Hurricane CARLOTTA

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HURRICANE CARLOTTA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP042006
800 PM PDT THU JUL 13 2006
 
THERE HAS BEEN A DECREASE IN THE COVERAGE AND THE INTENSITY OF THE
CONVECTION ASSOCIATED WITH CARLOTTA DURING THE PAST FEW HOURS...
WITH ONLY A SMALL AREA OF TOPS COLDER THAN -70C REMAINING TO THE
NORTHEAST OF A VERY POORLY-DEFINED EYE.  SATELLITE INTENSITY
ESTIMATES ARE 77 KT FROM ALL AGENCIES...SO THE INITIAL INTENSITY
REMAINS 75 KT.  HOWEVER...THIS MIGHT BE A LITTLE GENEROUS.  WHILE
CARLOTTA RETAINS A GOOD OUTFLOW PATTERN...SATELLITE IMAGERY
INDICATES CIRRUS CLOUDS FLOWING AROUND AN UPPER-LEVEL RIDGE ALONG
117W ARE MOVING EAST-SOUTHEASTWARD INTO THE HURRICANE...
UNDERCUTTING THE OUTFLOW.  THIS MAY BE CREATING SOME SHEAR THAT HAS
STOPPED INTENSIFICATION.

THE INITIAL MOTION IS 290/10.  WATER VAPOR IMAGERY SHOWS A LARGE
MID/UPPER-LEVEL RIDGE OVER NORTHWESTERN MEXICO AND THE ADJACENT
PACIFIC WATERS...WITH AN UPPER-LEVEL LOW NEAR 32N132W.  HURRICANE
BUD IS CENTERED ABOUT 700 N MI WEST OF CARLOTTA...WHILE A SMALL
UPPER-LEVEL LOW IS SOUTH OF THE RIDGE NEAR 22N117W.  LARGE-SCALE
MODELS FORECAST THE RIDGE TO BUILD WESTWARD DURING THE NEXT 3-4
DAYS...WHICH SHOULD TURN CARLOTTA TO A WESTWARD TRACK DURING THE
NEXT 24 HR AND KEEP IT GOING GENERALLY WESTWARD THEREAFTER.  THE
TRACK GUIDANCE IS IN GOOD AGREEMENT ON THE OVERALL DIRECTION OF
MOTION...BUT THERE IS STILL SOME SPREAD IN THE SPEED.  IT SHOULD BE
NOTED THAT THE GFS...GFDL...AND ECMWF ALL DEVELOP ONE OR MORE NEW
TROPICAL CYCLONES EAST OF CARLOTTA...WITH THE RESULT THAT THE GFS
LOSES THE STORM WITHIN 72 HR.  WHILE THESE NEW STORMS MAY
EVENTUALLY OCCUR...IT IS LIKELY THAT THEY WILL NOT FORM IN TIME TO
AFFECT CARLOTTA.  THE NEW FORECAST TRACK IS ESSENTIALLY AN UPDATE
OF THE PREVIOUS TRACK IN BEST AGREEMENT WITH THE GUNA AND CONU
CONSENSUS MODELS.

CARLOTTA IS MOVING OVER PROGRESSIVELY COOLER SEA SURFACE
TEMPERATURES AND SHOULD REACH THE 26C ISOTHERM IN ABOUT 24 HR. 
SINCE THE VERTICAL WIND SHEAR IS FORECAST TO BE LIGHT TO MODERATE
ALONG THE FORECAST TRACK...THE CYCLONE SHOULD GRADUALLY WIND
DOWN...BECOMING A DEPRESSION IN ABOUT 4 DAYS AND A REMNANT LOW IN
ABOUT 5 DAYS.  IT IS POSSIBLE THAT CARLOTTA COULD WEAKEN FASTER
THAT CURRENTLY FORECAST OVER THE COOLER WATER.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      14/0300Z 18.1N 112.1W    75 KT
 12HR VT     14/1200Z 18.4N 113.6W    70 KT
 24HR VT     15/0000Z 18.5N 115.5W    60 KT
 36HR VT     15/1200Z 18.6N 117.4W    50 KT
 48HR VT     16/0000Z 18.8N 119.3W    45 KT
 72HR VT     17/0000Z 19.5N 122.5W    40 KT
 96HR VT     18/0000Z 20.0N 125.0W    30 KT
120HR VT     19/0000Z 20.5N 127.5W    20 KT...REMNANT LOW
 
$$
FORECASTER BEVEN
 
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