000
WTPZ41 KNHC 130234
TCDEP1
 
TROPICAL STORM FABIO DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP062012
800 PM PDT THU JUL 12 2012
 
SATELLITE IMAGERY INDICATES THAT FABIO HAS BECOME BETTER ORGANIZED
DURING THE PAST FEW HOURS. THE NORTHERLY SHEAR THAT WAS INHIBITING
DEEP CONVECTIVE DEVELOPMENT OVER THE NORTHERN PORTION OF THE SYSTEM
APPEARS TO BE DIMINISHING. VISIBLE IMAGES SHOW A SMALL CENTRAL
DENSE OVERCAST FORMING OVER THE CENTER OF THE CYCLONE...AND A
13/0015Z SSMIS OVERPASS REVEALED THE PRESENCE OF A PARTIAL EYEWALL
IN THE EAST QUADRANT. A BLEND OF THE SAB AND TAFB FINAL-T NUMBERS
SUPPORTS AN INCREASE IN THE INITIAL INTENSITY TO 50 KT FOR THIS
ADVISORY. THE STATISTICAL/DYNAMICAL MODELS CONTINUE TO SHOW FABIO
STRENGTHENING TO A LOW-END HURRICANE DURING THE NEXT 48 HOURS.
AFTERWARD....THE CYCLONE IS FORECAST TO WEAKEN QUICKLY AS IT MOVES
OVER MUCH COOLER SEA SURFACE TEMPERATURES. THE INTENSITY FORECAST
IS BASICALLY A COMPROMISE OF THE SHIPS...HWRF...AND THE LGEM MODELS
AND IS SIMILAR TO THE PREVIOUS ADVISORY.
 
VISIBLE IMAGES AND A COUPLE OF TIMELY MICROWAVE OVERPASSES SHOWED
THAT THE CENTER OF CIRCULATION WAS A BIT FARTHER SOUTH THAN
PREVIOUSLY ESTIMATED.  SUBSEQUENTLY...THE INITIAL MOTION IS A
LITTLE TO THE LEFT THAN BEFORE...280/9.  THE DYNAMICAL MODELS ARE
IN FAIR AGREEMENT WITH A GROWING WEAKNESS IN THE SUBTROPICAL RIDGE
WITH TIME DUE TO AN APPROACHING SHORTWAVE TROUGH FROM THE
NORTHWEST.  THE DIFFERENCES IN THE GUIDANCE ARE EXHIBITED IN THE
AMPLITUDE OF THE MID- TO UPPER-LEVEL TROUGH.  THE ECMWF AND THE
GFDL INDICATE AN EARLIER AND FASTER TURN INTO THE WEAKNESS...AROUND
DAY 3 OR 4...WHILE THE GFS/HWRF/UKMET AND GFS ENSEMBLE MEAN SHOW
LESS INFLUENCE AND A MORE GRADUAL TURN TOWARD THE NORTHWEST NEAR
DAY 4.  THE OFFICIAL NHC FORECAST HAS SHIFTED A LITTLE TO THE
LEFT...PRIMARILY DUE TO THE INITIAL POSITION ADJUSTMENT...AND
REMAINS CLOSE TO...BUT TO THE LEFT OF...THE MODEL CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  13/0300Z 13.9N 109.0W   50 KT  60 MPH
 12H  13/1200Z 14.4N 110.1W   60 KT  70 MPH
 24H  14/0000Z 15.1N 111.5W   65 KT  75 MPH
 36H  14/1200Z 15.6N 113.0W   70 KT  80 MPH
 48H  15/0000Z 16.0N 114.3W   70 KT  80 MPH
 72H  16/0000Z 17.0N 116.5W   60 KT  70 MPH
 96H  17/0000Z 19.0N 118.0W   45 KT  50 MPH
120H  18/0000Z 21.5N 119.5W   30 KT  35 MPH
 
$$
FORECASTER ROBERTS