Tropical Depression SIXTEEN-E

ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION SIXTEEN-E DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP162008
800 PM PDT WED OCT 08 2008

TROPICAL DEPRESSION SIXTEEN-E IS GRADUALLY BECOMING BETTER ORGANIZED
THIS EVENING...WITH INFRARED SATELLITE IMAGERY SHOWING AN INCREASE
IN CONVECTIVE BANDING NEAR AND SOUTH OF THE CENTER.  SATELLITE
INTENSITY ESTIMATES ARE 30 KT FROM TAFB AND SAB...AND THERE WAS A
30 KT SHIP REPORT NEAR THE COAST OF GUATEMALA.  THE INITIAL
INTENSITY THUS REMAINS 30 KT.  THE CIRRUS OUTFLOW IS GOOD IN THE
WESTERN SEMICIRCLE...BUT THERE IS LITTLE OUTFLOW ELSEWHERE.

THE INITIAL MOTION IS 285/10.  THE DEPRESSION IS ON THE SOUTH SIDE
OF A WEAK MID-LEVEL RIDGE OVER MEXICO...WITH THE LARGE-SCALE MODELS
AGREEING THAT THE RIDGE SHOULD SHIFT NORTHEASTWARD INTO THE WESTERN
GULF OF MEXICO AND THE LOWER MISSISSIPPI VALLEY DURING THE FORECAST
PERIOD.  DESPITE THIS AGREEMENT...THE MODELS DO NOT AGREE WELL ON
THE FORECAST TRACK.  THE NOGAPS...UKMET...AND THE CANADIAN MOVE THE
SYSTEM VERY LITTLE FOR THE NEXT 5 DAYS...WITH THE UKMET SHOWING THE
DEPRESSION DISSIPATING.  THE GFS AND ECMWF FORECAST A WEST-
NORTHWESTWARD MOTION NEAR AND EVENTUALLY INTO THE COAST OF MEXICO. 
THE GFDL AND HWRF FORECAST TRACKS PARALLEL TO AND OFFSHORE OF THE
COAST OF MEXICO...WITH THE HWRF SHOWING A FASTER MOTION THAN THE
GFDL.  GIVEN THE SPREAD...THE NEW FORECAST TRACK CALLS FOR A SLOW
WEST-NORTHWESTWARD MOTION BETWEEN THE MORE SOUTHERLY HWRF AND THE
MORE NORTHERLY GFS/ECMWF.  THE NEW TRACK IS A LITTLE SOUTH OF THE
PREVIOUS TRACK AND NEAR THE CENTER OF THE GUIDANCE ENVELOPE.

UPPER-LEVEL WINDS AND SEA SURFACE TEMPERATURES ARE CURRENTLY
FAVORABLE FOR INTENSIFICATION...AND THE RAPID INTENSIFICATION INDEX
ATTACHED TO THE SHIPS MODEL SHOWS A 53 PERCENT CHANCE FOR 25 KT OF
STRENGTHENING IN THE NEXT 24 HR.  HOWEVER...IT SHOULD BE NOTED THAT
THE HWRF IS THE ONLY MODEL CALLING FOR THE SYSTEM TO BECOME A
HURRICANE....AND THE FIRST PART OF THE FORECAST SPLITS THE
DIFFERENCE BETWEEN IT AND THE LESS AGGRESSIVE MODELS.  THE FORECAST
BECOMES VERY UNCERTAIN AFTER 72 HR.  THE GFS AND ECMWF DEVELOP 45
KT UPPER-LEVEL NORTHEASTERLIES OVER THE CYCLONE...WHICH WOULD CAUSE
SIGNIFICANT VERTICAL WIND SHEAR.  THE UKMET SHOWS WEAKER
EASTERLIES...WHILE THE NOGAPS SHOWS AN UPPER-LEVEL LOW MOVING
WESTWARD ACROSS THE TROPICAL CYCLONE CAUSING SOUTHWESTERLY SHEAR. 
GIVEN THE AGREEMENT BETWEEN THE GFS AND ECMWF...THE INTENSITY
FORECAST SHOWS WEAKENING AFTER 96 HR.  HOWEVER...IT WILL NOT SHOW
AS MUCH WEAKENING AS THE GFDL...WHICH CALLS FOR DISSIPATION. 
 
THE OUTER FRINGES OF THE DEPRESSION ARE BRINGING SOME LOCALLY HEAVY
RAINS TO PORTIONS OF THE PACIFIC COAST OF CENTRAL AMERICA.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/0300Z 12.2N  91.8W    30 KT
 12HR VT     09/1200Z 12.7N  93.1W    35 KT
 24HR VT     10/0000Z 13.3N  94.5W    45 KT
 36HR VT     10/1200Z 13.9N  95.9W    50 KT
 48HR VT     11/0000Z 14.4N  97.3W    55 KT
 72HR VT     12/0000Z 15.5N 100.0W    60 KT
 96HR VT     13/0000Z 16.5N 102.0W    60 KT
120HR VT     14/0000Z 17.5N 104.5W    55 KT
 
$$
FORECASTER BEVEN
 
NNNN