[Tropical] Tropical Cyclone Discussion

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WTNT42 KNHC 020239
TCDAT2

Tropical Storm Bonnie Discussion Number  18
NWS National Hurricane Center Miami FL       AL022022
1100 PM EDT Fri Jul 01 2022

Reports from an Air Force Reserve Hurricane Hunter aircraft and
satellite imagery indicate that the center of Bonnie has just made
landfall near the Nicaragua-Costa Rica border.  The aircraft
reported that prior to landfall, Bonnie was forming an inner wind
core with a radius of maximum winds of 5-10 n mi, and on the last
fix a 10 n mi wide eye was present.  The maximum flight-level winds
were 61 kt at 850 mb, and the maximum reliable surface wind
estimates from the SFMR were in the 40-45 kt range.  Based on these
data, the landfall intensity is set to a possibly conservative 45
kt.

The initial motion is now 270/14.  A mid- to upper-level ridge to
the north of the cyclone should steer it generally westward for the
next 24 h or so, with the center crossing southern Nicaragua and
northern Costa Rica before reaching the eastern Pacific Saturday
morning.  After that, the cyclone should turn west-northwestward
parallel to the southern coasts of Central America and Mexico, with
this general motion persisting through the remainder of the
forecast period.  The track forecast guidance is tightly clustered,
and the new forecast track is little changed from the previous
track.  Given the expected proximity to land, interests in coastal
El Salvador, Guatemala and southwestern Mexico should continue to
monitor Bonnie's progress during the next several days.

Bonnie's small inner core will probably not survive the passage
over land during the next 12 h, but the cyclone is still expected to
be a tropical storm when it reaches the eastern Pacific.  Once
there, warm sea surface temperatures and a light shear environment
should allow re-intensification, and Bonnie is now forecast to
reach hurricane status about two days after it moves into the
Pacific.  The new intensity forecast has some minor adjustments from
the previous forecast.


KEY MESSAGES:

1. Heavy rainfall is expected across portions of Nicaragua and
Costa Rica through Saturday. Life-threatening flash flooding and
mudslides are expected.

2. Tropical storm conditions are expected along the Caribbean
coasts of Costa Rica and Nicaragua within the Tropical Storm Warning
areas for the next several hours, and along the Pacific coasts of
Costa Rica and Nicaragua overnight and early Saturday.


FORECAST POSITIONS AND MAX WINDS

INIT  02/0300Z 10.9N  83.8W   45 KT  50 MPH...INLAND
 12H  02/1200Z 10.9N  85.8W   35 KT  40 MPH...INLAND
 24H  03/0000Z 11.0N  88.5W   40 KT  45 MPH...OVER PACIFIC OCEAN
 36H  03/1200Z 11.6N  90.9W   50 KT  60 MPH
 48H  04/0000Z 12.4N  93.7W   60 KT  70 MPH
 60H  04/1200Z 13.3N  96.6W   65 KT  75 MPH
 72H  05/0000Z 14.2N  99.5W   70 KT  80 MPH
 96H  06/0000Z 15.5N 104.5W   75 KT  85 MPH
120H  07/0000Z 16.0N 109.0W   75 KT  85 MPH

$$
Forecaster Beven
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