000
WTPZ44 KNHC 152034
TCDEP4
TROPICAL STORM CARLOS DISCUSSION NUMBER  24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP042009
200 PM PDT WED JUL 15 2009
 
CARLOS HAS CONTINUED TO WEAKEN...AS VERTICAL WIND SHEAR OF 15 TO 20
KT AS ANALYZED BY THE SHIPS MODEL HAS REMOVED THE DEEP CONVECTION
TO THE EAST OF THE LOW-LEVEL CENTER. THE INITIAL INTENSITY IS SET
AT 55 KT BASED ON A BLEND OF 1800 UTC FINAL-T NUMBERS OF 3.5 AND
3.0 FROM TAFB AND SAB...RESPECTIVELY...AND THIS COULD BE GENEROUS.
 
THE INITIAL MOTION IS ESTIMATED TO BE 270/08. THE OFFICIAL FORECAST
TRACK HAS BEEN SHIFTED WELL TO SOUTH OF THE PREVIOUS PACKAGE BASED
ON THE CURRENT POSITION AND INITIAL MOTION. THIS TRACK IS SOUTH OF
MUCH OF THE GUIDANCE...WHICH IMMEDIATELY SHOWS A NORTHWARD
COMPONENT TO THE MOTION. I SEE LITTLE REASON FOR THE CYCLONE TO
GAIN MUCH LATITUDE AS IT MOVES TO THE SOUTH OF THE SUBTROPICAL
RIDGE...AND THIS THINKING IS SUPPORTED BY THE BAM MODELS. THE
MEDIUM AND DEEP BAMS EVEN SHOW A SOUTHWARD COMPONENT OF MOTION ON
DAYS 2 AND 3...AND THIS IS REFLECTED IN THE FORECAST. THE FORWARD
SPEED IS CLOSE TO THAT OF THE PREVIOUS FORECAST.
 
THE INTENSITY FORECAST REMAINS HIGHLY UNCERTAIN. IF THE LOW-LEVEL
CENTER REMAINS DETACHED FROM THE DEEP CONVECTION...CARLOS COULD
DEGENERATE INTO A REMNANT LOW OR BE RE-ABSORBED INTO THE ITCZ.
HOWEVER...IF THE CYCLONE CAN SURVIVE THE NEXT 12 HOURS...THE WATERS
REMAIN WARM AND THE VERTICAL WIND SHEAR IS FORECAST TO DECREASE BY
THE SHIPS MODEL...AND CARLOS COULD REMAIN A TROPICAL STORM FOR THE
NEXT COUPLE OF DAYS. BY DAY 3...CARLOS WILL ENCOUNTER INCREASED
VERTICAL WIND SHEAR...LIKELY RESULTING IN FURTHER WEAKENING. THE
OFFICIAL FORECAST FOLLOWS THIS THINKING AND IS CLOSE AGREEMENT WITH
THE ICON INTENSITY CONSENSUS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/2100Z 10.1N 130.8W    55 KT
 12HR VT     16/0600Z 10.1N 132.1W    45 KT
 24HR VT     16/1800Z 10.1N 134.0W    40 KT
 36HR VT     17/0600Z 10.1N 136.2W    40 KT
 48HR VT     17/1800Z 10.0N 138.7W    35 KT
 72HR VT     18/1800Z  9.5N 144.0W    35 KT
 96HR VT     19/1800Z  9.5N 150.0W    30 KT
120HR VT     20/1800Z  9.5N 156.0W    30 KT
 
$$
FORECASTER BRENNAN