000 WTPZ45 KNHC 262050 TCDEP5 HURRICANE DARBY DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010 200 PM PDT SAT JUN 26 2010 EARLIER THIS AFTERNOON...THE CIRCULATION CENTER OF DARBY BECAME PARTIALLY EXPOSED TO THE EAST OF THE CENTRAL DENSE OVERCAST.... APPARENTLY DUE TO INCREASING EASTERLY SHEAR. SINCE THAT TIME...A NEW BURST OF DEEP CONVECTION HAS DEVELOPED NEAR THE CENTER...BUT THIS NEW CONVECTIVE ACTIVITY COULD BE TEMPORARY. DVORAK SATELLITE CURRENT INTENSITY ESTIMATES ARE 85 KT FROM TAFB AND 95 KT FROM SAB...BUT THEY ARE CONSTRAINED DUE TO RULES. THE CIMSS ADT AT 1745 UTC WAS 75 KT...WHICH SEEMS MUCH MORE REASONABLE SINCE SMALL... COMPACT TROPICAL CYCLONES WEAKEN MORE RAPIDLY THAN A NORMAL CLIMATOLOGICAL RATE. THEREFORE...THE INITIAL INTENSITY IS LOWERED TO 75 KT. THE EASTERLY SHEAR SHOULD STRENGTHEN THROUGH THE REMAINDER OF THE FORECAST...RESULTING IN FURTHER WEAKENING. THE OFFICIAL INTENSITY FORECAST IS BASED ON THE SHIPS MODEL WHICH INDICATES A QUICKER WEAKENING TREND. THE INITIAL MOTION ESTIMATE IS A DRIFT OR 260/2...WITHIN THE EASTERLY MID- TO UPPER-TROPOSPHERIC STEERING FLOW OF A WEAKENING MID-LEVEL RIDGE EXTENDING WESTWARD OVER THE EASTERN TROPICAL PACIFIC FROM MEXICO. LARGE-SCALE MODELS CONTINUE TO SUGGEST THAT THE AFOREMENTIONED RIDGE WILL WEAKEN FURTHER DURING THE NEXT DAY OR SO...ALLOWING DARBY TO MAINTAIN A SLOW...AND POSSIBLY ERRATIC... WESTWARD MOTION. AFTERWARD...THE CYCLONE OR ITS REMNANTS SHOULD GRADUALLY TURN NORTHEASTWARD AND CONTINUE ON THIS HEADING THROUGH DAY 5. THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY WHICH CLOSELY FOLLOWS THE TVCN MULTI-MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 26/2100Z 13.4N 102.8W 75 KT 12HR VT 27/0600Z 13.4N 103.2W 65 KT 24HR VT 27/1800Z 13.5N 103.6W 60 KT 36HR VT 28/0600Z 13.8N 103.5W 55 KT 48HR VT 28/1800Z 14.2N 103.1W 50 KT 72HR VT 29/1800Z 14.5N 102.4W 40 KT 96HR VT 30/1800Z 14.9N 101.9W 35 KT 120HR VT 01/1800Z 15.2N 101.7W 30 KT $$ FORECASTER ROBERTS/AVILA