000
WTPZ42 KNHC 242032
TCDEP2
TROPICAL STORM NORA DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP172009
200 PM PDT THU SEP 24 2009
 
SATELLITE IMAGES SHOW A DEGRADED CLOUD PATTERN WITH THE LOW-LEVEL
CENTER NOW EXPOSED TO THE WEST OF THE DEEP CLOUDINESS. IN
ADDITION...CONVECTION HAS DECREASED AND HAS BECOME MORE LINEAR IN
APPEARANCE. THE INITIAL INTENSITY IS LOWERED TO 40 KT...IN
AGREEMENT WITH SATELLITE INTENSITY ESTIMATES.

NORA IS FEELING THE EFFECTS OF ABOUT 15 KT OF WESTERLY VERTICAL WIND
SHEAR...ACCORDING TO THE ANALYSIS FROM CIMSS AT THE UNIVERSITY OF
WISCONSIN. THE COMBINATION OF THE STRONG SHEAR DUE TO AN
UPPER-LEVEL TROUGH TO THE NORTHWEST AND COOLER WATERS ALONG THE
FORECAST TRACK SHOULD LEAD TO STEADY WEAKENING OF THE SYSTEM.  THE
INTENSITY FORECAST IS AN UPDATE OF THE PREVIOUS FORECAST.

THE INITIAL MOTION IS 285/7. NORA IS EXPECTED TO GRADUALLY TURN
TOWARD THE WEST OR WEST-SOUTHWEST AS IT BECOMES INCREASINGLY
SHALLOW AND STEERED BY THE LOW-LEVEL FLOW THROUGH 36 HOURS. BEYOND
THAT TIME...A WEAKNESS IN THE SUBTROPICAL RIDGE SHOULD ALLOW FOR
NORA OR ITS REMNANTS TO MOVE WEST-NORTHWESTWARD.  THIS TRACK
FORECAST IS VERY SIMILAR TO THE PREVIOUS ONE AND NEAR THE MIDDLE OF
THE GUIDANCE ENVELOPE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      24/2100Z 17.5N 120.8W    40 KT
 12HR VT     25/0600Z 17.4N 121.7W    40 KT
 24HR VT     25/1800Z 17.3N 123.1W    35 KT
 36HR VT     26/0600Z 17.3N 124.5W    30 KT
 48HR VT     26/1800Z 17.6N 126.2W    25 KT
 72HR VT     27/1800Z 18.0N 129.0W    20 KT...REMNANT LOW
 96HR VT     28/1800Z 18.5N 131.5W    20 KT...REMNANT LOW
120HR VT     29/1800Z 18.5N 133.5W    20 KT...REMNANT LOW
 
$$
FORECASTER CANGIALOSI/BEVEN