686
 WTPA45 PHFO 190851
 TCDCP5
 
 TROPICAL STORM UNALA DISCUSSION NUMBER   3
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP022013
 1100 PM HST SUN AUG 18 2013
 
 UNALA HAD A VERY SMALL AREA OF DEEP CONVECTION REMAINING NEAR ITS
 NORTHERN QUADRANT...BUT THAT APPEARS TO BE DYING AT BULLETIN TIME.
 THIS SYSTEM IS STRUGGLING AT THIS HOUR AS IT CONTINUES TO PUSH
 RAPIDLY WESTWARD UNDER THE HOSTILE OUTFLOW FROM RECENTLY UPGRADED
 TYPHOON PEWA...CENTERED NEAR 13.9N 177.9E AT 19/0600Z ACCORDING TO
 THE JOINT TYPHOON WARNING CENTER /JTWC/. THE INCREASING VERTICAL
 WIND SHEAR IS OBVIOUSLY TAKING A TOLL ON UNALA...SINCE ALL OF THE
 SATELLITE FIX AGENCIES INDICATED A CURRENT INTENSITY OF ONLY 2.0.
 HOWEVER...THE TIGHT PRESSURE GRADIENT NORTH OF THE TROPICAL CYCLONE
 CENTER IS LIKELY MAINTAINING WINDS OF AT LEAST 35 KT OVER PORTIONS
 OF THE NORTHERN SEMICIRCLE AT THIS TIME. SCATTEROMETER PASSES FROM
 EARLIER TODAY SHOWED THIS TYPE OF WIND FIELD...SO WE DO NOT BELIEVE
 THE WINDS HAVE DECREASED BELOW GALE FORCE AT THIS TIME. THEREFORE...
 WE WILL MAINTAIN UNALA AS A MINIMAL TROPICAL STORM FOR THE INITIAL
 PERIOD IN THIS FORECAST.
 
 THE INITIAL MOTION IS 275/17. THE LATEST TRACK GUIDANCE FOR UNALA IS
 ALL TO THE RIGHT OF THE CURRENT FORECAST TRACK...WHICH IS IN LINE
 WITH THE PREVIOUS FORECAST ISSUED IN A SPECIAL ADVISORY AT
 19/0500Z. IN COORDINATION WITH THE TYPHOON DUTY OFFICER AT
 JTWC...IT WAS DECIDED THAT A FUJIWARA INTERACTION BETWEEN TYPHOON
 PEWA AND UNALA WILL LIKELY STEER UNALA MORE WESTWARD AT AN
 ACCELERATED SPEED. ALSO...IN COORDINATION WITH JTWC...WE
 ANTICIPATED THE INTERACTION BETWEEN UNALA AND THE DOMINANT OUTFLOW
 FROM PEWA SHOULD CAUSE UNALA TO WEAKEN TO A TROPICAL DEPRESSION
 WITHIN 12 HOURS...AND TO DISSIPATE WITHIN 24 HOURS.
 
 PEWA HAS ALREADY CROSSED THE INTERNATIONAL DATELINE AS OF THIS
 BULLETIN TIME...AND THIS WILL BE THE FINAL ADVISORY FROM THE CENTRAL
 PACIFIC HURRICANE CENTER ON THIS SYSTEM. THE NEXT BULLETIN WILL BE
 ISSUED BY RSMC TOKYO JAPAN. FOR U.S. INTERESTS...SEE THE PUBLIC
 ADVISORIES ISSUED BY THE U.S. NWS WEATHER FORECAST OFFICE IN
 GUAM...AND DEPARTMENT OF DEFENSE WARNINGS ISSUED BY THE JOINT
 TYPHOON WARNING CENTER IN HONOLULU...HAWAII.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  19/0900Z 17.5N 179.6E   35 KT  40 MPH
  12H  19/1800Z 17.7N 177.1E   25 KT  30 MPH
  24H  20/0600Z...DISSIPATED
 
 $$
 FORECASTER HOUSTON

058
 WTPA44 PHFO 180230
 TCDCP4
 
 TROPICAL STORM PEWA DISCUSSION NUMBER   7
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012013
 500 PM HST SAT AUG 17 2013
 
 AFTER A BURST OF ORGANIZATION EARLIER TODAY...THE DEEP CONVECTION
 AROUND PEWA HAS ONCE AGAIN BECOME MORE RAGGED THIS AFTERNOON...AND
 UPPER LEVEL OUTFLOW HAS BECOME CONSTRICTED ON THE SOUTHWEST SIDE OF
 THE STORM. THE DVORAK CURRENT INTENSITY ESTIMATES WERE ONCE AGAIN
 3.5 ACROSS THE BOARD...SO THE INTENSITY WILL BE MAINTAINED AT 55 KT.
 
 THE INITIAL MOTION REMAINS 300/11. THE GUIDANCE REMAINS TIGHTLY
 CLUSTERED AROUND A FORECAST TRACK TO THE WEST-NORTHWEST...AS PEWA
 REMAINS TO THE SOUTHWEST OF A LARGE SUBTROPICAL HIGH THROUGH THE
 NEXT SEVERAL DAYS. THE FORECAST TRACK IS ESSENTIALLY UNCHANGED FROM
 THE PREVIOUS TRACK.
 
 THERE CONTINUE TO BE SOME MIXED SIGNALS THAT MAKE THE INTENSITY
 FORECAST QUITE CHALLENGING. THE CIMSS ANALYSES INDICATE THAT PEWA IS
 STARTING TO FEEL INCREASING SOUTHWESTERLY SHEAR FROM THE UPPER
 LOW DROPPING SOUTH NEAR 20N 174E. THERE IS PROBABLY ALSO SOME
INTERACTION OCCURING WITH THE DISTURBANCE A FEW HUNDRED MILES TO THE
 NORTHEAST. ON THE OTHER HAND...THE CYCLONE IS NOW ENTERING A VAST
 AREA OF HIGHER OCEANIC HEAT CONTENT AND WARMER SEA SURFACE
 TEMPERATURES...REACHING 29.5C ALONG THE EXPECTED TRACK. THE MODELS
 ARE SHOWING THAT IN ANOTHER 24 HOURS OR SO...THE UPPER LOW WILL
 START TO WEAKEN AND PULL NORTHWESTWARD...BUT NOT FAST ENOUGH TO
 RELIEVE THE SYSTEM FROM INCREASING SHEAR. THUS...ANY INTENSIFICATION
 SHOULD BE GRADUAL FOR THE NEXT COUPLE OF DAYS BEFORE IT HALTS. THERE
 IS THE POSSIBILITY INTENSIFICATION COULD RESUME IN THE LONGER RANGE
 IF PEWA CAN OVERCOME THE SOUTHWESTERLY SHEAR...AND THE UPPER TROUGH
 MOVES AWAY FAR ENOUGH FOR ANTICYCLONIC FLOW TO BUILD OVER THE
 SYSTEM...AS DEPICTED BY THE GFS AND NAVGEM. THE ECMWF REMAINS MORE
 STUBBORN WITH THE UPPER LOW IN PEWA/S PATH...WHICH WOULD CERTAINLY
 BE LESS FAVORABLE FOR INTENSIFICATION. 
 
 PEWA IS EXPECTED TO CROSS THE INTERNATIONAL DATE LINE BY 06Z...
 AND THIS WILL BE THE FINAL ADVISORY FROM THE CENTRAL PACIFIC
 HURRICANE CENTER. THE NEXT BULLETIN WILL BE ISSUED BY THE RSMC
 TOKYO. FOR U.S. INTERESTS...SEE THE PUBLIC ADVISORIES ISSUED BY THE
 U.S. NWS WEATHER FORECAST OFFICE GUAM AND DOD WARNINGS ISSUED BY THE
 JOINT TYPHOON WARNING CENTER.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  18/0300Z 11.8N 179.5W   55 KT  65 MPH
  12H  18/1200Z 12.8N 178.8E   60 KT  70 MPH
  24H  19/0000Z 13.9N 176.7E   60 KT  70 MPH
  36H  19/1200Z 15.2N 174.6E   65 KT  75 MPH
  48H  20/0000Z 16.5N 172.2E   65 KT  75 MPH
  72H  21/0000Z 19.3N 168.0E   65 KT  75 MPH
  96H  22/0000Z 21.9N 163.8E   70 KT  80 MPH
 120H  23/0000Z 24.9N 159.3E   75 KT  85 MPH
 
 $$
 
 FORECASTER R BALLARD