000 WTPZ42 KNHC 161538 TCDEP2 TROPICAL DEPRESSION TWO-E SPECIAL DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP022010 830 AM PDT WED JUN 16 2010 VISIBLE SATELLITE IMAGES AND AN SSMIS MICROWAVE PASS AT 1209 UTC INDICATE THAT THE LOW PRESSURE SYSTEM THAT HAS PERSISTED NEAR THE GULF OF TEHUANTEPEC FOR THE LAST DAY OR TWO HAS BECOME BETTER ORGANIZED. GIVEN THE PERSISTENCE OF DEEP CONVECTION NEAR THE CIRCULATION CENTER FOR 12-18 HOURS...THE TAFB CLASSIFICATION OF T1.5 AND AN IMPROVED DEFINITION OF THE CIRCULATION...ADVISORIES ARE BEING INITIATED ON TROPICAL DEPRESSION TWO-E. THE DEPRESSION IS EMBEDDED IN A MONSOON-LIKE ENVIRONMENT DOMINATED BY A BROAD WESTERLY FLOW IN THE LOW- TO MID-LEVELS AND A EASTERLY FLOW ALOFT. THIS PATTERN YIELDS A SLOW DEEP LAYER MEAN FLOW... AND HELPS TO EXPLAIN WHY THE CYCLONE HAS MOVED LITTLE. THIS IS BORNE OUT IN RECENT CENTER FIXES WHICH GIVE LITTLE MOTION...AND THE INITIAL MOTION ESTIMATE IS STATIONARY. OVER THE NEXT FEW DAYS... GLOBAL MODELS SHOW A BROAD SUBTROPICAL RIDGE EXTENDING FROM FLORIDA INTO THE WESTERN GULF BUILDING WESTWARD WHICH SHOULD STEER THE DEPRESSION ON A WEST-NORTHWESTWARD COURSE WITH SOME INCREASE IN FORWARD SPEED BEYOND 72 HOURS. HOWEVER...THIS FORECAST IS OF LOW CONFIDENCE GIVEN THE UNCERTAIN INTERACTION OF THE DEPRESSION WITH A TROPICAL DISTURBANCE TO THE WEST. THE APPEARANCE OF THE DEPRESSION SUGGESTS THAT IT IS SUBJECT TO MODERATE EASTERLY SHEAR...BUT SHIPS MODEL OUTPUT SUGGESTS THAT THE SHEAR IS LIGHT. THE SHIPS GUIDANCE MAY BE UNDERESTIMATING THE STRENGTH OF THE SHEAR...AND THE OFFICIAL FORECAST FAVORS THE LOWER LGEM GUIDANCE. FORECAST POSITIONS AND MAX WINDS INITIAL 16/1530Z 14.8N 95.6W 25 KT 12HR VT 17/0000Z 14.8N 96.2W 30 KT 24HR VT 17/1200Z 15.0N 97.1W 30 KT 36HR VT 18/0000Z 15.2N 98.0W 35 KT 48HR VT 18/1200Z 15.5N 99.3W 40 KT 72HR VT 19/1200Z 15.9N 101.2W 45 KT 96HR VT 20/1200Z 16.0N 103.5W 45 KT 120HR VT 21/1200Z 16.5N 106.5W 45 KT $$ FORECASTER KIMBERLAIN/BROWN