WTPA41 PHFO 190230
TCDCP1

TROPICAL STORM FERNANDA DISCUSSION NUMBER  14
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP062011
500 PM HST THU AUG 18 2011

FERNANDA CONTINUES TO FEEL THE EFFECTS OF INCREASING SOUTH
SOUTHEASTERLY SHEAR. THE CIMSS VERTICAL SHEAR MAGNITUDE IS
ESTIMATED TO BE AROUND 20 KT FROM THE SOUTH SOUTHEAST IN THE
VICINITY OF THE CYCLONE. SATELLITE IMAGERY CONTINUES TO INDICATE
DEEP CONVECTION PULSING NEAR THE CENTER WITH THE SHEAR CAUSING TO
SYSTEM TO BECOME ASYMMETRIC. THE SYSTEM IS MOVING TOWARD THE WEST
NORTHWEST AT AROUND 10 KT.
 
SATELLITE INTENSITY ESTIMATES FROM CPHC AND JTWC WERE 3.5...WHILE
SAB HAD 4.0. THE CURRENT INTENSITY WILL BE MAINTAINED AT 55 KT
THOUGH THIS MAY BE A BIT GENEROUS. FERNANDA HAS LIKELY PEAKED IN
INTENSITY WITH NO FURTHER STRENGTHENING ANTICIPATED. FERNANDA LIES 
BETWEEN AN UPPER LEVEL LOW CENTERED SEVERAL HUNDRED MILES SOUTH
SOUTHEAST OF HAWAII...AND AN UPPER LEVEL RIDGE TO THE EAST OF
FERNANDA. THE GLOBAL MODELS FORECAST THE UPPER LOW AND RIDGE TO
MOVE WESTWARD IN TANDEM WITH FERNANDA...MAINTAINING SOUTHERLY SHEAR
OVER THE SYSTEM THROUGH THE ENTIRE FORECAST PERIOD. IN
ADDITION...FERNANDA WILL BE MOVING OVER SLIGHTLY COOLER WATER FOR
THE FIRST 48 TO 60 HOURS. ALTHOUGH SSTS WARM OVER THE FORECAST
TRACK BEYOND 60 HOURS...BY THAT TIME THE DEEP CONVECTION IS LIKELY
TO BE WELL SEPARATED FROM THE LLCC.
 
FERNANDA IS CURRENTLY MOVING TOWARD A WEAKNESS IN THE MID LEVEL
RIDGE TO ITS NORTH. GLOBAL MODELS SHOW THE RIDGE REDEVELOPING
FRIDAY AND SATURDAY...WHICH SHOULD HELP TO STEER FERNANDA ON A MORE
WESTWARD COURSE. IN ADDITION...AS THE DEEP CONVECTION SEPARATES
FROM THE LLCC...THE LLCC WILL BE STEERED BY THE LOW LEVEL TRADE
WIND FLOW. THE OFFICIAL FORECAST TRACK REMAINS CLOSE TO THE
PREVIOUS TRACK AND LIES NEAR THE CENTER OF THE MODEL ENVELOPE WHICH
HAS SHIFTED A BIT SOUTHWARD FROM THE PREVIOUS FORECAST CYCLE. THE
FORECAST TRACK IS IN CLOSE AGREEMENT WITH THE GFS AND ECMWF MODELS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  19/0300Z 14.8N 142.7W   55 KT  65 MPH
 12H  19/1200Z 15.5N 144.2W   50 KT  60 MPH
 24H  20/0000Z 16.1N 146.3W   45 KT  50 MPH
 36H  20/1200Z 16.6N 148.5W   40 KT  45 MPH
 48H  21/0000Z 17.0N 150.5W   35 KT  40 MPH
 72H  22/0000Z 17.2N 154.7W   30 KT  35 MPH
 96H  23/0000Z 17.3N 158.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  24/0000Z 17.4N 162.8W   20 KT  25 MPH...DISSIPATED
 
$$
FORECASTER BURKE