[Ips-hf-warning] ASWFC HF DEPRESSION WARNING issued 2137 UT on 04 Jul 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC PRELIMINARY HF RADIO COMMUNICATIONS WARNING 25/68
ISSUED AT 2137UT/04 JULY 2025
BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

Due to coronal hole activity, maximum usable frequencies in the 
Australian region may become depressed by 10-20% over 4-7 Jul, 
with biggest depressions on 5-Jul.

DEGRADED HF PROPAGATION CONDITIONS EXPECTED
FROM 04-06 JULY 2025
IF COMMS DIFFICULTIES EXPERIENCED TRY A LOWER FREQUENCY BAND
A MORE DETAILED HF WARNING WILL FOLLOW IF DEPRESSIONS EVENTUATE.
_____________________________________________________________

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au