WTPA41 PHFO 222102
TCDCP1

TROPICAL DEPRESSION COSME DISCUSSION NUMBER  34
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP062007
1100 AM HST SUN JUL 22 2007

IS IT OPEN OR IS IT CLOSED...THAT IS THE QUESTION. A QUIKSCAT PASS
AT 17Z HAS COSME AS AN OPEN TROUGH WITH 30 KT NON-RAIN CONTAMINATED
WINDS NORTHEAST OF THE TROUGH AXIS. PERHAPS QUIKSCAT HAS IT AS A
TROUGH BECAUSE OF INPUT FROM GFS...WHICH ALSO SEES IT AS A TROUGH.
GOES-11 SATELLITE IMAGERY...ON THE OTHER HAND...SHOWS COSME AS A
CLOSED LOW WITH AN OBVIOUS LOW LEVEL CIRCULATION CENTER. THE
QUESTION IS...ARE THERE ANY WESTERLY SURFACE WINDS SOUTH OF THE
CENTER. CIRA MULTIPLATFORM SATELLITE SURFACE WIND ANALYSIS SAYS
THAT IT IS IN FACT A CLOSED LOW WITH 5 TO 10 KT WESTERLY WINDS IN
THE SOUTH QUADRANT. 

AS FOR CURRENT INTENSITY...HAVE OPTED TO GO WITH PERSISTENCE...
SEEING AS THERE HAS BEEN NO SIGNIFICANT CHANGE IN APPEARANCE OVER
THE LAST 12 TO 24 HOURS. THEREFORE...COSME REMAINS A TROPICAL
DEPRESSION WITH 30 KT MAXIMUM WINDS. A SUBJECTIVE DVORAK INTENSITY
ESTIMATE FROM PHFO WAS 2.0. SAB CAME IN WITH 1.5 WHILE THE ADVANCED
OBJECTIVE DVORAK TECHNIQUE YIELDED A HIGH 3.4.

COSME IS MOVING TO THE WEST AT ABOUT 19 KT...A SMALL INCREASE OF A
COUPLE OF KNOTS FROM 6 HOURS AGO. THE FORECAST TRACK KEEPS COSME
MOVING ON A GENERALLY WESTWARD TRACK...LAYING IN THE MIDDLE OF A
TIGHTLY BUNCHED GROUP OF OBJECTIVE AIDS. COSME WILL STAY ON A
WESTERLY COURSE SOUTH OF THE NORTH PACIFIC HIGH TO THE NORTH
NORTHEAST. COSME OR ITS REMNANT LOW SHOULD TURN MORE OUT OF THE
WEST-NORTHWEST AND SLOW DOWN AFTER 48 HOURS AS THE SUBTROPICAL
RIDGE TO THE NORTH WEAKENS.

FOR THE LAST DAY OR TWO...COSME HAS MANAGED TO HANG TOGETHER IN
SPITE OF A PERSISTENT NORTHWESTERLY SHEAR OF 20 TO 25 KT...PERHAPS
BECAUSE IT HAS BEEN MOVING OVER SLIGHTLY WARMER OCEAN WATER. NOGAPS
AND GFS GLOBAL MODELS SAY THAT COSME IN THE SHORT TERM WILL MOVE
INTO A MORE FRIENDLY ENVIRONMENT WITH LESS VERTICAL SHEAR. FORECAST
INTENSITIES REMAIN UNCHANGED FOR NOW...KEEPING COSME AS A DEPRESSION
THROUGH 24 HOURS THEN SLOWLY DISSIPATING THROUGH 48 HOURS AS SHEAR
INCREASES AGAIN.

THE FORECAST TRACK CONTINUES TO BRING COSME CLOSE TO JOHNSTON ISLAND
LATER TODAY. THEREFORE...EXPECT A GRADUAL DETERIORATION OF THE
WEATHER ON THIS SMALL ATOLL DURING THE NEXT 6 TO 12 HOURS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/2100Z 16.2N 167.5W    30 KT
 12HR VT     23/0600Z 16.3N 170.6W    30 KT
 24HR VT     23/1800Z 16.5N 174.7W    30 KT
 36HR VT     24/0600Z 16.9N 178.4W    25 KT
 48HR VT     24/1800Z 17.4N 178.6E    25 KT...DISSIPATING
 72HR VT     25/1800Z 18.5N 174.9E    20 KT...REMNANT LOW
 96HR VT     26/1800Z...REMNANT LOW
 
$$
FORECASTER CRAIG