000
WTPZ43 KNHC 080834
TCDEP3
TROPICAL DEPRESSION BLANCA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP032009
200 AM PDT WED JUL 08 2009
 
QUIKSCAT DATA AT 0218 UTC SHOWED THAT BLANCA WAS STILL A TROPICAL
STORM AT THAT TIME.  SINCE THEN...THE ASSOCIATED CONVECTION HAS
DISSIPATED...AND SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB
HAVE DECREASED TO 30 KT.  BASED ON THIS...BLANCA IS DOWNGRADED TO A
TROPICAL DEPRESSION.  THE SYSTEM IS NOW OVER 22-23C SEA SURFACE
TEMPERATURES...AND IF THERE IS NO CONVECTIVE FLARE-UP DURING THE
NORMAL DIURNAL MAXIMUM IT COULD BE DECLARED A REMNANT LOW LATER
TODAY.  THE REMNANTS SHOULD CONTINUE TO WEAKEN UNTIL THEY DISSIPATE
IN ABOUT 72 HR.

THE INITIAL MOTION IS 295/12.  BLANCA IS ON THE SOUTH SIDE OF A
MID/UPPER-LEVEL RIDGE EXTENDING WESTWARD FROM NORTHERN MEXICO...
WITH WATER VAPOR IMAGERY SHOWING A MID/UPPER-LEVEL LOW NEAR
19N129W.  THE LARGE-SCALE MODELS FORECAST THE RIDGE TO BREAK DOWN
AS A LARGE MID/UPPER-LEVEL TROUGH AMPLIFIES OFF THE WESTERN COAST
OF THE UNITED STATES...AND IF BLANCA WERE OVER WARM WATER IT WOULD
LIKELY TRY TO TURN NORTHWARD IN RESPONSE TO THE TROUGH.  SINCE THAT
IS NOT THE CASE...A CONTINUED MOTION TOWARD THE WEST-NORTHWEST WITH
A DECREASE IN FORWARD SPEED IS FORECAST UNTIL THE CYCLONE
DISSIPATES. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/0900Z 20.8N 119.0W    30 KT
 12HR VT     08/1800Z 21.4N 120.2W    25 KT
 24HR VT     09/0600Z 22.1N 121.6W    20 KT...REMNANT LOW
 36HR VT     09/1800Z 22.6N 122.6W    20 KT...REMNANT LOW
 48HR VT     10/0600Z 23.0N 123.5W    20 KT...REMNANT LOW
 72HR VT     11/0600Z...DISSIPATED
 
$$
FORECASTER BEVEN