000 WTPZ41 KNHC 152029 TCDEP1 TROPICAL DEPRESSION SIX-E DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062010 200 PM PDT THU JUL 15 2010 INTERMITTENT BURSTS OF DEEP CONVECTION HAVE CONTINUED TO DEVELOP MAINLY SOUTHWEST OF THE EXPOSED LOW-LEVEL CIRCULATION CENTER. THE CENTER OF TD-06E HAD TO BE RELOCATED FARTHER NORTH BASED ON VISIBLE SATELLITE IMAGERY AND A 1623Z ASCAT OVERPASS. THE ASCAT PASS ALSO INDICATED SURFACE WINDS OF 25-30 KT THAT EXTEND 160-250 NMI NORTH THROUGH NORTHEAST OF THE CENTER...WHICH MAY BE DUE TO OROGRAPHIC EFFECTS. MANZANILLO MEXICO HAS REPORTED A SUSTAINED EAST WIND OF ABOUT 20 KT FOR THE PAST SEVERAL HOURS...WHICH SUPPORTS THE ASCAT WINDS SITUATED OFFSHORE. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB REMAIN AT T1.5/25 KT. UW-CIMSS ADT ESTIMATES HAVE AVERAGED T2.5/35 KT OVER THE PAST 3 HOURS...WHILE UW-CIMSS AND CIRA-NESDIS AMSU INTENSITY ESTIMATES HAVE BEEN BOUNCING BETWEEN 30 TO 40 KT DURING THE PREVIOUS 6 HOURS. A BLEND OF THESE DATA WOULD GIVE AN INTENSITY OF ABOUT 35 KT...BUT GIVEN THAT THE LOW-LEVEL CENTER IS SHEARED ABOUT 85 NMI NORTHEAST OF THE MID-LEVEL CIRCULATION...THE ADVISORY INTENSITY IS BEING HELD AT 30 KT. THE INITIAL MOTION ESTIMATE IS AN UNCERTAIN 295/04. THE INITIAL POSITION AND 12Z POSITION WERE RELOCATED FARTHER NORTH AND EAST BASED ON VISIBLE IMAGERY AND THE ASCAT WIND DATA THAT SHOWED A MORE NORTHWARD POSITION. HOWEVER...THIS NORTHWARD JOG IS BELIEVED TO BE A TEMPORARY MOTION AND THAT TD-06E SHOULD SOON RESUME A SLOW WEST-NORTHWESTWARD MOTION. OVERALL...THERE REMAINS NO SIGNIFICANT CHANGE TO THE PREVIOUS TRACK FORECAST REASONING. THE NHC MODEL GUIDANCE IS IN GOOD AGREEMENT ON A WEST-NORTHWESTWARD MOTION THROUGH 48-60 HOURS WITH A GRADUAL TURN TOWARD THE WEST...OR EVEN WEST-SOUTHWEST...AFTER THAT WHEN THE CYCLONE IS EXPECTED TO WEAKEN OVER COOLER WATER AND BE STEERED MORE BY THE LOW-LEVEL EASTERLY FLOW. THE OFFICIAL FORECAST TRACK IS A LITTLE NORTH OF THE PREVIOUS ADVISORY AND REMAINS ALONG THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE. INTERMITTENT BURSTS OF DEEP CONVECTION NEAR THE CENTER SHOULD CONTINUE FOR THE NEXT 24 HOURS OR SO...WHICH COULD RESULT IN THE DEPRESSION BRIEFLY PRODUCING TROPICAL-STORM-FORCE WINDS. MODERATE EAST-NORTHEASTERLY VERTICAL SHEAR IS FORECAST TO CONTINUE FOR THE NEXT 18-24 HOURS...AND THEN GRADUALLY RELAX TO LESS THAN 15 KT BY 36 HOURS. AS THE SHEAR SLOWLY ABATES...CONVECTION SHOULD GRADUALLY DEVELOP CLOSER TO AND PERSIST NEAR THE LOW-LEVEL CENTER...ALLOWING FOR SOME SLIGHT STRENGTHENING TO OCCUR. HOWEVER...BY 48 HOURS THE CYCLONE IS FORECAST TO MOVE OVER SSTS COLDER THAN 26C...WHICH SHOULD INHIBIT ANY FURTHER INTENSIFICATION. THE SHIPS MODEL BRINGS THE DEPRESSION UP TO TROPICAL STORM INTENSITY BY 24 HOURS...WHEREAS THE LGEM MODEL KEEPS THE SYSTEM AS A 30-KT DEPRESSION. BOTH THE GFDL AND HWRF MODELS MAKE THE DEPRESSION A TROPICAL STORM IN 24-36 HOURS. THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THESE MODELS AND ONLY SHOWS SLIGHT STRENGTHENING TO A TROPICAL STORM...WHICH COULD OCCUR AT ANY TIME. FORECAST POSITIONS AND MAX WINDS INITIAL 15/2100Z 15.9N 108.2W 30 KT 12HR VT 16/0600Z 16.4N 109.6W 30 KT 24HR VT 16/1800Z 17.0N 111.3W 35 KT 36HR VT 17/0600Z 17.5N 113.3W 35 KT 48HR VT 17/1800Z 17.8N 115.2W 35 KT 72HR VT 18/1800Z 18.0N 119.0W 30 KT...DISSIPATING 96HR VT 19/1800Z 18.0N 123.0W 25 KT...POST-TROP/REMNT LOW 120HR VT 20/1800Z...DISSIPATED $$ FORECASTER STEWART