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Tropical Storm Mario Discussion Number   6
NWS National Hurricane Center Miami FL       EP142019
300 PM MDT Wed Sep 18 2019

ASCAT data, including from the new ASCAT-C instrument, was very
helpful in analyzing the location, size, and intensity of Mario
this afternoon. The tropical storm has contracted substantially,
and earlier microwave data suggested that it had developed a
mid-level eye-like feature. Since that time, it appears that
moderate easterly wind shear, associated at least in part with
outflow with Mario's larger sibling (Lorena) to the east, has
prevented the tropical storm from strengthening at a faster rate.
The intensity is nonetheless increased to 55 kt, and this could be
conservative given that the ASCAT data showed maximum winds of 50-55
kt.

The track and intensity of Mario will depend largely on what happens
with Lorena. If Lorena moves inland and weakens, Mario will likely
be located within a very favorable environment for intensification.
However, if Lorena stays offshore and strengthens (like shown in
the latest NHC forecast), it will likely continue to negatively
affect Mario for the next several days. Lorena's forecast may
become more clear later tonight, but until then the Mario intensity
forecast is, and will likely continue to be, highly uncertain. The
NHC forecast is slightly above the intensity consensus, but is
still well within the intensity model spread.

Mario continues to move northwestward at about 10 kt. Most of the
global models forecast that Mario will meander generally northward
to northwestward for the next couple of days toward a weakness in
the subtropical ridge. After that, if Lorena survives its brush
with Mexico and strengthens near the Baja California peninsula,
there is a chance that Mario could turn abruptly eastward as it
interacts with the other cyclone. That said, most of the global
models show no such interaction occuring, and instead show Mario
continuing broadly northward through day 5. The NHC forecast
follows the bulk of the guidance northward for now, but it should be
noted that uncertainty in the track forecast is still high.


FORECAST POSITIONS AND MAX WINDS

INIT  18/2100Z 15.0N 111.8W   55 KT  65 MPH
 12H  19/0600Z 15.8N 112.4W   60 KT  70 MPH
 24H  19/1800Z 16.7N 112.5W   65 KT  75 MPH
 36H  20/0600Z 17.5N 112.4W   70 KT  80 MPH
 48H  20/1800Z 17.9N 112.6W   70 KT  80 MPH
 72H  21/1800Z 18.6N 113.4W   55 KT  65 MPH
 96H  22/1800Z 21.5N 116.0W   55 KT  65 MPH
120H  23/1800Z 23.5N 117.0W   50 KT  60 MPH

$$
Forecaster Zelinsky

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