ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM TROPICAL STORM IVETTE DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102016 200 PM PDT THU AUG 04 2016 Vertical shear over Ivette is gradually decreasing, and the low-level center is now embedded beneath a persistent CDO feature. A recent ASCAT pass indicated that maximum winds are now near 45 kt, which is supported by an average of subjective and objective satellite intensity estimates. Ivette may finally be starting the gradual intensification trend that has been forecast, and the intensity guidance indicates that strengthening should continue for the next 48 hours while sea surface temperatures are warm and vertical shear is low. Most of the models continue to keep Ivette below hurricane strength, but the NHC intensity forecast still makes the cyclone a hurricane in 48 hours, which is supported by the Florida State Superensemble and the SHIPS model. After 48 hours, increasing shear and lower oceanic heat content should cause fast weakening through day 5. The ASCAT pass was useful in helping to reposition Ivette's center, and the initial motion estimate is now 270/12 kt. The subtropical ridge to the north of the cyclone is forecast to steer Ivette westward for the next 24 hours. Thereafter, a break in the ridge to the northeast of Hawaii should cause the cyclone to turn west-northwestward and decelerate. The updated NHC track forecast is adjusted a little southward during the first 3 days to account for the refinement of the initial position. Otherwise, it lies very close to the multi-model consensus in the middle of a tightly packed guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 04/2100Z 14.7N 127.3W 45 KT 50 MPH 12H 05/0600Z 14.8N 129.1W 50 KT 60 MPH 24H 05/1800Z 15.0N 131.2W 55 KT 65 MPH 36H 06/0600Z 15.5N 133.0W 60 KT 70 MPH 48H 06/1800Z 16.1N 134.7W 65 KT 75 MPH 72H 07/1800Z 17.4N 137.8W 60 KT 70 MPH 96H 08/1800Z 18.5N 141.0W 45 KT 50 MPH 120H 09/1800Z 19.0N 144.0W 35 KT 40 MPH $$ Forecaster Berg NNNN