[Ips-dsgr] ASWFC Daily Report - 10 December 25 issued 2332 UT on 10 Dec 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Dec 11 10:32:25 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/10 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 10 DECEMBER AND FORECAST FOR 11 DECEMBER - 13 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 10 Dec: R1
Flares Max Fadeout Freq. Sectors
M1.5 09/2327UT possible lower West Pacific
M1.2 0422UT possible lower E. Asia/Aust.
M1.9 0737UT possible lower Mid East/Indian
M1.0 0955UT possible lower Mid East/Indian
M1.6 1343UT possible lower European
M4.4 2208UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 10 Dec: 168/122
1B. SOLAR FORECAST
11 Dec 12 Dec 13 Dec
Activity R1-R2 R1-R2 R1
Fadeouts Probable Probable Possible
10.7cm/SSN 175/129 170/124 165/119
COMMENT: Solar activity was at the R1 level for UT day 10-Dec,
with five M class flares observed. The largest of these was an
M4.4 flare, originating from Active Region (AR) 4294 at 10/2208UT.
There are currently six numbered regions on the solar surface,
with AR4294 (S15W68, beta-gamma) the most magnetically complex.
This region was mostly stable over the last 24 hours, as it rotates
towards the western limb. Active Regions 4304 (N25W34, Beta),
and 4305 (S25E33, Beta) both showed growth over the past UT day.
A new unnumbered region also appeared at (S18W15), and appears
to have a Beta magnetic classification. All other regions are
either stable or in decay. R1-R2 conditions are forecast for
UT days 11-12 Dec, due to the ongoing flare activity from AR4294.
This will decrease to the R1 level by 13-Dec as it moves over
the limb. Solar proton conditions were at the S0 level, with
the 10 MeV proton flux consistent with background levels throughout
10-Dec. S0 conditions are expected to continue over 11-13 Dec.
No geoeffective CMEs we observed over the previous UT day. The
solar wind speed has increased over the past last 24 hours, with
two distinct events seen at 10/0430UT and 10/2020UT. These events
are coincident with two previously mentioned CMEs observed on
08-Dec. The solar wind speed has ranged from 240-460 km/s over
this time, and is currently at 460 km/s. The interplanetary magnetic
field strength (IMF, Bt) recently peaked at 18 nT, coinciding
with the second rise in solar wind speed. The North-South component
(Bz) has ranged between -16 and +7 nT over the last 24 hours,
and is currently at -15 due to the previously mentioned CME arrival.
The solar wind speed is forecast to remain high during 11-Dec,
before declining on 12-Dec as the effects of the CME pass. The
solar wind speed will then rise again, as an equatorial coronal
hole moves into a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 10 Dec: G1
Estimated Indices 10 Dec : A K
Australian Region 14 22312335
Cocos Island 8 1131233-
Darwin 20 22312346
Townsville 16 22312345
Learmonth 18 22312355
Alice Springs 9 1231233-
Gingin 11 2231333-
Canberra 8 1231223-
Kennaook Cape Grim 14 22312335
Hobart 15 22313335
Estimated Antarctic Regional K Indices 10 Dec :
Macquarie Island 13 2223442-
Casey 22 3552323-
Mawson 41 5573332-
Observed Regional daily pc3 Indices 10 Dec :
Darwin 4 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 22 (Quiet to unsettled)
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 10 Dec : A
Fredericksburg 11
Planetary 14
Observed AFr/Ap Indices 09 Dec : A K
Fredericksburg 4
Planetary 5 2111 1211
2B. MAGNETIC FORECAST
Date Ap Conditions
11 Dec 40 G1-G2
12 Dec 24 G0-G1
13 Dec 21 G0-G1
COMMENT: ASWFC Geomagnetic Warning 98 was issued on 10 December
and is current for 10-12 Dec. G1 geomagnetic conditions were
observed across the Australian region over UT day 10-Dec, due
to the arrival of a CME at Earth. G1 levels were seen across
the Antarctic region, with a brief period of G3 seen at Mawson.
Geomagnetic conditions are forecast to be at the G1- G2 level
during 11-Dec, due to the ongoing effects of this CME. These
conditions will decline to G0-G1 on 12 Dec, as the effects of
this CME wane. These conditions will remain during 13-Dec, as
an equatorial coronal hole moves into a geoeffective position.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
10 Dec Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
11 Dec Fair-normal Fair-normal Fair
12 Dec Fair-normal Fair-normal Fair
13 Dec Normal-fair Normal-fair Fair-normal
COMMENT: HF radio propagation conditions on UT day 10-Dec were
mostly normal, with fair-poor conditions observed throughout
the day across the Americans region. Some enhancements were observed
in the Australia and Asia regions. Conditions are expected to
be fair-normal over 11-12 Dec, due to ongoing geomagnetic activity.
Conditions will improve to normal-fair on 13 Dec, with some degradations
possible due to coronal hole high speed wind stream effects.
Shortwave fadeouts are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
10 Dec 148
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Enhanced by 15% during local day.
Enhanced by 35% during local night.
Northern Australian Region:
Enhanced by 25% during local day.
Enhanced by 25% during local night.
Southern Australian Region:
Enhanced by 15% during local day.
Enhanced by 15% during local night.
Enhanced by 20% 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
11 Dec 120 Near predicted monthly values
12 Dec 110 Near predicted monthly values
13 Dec 110 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 120 was issued on
9 December and is current for 9-11 Dec. Maximum usable frequencies
(MUFs) were mostly enhanced by 15-25% during UT day 10-Dec, with
up to 35% enhancements seen in Niue Island, and near predicted
monthly values seen in the Antarctic region. Low frequency sporadic-E
was observed in the southern Australian region. MUFs are forecast
to be near predicted monthly values throughout 11-12 Dec, reduced
from the current enhanced state due to the ongoing geomagnetic
activity. This will likely continue into 13-Dec as high speed
wind stream effects will commence. Sporadic-E during local night
hours may also be observed. Shortwave fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 09 Dec
Daily Proton Fluence >1 MeV: 2.2E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 6.60E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.8
DSCOVR Satellite Solar Wind Day Averaged Data for 09 Dec
Speed: 370 km/sec Density: 0.6 p/cc Temp: 64700 K Bz: -3 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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