000 WTPZ42 KNHC 030246 TCDEP2 HURRICANE BLANCA DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP022015 1000 PM CDT TUE JUN 02 2015 An 0100Z SSMIS pass revealed that the mid-level eye which was observed earlier today has shrunk, and spiral convective bands are emanating away from the central convection, favoring the southern semicircle. Dvorak estimates from TAFB and SAB have increased to T4.5/77 kt, so Blanca's initial intensity is raised to 75 kt. This is the first instance in which Blanca's intensity has increased by at least 30 kt over a 24-hour period, so it appears that the hurricane is now experiencing the period of rapid intensification that has been forecast. Rapid intensification is expected to continue for at least the next 24-36 hours due to an environment of negligible vertical shear, deep warm water, and abundant atmospheric moisture. Because of these conditions, the statistical-dynamical models (SHIPS, LGEM, and Florida State Superensemble) all show Blanca reaching major hurricane strength in the next 18-24 hours and then peaking at category 4 strength in about 48 hours. Meanwhile, for reasons that are unclear at the moment, the HWRF and GFDL models keep Blanca essentially steady at category 1 strength for the next four days. Since there are no apparent reasons why the environment shouldn't support strengthening, the official forecast is a blend of the statistical-dynamical models and is just a little higher than the previous forecast during the first 48 hours. By days 4 and 5, increasing vertical shear and sub-optimal sea surface temperatures should cause Blanca to weaken fairly quickly while it approaches the Baja California peninsula. Blanca appears to have drifted southwestward during the past 12-18 hours, and the hurricane is expected to move little during the next 24 hours. After that time, a deepening trough along the U.S. west coast should cause Blanca to accelerate gradually and move north- northwestward between 36-120 hours. With the exception of the GFDL and UKMET models, there is very little cross-track variability among the other reliable track models, but there are some differences in forward speed. The GFS continues to be one of the fastest models, while the ECMWF is one of the slowest and doesn't show Blanca reaching the Baja California peninsula during the five-day forecast period. Since the 00Z multi-model consensus (TVCE) is very close to the previous NHC forecast (OFCI), I elected not to make any significant changes to the track forecast on this cycle. Even though Blanca's forecast track has not shifted eastward, there is the potential for the tropical-storm-force wind field to expand in that direction during the next few days. Therefore, interests along the west-central coast of mainland Mexico, especially in the state of Jalisco, should monitor the progress of Blanca. FORECAST POSITIONS AND MAX WINDS INIT 03/0300Z 12.8N 104.7W 75 KT 85 MPH 12H 03/1200Z 12.7N 104.7W 95 KT 110 MPH 24H 04/0000Z 12.8N 104.7W 110 KT 125 MPH 36H 04/1200Z 13.4N 105.0W 120 KT 140 MPH 48H 05/0000Z 14.7N 105.8W 125 KT 145 MPH 72H 06/0000Z 17.5N 108.2W 110 KT 125 MPH 96H 07/0000Z 20.5N 109.5W 85 KT 100 MPH 120H 08/0000Z 23.5N 110.5W 55 KT 65 MPH $$ Forecaster Berg