000 WTPZ42 KNHC 230847 TCDEP2 TROPICAL STORM DALILA DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP072007 200 AM PDT MON JUL 23 2007 IN THE PAST FEW HOURS...A BURST OF DEEP CONVECTION HAS DEVELOPED SOUTHWEST OF THE LOW-LEVEL CIRCULATION. A BANDING FEATURE IS ALSO TRYING TO FORM...WHICH IS A BIT IMPRESSIVE DUE TO THE 25 KT OF NORTHEASTERLY SHEAR THE CYCLONE IS CURRENTLY UNDER. TAFB AND SAB DVORAK SATELLITE INTENSITY ESTIMATES ARE BOTH 2.5 OR 35 KT. I WAS ORIGINALLY GOING TO MAINTAIN THE CYCLONE AS A DEPRESSION...BUT THE DEEP CONVECTION HAS PERSISTED AND THE OVERALL ORGANIZATION OF THE SYSTEM HAS CONTINUED TO IMPROVE. THE INITIAL INTENSITY IS SET AT 35 KT...AND SEVEN-E HAS BEEN UPGRADED TO TROPICAL STORM DALILA. THE INITIAL MOTION IS ESTIMATED AT 290/7. DALILA REMAINS SOUTH OF A WEAK MID-LEVEL RIDGE OF HIGH PRESSURE OVER NORTHWESTERN MEXICO... WITH A MID-LEVEL TROUGH OVER NORTHEASTERN MEXICO. AS THE RIDGE AND TROUGH PROGRESS WESTWARD...MOST OF THE GLOBAL MODEL GUIDANCE CONCURS THAT THE STEERING CURRENTS WILL WEAKEN AND DALILA'S NORTHWESTWARD MOTION IS EXPECTED TO SLOW FOR THE NEXT COUPLE OF DAYS. THEREAFTER...A SLIGHT ACCELERATION TOWARD THE NORTHWEST OR WEST-NORTHWEST IS ANTICIPATED. THE OFFICIAL TRACK FORECAST IS VERY SIMILAR TO THE PREVIOUS ADVISORY AND ALIGNED WITH THE MODEL CONSENSUS. THE CURRENT STRONG NORTHEASTERLY SHEAR IS FORECAST TO ABATE IN 36 TO 48 HOURS...AND DALILA WILL BE IN A MORE CONDUCIVE ENVIRONMENT FOR STRENGTHENING. BY DAY FOUR...HOWEVER...THE STORM IS EXPECTED TO ENCOUNTER COOLER WATERS NORTH OF 20N LATITUDE AND GRADUALLY WEAKEN. THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE SHIPS...GFDL... AND HWRF SOLUTIONS. FORECAST POSITIONS AND MAX WINDS INITIAL 23/0900Z 13.6N 108.6W 35 KT 12HR VT 23/1800Z 14.1N 109.2W 40 KT 24HR VT 24/0600Z 14.8N 110.0W 40 KT 36HR VT 24/1800Z 15.6N 110.7W 45 KT 48HR VT 25/0600Z 16.5N 111.4W 55 KT 72HR VT 26/0600Z 18.5N 113.5W 60 KT 96HR VT 27/0600Z 20.5N 116.5W 55 KT 120HR VT 28/0600Z 22.5N 120.0W 45 KT $$ FORECASTER MAINELLI