000 WTPZ41 KNHC 240256 TCDEP1 TROPICAL STORM JULIO DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112008 800 PM PDT SAT AUG 23 2008 A SERIES OF MICROWAVE PASSES JUST BEFORE 0000 UTC INDICATES THAT THE CENTER OF JULIO IS A LITTLE EAST OF THE PREVIOUS TRACK...BUT STILL NEAR THE EASTERN EDGE OF THE LARGE AREA OF DEEP CONVECTION. SUCH A CENTER PLACEMENT SUGGESTS THAT VERTICAL SHEAR CONTINUES TO HINDER THE DEVELOPMENT OF THE CYCLONE. IN ADDITION...LATEST DVORAK INTENSITY ESTIMATES ALONG WITH A COUPLE OF SHIP OBSERVATIONS SUPPORT KEEPING THE INITIAL INTENSITY AT 35 KT. WITH JULIO EXPECTED TO BE OVER SUFFICIENTLY WARM WATER DURING THE NEXT 12-24 HOURS...THE SHORT-TERM INTENSITY FORECAST HINGES ON THE VERTICAL SHEAR. UNFORTUNATELY...GLOBAL MODELS ARE NOT IN GOOD AGREEMENT ON THE FORECAST UPPER-LEVEL PATTERN WITH SOME SHOWING AN INCREASE IN SHEAR WHILE OTHERS IMPLY SOME DECREASE IN SHEAR. THE OFFICIAL FORECAST ASSUMES THAT JULIO WILL ENCOUNTER AN ENVIRONMENT OF SLIGHTLY WEAKER VERTICAL SHEAR ALLOWING SOME OPPORTUNITY FOR A LITTLE STRENGTHENING DURING THE NEXT DAY OR SO BEFORE INTERACTION WITH LAND RESULTS IN WEAKENING. BASED ON THE AFOREMENTIONED MICROWAVE PASSES...JULIO IS NOW MOVING TOWARD THE NORTH-NORTHWEST OR 335/11. THE SHORT-TERM TRACK FORECAST IS A CHALLENGE TO SAY THE LEAST...AS IT IS DIFFICULT TO ANTICIPATE WHETHER THE CENTER OF JULIO WILL REMAIN CONNECTED WITH THE DEEP CONVECTION. SHOULD THE CENTER BECOME DETACHED...IT WOULD MOVE NORTHWESTWARD WITH THE SHALLOW STEERING. HOWEVER...IF THE CENTER REMAINS CONNECTED...IT WOULD TEND TO MOVE MORE NORTH- NORTHWESTWARD AS SHOWN BY THE GFDL. THIS RESULTS IN CONSIDERABLE UNCERTAINTY AS TO WHETHER JULIO WILL TRACK EAST OF...WEST OF...OR OVER THE BAJA CALIFORNIA PENINSULA. GIVEN THE GFDL'S RESPECTABLE TRACK RECORD IN SIMILAR SITUATIONS...THE OFFICIAL FORECAST LEANS TOWARD THAT MODEL AND IS A LITTLE TO THE RIGHT OF THE DYNAMICAL MODEL CONSENSUS. THIS REASONING COUPLED WITH A SLIGHT INITIAL CENTER RELOCATION NECESSITATES AN EASTWARD SHIFT OF THE OFFICIAL TRACK FORECAST. THE NEW FORECAST ALSO REQUIRES A NORTHWARD EXTENSION OF THE TROPICAL STORM WATCHES AND WARNINGS FOR THE SOUTHERN BAJA CALIFORNIA PENINSULA. THE TROPICAL STORM WIND RADII ARE BASED ON NEARBY SHIPS DHER AND DDFD2 FORECAST POSITIONS AND MAX WINDS INITIAL 24/0300Z 20.5N 108.6W 35 KT 12HR VT 24/1200Z 21.8N 109.2W 45 KT 24HR VT 25/0000Z 23.2N 109.9W 45 KT 36HR VT 25/1200Z 24.6N 110.6W 40 KT 48HR VT 26/0000Z 25.7N 111.3W 35 KT 72HR VT 27/0000Z 27.5N 112.5W 30 KT 96HR VT 28/0000Z 29.5N 113.0W 25 KT...REMNANT LOW 120HR VT 29/0000Z...DISSIPATED $$ FORECASTER RHOME