[Ips-dsgr] ASWFC Daily Report - 08 December 25 issued 2340 UT on 08 Dec 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Tue Dec 9 10:40:22 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/08 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 08 DECEMBER AND FORECAST FOR 09 DECEMBER - 11 DECEMBER
STATUS INDICATORS SOL:** RED ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 08 Dec: R3
Flares Max Fadeout Freq. Sectors
M2.4 0012UT possible lower West Pacific
M2.0 0036UT possible lower West Pacific
X1.1 0501UT probable all E. Asia/Aust.
M1.8 0654UT possible lower Mid East/Indian
M1.0 1306UT possible lower European
M3.1 2117UT possible lower East Pacific/
North American
M1.2 2228UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 08 Dec: 186/139
1B. SOLAR FORECAST
09 Dec 10 Dec 11 Dec
Activity R2-R3 R2-R3 R2-R3
Fadeouts Probable Probable Probable
10.7cm/SSN 190/143 185/138 175/129
COMMENT: On UT day 8-Dec solar activity was at the R3 level.
An X1.1 flare was observed from AR4298 (S17W59, alpha), peaking
at 0501UT. Additionally, there were several M-class flares observed.
There are currently eight numbered and two unnumbered sunspot
regions on the solar disk. Active region AR4294 (S14W43, beta-gamma-delta)
has shown mild growth. AR4304 (N25W09, beta-gamma) has also seen
mild growth. AR4299 (N23W10, beta-delta) continues to decay.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be R2-R3. This is due to the presence
of regions on the disk which have produced X and M-class flares,
which will remain on disk over the next three days. Two Earth-directed
CMEs were observed on the 08-Dec, one being associated with the
X-class flare. These have been modelled and are anticipated to
arrive early on the 11-Dec. S0 solar radiation storm conditions
were observed on UT day 8-Dec. Mostly S0 solar radiation storm
conditions are expected over 8-Dec, however further solar flares
from AR4299 may cause S1 conditions as it transits the western
side of the solar disk. On UT day 8-Dec the solar wind environment
was steady. The solar wind speed was on a decline from 455 km/s
to near 340 km/s. The peak total interplanetary field strength
(IMF, Bt) was 7 nT and the north-south IMF component range (Bz)
was -5 to +7 nT. A CME is expected to arrive early on 9-Dec,
which will likely result in an increase to the solar wind speed.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 08 Dec: G0
Estimated Indices 08 Dec : A K
Australian Region 2 12100011
Cocos Island 1 12000000
Darwin 3 13200011
Townsville 4 32100012
Learmonth 3 13100011
Alice Springs 2 12100011
Gingin 3 13100011
Canberra 2 12000011
Kennaook Cape Grim 3 13000011
Hobart 2 12000011
Estimated Antarctic Regional K Indices 08 Dec :
Casey 10 33322222
Mawson 5 21111132
Observed Regional daily pc3 Indices 08 Dec :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 0 (Quiet)
Pc3 pulsations are high frequency (10-45 second period) variations
of the Earths magnetic field. Daily pc3-indices are the daily sum
of 20 minute pc3-indices for that station and have been shown to be
well correlated with rejection of high resolution aeromagnetic
survey flight-line data.
NOTE: Indices may have been generated from data obtained in
cooperation with the following organisations: Geoscience Australia,
University of Newcastle Space Physics Group, Australian Government
Antarctic Division and International Center for Space Weather
Science and Education, Japan.
Estimated AFr/Ap Indices 08 Dec : A
Fredericksburg 13
Planetary 18
Observed AFr/Ap Indices 07 Dec : A K
Fredericksburg 5
Planetary 9 3432 200-
2B. MAGNETIC FORECAST
Date Ap Conditions
09 Dec 45 G3
10 Dec 18 G0-G1
11 Dec 21 G1, chance G2
COMMENT: ASWFC Geomagnetic Warning 97 was issued on 6 December
and is current for 9-10 Dec. Geomagnetic conditions in the Australian
and Antarctic regions on UT day 8-Dec were G0. G3 geomagnetic
conditions are expected on UT day 9-Dec. This is due to a CME
that is expected to arrive early on 9-Dec. G0-G1 geomagnetic
conditions are expected on 10-Dec as the geomagnetic field recovers.
G1, chance G2 conditions are then expected early on the 11th,
due to the arrival of a number of CMEs recently observed.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
08 Dec Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
09 Dec Fair Fair-poor Poor
10 Dec Normal Normal-fair Fair
11 Dec Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 8-Dec were
normal. HF radio propagation conditions are expected to be fair-poor
on UT day 9-Dec, due to the arrival of a CME. Conditions are
expected to be normal-fair on 10-Dec due to waning effects of
this CME. Conditions are expected to remain this way throughout
the 11th, given the arrival of several, smaller CMEs early on
this day. Shortwave fadeouts are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
08 Dec 132
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Enhanced by 25% after local dawn.
Niue Island Region:
Enhanced by 15% during local day.
Enhanced by 25% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Enhanced by 25% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Nov 103
Dec 89
Jan 89
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
09 Dec 90 Near predicted monthly values
10 Dec 100 Near predicted monthly values
11 Dec 100 Near predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 117 was
issued on 6 December and is current for 9-10 Dec. ASWFC SWF HF
Communications Warning 119 was issued on 8 December and is current
for 8-9 Dec. Maximum usable frequencies (MUFs) in the Australian
region on UT day 8-Dec were near predicted values to 25% enhanced.
Sporadic-E was observed in several sites. MUFs are expected to
be near monthly predicted values, as several CMEs suppress already
enhanced MUFs. Depressions of 20% may begin by local night hours
on 9-Dec and into 10-Dec. Nighttime sporadic-E is expected. Shortwave
fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 07 Dec
Daily Proton Fluence >1 MeV: 9.3E+06
Daily Proton Fluence >10 MeV: 4.4E+04
Daily Electron Fluence >2 MeV: 6.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.7
DSCOVR Satellite Solar Wind Day Averaged Data for 07 Dec
Speed: 500 km/sec Density: 1.4 p/cc Temp: 157000 K Bz: 4 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
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Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
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