短暫發展，03Z發出最終報，預計明日於西班牙境內消散。

ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM

Post-Tropical Cyclone Alpha Discussion Number   3
NWS National Hurricane Center Miami FL       AL242020
300 AM GMT Sat Sep 19 2020

METEOSAT imagery, IPMA radar data, and surface observations
indicate that Alpha has degenerated to a post-tropical remnant low
just a few miles to the southeast of Viseu, Portugal.  Therefore,
this the last NHC advisory.  Surface wind data support an initial
intensity of 25 kt.  The rapidly deteriorating small remnant low is
expected to move generally toward the northeast at about 14 kt for
the next 6 to 12 hours before dissipating over northern Spain by
Saturday night.  The NHC forecast track is basically an update of
the previous advisory and lies between the tightly clustered
deterministic guidance.

Additional information on the hazards from this system can be found
in products from the Portuguese Institute for Sea and Atmosphere at
www.ipma.pt.


FORECAST POSITIONS AND MAX WINDS

INIT  19/0300Z 40.9N   6.9W   25 KT  30 MPH...POST-TROPICAL
12H  19/1200Z 42.6N   4.4W   20 KT  25 MPH...POST-TROP/INLAND
24H  20/0000Z...DISSIPATED

$$
Forecaster Roberts

NNNN

NHC發布特別報命名副熱帶氣旋Alpha。

NHC will initiate advisories on Subtropical Storm Alpha, located near the coast of Portugal, at 1230 PM AST (1630 UTC).

WTNT44 KNHC 181634
TCDAT4

Subtropical Storm Alpha Special Discussion Number   1
NWS National Hurricane Center Miami FL       AL242020
430 PM GMT Fri Sep 18 2020

The small low pressure area that has been rotating around a larger
extratropical low in the far northeastern Atlantic has become better
organized this morning.  Moderate-to-deep convection has persisted
near the center since last night, scatterometer data shows a closed
40-kt low, and radar images from Portugal show a definite organized
convective pattern.  While the system is still in the cyclonic
envelope of the large extratropical low and likely neutral- or
cold-core, it has developed enough tropical characteristics to be
considered a subtropical storm.  The initial intensity is set to 45
kt in accordance with the scatterometer data, assuming some
undersampling for this small system.

Little change in strength is forecast until landfall in Portugal
during the next couple of hours.  Global models show the small low
moving northeastward at about 15 kt for the next 24 hours before
dissipating over northern Spain or the Bay of Biscay. The track and
intensity forecasts are consistent with the consensus guidance.

Additional information on the hazards from this system can be found
in products from the Portuguese Institute for Sea and Atmosphere at
www.ipma.pt.

FORECAST POSITIONS AND MAX WINDS

INIT  18/1630Z 39.9N   9.3W   45 KT  50 MPH
12H  19/0000Z 41.5N   7.5W   30 KT  35 MPH...POST-TROP/INLAND
24H  19/1200Z 44.2N   4.2W   30 KT  35 MPH...POST-TROP/EXTRATROP
36H  20/0000Z...DISSIPATED

$$
Forecaster Blake

後記：
根據NHC命名規則，由於今年已超過21個系統被命名，熱帶氣旋命名表名稱已用盡，從24L(含)後採用希臘字母系統命名，命名表如下：

1. Alpha
   
2. Beta
   
3. Gamma
   
4. Delta
   
5. Epsilon
   
6. Zeta
   
7. Eta
   
8. Theta
   
9. Iota
   
10. Kappa
    
11. Lambda
    
12. Mu
    
13. Nu
    
14. Xi
    
15. Omicron
    
16. Pi
    
17. Rho
    
18. Sigma
    
19. Tau
    
20. Upsilon
    
21. Phi
    
22. Chi
    
23. Psi
    
24. Omega

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