 147.3W   55 KT  65 MPH

 72H  15/0000Z 17.9N 147.1W   50 KT  60 MPH

 96H  16/0000Z 20.4N 145.4W   45 KT  50 MPH

120H  17/0000Z 22.6N 143.3W   35 KT  40 MPH



$$

FORECASTER POWELL