184 
 WTPA41 PHFO 112058
 TCDCP1
 
 TROPICAL STORM PALI DISCUSSION NUMBER  18
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012016
 ISSUED BY NWS NATIONAL HURRICANE CENTER MIAMI FL
 1100 AM HST MON JAN 11 2016
 
 DURING THE PAST SIX HOURS...THE OVERALL CLOUD PATTERN OF PALI HAS
 IMPROVED...INCLUDING THE DEVELOPMENT OF A RAGGED 20 NMI DIAMETER EYE
 FEATURE IN VISIBLE...INFRARED...AND PASSIVE MICROWAVE SATELLITE
 IMAGERY. THE UPPER-LEVEL OUTFLOW HAS ALSO IMPROVED...WITH PRONOUNCED
 CIRRUS BANDING NOW QUITE EVIDENT IN THE SOUTHERN SEMICIRCLE. THE
 INITIAL INTENSITY HAS BEEN INCREASED TO 60 KT BASED ON A BLEND OF
 SATELLITE INTENSITY ESTIMATES OF T4.0 FROM SAB AND 3.9/63 KT FROM
 UW-CIMSS ADT...WHICH IS SLIGHTLY LOWER THAN THE AVERAGE OF THOSE
 ESTIMATES SINCE THE EYE FEATURE HAS ONLY DEVELOPED DURING THE PAST
 FEW HOURS.
 
 THE INITIAL MOTION IS 090/02 KT. THERE IS NO SIGNIFICANT CHANGE TO
 THE PREVIOUS FORECAST TRACK REASONING OR MODEL GUIDANCE. THE GLOBAL
 AND HURRICANE MODELS REMAIN IN DECENT AGREEMENT ON THE SUBTROPICAL
 RIDGE TO THE NORTH OF PALI ALONG 15N CONTINUING TO BUILD EASTWARD
 AND ALSO EXPAND SOUTHWARD. THIS SHOULD ACT TO DRIVE THE CYCLONE
 SOUTHWARD AROUND THE EASTERN PERIPHERY OF THE RIDGE DURING THE NEXT
 48 HOURS OR SO...FOLLOWED BY A WESTWARD MOTION ON DAYS 3-5 AS PALI
 BECOMES INFLUENCED BY DEEP EASTERLY STEERING FLOW ON THE SOUTH SIDE
 OF THE SUBTROPICAL RIDGE. THE OFFICIAL FORECAST TRACK HAS BEEN
 NUDGED A LITTLE TO THE WEST OF AND FASTER THAN THE PREVIOUS
 FORECAST TRACK...AND LIES CLOSE TO THE CONSENSUS OF THE GFS AND
 ECMWF MODELS THROUGH 72 HOURS. THE OFFICIAL FORECAST MORE CLOSELY
 FOLLOWS A GFS-HWRF SOLUTION AFTER THAT TIME DUE TO THE ECMWF MODEL
 SIGNIFICANTLY WEAKENING PALI AND DRIVE IT MORE SOUTHWARD NEAR THE
 EQUATOR ON DAYS 4-5.
 
 GIVEN THE CURRENT STRUCTURE OF PALI AND THE DEEP-LAYER VERTICAL
 SHEAR ONLY EXPECTED TO BE AROUND 12-14 KT FOR THE NEXT 24-36 HOURS
 WHILE PALI REMAINS OVER 28C-28.5C SSTS...THE POSSIBILITY OF THE
 CYCLONE ACHIEVING HURRICANE STATUS SEEMS FAIRLY REASONABLE...DESPITE
 ITS LOW LATITUDE. THE ONLY HINDERING FACTOR TO SIGNIFICANT
 STRENGTHENING IS PROXIMITY TO VERY DRY MID-LEVEL AIR NOTED IN A 1234
 UTC GCOM-AMSR2 WATER VAPOR IMAGE. AFTER THAT TIME...CROSS-EQUATORIAL
 UPPER-LEVEL SOUTHERLY FLOW ASSOCIATED WITH A BROAD SOUTHERN
 HEMISPHERE DISTURBANCE IS FORECAST TO INDUCE SOUTHERLY TO
 SOUTHWESTERLY VERTICAL WIND SHEAR OF NEAR 20 KT AT 48 AND 72 HOURS.
 THIS SHOULD INDUCE SOME SLOW WEAKENING...BUT NOT AS MUCH AS THE
 SHIPS/LGEM MODELS ARE SUGGESTING SINCE PALI WILL BE MOVING OVER 29C
 SSTS...WHICH SHOULD ACT TO INCREASE ATMOSPHERIC INSTABILITY AND
 ALLOW FOR PERIODIC BURSTS OF DEEP CONVECTION TO DEVELOP NEAR THE
 CENTER OF THE CYCLONE. BY DAYS 4 AND 5...THE SHEAR IS FORECAST TO
 DECREASE TO AROUND 5 KT...WHICH SHOULD ALLOW FOR PALI TO AT LEAST
 MAINTAIN ITS INTENSITY AT THAT TIME. SUCH LOW SHEAR CONDITIONS
 TYPICALLY FAVOR SIGNIFICANT STRENGTHENING. HOWEVER...A MORE
 CONSERVATIVE FORECAST APPROACH IS BEING USED SINCE PALI WILL BE
 CLOSE TO THE EQUATOR...FOR WHICH WE HAVE EXTREMELY LIMITED
 CLIMATOLOGICAL RECORDS ON TROPICAL CYCLONES OCCURRING SOUTH OF 3N
 LATITUDE IN THIS REGION OF THE WORLD.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  11/2100Z  8.3N 172.5W   60 KT  70 MPH
  12H  12/0600Z  7.8N 172.1W   65 KT  80 MPH
  24H  12/1800Z  6.8N 171.7W   60 KT  75 MPH
  36H  13/0600Z  5.5N 172.0W   55 KT  65 MPH
  48H  13/1800Z  4.4N 172.5W   50 KT  60 MPH
  72H  14/1800Z  3.4N 174.2W   50 KT  60 MPH
  96H  15/1800Z  3.0N 176.0W   50 KT  60 MPH
 120H  16/1800Z  3.0N 179.0W   50 KT  60 MPH
 
 $$
 FORECASTER STEWART