000
WTPZ43 KNHC 070303
TCDEP3
TROPICAL DEPRESSION LOWELL DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP132008
800 PM PDT SAT SEP 06 2008
 
CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY INDICATE THE STRONG
TROPICAL DISTURBANCE LOCATED SOUTH OF MANZANILLO MEXICO HAS RAPIDLY
ORGANIZED INTO TROPICAL STORM LOWELL. THE INITIAL INTENSITY IS SET
AT 35 KT BASED ON A CONSENSUS DVORAK SATELLITE INTENSITY ESTIMATE
OF T2.5/35 KT FROM BOTH TAFB AND SAB. SHIP DGTX LOCATED WELL TO THE
NORTHEAST OF THE CENTER ALSO REPORTED A SUSTAINED WIND OF 32 KT AT
07/0000Z.

THE INITIAL MOTION ESTIMATE IS 295/10. THE MODEL GUIDANCE IS IN
GENERAL AGREEMENT THAT LOWELL WILL MOVE IN A WEST-NORTHWESTWARD
DIRECTION...ACCOMPANIED BY A DECREASE IN FORWARD SPEED AS THE
SUBTROPICAL RIDGE TO THE NORTH WEAKENS IN THE 72-120 HOUR TIME
FRAME. THE OFFICIAL FORECAST IS DOWN THE MIDDLE OF THE MODEL
GUIDANCE ENVELOPE...AND IS SIMILAR TO SPEED OF THE NHC MODEL
CONSENSUS.

LOWELL IS A WELL-ORGANIZED TROPICAL STORM OVER SSTS OF ABOUT 29C AND
BENEATH MODERATE EASTERLY WIND SHEAR. THE PRESENT 20-KT SHEAR IS
FORECAST TO WEAKEN TO LESS THAN 10 KT BY 48 HOURS...SO STEADY
INTENSIFICATION IS EXPECTED UNTIL LOWELL REACHES MUCH COOLER SSTS
BY 72 HOURS. THE OFFICIAL INTENSITY FORECAST FOLLOWS THE STEADY
DEVELOPMENT TREND OF THE SHIPS INTENSITY MODEL...BUT IS SLIGHTLY
HIGHER SINCE THE SHIPS FORECAST WAS BASED ON THE MORE NORTHERLY BAM
MEDIUM MODEL TRACK...WHICH TAKES LOWELL OVER COOLER WATER AND
BENEATH STRONGER SHEAR CONDITIONS SOONER THAN THE OFFICIAL TRACK
FORECAST IS CALLING FOR.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/0300Z 15.7N 106.4W    35 KT
 12HR VT     07/1200Z 16.4N 107.8W    45 KT
 24HR VT     08/0000Z 17.4N 110.0W    55 KT
 36HR VT     08/1200Z 18.0N 111.9W    65 KT
 48HR VT     09/0000Z 18.4N 113.6W    65 KT
 72HR VT     10/0000Z 18.8N 115.1W    55 KT
 96HR VT     11/0000Z 19.8N 116.4W    45 KT
120HR VT     12/0000Z 20.5N 117.5W    35 KT
 
$$
FORECASTER STEWART