Atlantic Basin Tropical Cyclones

Tropical Storm Alex Forecast Discussion


000
WTNT41 KNHC 051448
TCDAT1

Tropical Storm Alex Discussion Number  12
NWS National Hurricane Center Miami FL       AL012022
1100 AM EDT Sun Jun 05 2022

Reports from an Air Force Reserve Hurricane Hunter aircraft indicate 
that Alex has strengthened a little since the last advisory.  The 
aircraft reported a central pressure near 993 mb and maximum 
flight-level winds of 89 kt at 850 mb in the southeastern quadrant.  
However, the maximum reliable SFMR surface wind estimates are near 
50 kt, so as mentioned previously the strongest winds may not be 
mixing down to the surface. Based on these data, the initial 
intensity is set to a possibly conservative 50 kt.  Satellite 
imagery shows that Alex remains sheared, with the strongest 
convection to the east and northeast of the center.  This was 
confirmed by the aircraft data, which indicated that the 850 and 700 
mb centers were displaced from the surface center.

The initial motion is quickly east-northeastward or 060/20 kt.  A
general east-northeastward motion is expected during the next 24 h
or so, with the center of Alex passing north of Bermuda on Monday.
After that, the GFS, ECWMF, and Canadian models forecast an
eastward motion at a slower forward speed as Alex weakens, becomes
extratropical, and becomes a shallow and elongated vortex.  The
new intensity forecast follows this scenario and is similar to the
previous forecast.  However, by 72-96 h the forecast track is to
the south of the various consensus models, and some adjustment to
this part of the forecast may be necessary later.

Some additional strengthening is possible during the next 12 h.
After that, a combination of strong shear, dry air entrainment, and
cooler sea surface temperatures along the forecast track should
cause Alex to weaken.  The cyclone is expected to become
extratropical by 48 h and dissipate completely by 120 h.  The new
intensity forecast has only minor changes from the previous
forecast.

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  05/1500Z 30.4N  73.9W   50 KT  60 MPH
 12H  06/0000Z 31.7N  70.8W   55 KT  65 MPH
 24H  06/1200Z 33.1N  66.4W   50 KT  60 MPH
 36H  07/0000Z 34.2N  61.7W   45 KT  50 MPH
 48H  07/1200Z 34.6N  57.4W   40 KT  45 MPH...POST-TROP/EXTRATROP
 60H  08/0000Z 34.9N  53.4W   35 KT  40 MPH...POST-TROP/EXTRATROP
 72H  08/1200Z 35.0N  50.3W   30 KT  35 MPH...POST-TROP/EXTRATROP
 96H  09/1200Z 35.5N  47.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
120H  10/1200Z...DISSIPATED

$$
Forecaster Beven



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