[ips-sf] ASWFC Summary Forecast for 29 December - issued 0450UT/29-Dec-2025 [SEC=OFFICIAL]

[Australian Space Weather Forecasting Centre]

An R1 (M4.2) flare was observed 28/2239UT just southeast of region
AR4317 and associated with a north and west directed CME. Preliminary
modelling indicates a potential CME arrival during the second half of
the UT day on 31-Dec. G2, chance G3 geomagnetic conditions may then
follow. On UT day 29-Dec solar activity is expected to be R1, chance
R2. S0 solar radiation storm conditions are expected. The solar wind
speed is expected to be moderate. Geomagnetic conditions are expected
to be G0. Increased geomagnetic activity is expected over 30-31 Dec
due to a coronal hole wind stream. HF radio propagation conditions are
expected to be normal. Maximum usable frequencies in the Australian
region are expected to be near predicted values to 15% enhanced.
Isolated fadeouts are possible.

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