399 
 WTPA44 PHFO 031508
 TCDCP4
 
 TROPICAL STORM GUILLERMO DISCUSSION NUMBER  19
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP092015
 500 AM HST MON AUG 03 2015
  
 LATEST INFRARED SATELLITE IMAGERY CONTINUES TO SHOW A RAGGED 
 APPEARANCE TO GUILLERMO...WITH DEEP CONVECTION STRUGGLING TO REMAIN 
 OVER THE LOW LEVEL CIRCULATION CENTER DUE TO INCREASING WESTERLY 
 WIND SHEAR ALOFT. THE U.S. 53RD WEATHER RECONNAISSANCE AIRCRAFT 
 WHILE SAMPLING THE INNER CORE OF GUILLERMO LAST EVENING...FAILED TO 
 FIND FLIGHT LEVEL OR SURFACE WINDS OF 64 KNOTS OR GREATER. THE MOST 
 RECENT DVORAK CLASSIFICATIONS WERE 4.0/65KT FROM PHFO...JTWC AND 
 SAB...WHILE FINAL T NUMBERS WERE LOWER AT 3.5. ADDITIONALLY...THE 
 ADVANCED DVORAK TECHNIQUE FROM UW-CIMSS INDICATED A CURRENT 
 INTENSITY T NUMBER OF 4.0 AND A FINAL T NUMBER OF 3.5. RELYING 
 HEAVILY ON THE FACT THAT THE AIRCRAFT FAILED TO FIND 64 KNOT WINDS 
 DURING THE MISSION LAST EVENING THROUGH GUILLERMO...ALONG WITH A 
 1220Z SSMI MICROWAVE PASS SHOWING A WELL DEFINED CIRCULATION CENTER 
 BUT NO THUNDERSTORMS IN THE SOUTHWEST QUADRANT...AND THE CONTINUED 
 RAGGED PRESENTATION IN INFRARED SATELLITE IMAGERY...THE 1500Z 
 INTENSITY WILL BE LOWERED SLIGHTLY TO 60 KNOTS. AS A RESULT... 
 GUILLERMO HAS WEAKENED TO TROPICAL STORM STATUS. 
 
 THE INITIAL POSITION OF THE SYSTEM WAS HEAVILY WEIGHTED ON A COUPLE 
 CENTER FIX POSITIONS FROM THE AIRCRAFT MISSION LAST EVENING ALONG 
 WITH EXTRAPOLATION USING INFRARED SATELLITE IMAGERY. AS A 
 RESULT...THE CURRENT MOTION IS TOWARD THE WEST-NORTHWEST...300 
 DEGREES...AT 9 KNOTS. THIS GENERAL MOTION IS EXPECTED TO CONTINUE 
 FOR THE NEXT COUPLE OF DAYS AS THE SYSTEM IS GUIDED BY A LARGE 
 SURFACE RIDGE NEARLY 1600 NM TO THE NORTHEAST OF THE MAIN HAWAIIAN 
 ISLANDS AND A WEAKNESS IN THE RIDGING ALOFT RUNNING ROUGHLY 
 SOUTHEAST TO NORTHWEST JUST TO THE NORTH OF THE SYSTEM. THE LATEST 
 MODEL GUIDANCE HAS SHIFTED TOWARD THE RIGHT OR NORTH OF THE
 PREVIOUS FORECAST TRACK...LIKELY THE RESULT OF THE IMPROVED SAMPLING
 OF THE SYSTEM BY THE NOAA G-IV AIRCRAFT ON ITS SYNOPTIC SAMPLING
 MISSION SUNDAY AFTERNOON. THE SPREAD AMONGST THE MODELS HAS ALSO
 INCREASED IN THE FIRST 48 HOURS OF THE FORECAST...WITH QUITE A BIT
 OF SPREAD CONTINUING THROUGH THE FORECAST PERIOD. AS A RESULT...WE
 HEAVILY RELIED ON A COMBINATION OF THE TVCN...GFS...AND THE HWRF
 SOLUTIONS WITH A SIZEABLE WEIGHT PLACED ON THE PREVIOUS OFFICIAL
 FORECAST. THE NEW OFFICIAL FORECAST TRACK SHOWS A SLIGHT SHIFT
 TO THE RIGHT OR NORTH FROM THE PREVIOUS FORECAST ADVISORY.
 
 THE LATEST UW-CIMSS VERTICAL WIND SHEAR ANALYSIS SHOWED 14 KNOTS
 FROM 270 DEGREES...WHILE THE LATEST SHIPS ANALYSIS SHOWED 16 KNOTS
 FROM 285 DEGREES. THIS IS LIKELY RESPONSIBLE FOR THE CONTINUED 
 RAGGED SATELLITE PRESENTATION AND THE WEAKENING OF THE SYSTEM SINCE 
 THE PREVIOUS ADVISORY. SLOW BUT STEADY WEAKENING IS EXPECTED TO 
 CONTINUE THROUGH THE FORECAST PERIOD. AS GUILLERMO CONTINUES TO
 MOVE INTO THE WEAKNESS IN THE MID TO UPPER LEVEL RIDGE...OUTFLOW
 WITHIN THE NORTHWEST QUADRANT WILL BECOME FURTHER DISRUPTED AND
 VERTICAL WIND SHEAR WILL SLOWLY INCREASE. THE INTENSITY FORECAST
 CLOSELY FOLLOWS THE ICON...WITH SHIPS PREDICTING MORE RAPID
 WEAKENING BEYOND 48 HOURS. THE FORECAST AND INITIAL WIND RADII WERE
 ADJUSTED BASED ON THE AIRCRAFT DATA LAST EVENING AND THE CURRENT
 INTENSITY TRENDS OF GUILLERMO.
 
 AS GUILLERMO MOVES CLOSER TO HAWAII...WATCHES MAY BE ISSUED LATER 
 TODAY OR TONIGHT FOR PORTIONS OF THE STATE. HOWEVER...IT IS STILL 
 TOO SOON TO DETERMINE WITH CERTAINTY WHICH ISLANDS ARE MOST LIKELY 
 TO EXPERIENCE THE GREATEST IMPACTS FROM GUILLERMO. IT IS ALSO 
 IMPORTANT TO NOTE THAT SIGNIFICANT IMPACTS CAN EXTEND WELL AWAY
 FROM THE CENTER.
  
 ANOTHER RECONNAISSANCE AIRCRAFT MISSION INTO GUILLERMO IS SCHEDULED 
 FOR THIS MORNING. THE VALUABLE DATA TRANSMITTED IN REAL-TIME FROM 
 THESE MISSIONS WILL HELP US TO BETTER DETERMINE THE LOCATION... 
 INTENSITY AND SIZE OF THE TROPICAL STORM. IN ADDITION...THE NOAA 
 G-IV JET IS SCHEDULED TO CONDUCT ANOTHER SYNOPTIC SAMPLING MISSION 
 AROUND GUILLERMO THIS AFTERNOON. THIS SAMPLING SHOULD HELP IMPROVE 
 THE MODEL INITIALIZATION AND IMPROVE THE MODEL FORECAST TRACKS FOR 
 GUILLERMO.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  03/1500Z 16.6N 146.1W   60 KT  70 MPH
  12H  04/0000Z 17.2N 147.2W   55 KT  65 MPH
  24H  04/1200Z 17.9N 148.8W   50 KT  60 MPH
  36H  05/0000Z 18.7N 150.5W   45 KT  50 MPH
  48H  05/1200Z 19.6N 152.2W   45 KT  50 MPH
  72H  06/1200Z 21.4N 155.9W   40 KT  45 MPH
  96H  07/1200Z 23.1N 159.9W   35 KT  40 MPH
 120H  08/1200Z 25.0N 164.1W   30 KT  35 MPH
  
 $$
 FORECASTER JELSEMA/HOUSTON