Tropical Storm John Discussion Number 16
Wiki-Hurricanes Forecast Center
8:00 AM PDT Thu Aug 9 2018
Tropical Storm John is headed out to its death throes in the subtropical Pacific as it continues to track towards the northwest. However, over the last six hours the tropical storm has been rather stable in appearance, with a small centralized convective cluster about its center of circulation, surrounded by an expansive field of low-level cumulus. Microwave data from a SSMIS pass at 1153Z suggest that this convective activity is powered by the final mid-level eyewall remnants of John, which should wither off later today. Still, the stability of the storm's organization on satellite imagery this morning implicates leaving the intensity at 55 kt, in line with the previous advisory and curently relevant raw final-t values from SAB and TAFB.
John continues to track towards the northwest but will curve west as it weakens, restoring the low-level tradewind flow. Weakening will be precipitated by cooling sea surface temperatures, degenerating the system to a remnant low. Some of the guidance shows that a weak surface trough could cause John to quit its westerly heading and turn northeast towards California after about three days. By that time, John should not be of much consequence given its anticipated remnant low status, but could bring some much needed moisture to the parched state.
MAXIMUM WINDS FORECAST
INIT 09/1500Z 55 KT 65 MPH
12H 10/0000Z 50 KT 60 MPH
24H 10/1200Z 45 KT 50 MPH
36H 11/0000Z 35 KT 40 MPH
48H 11/1200Z 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 12/1200Z 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 13/1200Z 20 KT 25 MPH...POST-TROP/REMNT LOW