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HURRICANE OTTO DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL162016
1000 PM EST WED NOV 23 2016

A strong convective burst occurred near the center of Otto as an
Air Force Reserve Hurricane Hunter aircraft investigated the
cyclone near 0000 UTC.  This resulted in the aircraft reporting
central pressures near 977-979 mb, 850-mb flight-level winds in
excess of 100 kt, and dropsondes supporting surface winds of at
least 80 kt. However, these winds may have been associated with a
transient mesocyclone in the strong convection, as data from a
subsequent penetration showed a central pressure near 981 mb and
lower winds. The initial intensity is now 75 kt based on 700-mb
flight-level winds from the last aircraft pass, and there is a
larger than normal uncertainty about this value.

Conditions appear favorable for additional strengthening before the
hurricane makes landfall over Central America on Thursday, and the
intensity forecast shows modest strengthening for the first 12
hours. Otto should weaken significantly while crossing southern
Nicaragua and northern Costa Rica, and it is expected to emerge into
the Pacific as a tropical storm between 24 and 36 hours.  Strong
easterly vertical shear should prevent re-intensification, and the
new intensity forecast follows the trend of the previous forecast in
showing a slow decay to a remnant low by 120 hours.  However, it
should be noted that the Pacific portion of the intensity forecast
lies near the low end of the intensity guidance.

Otto is moving a little faster with the initial motion now 275/8.
The hurricane should make landfall over southern Nicaragua or
northern Costa Rica sometime on Thursday.  After landfall, a strong
low- to mid-level ridge to the north should steer the cyclone
westward to west-southwestward through 96 hours.  Near the end of
the forecast period, Otto or its remnants should approach the
western end of the ridge and turn west-northwestward. The track
guidance remains in good agreement, and the new forecast track is a
slightly faster version of the previous track.


FORECAST POSITIONS AND MAX WINDS

INIT  24/0300Z 11.2N  82.2W   75 KT  85 MPH
 12H  24/1200Z 11.2N  83.3W   80 KT  90 MPH
 24H  25/0000Z 10.9N  85.2W   60 KT  70 MPH...INLAND
 36H  25/1200Z 10.5N  87.4W   45 KT  50 MPH...OVER WATER
 48H  26/0000Z 10.0N  89.5W   40 KT  45 MPH
 72H  27/0000Z  9.5N  94.5W   40 KT  45 MPH
 96H  28/0000Z  9.5N  99.0W   35 KT  40 MPH
120H  29/0000Z 11.0N 103.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven

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