000 WTNT42 KNHC 131435 TCDAT2 TROPICAL STORM BERTHA DISCUSSION NUMBER 42 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008 1100 AM EDT SUN JUL 13 2008 SATELLITE IMAGES INDICATE THAT MOST OF THE DEEP CONVECTION ASSOCIATED WITH BERTHA HAS DECREASED EXCEPT WITHIN A BAND TO THE NORTH OF THE CENTER. HOWEVER...BERTHA STILL HAS A LARGE AND VIGOROUS LOW LEVEL CIRCULATION. INITIAL INTENSITY IS SET AT 55 KNOTS AND A RECONNAISSANCE PLANE WILL GIVE US ADDITIONAL INTENSITY AND WIND RADII INFORMATION LATER TODAY. SHEAR AND COOL WATER SHOULD INDUCE WEAKENING...BUT MOST OF THE GLOBAL AND INTENSITY MODELS EITHER STRENGTHEN OR KEEP BERTHA WITH THE SAME INTENSITY. THE OFFICIAL FORECAST HAS OPTED FOR AN INITIAL WEAKENING AND THEN FOLLOWS THE SHIPS MODELS CALLING FOR NO CHANGE IN INTENSITY. BERTHA HAS BEEN MEANDERING FOR THE PAST 24 HOURS OR SO...BUT NOW APPEARS TO BE MOVING TOWARD THE NORTHWEST OR 320 DEGREES AT ABOUT 2 TO 3 KNOTS. AS THE SUBTROPICAL RIDGE DEVELOPS AND A TROUGH APPROACHES...THE CYCLONE SHOULD CONTINUE TO MOVE ON A SLOW NORTHWESTERLY AND THEN NORTHERLY TRACK FOR A COUPLE OF DAYS. THEREAFTER...THE CYCLONE IS EXPECTED TO BE EMBEDDED WITHIN THE MID-LATITUDE WESTERLIES AND BE STEERED SLOWLY EASTWARD. HOWEVER...THIS PROCESS WILL SLOW AND TROPICAL CYCLONE BERTHA COULD BE WITH US FOR SEVERAL MORE DAYS AS INDICATED BY GLOBAL MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 13/1500Z 30.2N 63.0W 55 KT 12HR VT 14/0000Z 30.4N 63.0W 50 KT 24HR VT 14/1200Z 31.5N 63.5W 50 KT 36HR VT 15/0000Z 33.0N 63.6W 50 KT 48HR VT 15/1200Z 34.5N 63.0W 50 KT 72HR VT 16/1200Z 36.0N 61.0W 50 KT 96HR VT 17/1200Z 36.0N 58.0W 50 KT 120HR VT 18/1200Z 35.0N 54.0W 50 KT $$ FORECASTER AVILA