000 WTPZ42 KNHC 221447 TCDEP2 TROPICAL DEPRESSION SEVEN-E DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP072007 800 AM PDT SUN JUL 22 2007 FIRST-LIGHT VISIBLE IMAGERY SHOWS THAT THE BROAD CENTER OF TROPICAL DEPRESSION SEVEN-E IS EAST OF THE PREVIOUS ADVISORY POSITION... REQUIRING A RE-LOCATION. THE SYSTEM IS QUITE DISORGANIZED...WITH THE CIRCULATION ELONGATED FROM NORTHEAST TO SOUTHWEST...AND THE CONVECTION DISPLACED WEST OF THE CENTER BY 20-25 KT OF EAST-NORTHEASTERLY VERTICAL WIND SHEAR. SATELLITE INTENSITY ESTIMATES ARE 35 KT FROM BOTH TAFB AND SAB...BUT THESE MAY BE A BIT GENEROUS. THE INITIAL INTENSITY IS SET TO A MORE CONSERVATIVE 30 KT. THE INITIAL MOTION IS A RATHER UNCERTAIN 285/6. THE DEPRESSION IS ON THE SOUTHWEST SIDE OF A RIDGE OVER MEXICO...WHICH SHOULD PERSIST WITH SOME FLUCTUATIONS IN STRENGTH DURING THE NEXT 5 DAYS. THE MODELS INDICATE THAT A MID-LEVEL SHORTWAVE TROUGH OVER NORTHEASTERN MEXICO WILL MOVE SOUTHWESTWARD AROUND THE RIDGE AND INTERACT WITH THE TROPICAL CYCLONE IN 36 HR OR SO. THIS EVOLUTION WOULD ALLOW THE DEPRESSION TO MOVE WEST-NORTHWESTWARD FOR 24-36 HR FOLLOWED BY A TURN TOWARD THE NORTHWEST. THE TRACK GUIDANCE GENERALLY AGREES ON THIS...BUT THERE IS SOME SPREAD ON THE TIMING AND SHARPNESS OF THE TURN. THE NOGAPS AND GFDN CALL FOR A MORE NORTHWARD TURN CLOSER TO 110W...WHILE THE UKMET CALLS FOR A NORTHWESTWARD MOTION STARTING AT 112W. THE NEW FORECAST TRACK IS SHIFTED SOMEWHAT THE EAST OF THE PREVIOUS TRACK BASED ON THE INITIAL POSITION AND MOTION...AND IS IN BEST AGREEMENT WITH THE CCON CONSENSUS MODEL. IT SHOULD BE NOTED THAT THE SHORTWAVE TROUGH IS NOT READILY APPARENT IN WATER VAPOR IMAGERY...AS IT MAY BE MASKED BY CLOUDS AND MOISTURE AT HIGHER LEVELS. LARGE-SCALE MODELS FORECAST THE CURRENT STRONG UPPER-LEVEL WINDS TO CONTINUE FOR 36-48 HR...WHICH AT THE VERY LEAST SHOULD SLOW DEVELOPMENT. THE MODELS FORECAST THE SHEAR TO DECREASE AFTER THAT TIME. THE INTENSITY GUIDANCE FORECASTS SOME INTENSIFICATION DESPITE THE SHEAR...WITH THE GFDL AND HWRF FORECAST A FASTER DEVELOPMENT RATE AFTER THE SHEAR DECREASES. THE INTENSITY FORECAST WILL CONTINUE THE TREND OF SLOW DEVELOPMENT FROM THE PREVIOUS FORECAST...WITH A SLIGHTLY HIGHER PEAK INTENSITY AT 96 HR FOLLOWED BY A WEAKENING TREND OVER COOLER SEA SURFACE TEMPERATURES AT 120 HR. AN ALTERNATE SCENARIO IS THAT LITTLE DEVELOPMENT MAY OCCUR DURING THE FIRST 36-48 HR DUE TO THE SHEAR...FOLLOWED BY A MORE NORMAL DEVELOPMENT RATE. FORECAST POSITIONS AND MAX WINDS INITIAL 22/1500Z 12.8N 105.9W 30 KT 12HR VT 23/0000Z 13.2N 107.2W 30 KT 24HR VT 23/1200Z 13.7N 108.6W 35 KT 36HR VT 24/0000Z 14.0N 109.7W 40 KT 48HR VT 24/1200Z 14.6N 110.5W 45 KT 72HR VT 25/1200Z 16.0N 111.5W 50 KT 96HR VT 26/1200Z 18.5N 113.0W 55 KT 120HR VT 27/1200Z 20.5N 115.5W 50 KT $$ FORECASTER BEVEN