- Search for Search
Tropical Storm HERNAN

ZCZC MIATCDEP3 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM HERNAN DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP082014
800 AM PDT SUN JUL 27 2014

Enhanced BD-curve infrared imagery and an earlier GCOM-W1 (AMSR2)
microwave overpass indicate that Hernan has continued to strengthen
this morning.  The imagery shows an impressive well-developed
banding feature over the northwest quadrant of the cyclone with -80
to -90 deg C cloud tops, while the microwave pass reveals a more
distinct inner core with a partial eyewall feature.  Based on a
blend of the Dvorak classifications from TAFB and SAB, and the
latest UW-CIMSS SATCON estimate, the NHC initial intensity is raised
to 60 kt.

Current favorable environmental conditions should allow for further
intensification during the next 8-12 hours, and Hernan still has a
chance to become a hurricane today or tonight.  Afterward,
increasing westerly shear and decreasing sea surface temperatures
are expected to weaken Hernan through the remainder of the forecast
period.  The available statistical/dynamical guidance agree with
weakening Hernan into a remnant low in 96 hours.

The initial motion is estimated to be northwestward, or 305/13 kt.
Hernan continues to be steered by the mid-level southeasterly flow
produced by a ridge over the southwestern United States.  The
cyclone should move in this general direction through the 36 hour
period, and then turn westward within the low-level trade wind flow
as a degenerated, vertically shallow system.  The official NHC
forecast is based on the multi-model consensus and is slightly to
the right of the previous forecast beyond 48 hours.

FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 17.8N 111.1W   60 KT  70 MPH
 12H  28/0000Z 19.0N 112.8W   65 KT  75 MPH
 24H  28/1200Z 20.5N 115.2W   60 KT  70 MPH
 36H  29/0000Z 21.9N 117.6W   50 KT  60 MPH
 48H  29/1200Z 22.9N 119.8W   45 KT  50 MPH
 72H  30/1200Z 23.9N 123.0W   30 KT  35 MPH
 96H  31/1200Z 24.0N 126.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  01/1200Z 24.0N 129.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Roberts

NNNN