000
WTPZ42 KNHC 070841
TCDEP2
 
TROPICAL DEPRESSION LORENA DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP122013
200 AM PDT SAT SEP 07 2013
 
DEEP CONVECTION HAS NOW BECOME SPORADIC IN ASSOCIATION WITH LORENA
AS THE COOLER SEA SURFACE TEMPERATURES AND A MORE STABLE ATMOSPHERE
ARE TAKING THEIR TOLL.  USING A BLEND OF THE TAFB AND SAB DVORAK
FINAL-T AND CURRENT INTENSITY NUMBERS SUGGESTS THAT THE SYSTEM HAS
WEAKENED TO ABOUT A 30 KT TROPICAL DEPRESSION...WHICH IS THE
CURRENT INTENSITY.  

STANDARD INFRARED AND SHORT-WAVE INFRARED IMAGERY DO NOT PROVIDE FOR
AN ACCURATE ASSESSMENT OF THE CURRENT LOCATION OF THE CYCLONE...DUE
TO THE MID-LEVEL CLOUDINESS OBSCURING THE LOW-LEVEL CENTER. 
FORTUNATELY...0054Z TRMM AND 0312Z SSMIS MICROWAVE PASSES ALLOW FOR
A MUCH BETTER DETERMINATION OF THE INITIAL POSITION OF LORENA. 
THESE INDICATE A MOTION OF THE CYCLONE OF 290 DEGREES AT 7 KT. 
LORENA SHOULD SLOW ITS FORWARD SPEED AND TURN TO THE NORTH AS IT IS
STEERED BY THE RATHER WEAK LOW-LEVEL FLOW IN THE NEXT TWO DAYS. 
THE PREDICTED TRACK IS BASED UPON A BLEND OF THE GLOBAL MODELS AND
IS JUST WEST OF THE PREVIOUS FORECAST.
 
LORENA SHOULD NOT LAST MUCH LONGER AS A TROPICAL CYCLONE DUE TO
INCREASINGLY HOSTILE THERMODYNAMICS.  ALL STATISTICAL AND DYNAMICAL
GUIDANCE SUGGEST A GRADUAL WINDING DOWN OF THE CYCLONE...WHICH IS
ALSO INDICATED IN THIS INTENSITY PREDICTION.  TRANSITION TO A
REMNANT LOW IS FORECAST TO OCCUR IN ABOUT A DAY...BUT THIS COULD
OCCUR SOONER IF SIGNIFICANT DEEP CONVECTION DOES NOT REDEVELOP
SHORTLY.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/0900Z 23.2N 111.6W   30 KT  35 MPH
 12H  07/1800Z 23.6N 112.2W   25 KT  30 MPH
 24H  08/0600Z 23.8N 112.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  08/1800Z 24.0N 112.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  09/0600Z 24.0N 112.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  10/0600Z...DISSIPATED
 
$$
FORECASTER LANDSEA