000 WTNT44 KNHC 210842 TCDAT4 TROPICAL DEPRESSION NINETEEN DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL192010 500 AM EDT THU OCT 21 2010 THE THUNDERSTORM ACTIVITY HAS INCREASED DURING THE PAST SEVERAL HOURS AND THERE HAS BEEN SOME INCREASE IN ORGANIZATION. ALTHOUGH THE SHEAR SEEMS TO BE RELAXING AS INDICATED BY MOTION OF THE HIGH CLOUDS...THE CENTER IS STILL LOCATED ON THE WESTERN PORTION OF A CYCLONICALLY CURVED CONVECTIVE BAND. SATELLITE INTENSITY ESTIMATES FROM BOTH TAFB AND SAB ARE 2.5 ON THE DVORAK SCALE...INDICATING THAT THE DEPRESSION COULD BE A TROPICAL STORM. HOWEVER...AN AIR FORCE PLANE WILL BE IN THE AREA IN A FEW HOURS...AND I WOULD RATHER WAIT FOR THE RECONNAISSANCE DATA TO UPGRADE THE SYSTEM TO A TROPICAL STORM. HAVING SAID THAT...MOST OF THE GLOBAL MODELS ARE SHOWING THE DEVELOPMENT OF AN UPPER-LEVEL ANTICYCLONE NEAR OR OVER THE DEPRESSION IN A DAY OR SO...AND A TRACK A LITTLE BIT MORE DISTANT FROM THE HIGH TERRAIN OF CENTRAL AMERICA. THESE CONDITIONS AND THE PREVAILING WARM OCEAN WOULD BE FAVORABLE FOR INTENSIFICATION. THE OFFICIAL FORECAST CALLS FOR A LITTLE MORE STRENGTHENING THAN INDICATED IN THE PREVIOUS ADVISORY BUT NOT AS AGGRESSIVE AS THE GFDL AND THE HWRF. THE DEPRESSION IS FORECAST TO BECOME A HURRICANE IN THE NORTHWESTERN CARIBBEAN AS INDICATED BY THE INTENSITY MODEL CONSENSUS. THE DEPRESSION HAS BEEN MOVING SLOWLY TOWARD THE SOUTHEAST OR 135 DEGREES AT 3 KNOTS...EMBEDDED IN VERY LIGHT STEERING CURRENTS. LITTLE MOTION IS ANTICIPATED DURING THE NEXT DAY OR SO. THEREAFTER...ALL GLOBAL MODELS LIFT OUT THE CURRENT TROUGH OVER THE WESTERN ATLANTIC AND REPLACE IT WITH A SUBTROPICAL RIDGE. THIS NEW STEERING PATTERN WOULD FORCE THE CYCLONE ON A WEST TO WEST-NORTHWEST TRACK ACROSS THE NORTHWESTERN CARIBBEAN SEA AND THE YUCATAN PENINSULA. THE OFFICIAL TRACK FORECAST HAS SHIFTED A LITTLE BIT TO THE NORTH...AND IS HEAVILY BASED ON THE GFS...THE UK MODELS AND CONTINUITY. I HAVE LESS CONFIDENCE IN THE FORECAST BEYOND 72 HOURS BECAUSE THE GFDL...THE HWRF AND THE ECMWF TURN THE CYCLONE TOWARD THE NORTH OVER THE YUCATAN CHANNEL AND THE SOUTHEASTERN GULF OF MEXICO. I WOULD NOT BE SURPRISED IF THE TRACK HAS TO BE ADJUSTED NORTHWARD LATER ON. FORECAST POSITIONS AND MAX WINDS INITIAL 21/0900Z 17.0N 80.7W 30 KT 12HR VT 21/1800Z 16.8N 80.7W 40 KT 24HR VT 22/0600Z 16.5N 81.0W 45 KT 36HR VT 22/1800Z 16.5N 81.5W 55 KT 48HR VT 23/0600Z 16.5N 82.0W 65 KT 72HR VT 24/0600Z 17.5N 84.5W 65 KT 96HR VT 25/0600Z 19.0N 88.0W 40 KT...INLAND 120HR VT 26/0600Z 21.0N 90.0W 30 KT...INLAND $$ FORECASTER AVILA