000 WTPZ42 KNHC 302042 TCDEP2 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