| Track at Central Pacific Hurricane Center: http://www.prh.noaa.gov/cphc/tcpages/?storm=Madeline Floater: http://www.ssd.noaa.gov/PS/TROP/floaters/14E/14E_floater.html Wider view: http://www.ssd.noaa.gov/imagery/cpac.html 5am EDT Monday (11pm HST Sunday) discussion: "HURRICANE MADELINE DISCUSSION NUMBER 11 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP142016 1100 PM HST SUN AUG 28 2016 Madeleine has become more organized over the past 12 hours, with an eye feature forming within the central dense overcast and becoming apparent this evening. Little or no shear deformation is noted and outflow is particularly good to the north. Subjective Dvorak satellite intensity estimates are 4.5, 77 kt, from all three satellite analysis centers. Given the greatly improved organization, eye feature and unanimous intensity estimates, Madeline is upgraded to a hurricane and assigned an initial intensity of 75 kt for this advisory cycle. An upper trough northwest of the main Hawaiian Islands continues to allow Madeline to gain latitude as this system tracks along the southern flank of the subtropical ridge. Global models show this upper trough will lift northward through 72 hours, allowing the ridge to steer Madeline along a more westerly track beyond 12 hours. Interestingly, the upper trough is then forecast to begin digging southward again by 72 hours a bit farther to the east, causing some of the track guidance to deflect Madeline to the west northwest again near 120 hours, after this system has passed the Hawaiian Islands. Track guidance is reassuringly tightly packed through 72 hours with even GFDL, which had been the right outlier for the guidance we most commonly use, now taking Madeline south of the Big Island. There is little change in the forecast track, which lies south of GFDL but just north of most of the consensus guidance. SHIPS probability for rapid intensification is over 30 percent through 24 hours. This aligns with most intensity guidance showing Madeline reaching peak intensity by day 2, then suffering a gradual decline as SSTs drop and shear begins to increase. Our intensity forecast tops Madeline out at 85 kt at 24 hours, followed by a decline through day 5. While depicted as stronger than last time at all tau beyond day 2, the rate of weakening beyond day 2 was actually increased with this package to keep pace with SHIPS and IVCN consensus. As usual, the confidence in the track forecast decreases by day 3, so it is difficult to determine what impacts Madeline could have on the Hawaiian Islands late in the forecast period. It is important to remember that the average day 4 and 5 track forecast errors for central Pacific tropical cyclones is around 185 and 250 miles, respectively. FORECAST POSITIONS AND MAX WINDS INIT 29/0900Z 17.8N 143.7W 75 KT 85 MPH 12H 29/1800Z 18.4N 145.1W 80 KT 90 MPH 24H 30/0600Z 18.9N 146.8W 85 KT 100 MPH 36H 30/1800Z 19.1N 148.6W 80 KT 90 MPH 48H 31/0600Z 19.0N 150.6W 75 KT 85 MPH 72H 01/0600Z 18.5N 154.8W 70 KT 80 MPH 96H 02/0600Z 17.6N 159.0W 60 KT 70 MPH 120H 03/0600Z 16.7N 163.3W 55 KT 65 MPH $$ Forecaster Powell" |