Potential Tropical Cyclone Two Forecast Discussion Number 7

By | June 29, 2022

000
WTNT42 KNHC 290855
TCDAT2

Potential Tropical Cyclone Two Discussion Number   7
NWS National Hurricane Center Miami FL       AL022022
500 AM AST Wed Jun 29 2022

If I just took a casual look at conventional satellite data, I would 
think the system was already a tropical storm.  There is a big ball 
of convection near the center, along with banding features forming 
in most of the quadrants of the system.  Microwave data, however, 
does not show much low-level structure, with only broad curvature 
and no obvious indications of a well-defined center.  Thus, the 
system remains a disturbance, and the initial wind speed remains 35 
kt based on Dvorak estimates from TAFB.

One reason that the system has been unable to close off a 
circulation so far is the very rapid speed, now estimated at 26 kt 
(or even faster in the short-term).  All of the guidance continue 
to insist the system will slow down over the next few days due to 
less low-level ridging over the western part of the Atlantic basin. 
The low could even lose latitude over the southwestern Caribbean 
due to the orientation of the mid-level ridge, which more models 
are showing. The new forecast is faster than the previous one, 
ahead of the model consensus, placing more weight on the ECMWF than 
the GFS, the latter of which has been much too slow with this 
system.  

The disturbance will probably be struggling with, or recovering 
from, land interaction over the next day or so.  So little 
intensification is shown during that time.  Thereafter, the 
environment would seem to be conducive for significant 
strengthening, but it is unknown what kind of structure the system 
will have to potentially take advantage of the conducive conditions. 
Additionally, with the faster forward speed, it should spend less 
time over water for strengthening.  Thus, the intensity forecast is 
reduced somewhat from the previous one, but generally remains above 
the model consensus.  Interestingly, almost all of the models 
indicate that the system will survive passage across Central America 
and intensify in the eastern Pacific.  This is now indicated in the 
official forecast, and could be conservative at long range. 


KEY MESSAGES:

1.  Heavy rainfall is expected to continue across the Windward 
Islands and spread into parts of northern Venezuela through tonight. 
Localized flash flooding will be possible.

2.  Winds to tropical-storm-force are expected over Islas Margarita 
for a few more hours, and over the ABC Islands by this afternoon.  
Tropical storm conditions are expected along the northwestern coast 
of Venezuela and northeastern Colombia tonight and early Thursday.

3.  There is a greater-than-normal uncertainty in the system's 
forecast intensity once it reaches the southwestern Caribbean Sea 
late Thursday and Friday, which will depend on how much it interacts 
with land from tonight through Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT  29/0900Z 11.3N  65.4W   35 KT  40 MPH...POTENTIAL TROP CYCLONE
 12H  29/1800Z 11.7N  68.4W   40 KT  45 MPH...TROPICAL CYCLONE
 24H  30/0600Z 12.2N  72.2W   40 KT  45 MPH
 36H  30/1800Z 12.2N  75.7W   40 KT  45 MPH
 48H  01/0600Z 12.0N  79.5W   50 KT  60 MPH
 60H  01/1800Z 11.8N  82.5W   60 KT  70 MPH
 72H  02/0600Z 11.8N  85.8W   40 KT  45 MPH...INLAND
 96H  03/0600Z 12.3N  91.3W   35 KT  40 MPH
120H  04/0600Z 13.5N  97.0W   45 KT  50 MPH

$$
Forecaster Blake

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