Tropical Cyclone Discussion
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WTPA44 PHFO 042050
TCDCP4

TROPICAL STORM GUILLERMO DISCUSSION NUMBER  24
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP092015
1100 AM HST TUE AUG 04 2015

AFTER A BRIEF INCREASE IN DEEP CONVECTION LAST NIGHT...THE
APPEARANCE OF GUILLERMO IN THE SATELLITE IMAGES HAS BECOME DEGRADED
ONCE AGAIN. THE SYSTEM IS VERY ASYMMETRIC WITH THE COLDEST CLOUD
TOPS MAINLY IN THE NORTHEAST QUADRANT AND SOME OF THE CIRRUS
REACHING CALIFORNIA. A USAF RESERVE WEATHER RECON MISSION THIS
MORNING REPORTED A MAXIMUM FLIGHT LEVEL WIND OF 65 KT AND A MAXIMUM
SFMR VALUE OF 55 KT IN THE NORTHEAST QUADRANT. THE INBOUND LEG FROM
THE NORTHWEST PICKED UP SFMR VALUES OF 65 AND 69 KT BUT THIS WAS
THROUGH A BURST OF DEEP CONVECTION AND IS CONSIDERED NOT
REPRESENTATIVE. BASED ON THE ADJUSTMENT TO THE FLIGHT LEVEL WINDS
AND THE VALID SFMR VALUES...THE INITIAL INTENSITY WILL BE MAINTAINED
AT 60 KT.

GUILLERMO HAS CONTINUED TO MOVE NORTHWEST THROUGH A BREAK IN THE
RIDGE ALOFT WITH THE INITIAL MOTION FOR THIS PACKAGE AT 310/09 KT.
THE RELIABLE OBJECTIVE AIDS HAS ONCE AGAIN SHIFTED NORTH A BIT FOR
THIS PACKAGE...AND THE FORECAST TRACK HAS BEEN NUDGED NORTH
SLIGHTLY FROM THE PREVIOUS FORECAST IN RESPONSE. THE CURRENT
FORECAST IS CLOSELY ALIGNED WITH THE ECMWF FORECAST THROUGH 48
HOURS THEN SOUTH OF MOST OF THE DYNAMICAL GUIDANCE BEYOND THAT TIME
FRAME. ON THE FORECAST TRACK...GUILLERMO IS FORECAST TO REMAIN WELL
NORTHEAST OF THE MAIN HAWAIIAN ISLANDS AT ITS CLOSEST POINT OF
APPROACH. IF THIS MOTION CONTINUES...AND THERE IS NO
SIGNIFICANT DEVIATION TO THE LEFT OF THE FORECAST TRACK...THE
TROPICAL STORM WATCH FOR THE BIG ISLAND AND MAUI COUNTY MAY BE
CANCELED LATER TODAY OR TONIGHT.

THE CIMSS ANALYSIS AT 1800 UTC SHOWED OVER 26 KT OF VERTICAL SHEAR
IMPACTING GUILLERMO.  THE SYSTEM IS MOVING INTO AN AREA OF
INCREASING VERTICAL SHEAR. IT IS ALSO MOVING TOWARD A DRIER
AIRMASS. THESE FACTORS SHOULD STEADILY WEAKEN GUILLERMO EVEN THOUGH
SEA SURFACE TEMPERATURES ARE ADEQUATE. SHIPS GUIDANCE SHOWS A SHARP
WEAKENING WITH DISSIPATION BY 72 HOURS. HWRF MAINTAINS THE SYSTEM
NEAR 50 KT FOLLOWED BY A SHARPER WEAKENING TREND. THE FORECAST
FOLLOWS THE IVCN CONSENSUS WITH GUILLERMO STEADILY WEAKENING TO
A TROPICAL DEPRESSION AFTER DAY 3.


FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 20.2N 149.0W   60 KT  70 MPH
 12H  05/0600Z 21.0N 150.2W   55 KT  65 MPH
 24H  05/1800Z 22.0N 152.0W   50 KT  60 MPH
 36H  06/0600Z 23.0N 154.0W   45 KT  50 MPH
 48H  06/1800Z 24.0N 155.7W   40 KT  45 MPH
 72H  07/1800Z 25.6N 159.4W   35 KT  40 MPH
 96H  08/1800Z 27.0N 163.5W   30 KT  35 MPH
120H  09/1800Z 28.5N 167.5W   25 KT  30 MPH

$$
FORECASTER KODAMA







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