000
WTPZ44 KNHC 282037
TCDEP4
 
TROPICAL STORM NORMAN DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP142012
200 PM PDT FRI SEP 28 2012
 
CONVENTIONAL SATELLITE IMAGERY INDICATES A LESS-ORGANIZED CLOUD
PATTERN THIS AFTERNOON...ALTHOUGH THE PARTLY EXPOSED CIRCULATION
ASSOCIATED WITH NORMAN IS WELL-DEFINED IN RADAR IMAGERY FROM
GUASAVE MEXICO. BASED ON THE DETERIORATING CLOUD PATTERN THE
INITIAL INTENSITY IS LOWERED TO 35 KT. NORMAN IS IN A RATHER HARSH
ENVIRONMENT OF 30 TO 40 KT OF SOUTHWESTERLY SHEAR...AS INDICATED ON
THE UW-CIMSS WIND SHEAR PRODUCT. AS A RESULT...THE CIRCULATION IS
SEVERELY TILTED IN THE VERTICAL...WITH THE CONVECTIVE CANOPY
DISPLACED ABOUT A DEGREE TO THE NORTH OF THE SURFACE CIRCULATION.
THE GLOBAL MODELS AND THE SHIPS MODEL OUTPUT SHOW THE SHEAR
INCREASING AND BECOMING MORE WESTERLY AS THE CYCLONE APPROACHES THE
COAST OF MEXICO. THEREFORE...LITTLE CHANGE IN STRENGTH IS EXPECTED
BEFORE LANDFALL. WEAKENING IS FORECAST AFTER NORMAN MOVES INLAND...
AND THE CYCLONE IS EXPECTED TO DISSIPATE BY 36 HOURS.
 
THE INITIAL MOTION ESTIMATE IS 355/14. NORMAN IS CURRENTLY BEING
STEERED NORTHWARD BY A MID-LEVEL RIDGE OVER CENTRAL MEXICO AND A
MID- TO UPPER-LEVEL LOW SITUATED JUST WEST OF THE SOUTHERN TIP OF
BAJA CALIFORNIA. THIS SYNOPTIC STEERING PATTERN SHOULD KEEP THE
CYCLONE ON A GENERAL NORTHWARD HEADING THROUGH DISSIPATION.

FORECAST POSITIONS AND MAX WINDS
 
INIT  28/2100Z 24.4N 108.7W   35 KT  40 MPH
 12H  29/0600Z 25.6N 108.8W   30 KT  35 MPH...INLAND
 24H  29/1800Z 26.2N 109.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  30/0600Z...DISSIPATED
 
$$
FORECASTER ROBERTS/BRENNAN