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Tropical Storm Lisa Forecast Discussion


538 
WTNT45 KNHC 311453
TCDAT5

Tropical Storm Lisa Discussion Number   4
NWS National Hurricane Center Miami FL       AL152022
1100 AM EDT Mon Oct 31 2022

GOES-16 1-minute visible imagery indicates that the low-level 
circulation of the system has closed off again, although the system 
is still a bit elongated north-to-south.  Westerly shear has caused 
the center to be exposed to the west and north of the primary 
convective banding features.  NOAA Hurricane Hunter tail Doppler 
radar data also show that the low is tilted southeastward with 
height, a reflection of the current shear.  Still, the plane had 
numerous SFMR values of around 35 kt, and dropsonde data showed the 
pressure has dropped to 1003 mb.  These values are sufficient to 
call the system a tropical storm with an initial wind speed of 35 
kt.

After a dip southward overnight, Lisa is moving westward again at
about 12 kt.  The storm should move westward to west-northwestward
for the next day or two under a mid-level ridge to the north.  As
the ridge intensifies in a few days, Lisa is likely to move
westward, or possibly a little south-of-west, while it approaches
Belize.  Model guidance remains in very good agreement, and 
only a small southward adjustment was made to the previous forecast.

Lisa should encounter more conducive atmospheric and oceanic 
conditions for the next few days, with increasing mid-level 
humidities and generally lower shear.  The storm will likely still 
have some bouts with drier air infiltrating in the northwestern 
quadrant of the circulation, but the diminishing shear should lessen 
the impact of this factor.  Thus slow intensification is shown for 
the next few days, consistent with the interpolated previous 
forecast.  It should be noted that the new NHC forecast is on the 
high side of the guidance for this cycle, with a notable decrease of 
the forecast intensity in many of the models.  The official 
forecast is lower than the previous one, owing to the model trend, 
but it is preferable to wait another cycle to make any larger 
changes after the model suite ingests the plentiful aircraft data 
for the 12 UTC suite.


Key Messages:

1. Tropical storm conditions are possible on Jamaica today.

2. Interests along the coast of Central America, especially near
Belize and the Yucatan Peninsula of Mexico, should monitor the
progress of this system. Additional watches and warnings will
likely be required by late today.


FORECAST POSITIONS AND MAX WINDS

INIT  31/1500Z 15.5N  77.3W   35 KT  40 MPH
 12H  01/0000Z 15.8N  79.0W   40 KT  45 MPH
 24H  01/1200Z 16.3N  81.4W   45 KT  50 MPH
 36H  02/0000Z 16.8N  83.9W   50 KT  60 MPH
 48H  02/1200Z 17.1N  86.3W   55 KT  65 MPH
 60H  03/0000Z 17.1N  88.2W   65 KT  75 MPH
 72H  03/1200Z 16.7N  90.0W   40 KT  45 MPH...INLAND
 96H  04/1200Z...DISSIPATED

$$
Forecaster Blake




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