163
WTPZ45 KNHC 020242
TCDEP5
TROPICAL STORM OCTAVE DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP152025
800 PM PDT WED OCT 01 2025
THE SATELLITE PRESENTATION OF OCTAVE HAS IMPROVED SLIGHTLY SINCE THE
PREVIOUS ADVISORY, WITH BETTER-DEFINED CURVED BANDING DEVELOPING ON
THE SOUTH AND WEST SIDES OF THE LOW-LEVEL CENTER. THE CYCLONE
CONTINUES TO BE INFLUENCED BY MODERATE EASTERLY WIND SHEAR, ANALYZED
AT AROUND 22 KT BY UW-CIMSS. THIS SHEAR IS RESTRICTING OUTFLOW IN
THE EASTERN SEMICIRCLE AND KEEPING THE LOW-LEVEL CENTER DISPLACED ON
THE EASTERN SIDE OF THE DEEPER CONVECTION. THE MOST RECENT
SUBJECTIVE DVORAK INTENSITY ESTIMATE FROM TAFB WAS 3.5/55 KT, WHILE
THE UW-CIMSS OBJECTIVE ESTIMATES HAVE RANGED FROM 45 TO 58 KT SINCE
THE PRIOR ADVISORY. BASED ON A BLEND OF THESE DATA, AND CONSIDERING
THE MODEST IMPROVEMENT IN THE SATELLITE PRESENTATION DURING THE PAST
SEVERAL HOURS, THE INITIAL INTENSITY IS HELD AT 55 KT FOR THIS
ADVISORY.
OCTAVE IS ESTIMATED TO BE MOVING WEST-NORTHWESTWARD, OR 290 DEGREES
AT 6 KT. THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT
SEVERAL DAYS AS OCTAVE IS STEERED ALONG THE SOUTHERN PERIPHERY OF A
SUBTROPICAL RIDGE LOCATED TO ITS NORTH. BY DAYS 4 AND 5, OCTAVE IS
FORECAST TO SLOW CONSIDERABLY AND TURN NORTHWARD, THEN EASTWARD, AS
A LONGWAVE TROUGH APPROACHES FROM THE NORTHWEST AND THE SUBTROPICAL
RIDGE TO ITS EAST WEAKENS DUE TO THE INFLUENCE OF A LARGER TROPICAL
CYCLONE DEVELOPING OFFSHORE OF THE SOUTHWESTERN OR WEST-CENTRAL
COAST OF MEXICO. THE NEW NHC TRACK FORECAST IS SIMILAR TO THE
PREVIOUS ONE AND REMAINS CLOSE TO A BLEND OF THE MULTI-MODEL
CONSENSUS AND AI-BASED TRACK AIDS.
OCTAVE WILL REMAIN OVER WARM WATERS AND WITHIN A MOIST ENVIRONMENT
FOR THE NEXT FEW DAYS. HOWEVER, VERTICAL WIND SHEAR IS FORECAST TO
FLUCTUATE BETWEEN MODERATE AND STRONG LEVELS DURING THE NEXT 36
HOURS, WHICH SHOULD INHIBIT SIGNIFICANT INTENSIFICATION DURING THAT
PERIOD. AS A RESULT, THE OFFICIAL FORECAST INDICATES LITTLE CHANGE
IN STRENGTH THROUGH THAT TIME. SOME MODEST STRENGTHENING IS THEN
FORECAST BETWEEN 48 AND 96 HOURS AS THE SHEAR RELAXES, ALTHOUGH SEA
SURFACE TEMPERATURES WILL GRADUALLY COOL AND MID-LEVEL MOISTURE IS
EXPECTED TO DECREASE. THE OFFICIAL FORECAST NOW SHOWS OCTAVE
REACHING HURRICANE INTENSITY BY DAYS 3 AND 4, THOUGH THIS REMAINS
BELOW THE MORE AGGRESSIVE SOLUTIONS FROM SOME REGIONAL HURRICANE
MODELS. BY DAY 5, WEAKENING SHOULD BE WELL UNDERWAY AS OCTAVE MOVES
INTO A DRIER, MORE STABLE AIR MASS, OVER COOLER WATERS AROUND 26C,
AND EXPERIENCES INCREASING SHEAR. THE OFFICIAL FORECAST IS SIMILAR
TO THE PREVIOUS ONE AND REMAINS MOST CLOSELY ALIGNED WITH THE HCCA
AND FSSE INTENSITY AIDS.
FORECAST POSITIONS AND MAX WINDS
INIT 02/0300Z 12.2N 117.0W 55 KT 65 MPH
12H 02/1200Z 12.6N 117.8W 55 KT 65 MPH
24H 03/0000Z 13.1N 119.1W 55 KT 65 MPH
36H 03/1200Z 13.5N 120.5W 55 KT 65 MPH
48H 04/0000Z 14.0N 121.9W 60 KT 70 MPH
60H 04/1200Z 14.5N 123.0W 60 KT 70 MPH
72H 05/0000Z 15.0N 123.8W 65 KT 75 MPH
96H 06/0000Z 15.7N 123.2W 65 KT 75 MPH
120H 07/0000Z 16.0N 121.5W 50 KT 60 MPH
FORECASTER JELSEMA (CPHC)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page