TROPICAL STORM ELA NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI 500 AM HST THU JUL 09 2015 A 1052Z VIIRS DAY/NIGHT BAND IMAGE WAS INSTRUMENTAL IN HELPING TO LOCATE THE PARTIALLY EXPOSED CENTER OF ELA THIS MORNING. LATEST DVORAK SUBJECTIVE INTENSITY ESTIMATES FROM HFO/SAB/JTWC INDICATE THAT ELA IS A WEAK SYSTEM...WITH CURRENT INTENSITY VALUES RANGING FROM 1.0 TO 1.5. MEANWHILE...INFRARED SATELLITE IMAGES SHOW PULSING DEEP CONVECTION JUST NORTHEAST OF THE CENTER OVER THE PAST SEVERAL HOURS...SIMILAR TO WHAT WAS SEEN WHEN U.S. AIR FORCE HURRICANE HUNTERS FOUND TROPICAL STORM FORCE WINDS EARLIER IN THE EVENING. THEREFORE...ELA IS BEING MAINTAINED AS A 35 KT TROPICAL STORM WITH THIS ADVISORY. THE INITIAL MOTION ESTIMATE IS 315/11 KT...WITH ELA BEING STEERED TOWARD THE NORTHWEST BY A DEEP LAYER RIDGE TO THE EAST. THE CYCLONE IS AN AREA OF MODERATE SOUTHWESTERLY SHEAR...ANALYZED AS BEING AS HIGH AS 25 KT BY UW-CIMSS. EVEN GREATER SHEAR VALUES LIE ALONG THE FORECAST TRACK...ESPECIALLY AFTER THE FIRST 24 HOURS...MAINLY DUE TO THE PRESENCE OF A SLOW-MOVING CLOSED LOW ALOFT CENTERED TO THE NORTHEAST OF THE MAIN HAWAIIAN ISLANDS. THE INCREASING SHEAR IS FORECAST TO LEAD TO THE EVENTUAL DEMISE OF THE SYSTEM...WITH SHIPS GUIDANCE INDICATING DISSIPATION BY DAY 2. THE OFFICIAL FORECAST FOLLOWS THIS TREND...BUT IS NOT AS AGGRESSIVE IN WEAKENING THE SYSTEM IN DEFERENCE TO THE GFS AND ECMWF...WHICH MAINTAIN A CLOSED LOW THROUGH DAY 3 BEFORE THE SYSTEM BECOMES A WESTWARD-MOVING OPEN WAVE ON DAY 4. THEREFORE...THE EXPECTATION IS THAT ELA WILL BECOME AN INCREASINGLY SHALLOW SYSTEM TONIGHT AND FRIDAY...WHICH WILL ALLOW THE LOW-LEVEL TRADE WIND FLOW TO BEGIN CARRYING IT WESTWARD. ELA IS THEN FORECAST TO WEAKEN TO A REMNANT LOW JUST NORTH OF THE MAIN HAWAIIAN ISLANDS THIS WEEKEND BEFORE DISSIPATING. THE UPDATED TRACK FORECAST WAS NUDGED TO THE RIGHT IN THE EARLIER PERIODS OF THE FORECAST...TO THE LEFT AT THE END OF THE FORECAST...AND THE FORWARD MOTION HAS BEEN DECREASED AFTER 36 HOURS...FOLLOWING TRENDS PRESENTED BY THE TVCX CONSENSUS.
