WTPA42 PHFO 221453 TCDCP2 TROPICAL DEPRESSION LOKE DISCUSSION NUMBER 7 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP042015 500 AM HST SAT AUG 22 2015 THE SATELLITE PRESENTATION OF LOKE HAS DETERIORATED DURING THE NIGHT...WITH ONLY INTERMITTENT SMALL BURSTS OF DEEP CONVECTION ABOUT THE LOW-LEVEL CIRCULATION CENTER /LLCC/. DVORAK DATA-T NUMBERS RANGED FROM T1.0/25KT TO T2.0/30KT... AND A WELL-PLACED 0930Z SCATTEROMETER PASS SAMPLED MAXIMUM WINDS OF ONLY 25 KT IN THE NORTHEAST QUADRANT. ON THIS BASIS... LOKE IS DOWNGRADED TO A 30 KT TROPICAL DEPRESSION WITH THIS ADVISORY. A SERIES OF MICROWAVE IMAGES AND THE SCATTEROMETER PASS INDICATE THAT LOKE HAS NOW TURNED TOWARD THE NORTHWEST AS EXPECTED... AND THE INITIAL MOTION ESTIMATE IS 325/05 KT. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST TRACK PHILOSOPHY. A MID-LEVEL RIDGE TO THE EAST AND A WEAK MID/UPPER LEVEL TROUGH TO THE WEST SHOULD DRIVE A RATHER SLOW GENERALLY NORTH-NORTHWEST MOTION DURING THE NEXT 24 HOURS...AS SHOWN BY THE TIGHTLY CLUSTERED MODEL GUIDANCE. LOKE SHOULD TURN TO THE NORTH AND ROUND THE WESTERN END OF THE RIDGE BETWEEN TAU 24 AND TAU 48...AND THEREAFTER MOVE MORE QUICKLY TO THE NORTH-NORTHEAST AS IT COMES UNDER INCREASING INFLUENCE FROM A LARGE MID-LATITUDE TROUGH WHICH IS FORECAST TO DEEPEN ALONG THE INTERNATIONAL DATE LINE. THE NEW OFFICIAL FORECAST TRACK IS ADJUSTED SLIGHTLY TO THE WEST OF THE PREVIOUS TRACK DURING THE FIRST 48 HOURS TO ACCOUNT FOR THE MORE WESTERLY INITIAL POSITION...BUT FOLLOWS A VERY SIMILAR TRAJECTORY TO THE PREVIOUS FORECAST AND IS VERY CLOSE TO THE TVCN MODEL CONSENSUS. THIS TRACK CONTINUES TO KEEP LOKE JUST TO THE EAST OF THE INTERNATIONAL DATE LINE. LOKE IS THEN FORECAST TO MOVE TO THE NORTH-NORTHEAST FROM TAU 72 THROUGH 96...THEN SWING BACK TO THE NORTHWEST BY TAU 120...AS THE MODEL SUITE REMAINS IN RATHER GOOD AGREEMENT THAT THE CYCLONE WILL BECOME CAPTURED WITHIN THE MUCH LARGER EXTRATROPICAL CIRCULATION ASSOCIATED WITH BY THEN FORMER WEST PACIFIC TYPHOON ATSANI. THE INTENSITY FORECAST REMAINS PROBLEMATIC. DESPITE VERY LOW VERTICAL WIND SHEAR...WITH THE LATEST CIMSS ANALYSIS INDICATING A SHEAR MAGNITUDE OF ONLY 3 KT...AND WARM SEA SURFACE TEMPERATURES ALONG WITH AMPLE OCEAN HEAT CONTENT...LOKE HAS WEAKENED RATHER THAN INTENSIFIED. THE OUTFLOW DOES APPEAR TO BE RESTRICTED TO THE NORTHWEST...AND THERE ARE CONTINUED INDICATIONS THAT DRY MID-LEVEL AIR NORTH AND WEST OF THE CYCLONE IS WRAPPING INTO THE CIRCULATION. THE NEW OFFICIAL FORECAST WILL GENERALLY FOLLOW THE SHIPS GUIDANCE THROUGH 72 HOURS...WITH LITTLE CHANGE IN INTENSITY THROUGH THE NEXT 36 HOURS AND SOME SLOW INTENSIFICATION THEREAFTER. UNCERTAINTY INCREASES BEYOND TAU 72...WHEN THE CYCLONE MAY BE IMPACTED BY INCREASING WESTERLY WIND SHEAR AND WILL ALSO BE MOVING ACROSS COOLER WATERS. THE SHIPS GUIDANCE ACTUALLY STRENGTHENS THE SYSTEM AT THE LATER FORECAST TIMES DESPITE THESE FACTORS...BUT THE OFFICIAL FORECAST WILL HOLD LOKE AS A 45 KNOT TROPICAL STORM FOR DAYS 4 AND 5. INTERESTS IN THE WESTERN PAPAHANAUMOKUAKEA MARINE NATIONAL MONUMENT SHOULD CONTINUE TO MONITOR THE PROGRESS OF LOKE DURING THE NEXT SEVERAL DAYS. FORECAST POSITIONS AND MAX WINDS INIT 22/1500Z 17.4N 177.9W 30 KT 35 MPH 12H 23/0000Z 18.3N 178.6W 30 KT 35 MPH 24H 23/1200Z 19.8N 179.3W 30 KT 35 MPH 36H 24/0000Z 21.3N 179.5W 30 KT 35 MPH 48H 24/1200Z 22.8N 178.9W 35 KT 40 MPH 72H 25/1200Z 26.0N 176.0W 45 KT 50 MPH 96H 26/1200Z 30.5N 175.0W 45 KT 50 MPH 120H 27/1200Z 35.0N 178.0W 45 KT 50 MPH $$ FORECASTER JACOBSON/HOUSTON