000
WTPZ43 KNHC 111440
TCDEP3
TROPICAL DEPRESSION LOWELL DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP132008
800 AM PDT THU SEP 11 2008
 
SURFACE OBSERVATIONS AND SATELLITE IMAGERY INDICATE LOWELL'S
LOW-LEVEL CIRCULATION HAS MADE A JOG TO THE EAST AROUND THE
PERIPHERY OF THE MOUNTAIN RANGE OF SOUTHERN BAJA CALIFORNIA...AND
HAS NOW EMERGED OVER THE SOUTHERN GULF OF CALIFORNIA. STRONG
CONVECTION WITH CLOUD TOPS OF -80C TO -86C HAVE DEVELOPED OVER AND
NORTHEAST OF THE CENTER...INDICATING THAT LOWELL MAKE HANG ON AS A
TROPICAL CYCLONE LONGER THAN PREVIOUSLY EXPECTED. THE INITIAL
INTENSITY REMAINS 25 KT BASED ON SATELLITE ESTIMATES OF T2.0/30 KT
AND T1.5/25 KT FROM TAFB AND SAB...RESPECTIVELY. HOWEVER...THE
STANDARD GUST DIFFERENTIAL WAS INCREASED TO 40 KT DUE TO THE STRONG
CONVECTION THAT HAS RECENTLY DEVELOPED.

THE INITIAL MOTION ESTIMATE IS 045/09. ONCE LOWELL COMPLETELY CLEARS
THE TERRAIN OF THE BAJA...THOSE MINOR STEERING EFFECTS SHOULD BE
ELIMINATED AND THE CYCLONE IS EXPECTED TO RESUME A BASE COURSE
TOWARD THE NORTHEAST FOR THE NEXT 12 HOURS...AND THEN TURN TOWARD
THE NORTH-NORTHEAST AFTER THAT AND MOVE INLAND OVER THE STATE OF
SINALOA IN NORTHWESTERN MAINLAND MEXICO. THE OFFICIAL FORECAST
TRACK IS SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE TO A BLEND
OF THE GFDL...HWRF...AND GFS MODELS.
 
GIVEN THE RELATIVELY NARROW WIDTH OF THE GULF OF CALIFORNIA AND
LOWELL'S FORWARD SPEED...THERE IS ONLY A SMALL WINDOW OF
OPPORTUNITY FOR ANY STRENGTHENING TO OCCUR...AND EVEN THEN IT IS
UNLIKELY THAT LOWELL WOULD REGAIN TROPICAL STORM STATUS BEFORE
LANDFALL OCCURS. HOWEVER...THE VIGOROUS CONVECTION THAT HAS
DEVELOPED COULD EASILY PRODUCE WINDS GUSTS TO TROPICAL STORM-FORCE.

THE BIGGEST THREAT WITH LOWELL WILL CONTINUE TO BE LOCALLY HEAVY
RAINFALL AND POSSIBLE FLASH FLOODS AND MUD SLIDES...ESPECIALLY IN
AREAS OF HIGHER TERRAIN.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/1500Z 23.8N 109.2W    25 KT
 12HR VT     12/0000Z 25.0N 108.7W    25 KT
 24HR VT     12/1200Z 26.5N 108.5W    20 KT...REMNANT LOW INLAND
 36HR VT     13/0000Z...DISSIPATED INLAND
 
$$
FORECASTER STEWART