000 WTNT42 KNHC 290842 TCDAT2 TROPICAL STORM EARL DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010 500 AM AST SUN AUG 29 2010 DEEP CONVECTION HAS DECREASED NEAR THE ESTIMATED CENTER OF EARL OVER THE PAST FEW HOURS...AND THE COLDEST CLOUD TOPS ARE NOW LOCATED IN A LARGE BAND TO THE SOUTHWEST OF THE CENTER. EARL APPEARS TO BE EXPERIENCING SOME NORTHERLY SHEAR ASSOCIATED WITH THE OUTFLOW FROM HURRICANE DANIELLE...AND THE OUTFLOW IS RESTRICTED IN THE NORTHERN SEMICIRCLE. THE INITIAL INTENSITY IS HELD AT 55 KT IN AGREEMENT WITH DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB. THE SHEAR WILL BE DECREASING SOON AS DANIELLE CONTINUES MOVING AWAY...AND EARL SHOULD BE IN AN ENVIRONMENT THAT WILL SUPPORT STEADY STRENGTHENING THROUGH THE PERIOD. MOST OF THE GUIDANCE SUGGESTS EARL WILL BECOME A HURRICANE IN 12 TO 24 HOURS ...AND REACH MAJOR HURRICANE STRENGTH IN 72 TO 96 HOURS. THE NHC INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND CLOSE TO THE ICON CONSENSUS. THE CENTER HAS BEEN DIFFICULT TO LOCATE ON INFRARED IMAGERY OVERNIGHT...SO THE INITIAL MOTION ESTIMATE OF 280/16 IS LARGELY BASED ON CONTINUITY. EARL WILL SOON REACH THE SOUTHWESTERN EDGE OF THE SUBTROPICAL RIDGE CENTERED ALONG 25N...WHICH SHOULD RESULT IN A TURN TOWARD THE WEST-NORTHWEST AND A DECREASE IN FORWARD SPEED OVER THE NEXT 24 TO 36 HOURS. BEYOND THAT TIME...A BREAK DEVELOPS IN THE SUBTROPICAL RIDGE ALONG 65 TO 70W AS THE LARGE UPPER TROUGH INTERACTING WITH DANIELLE LIFTS OUT TO THE NORTHEAST. THE TRACK GUIDANCE IS IN GOOD AGREEMENT IN SHOWING EARL TURNING NORTHWESTWARD INTO THIS WEAKNESS IN 2 OR 3 DAYS...AND THEN ACCELERATING NORTHWARD...ALTHOUGH THERE IS SOME SPREAD IN THE FORWARD SPEED AT DAYS 4 AND 5. THE OFFICIAL NHC FORECAST IS SIMILAR TO THE PREVIOUS PACKAGE THROUGH THE FIRST 48 HOURS...AND IS FASTER LATE IN THE PERIOD IN AGREEMENT WITH THE MULTI-MODEL CONSENSUS. ON THE FORECAST TRACK...EARL WILL MOVE VERY CLOSE TO THE NORTHERN LEEWARD ISLANDS IN THE NEXT 24 TO 36 HOURS. CONDITIONS WILL BEGIN TO DETERIORATE IN THOSE AREAS LATER TODAY AND TONIGHT. FORECAST POSITIONS AND MAX WINDS INITIAL 29/0900Z 16.9N 56.9W 55 KT 12HR VT 29/1800Z 17.3N 59.1W 65 KT 24HR VT 30/0600Z 17.9N 61.4W 70 KT 36HR VT 30/1800Z 18.7N 63.6W 80 KT 48HR VT 31/0600Z 19.9N 65.4W 90 KT 72HR VT 01/0600Z 23.5N 69.0W 100 KT 96HR VT 02/0600Z 29.0N 72.0W 105 KT 120HR VT 03/0600Z 34.5N 72.0W 105 KT $$ FORECASTER BRENNAN