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Potential Tropical Cyclone One Forecast Discussion



000
WTNT41 KNHC 030856
TCDAT1

Potential Tropical Cyclone One Discussion Number   3
NWS National Hurricane Center Miami FL       AL012022
400 AM CDT Fri Jun 03 2022

The disturbance near the northeastern tip of the Yucatan Peninsula 
appears slightly more organized this morning, with persistent deep 
convection ongoing near and to the east of the estimated center.  An 
Air Force Reserve Hurricane Hunter aircraft investigated the system 
a couple hours ago, and although they found a sharp low-level wind 
shift, there was not yet conclusive evidence of a west wind to close 
off a circulation.  The plane did, however, measure peak 925-mb 
flight-level winds of 46 kt, which along with believable SFMR winds 
of 30-35 kt, suggests that the disturbance is producing 
tropical-storm-force winds.  The system does not get the designation 
of a tropical storm until we have evidence that a well-defined 
center has formed, and another reconnaissance aircraft is scheduled 
to investigate the disturbance in a couple of hours to see if that 
has happened.

Although there is uncertainty in the system's center location, the 
disturbance appears to have turned toward the northeast with a 
motion of 040/4 kt.  As the system gets picked up by mid-latitude 
westerlies to its north, it is expected to accelerate toward the 
northeast or east-northeast during the next few days, bringing it 
across Florida within the next day or two and then over the waters 
of the western Atlantic.  There is very little cross-track spread 
in the guidance, which usually means there is high confidence in 
the forecast track.  However, given that a center has not yet 
formed, it's entirely possible that the entire suite of track 
models could shift north or south on subsequent forecast cycles if 
a center forms farther north or south than we're expecting.  The 
track guidance has sped up a little on this cycle, and the updated 
NHC track forecast is a little faster than the previous forecast in 
an attempt to catch up to the model consensus aids.

The disturbance is not expected to break free from the grasps of 
strong 20-30 kt of southwesterly shear, which is expected to limit 
the amount of intensification in the coming days.  More or less in 
line with a blend of the GFS and ECMWF models, which should have a 
decent handle on a sprawling system like this one, the NHC 
intensity forecast only shows the system strengthening slightly 
during its approach to Florida and exit to the western Atlantic 
waters.  Global model guidance suggests that the system could 
become involved with frontal boundaries in about 4 days, and the 
new forecast now shows extratropical transition being complete by 
that time.

Based on the latest forecast and its inherent uncertainties, 
additional Tropical Storm Warnings have been issued for the east 
coast of Florida, western Cuba, and the northwestern Bahamas.
The main impact from this system continues to be widespread heavy 
rain that is expected to spread over portions of western Cuba, the
southern Florida Peninsula, the Florida Keys, and the northwestern
Bahamas during the next couple of days.


KEY MESSAGES:

1. Heavy rain associated with the system is expected across western 
Cuba, where life-threatening flash flooding and mudslides are 
possible. 

2. Heavy rain will affect portions of Central Florida, South 
Florida, and the Florida Keys today and continue through Saturday. 
Considerable flash and urban flooding is possible across South 
Florida and in the Keys.  Flash and urban flooding is also possible 
across the northwestern Bahamas.

3. Tropical storm conditions are expected in the warning area in 
western Cuba today and tonight, in Florida tonight and on Saturday, 
and in the northwestern Bahamas on Saturday.  Tropical storm 
conditions are also possible in the watch area in western Cuba 
today and tonight.


FORECAST POSITIONS AND MAX WINDS

INIT  03/0900Z 22.3N  86.6W   35 KT  40 MPH...POTENTIAL TROP CYCLONE
 12H  03/1800Z 23.5N  85.5W   35 KT  40 MPH...TROPICAL CYCLONE
 24H  04/0600Z 25.3N  83.2W   40 KT  45 MPH
 36H  04/1800Z 27.1N  80.5W   40 KT  45 MPH...INLAND
 48H  05/0600Z 29.1N  77.5W   40 KT  45 MPH...OVER WATER
 60H  05/1800Z 31.0N  74.0W   45 KT  50 MPH
 72H  06/0600Z 32.5N  70.2W   45 KT  50 MPH
 96H  07/0600Z 34.1N  62.8W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  08/0600Z 34.8N  57.4W   40 KT  45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Berg



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