000
WTPZ42 KNHC 070240
TCDEP2

HURRICANE BLANCA DISCUSSION NUMBER  26
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP022015
900 PM MDT SAT JUN 06 2015

Blanca's eye remains well defined, but the surrounding cloud-top
temperatures have continued to warm.  There has also been some
erosion of the convective canopy on the southeastern side of the
hurricane, suggesting that vertical shear is increasing.  Despite
the slightly worse satellite presentation, Dvorak CI numbers from
TAFB and SAB are the same as six hours ago, which supports
maintaining an initial intensity of 105 kt.  Data T-numbers are
decreasing, however, and Blanca will likely begin weakening soon due
to the increasing shear and cooler sea surface temperatures.  The
intensity models all weaken Blanca, but they do so at different
rates.  The SHIPS model appears to weaken the cyclone a little too
fast, showing dissipation in 48 hours.  On the other hand, the
GFS--which seems to have been handling Blanca's intensity trends
quite well--shows a much slower rate of weakening.  The NHC
intensity forecast is therefore a little higher than the intensity
consensus (IVCN) between 12-48 hours, lying closest to the LGEM.
Blanca should degenerate into a remnant low by 72 hours and then
dissipate by 96 hours, if not sooner.

Blanca has turned north-northwestward, or 330 degrees at 9 kt.
This motion is expected to continue until dissipation as Blanca
moves between a mid-level high centered over northern Mexico and a
deep-layer trough extending from the western U.S. southwestward
over the Pacific.  The track guidance remains tightly clustered,
with only a slight westward shift noted at 48 hours.  The updated
NHC track forecast is just a little bit slower than the previous
forecast in order to fall closer to the TVCE multi-model consensus.

The updated forecast does not require any changes to the watches or
warnings.

FORECAST POSITIONS AND MAX WINDS

INIT  07/0300Z 19.2N 110.4W  105 KT 120 MPH
 12H  07/1200Z 20.4N 110.9W   90 KT 105 MPH
 24H  08/0000Z 22.4N 111.5W   65 KT  75 MPH
 36H  08/1200Z 24.6N 112.3W   45 KT  50 MPH
 48H  09/0000Z 26.4N 113.1W   35 KT  40 MPH
 72H  10/0000Z 29.9N 114.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  11/0000Z...DISSIPATED

$$
Forecaster Berg