ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM FRANK DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP072016
1000 PM CDT THU JUL 21 2016

Convention and microwave satellite imagery indicate that the
convection associated with Frank has become better organized, with
a strong burst occurring just south of the center.  Based on the
previous scatterometer data and the increase in organization, the
initial intensity is increased to 45 kt.

The best estimate of the current motion is 310/15, a little faster
than earlier.  Frank is located to the south of a large and strong
mid-level anticyclone which is centered over the Southern Plains of
the United States and has a ridge extending well westward into the
eastern Pacific.  The dynamical models forecast a slight
weakness in the ridge over the northeastern Pacific during the next
few days.  The ECMWF shows a stronger weakness and thus forecasts
Frank to move farther north, while the GFS keeps a stronger ridge
and forecasts a more westward motion.  Overall, the guidance
envelope has shifted westward away from the coast of Mexico during
the later part of the forecast period, and the official forecast
follows suit.  However, there is still enough uncertainty that
interests in the southern portion of the Baja California peninsula
should monitor the progress of Frank.

Frank is expected to remain over warm water for the next 3 days or
so.  However, easterly shear could inhibit intensification,
especially if the stronger upper-level winds forecast by the ECMWF
verify. The new intensity forecast is similar to the previous
forecast in showing strengthening through 72 hours, and like the
previous forecast it lies near the upper end of the intensity
guidance.  Weakening is forecast after 72 hours due to decreasing
sea surface temperatures along the forecast track and continued
shear.


FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 16.1N 105.2W   45 KT  50 MPH
 12H  22/1200Z 17.0N 106.7W   50 KT  60 MPH
 24H  23/0000Z 17.9N 108.2W   60 KT  70 MPH
 36H  23/1200Z 18.6N 109.5W   65 KT  75 MPH
 48H  24/0000Z 19.4N 110.9W   70 KT  80 MPH
 72H  25/0000Z 21.0N 113.0W   75 KT  85 MPH
 96H  26/0000Z 22.5N 115.0W   65 KT  75 MPH
120H  27/0000Z 23.5N 117.0W   55 KT  65 MPH

$$
Forecaster Beven

NNNN