000
WTPZ42 KNHC 250248
TCDEP2

TROPICAL STORM FRANK DISCUSSION NUMBER  14
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP072016
900 PM MDT SUN JUL 24 2016

After the earlier burst of strong convection, thunderstorm activity
in the inner-core region of Frank has deteriorated with cloud tops
having warmed significantly since the previous advisory. Moreover, a
2217Z AMSU microwave pass indicated that the eyewall convection had
become fragmented. The initial intensity remains at 60 kt for this
advisory, which is close to the average of the 0000Z subjective and
objective satellite intensity estimates.

Frank has continued to slow down and is now moving 275/04 kt. Frank
has made a westerly jog for the past 12 h, possibly due to the sharp
increases and decreases in the inner-core structure during that
time. However, the consensus of the global and regional models calls
for the cyclone to resume a west-northwestward motion by early
Monday. That motion is forecast to throughout at least 72 h as Frank
moves along the southwestern periphery of a deep-layer subtropical
ridge. By 96-120 h, the cyclone is forecast to weaken to shallow
remnant low pressure system, which should then be steered more
westward by the low-level easterly trade wind flow. The official
forecast track is similar to the previous advisory track and follows
the consensus track model TVCN.

Although the intensity is forecast to remain steady for the next 24
hours, Frank is expected to remain over SSTs greater than 26 deg C
and in a low vertical wind shear environment during that time, which
should provide the cyclone with the opportunity to mix out the
inner-core dry air and still become a hurricane. By 36-48 h,
however, Frank will be moving over sub-26 deg C water, which should
start a slow but steady weakening trend, with the cyclone
degenerating into a remnant low by day 4. The new NHC intensity
forecast is essentially just an update of the previous advisory, and
closely follows the intensity consensus model IVCN.

FORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 20.0N 113.0W   60 KT  70 MPH
 12H  25/1200Z 20.2N 113.8W   60 KT  70 MPH
 24H  26/0000Z 20.4N 114.8W   60 KT  70 MPH
 36H  26/1200Z 20.7N 116.1W   55 KT  65 MPH
 48H  27/0000Z 21.1N 117.6W   45 KT  50 MPH
 72H  28/0000Z 22.3N 120.6W   35 KT  40 MPH
 96H  29/0000Z 23.0N 123.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  30/0000Z 23.3N 125.2W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Stewart