Tropical Depression FIVE-E
ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION FIVE-E DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052006 200 AM PDT MON JUL 17 2006 THE DEPRESSION IS STILL IN THE ORGANIZING STAGE...AND LACKS A CONCENTRATION OF DEEP CONVECTION NEAR THE CENTER AT THIS TIME. THERE ARE BROKEN CONVECTIVE BANDING FEATURES EVIDENT...BUT THESE ARE SOMEWHAT REMOVED FROM THE CENTER. DVORAK CLASSIFICATIONS FROM TAFB...SAB...AND AFWA INDICATE THAT THE MAXIMUM WINDS REMAIN NEAR 30 KT. ALTHOUGH THE TROPICAL CYCLONE HAS NOT INTENSIFIED SIGNIFICANTLY THUS FAR...ANTICYCLONIC UPPER-LEVEL OUTFLOW IS ESTABLISHED OVER THE SYSTEM...SEA SURFACE TEMPERATURES ARE FAIRLY WARM...AND THE VERTICAL SHEAR IS EXPECTED TO REMAIN VERY LOW. THE OFFICIAL WIND SPEED FORECAST MIGHT BE CONSERVATIVE SINCE...ONCE THE SYSTEM ACQUIRES AN INNER-CORE CONVECTIVE STRUCTURE...RAPID INTENSIFICATION IS POSSIBLE. LATER IN THE FORECAST PERIOD THE INTENSITY IS EXPECTED TO LEVEL OFF OR EVEN DECREASE IN STRENGTH SINCE THE TROPICAL CYCLONE MAY BE NEAR/OVER COOLER WATERS... PARTICULARLY IF IT MOVES SOMEWHAT NORTH OF MY PROJECTED TRACK. THE OFFICIAL INTENSITY FORECAST IS A LITTLE ABOVE THE SHIPS GUIDANCE AND SIMILAR TO THE LATEST GFDL RUN ALBEIT NOT QUITE AS STRONG AS THE LATTER MODEL AT DAYS 3-5. INITIAL MOTION IS ESTIMATED TO BE WESTWARD AROUND 12 KT. SOME SLOWING OF THE FORWARD SPEED IS EXPECTED DUE TO A WEAKNESS IN THE SUBTROPICAL RIDGE...SHOWN BY WATER VAPOR IMAGES AND THE GLOBAL MODELS...IN THE VICINITY OF 115-120W. OTHERWISE A CONTINUED WESTWARD MOTION APPEARS TO BE FORTHCOMING. LOOKING AT THE VARIOUS DYNAMICAL GUIDANCE MODELS...THE U.K. MET. OFFICE AND NOGAPS GLOBAL MODELS DO NOT SEEM TO HAVE A VERY GOOD HANDLE ON 5-E. THE U.K. MODEL ELONGATES THE LOW-LEVEL VORTICITY OF THE TROPICAL CYCLONE AND IS UNABLE TO TRACK A DISTINCT CENTER WHILE THE NOGAPS SPLITS THE SYSTEM IN TWO. ON THE OTHER HAND THE GFS...GFDL...AND ECMWF MODELS MAINTAIN A COHERENT STRUCTURE THROUGH THE FORECAST PERIOD. THE OFFICIAL TRACK FORECAST IS A LITTLE SLOWER THAN THE PREVIOUS ONE BUT IN GOOD AGREEMENT WITH THE GFS...GFDL...AND DEEP/MEDIUM BAM PREDICTIONS. FORECAST POSITIONS AND MAX WINDS INITIAL 17/0900Z 12.4N 111.0W 30 KT 12HR VT 17/1800Z 12.5N 112.5W 35 KT 24HR VT 18/0600Z 12.7N 114.5W 45 KT 36HR VT 18/1800Z 12.8N 116.4W 55 KT 48HR VT 19/0600Z 12.9N 118.2W 65 KT 72HR VT 20/0600Z 13.0N 121.0W 80 KT 96HR VT 21/0600Z 13.0N 123.5W 80 KT 120HR VT 22/0600Z 13.5N 126.5W 75 KT $$ FORECASTER PASCH NNNN