Tropical Storm BARBARA

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TROPICAL STORM BARBARA DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP022007
200 PM PDT WED MAY 30 2007
 
BARBARA HAS BECOME BETTER ORGANIZED THIS AFTERNOON...WITH THE
DEVELOPMENT OF TIGHTLY-CURVED BANDS NEAR THE CENTER.  SATELLITE
INTENSITY ESTIMATES AT 18Z WERE 35 KT FROM SAB...45 KT FROM
TAFB...AND 47 KT FROM THE CIMSS ADT.  BECAUSE A TRMM PASS AT 17Z
SUGGESTED THAT THE LOW-LEVEL AND MID-LEVEL CIRCULATIONS WERE NOT
YET WELL CONNECTED...I'M LEANING ON THE LOW SIDE OF THE SATELLITE
ESTIMATES FOR THE ADVISORY INTENSITY OF 40 KT.  THE UPPER-LEVEL
OUTFLOW PATTERN IS STRONG AND BARBARA WILL REMAIN OVER VERY WARM
WATERS FOR THE NEXT FEW DAYS.  THE SHIPS GUIDANCE TAKES BARBARA TO
HURRICANE STRENGTH IN A LITTLE OVER 24 HOURS...WHILE THE GFDL TAKES
48 HOURS TO DO SO.  IN THE SHORT TERM...NORTHERLY FLOW CURRENTLY
UNDERCUTTING THE OUTFLOW SHOULD REACH THE CENTER OF BARBARA IN THE
NEXT 12 HOURS OR SO...WHICH COULD SLOW THE INTENSIFICATION...BUT I
SEE NO OTHER INHIBITING FACTORS AT THE MOMENT.  THE OFFICIAL
INTENSITY FORECAST IS CLOSE TO A BLEND OF THE GFDL AND SHIPS
GUIDANCE.  

THE EXPECTED SOUTHWARD MOTION HAS OCCURRED...AND THE INITIAL MOTION
IS NOW ESTIMATED AS 170/4.  NORTHERLY FLOW BEHIND A MID- TO
UPPER-LEVEL TROUGH IN THE WESTERN GULF OF MEXICO SHOULD RESULT IN A
CONTINUED SLOW SOUTHWARD MOTION OVER THE NEXT DAY OR SO.  THE MODEL
GUIDANCE HAS SHIFTED CONSIDERABLY EASTWARD...AND MOSTLY NOW LIFTS
BARBARA NORTHWARD OR NORTHEASTWARD IN RESPONSE TO THE TROUGH.  THE
12Z ECMWF HAS THE MOST EXTREME SOLUTION...BRINGING BARBARA ACROSS
GUATEMALA IN THREE DAYS.  THE ONLY REMAINING GUIDANCE FAVORING THE
NORTHWEST TRACK...INTERESTINGLY ENOUGH...IS THE NOT QUITE YET
OPERATIONAL HWRF MODEL.  AS MODELS OFTEN FLIP IN THESE KINDS OF
SITUATIONS...I'M NOT PREPARED TO MOVE AS FAR EAST AS MY
GUIDANCE...BUT I HAVE MADE A SIGNIFICANT EASTWARD ADJUSTMENT IN THE
OFFICIAL TRACK.      

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/2100Z 13.3N  97.1W    40 KT
 12HR VT     31/0600Z 12.9N  97.1W    45 KT
 24HR VT     31/1800Z 12.4N  96.9W    50 KT
 36HR VT     01/0600Z 12.4N  96.7W    60 KT
 48HR VT     01/1800Z 13.0N  96.4W    70 KT
 72HR VT     02/1800Z 13.7N  96.4W    75 KT
 96HR VT     03/1800Z 14.5N  96.5W    75 KT
120HR VT     04/1800Z 15.5N  97.0W    70 KT
 
$$
FORECASTER FRANKLIN
 
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