000 WTPZ42 KNHC 252033 TCDEP2 TROPICAL STORM IGNACIO DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP122009 200 PM PDT TUE AUG 25 2009 VISIBLE SATELLITE PICTURES SUGGEST THAT THE CLOUD PATTERN OF IGNACIO HAS BECOME BETTER ORGANIZED...WITH SOME HINT OF THE BEGINNING STAGE OF A CENTRAL DENSE OVERCAST FORMING. EVEN THOUGH THE NORTHWEST SEMICIRCLE IS VOID OF DEEP CONVECTIVE CLOUDS...A WELL-DEFINED BAND IS OBSERVED OVER THE SOUTHEAST SEMICIRCLE. DVORAK T-NUMBERS REMAIN AT T3.0 FROM BOTH TAFB AND SAB AND THE OFFICIAL INTENSITY IS MAINTAINED AT 45 KT. A 1417 UTC QUIKSCAT PASS REVEALED A FEW UNCONTAMINATED 45-50 KT WIND VECTORS...WHICH AGREE WELL WITH THE CURRENT INTENSITY ESTIMATE. EVEN THOUGH THE SHEAR SHOULD REMAIN RELATIVELY LIGHT...THE WINDOW OF OPPORTUNITY FOR STRENGTHENING WILL BE CLOSING SOON SINCE THE CYCLONE SHOULD REMAIN OVER 26.5C WATERS FOR LESS THAN 12 HOURS. THEREAFTER...PROGRESSIVELY COOLER WATERS ALONG THE FORECAST TRACK SHOULD CAUSE RAPID WEAKENING...AND IGNACIO IS EXPECTED TO BECOME A REMNANT LOW BY 72 HOURS. THE EARLIER QUIKSCAT PASS AND RECENT VISIBLE SATELLITE FIXES HAVE YIELDED FAIRLY HIGH CONFIDENCE ESTIMATES OF THE CENTER LOCATION. BASED UPON THOSE ESTIMATES...THE INITIAL MOTION IS 300/11. THERE HAS BEEN LITTLE CHANGE TO THE OFFICIAL FORECAST TRACK. IGNACIO SHOULD MAINTAIN A NORTHWESTERLY COURSE AS IT MOVES AROUND THE WESTERN PERIPHERY OF A DEEP-LAYER ANTICYCLONE EXTENDING FROM THE SOUTHERN UNITED STATES INTO THE EAST PACIFIC TO NEAR 130W. TOWARD THE END OF THE PERIOD...THE CYCLONE SHOULD ASSUME A MORE WESTERLY TRACK ONCE IGNACIO WEAKENS AND BECOMES MORE SHALLOW. THE OFFICIAL TRACK DIFFERS LITTLE FROM THE PREVIOUS ADVISORY AND LIES BETWEEN THE PREVIOUS FORECAST AND THE MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 25/2100Z 19.4N 120.3W 45 KT 12HR VT 26/0600Z 20.4N 121.8W 50 KT 24HR VT 26/1800Z 21.9N 123.8W 50 KT 36HR VT 27/0600Z 23.6N 125.7W 45 KT 48HR VT 27/1800Z 25.2N 127.6W 35 KT 72HR VT 28/1800Z 27.0N 130.5W 25 KT...REMNANT LOW 96HR VT 29/1800Z 27.0N 134.0W 20 KT...REMNANT LOW 120HR VT 30/1800Z...DISSIPATED $$ FORECASTER KIMBERLAIN