WTPA41 PHFO 212048
TCDCP1

TROPICAL DEPRESSION COSME DISCUSSION NUMBER  30
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP062007
1100 AM HST SAT JUL 21 2007

COSME CONTINUES TO HAVE AN EXPOSED LOW LEVEL CIRCULATION WITH ONLY
INTERMITTENT DEEP CONVECTION AROUND THE CENTER. SATELLITE INTENSITY
ESTIMATES RANGED FROM 1.5 TO 2.0...WITH JTWC RATING THE SYSTEM AS
UNCLASSIFIABLE. IT HAS BEEN ABOUT 18 HOURS SINCE COSME HAS BEEN
ABLE TO SUSTAIN PERSISTENT DEEP CONVECTION NEAR THE CENTER. AS A
GENERAL RULE OF THUMB...WE LIKE TO SEE ABOUT 24 HOURS WITHOUT
PERSISTENT DEEP CONVECTION AROUND THE CENTER BEFORE DISCONTINUING
ADVISORIES. THE CYCLONE PASSED ABOUT 65 MILES SOUTH OF BUOY 51002
AROUND 13Z...BRINGING 28 KT SUSTAINED WINDS AND GUSTS TO 35 
KT...ALONG WITH A SHARP PEAK OF 18 FOOT SEAS. THUS...WE WILL 
MAINTAIN COSME AS A 30 KT DEPRESSION IN THIS ADVISORY.

THE TRACK FORECAST REMAINS STRAIGHTFORWARD. THE RELATIVELY SHALLOW
CIRCULATION OF COSME WILL CONTINUE TO TRACK WESTWARD SOUTH OF A
VERY LARGE SUBTROPICAL RIDGE. NEAR THE END OF THE FORECAST
PERIOD...COSME WILL BEGIN TO SLOW DOWN AND TURN A LITTLE MORE
NORTHERLY AS IT FINALLY REACHES THE WESTERN PERIPHERY OF THE VAST
RIDGE. IT SHOULD BE NOTED THAT OUR TRACK FORECAST BRINGS COSME
CLOSE TO JOHNSTON ISLAND IN ABOUT 30 HOURS.

THE INTENSITY FORECAST IS A BIT MORE TROUBLESOME. THE UW/CIMSS SHEAR
ANALYSIS CONTINUES TO INDICATE ABOUT 20 KT OF SHEAR OVER THE
CYCLONE. THE SHEAR IS DUE TO AN UPPER TROUGH NORTH-NORTHEAST OF
COSME. WATER VAPOR IMAGERY SHOWS THE TROUGH IS MOVING WESTWARD A
LITTLE MORE SLOWLY THAN THE CYCLONE. ALTHOUGH THE GENERAL CONSENSUS
AMONG THE GLOBAL MODELS IS THAT MODERATE NORTHWESTERLY SHEAR WILL
CONTINUE TO SHEAR OFF ANY DEEP CONVECTION THAT CAN DEVELOP...SOME
OF THE MODELS SEEM TO SUGGEST THAT THE TROPICAL CYCLONE WILL BE
ABLE TO OUTRUN THE SIGNIFICANT SHEAR. THE CYCLONE IS CURRENTLY OVER
27C WATER...AND WILL BE MOVING OVER STEADILY INCREASING OCEANIC
HEAT CONTENT AS IT HEADS TOWARD THE DATELINE...SO IT IS DIFFICULT
TO COMPLETELY RULE OUT REINTENSIFICATION. OUR FORECAST WILL
MAINTAIN COSME AS A DEPRESSION A LITTLE LONGER THAN PREVIOUSLY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/2100Z 16.2N 160.0W    30 KT
 12HR VT     22/0600Z 16.3N 162.6W    30 KT
 24HR VT     22/1800Z 16.4N 166.3W    30 KT
 36HR VT     23/0600Z 16.5N 170.1W    30 KT
 48HR VT     23/1800Z 16.9N 173.8W    25 KT
 72HR VT     24/1800Z 18.4N 179.3E    25 KT...DISSIPATING
 96HR VT     25/1800Z 20.3N 174.7E    20 KT...REMNANT LOW
120HR VT     26/1800Z 22.5N 169.8E    20 KT...REMNANT LOW
 
$$
FORECASTER R BALLARD