000
WTPZ44 KNHC 132036
TCDEP4
TROPICAL STORM CARLOS DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP042009
200 PM PDT MON JUL 13 2009
 
AN EYE-LIKE FEATURE APPEARED IN VISIBLE IMAGERY AROUND 1700 UTC BUT
HAS SINCE BEEN PARTIALLY COVERED BY A SMALL CENTRAL DENSE OVERCAST. 
SUBJECTIVE SATELLITE INTENSITY ESTIMATES ARE NOW 3.5 FROM TAFB AND
4.0 FROM SAB...AND THE OBJECTIVE ADT IS HOVERING AROUND 3.3.  IN
ADDITION...AN AMBIGUITY ANALYSIS OF A 1433 UTC QUIKSCAT PASS
INDICATED THAT THE INTENSITY OF CARLOS WAS AT LEAST 45-50 KT.  THE
INITIAL INTENSITY IS SET AT 55 KT AS A CONSENSUS.  THE QUIKSCAT
PASS ALSO INDICATED THAT TROPICAL STORM FORCE WINDS ONLY EXTEND 30
N MI FROM THE CENTER.

CARLOS CONTINUES TO MOVE WITH A SOUTHWARD COMPONENT AT 255/10.  THE
CYCLONE IS ATTACHED TO A CONVERGENCE BAND...PART OF THE ITCZ...THAT
EXTENDS ALMOST 1000 N MI TO THE WEST-SOUTHWEST.  IT DOES NOT APPEAR
THAT CARLOS IS STRONG ENOUGH OR BIG ENOUGH AT THIS POINT TO
OVERCOME THIS FEATURE...AND THERE IS SOME CONCERN THAT IT WILL
CONTINUE MOVING WEST-SOUTHWESTWARD AND NOT SURVIVE.  WITH THE
ASSUMPTION THAT THE CYCLONE PERSISTS...THE OFFICIAL TRACK FORECAST
KEEPS CARLOS NEAR THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE. 
CARLOS' SMALL SIZE HAS ALSO MADE IT...AND WILL PROBABLY CONTINUE TO
MAKE IT...SUSCEPTIBLE TO SHORT-TERM INTENSITY CHANGES THAT WE DO
NOT HAVE SKILL IN FORECASTING.  AS A RESULT...THE OFFICIAL
INTENSITY FORECAST HOLDS CARLOS AT 55 KT FOR THE NEXT 72 HOURS WITH
THE RECOGNITION THAT THE INTENSITY COULD OSCILLATE A LITTLE ABOVE
AND BELOW THIS VALUE.  ULTIMATELY...WEAKENING IS EXPECTED AFTER 72
HOURS DUE TO INCREASING VERTICAL SHEAR.  NEEDLESS TO SAY...THE
UNCERTAINTY IN THIS FORECAST IS LARGER THAN NORMAL.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/2100Z  9.4N 126.1W    55 KT
 12HR VT     14/0600Z  9.5N 127.8W    55 KT
 24HR VT     14/1800Z  9.7N 130.1W    55 KT
 36HR VT     15/0600Z 10.0N 132.2W    55 KT
 48HR VT     15/1800Z 10.4N 134.2W    55 KT
 72HR VT     16/1800Z 11.0N 138.5W    55 KT
 96HR VT     17/1800Z 11.5N 144.5W    50 KT
120HR VT     18/1800Z 11.5N 151.5W    40 KT
 
$$
FORECASTER BERG