Atlantic Basin Tropical Cyclones

Tropical Storm Alex Forecast Discussion


000
WTNT41 KNHC 060246
TCDAT1

Tropical Storm Alex Discussion Number  14
NWS National Hurricane Center Miami FL       AL012022
1100 PM AST Sun Jun 05 2022

The satellite presentation of Alex has evolved from a more classic 
sheared tropical cyclone this morning to that of an extratropical 
transitioning cyclone.  There are still some fragments of convection 
near the center, but most of the shower and thunderstorm activity is 
well removed from the center in a band around the eastern portion of 
the circulation. This change in structure is due to an approaching  
mid- to upper-level trough and associated dry air that has become 
entrained into the circulation. Air Force reconnaissance aircraft 
observations and data from NOAA buoy 41048 indicate that Alex is 
slightly stronger.  Reports from a center drop from the aircraft 
showed that the pressure had fallen to around 984 mb, and the buoy 
reported a peak one-minute wind of 52 kt at 4 meters.  Based on 
these data the initial intensity has been set at 60 kt.  However, 
the cyclone may already be beginning to fill as the latest 
reconnaissance aircraft pass through the center reported that the 
pressure had risen 4 mb. 

Alex will be moving over cooler waters and into a higher shear 
environment during the next 12-24 hours, therefore weakening should 
commence very soon.  Simulated satellite imagery from the GFS and 
ECMWF suggest the system will struggle to redevelop deep convection 
near the center and the system is now forecast to become 
post-tropical by 24 hours, if not sooner.  The global model guidance 
now also indicates that the post-tropical cyclone will be absorbed 
along a frontal boundary as a new baroclinic low develops from a 
strong mid-latitude trough moving southeastward from Atlantic Canada 
in a day or two.  As a result, the new NHC forecast calls for 
absorption within the new low within 48 hours.

Alex is moving 060/24 kt. The cyclone should remain on a general
east-northeastward motion during the next day or so, with the
center passing north of Bermuda on Monday.  The new forecast is
again faster than the previous advisory and lies near a blend of
the GFS and ECMWF models.

KEY MESSAGES:

1. Alex is forecast to pass near or just north of Bermuda on Monday,
and tropical storm conditions are expected on the island late
tonight and Monday.


FORECAST POSITIONS AND MAX WINDS

INIT  06/0300Z 32.5N  69.0W   60 KT  70 MPH
 12H  06/1200Z 33.7N  65.3W   50 KT  60 MPH
 24H  07/0000Z 35.3N  60.2W   45 KT  50 MPH...POST-TROP/EXTRATROP
 36H  07/1200Z 37.4N  54.3W   45 KT  50 MPH...POST-TROP/EXTRATROP
 48H  08/0000Z...ABSORBED BY EXTRATROPICAL LOW

$$
Forecaster Brown



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