[Ips-hf-warning] ASWFC HF DEPRESSION WARNING issued 0747 UT on 15 Sep 2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

SUBJ: ASWFC HF RADIO COMMUNICATIONS WARNING 25/84
ISSUED AT 0747UT/15 SEPTEMBER 2025
BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

Geomagnetic activity that has been observed during the UT day 
15 Sep, has caused depressions to Maximum Usable Frequencies 
(MUF's) by 15-20%. MUF's may continue to be depressed over 16-17th 
Sep, particularly during night hours. Equatorial scintillation 
is possible.

DEGRADED HF PROPAGATION CONDITIONS EXPECTED
FROM 15-17 SEPTEMBER 2025
IF COMMS DIFFICULTIES EXPERIENCED TRY A LOWER FREQUENCY BAND
_____________________________________________________________

HF COMMUNICATIONS FORECAST (AUSTRALIAN/NEW ZEALAND REGION)
                                   FREQUENCY BANDS
       T-index      MUFs        2  4  6  8 12 16 22 26
_____________________________________________________________
15 Sep:   80   normal/-15%      2  4  6  8 12 12 16 22
16 Sep:   75   normal/-20%      2  4  6  8  8 12 16 16
17 Sep:   85   normal/-15%      2  4  6  8 12 12 16 22

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