[Ips-hf-warning] IPS HF COMMS WARNING

[rwc]

SUBJ: IPS HF RADIO COMMUNICATIONS WARNING 01/70
ISSUED AT 05/2225Z NOVEMBER 2001
BY THE AUSTRALIAN SPACE FORECAST CENTRE.

MILD GEOMAGNETIC ACTIVITY OBSERVED SECOND 
HALF OF UT DAY 05 NOV POSSIBLY IN ASSOCIATION
WITH EARLIER WEAK/SLOW M1 FLARE/MASS EJECTION EVENT.

MILDY DEPRESSED HF PROPAGATION CONDITIONS OBSERVED
SOUTHERN REGION ONLY AFTER LOCAL DAWN ON 06 NOVEMBER 
2001 FOLLOWING THIS MILD OVERNIGHT GEOMAGNETIC ACTIVITY.

A MUCH STRONGER DEPRESSION RESPONSE IS EXPECTED LATER 
ON THE 06 NOV DUE TO MASS EJECTION FROM RECENT X1 EVENT.
DEPRESSIONS OF 30-40% ARE EXPECTED TOWARD THE END OF THE UT 
DAY ON 06 NOV, AND CONTINUING ON 07 NOV. 

POLAR REGION HF COMMUNICATION CURRENTLY SEVERELY DEGRADED
DUE TO PROTON EVENT (PCA) FROM X1 FLARE.

IF COMMS DIFFICULTIES EXPERIENCED TRY A LOWER FREQUENCY BAND
FOLLOW ON HF WARNING FROM HF WARNING: 68 AND 69
-------------------------------------------------------------
SOLAR ACTIVITY FORECAST       HF COMMS FADEOUTS             
06 Nov:  moderate to high     Probable             

HF COMMUNICATIONS FORECAST (AUSTRALIAN/NEW ZEALAND REGION)
                                   FREQUENCY BANDS  
       T-index  MUFs          2  4  6  8 12 16 22 26
-------------------------------------------------------------
6 Nov   100    -15%           2  4  6  8 12 12 16 22 
7 Nov    80    -35%           2  4  6  8  8 12 16 16 


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