“VERTICAL SHEAR HAS APPARENTLY HAD A BIGGER IMPACT ON OHO THAN EXPECTED. RIGHT AROUND THE LAST ADVISORY ISSUANCE TIME…2100 UTC… THE LOW LEVEL CIRCULATION CENTER REVEALED ITSELF TO BE SOUTHWEST OF THE PREVIOUSLY ANALYZED POSITION. THE WORKING BEST TRACK HAS BEEN ADJUSTED BY ANALYZING OLDER DATA AS FAR BACK AS YESTERDAY TO TRY AND IDENTIFY THE MOTION OF THE ACTUAL CENTER.

THE SATELLITE PRESENTATION OF OHO HAS DETERIORATED THROUGH THE DAY WITH WARMER CLOUD TOPS AND A REDUCTION IN THE OUTFLOW. FOR NOW… A LARGE RAINBAND EMBEDDED WITHIN THE STRONG SOUTHWESTERLY MONSOON FLOW HAS BECOME THE DOMINANT FEATURE IN THE AREA AND MAY BE HINDERING THE DEVELOPMENT OF OHO. THE LATEST DVORAK ESTIMATES FROM THE FIX AGENCIES REFLECT THE NEW POSITION OF THE LOW LEVEL CENTER WITH INTENSITIES OF 2.5/35 KT FROM PHFO AND JTWC… AND 2.0/30 KT FROM SAB. THE CIMSS ADT ANALYSIS OF 55 KT AT 0000 UTC IS NOT REPRESENTATIVE BECAUSE THE CENTER POSITION USED DOES NOT REFLECT THE RELOCATED COORDINATES.

AN ASCAT PASS FROM THIS MORNING SAMPLED THE OUTER CIRCULATION OF OHO AND PICKED UP SOUTHWESTERLY WINDS AT 35 KT ALMOST 300 NM SOUTHEAST OF THE CENTER. THIS STRONG GRADIENT FLOW SUGGESTS THAT OHO IS MORE LIKE A MONSOONAL LOW PRESSURE SYSTEM SEEN MORE OFTEN IN THE WESTERN NORTH PACIFIC. IT IS EXPECTED THAT DEEP CONVECTION WILL REDEVELOP AND CONCENTRATE NEAR THE SYSTEM CENTER TONIGHT OR SUNDAY… AND OHO SHOULD TAKE ON THE APPEARANCE OF A MORE CLASSICAL TROPICAL CYCLONE. THIS EXPECTATION IS DUE TO THE DECREASE IN VERTICAL WIND FROM 13 KT AT 1800 UTC TO 10 KT IN THE 0000 UTC CIMSS ANALYSIS. WITH WEAKENING SHEAR AND WARM SEA SURFACE TEMPERATURES WITHIN A MOIST ATMOSPHERIC ENVIRONMENT… THE FORECAST CALLS FOR INTENSIFICATION TO RESUME AND OHO TO BECOME A HURRICANE ON MONDAY. THIS MAY BE OVERLY AGGRESSIVE BUT IS IN LINE WITH THE INTENSITY CONSENSUS. NEEDLESS TO SAY… THERE IS A HIGHER THAN USUAL DEGREE OF UNCERTAINTY HERE.

THE INITIAL MOTION OF OHO IS 085/06 KT WITH THE LOW LEVEL FLOW PROVIDING THE SHORT TERM STEERING CURRENT. IF OHO REDEVELOPS PERSISTENT DEEP CONVECTION… A RIDGE BUILDING WESTWARD TO THE NORTHEAST OF THE CYCLONE SHOULD TURN THE SYSTEM TOWARD THE WEST-NORTHWEST. A NEW SHORT WAVE TROUGH IS PROJECTED TO DEEPEN THE LONG WAVE TROUGH NORTH OF OHO ON MONDAY… RESULTING IN A SHARP TURN BACK TO THE EAST OR NORTHEAST. THE RELOCATED CENTER AND THE POOR CURRENT CONDITION OF OHO HAS GREATLY INCREASED THE AMOUNT UNCERTAINTY INVOLVED IN THE TRACK FORECAST. CURRENT OBJECTIVE AIDS DO NOT YET REFLECT THE EFFECTS OF THE CHANGE IN POSITION ON THE OVERALL FORECAST. THESE CHANGES SHOULD MANIFEST ITSELF IN THE NEXT MODEL CYCLE. THE EXCEPTION TO THIS WILL BE THE GFS WHICH WE HAVE BEEN INFORMED DID NOT PROPERLY INITIALIZE POSITIONS OF ALL TROPICAL CYCLONES FOR THE 0000 UTC RUN. THE CURRENT FORECAST HAS MAINTAINED THE S-SHAPED TRACK OF THE PREVIOUS FORECAST BUT HAS BEEN SHIFTED EAST A BIT TO REFLECT A LATER TURN TO THE WEST-NORTHWEST. IF DEEP CONVECTION FAILS TO REDEVELOP… THE TRACK SHOULD APPEAR TO BE MORE LIKE THE BAMS FORECAST WITH OHO CONTINUING TOWARD THE EAST… THEN TURN TOWARD THE NORTHEAST AFTER ABOUT 36 HOURS.

THE 53RD WEATHER RECONNAISSANCE SQUADRON HAS BEEN TASKED TO FLY THIS SYSTEM IN SUPPORT OF CPHC OPERATIONS. INITIAL FLIGHTS INTO THE SYSTEM ARE PLANNED FOR SUNDAY EVENING AND MONDAY MORNING. THE G-IV AIRCRAFT IS ALSO HEADING TO HAWAII TO FLY SYNOPTIC MISSIONS… WITH HIGH-ALTITUDE FLIGHTS PLANNED FOR SUNDAY AND MONDAY MORNINGS… IN ORDER FOR THE DATA TO BE UTILIZED BY AFTERNOON MODEL RUNS.

FORECAST POSITIONS AND MAX WINDS

INIT 04/0300Z 12.9N 154.2W 35 KT 40 MPH
12H 04/1200Z 13.6N 154.3W 40 KT 45 MPH
24H 05/0000Z 13.8N 154.9W 50 KT 60 MPH
36H 05/1200Z 14.2N 155.0W 60 KT 70 MPH
48H 06/0000Z 14.5N 154.6W 65 KT 75 MPH
72H 07/0000Z 15.0N 153.0W 70 KT 80 MPH
96H 08/0000Z 16.5N 151.5W 70 KT 80 MPH
120H 09/0000Z 20.0N 149.5W 60 KT 70 MPH”National Weather Service on Oct. 3, 2015