[Ips-dsgr] ASWFC Daily Report - 06 December 25 issued 2330 UT on 06 Dec 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Dec 7 10:30:49 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/06 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 06 DECEMBER AND FORECAST FOR 07 DECEMBER - 09 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 06 Dec: R2
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 06 Dec: 200/152
1B. SOLAR FORECAST
07 Dec 08 Dec 09 Dec
Activity R1, chance R2 R1, chance R2 R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 195/147 190/143 190/143
COMMENT: Solar activity on UT day 6-Dec was R2, with an isolated
M8 solar flare from active region (AR) 4299 (N23E03, beta-gamma)
disk. All sunspots are mostly stable, with AR 4294 (S15W19, beta-gamma)
remaining the largest on disk but appears to have peaked in terms
of its lifecycle and is likely to begin decaying. Solar activity
is expected to be R1, with a chance of R2 over 7-9 Dec.
A small CME was associated with an M1 flare event from AR4299 that can
be seen from 1948 UT. This CME may arrive at the earth on 9-Dec
but due to its slow speed is not expected to cause a noticeable
impact. An earth-directed halo CME is associated with the M8
solar flare event, and preliminary analysis indicates an arrival
early on 9-Dec.
S0 solar radiation storm conditions were observed on UT day 6-Dec.
S0 solar radiation storm conditions are mostly expected over 7-9 Dec.
The solar wind environment on UT day 6-Dec was mildly disturbed due to
ongoing but weakening coronal hole effects. The solar wind speed ranged
from near 600-700km/s. The peak total interplanetary field strength
(IMF, Bt) was 6nT and the north-south IMF component range (Bz) was +6
to -6nT. The solar wind speed is expected to decline over 7-8 Dec, before
a disturbance is expected early on 9-Dec.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 06 Dec: G0
Estimated Indices 06 Dec : A K
Australian Region 10 33322222
Cocos Island 8 32322211
Darwin 12 33323223
Townsville 11 33322232
Learmonth 13 33323323
Alice Springs 10 33322222
Gingin 13 43323322
Canberra 9 33322221
Kennaook Cape Grim 12 33432222
Hobart 12 33432222
Estimated Antarctic Regional K Indices 06 Dec :
Macquarie Island 30 33554---
Casey 76 57744---
Mawson 35 555443--
Observed Regional daily pc3 Indices 06 Dec :
Darwin 6 (Quiet)
Townsville 0 (Quiet)
Learmonth 4 (Quiet)
Alice Springs 2 (Quiet)
Gingin 62 (Active)
Canberra 87 (Minor storm)
Hobart 104 (Major storm)
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 06 Dec : A
Fredericksburg 16
Planetary 21
Observed AFr/Ap Indices 05 Dec : A K
Fredericksburg 10
Planetary 13 3332 2233
2B. MAGNETIC FORECAST
Date Ap Conditions
07 Dec 10 G0
08 Dec 8 G0
09 Dec 45 G3
COMMENT: ASWFC Geomagnetic Warning 97 was issued on 6 December
and is current for 9-10 Dec. G0 geomagnetic conditions were observed
in the Australian region. G0-G3 geomagnetic conditions were observed
in the Antarctic region. G0 geomagnetic conditions are expected
over 7-8 Dec. G3 geomagnetic conditions are expected on 9-Dec
due to a halo CME launched on 6-Dec.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
06 Dec Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
07 Dec Normal Normal Normal
08 Dec Normal Normal Normal
09 Dec Fair Fair Poor
COMMENT: HF radio propagation conditions wer mostly normal, with
some mild degradations in the southern hemisphere. HF radio propagation
conditions are expected to be mostly normal over 7-8 Dec. Conditions
are expected to become degraded at the beginning of 9-Dec due
to anticipated geomagnetic activity. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
06 Dec 135
Observed Australian Regional MUFs
Cocos Island Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 25% during local night.
Northern Australian Region:
Enhanced by 20% during local day.
Enhanced by 20% during local night.
Southern Australian Region:
Near predicted monthly values.
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
07 Dec 120 Near predicted monthly values to 20% enhanced
08 Dec 120 Near predicted monthly values to 20% enhanced
09 Dec 80 Near predicted monthly values to 20% depressed
COMMENT: ASWFC Preliminary HF Communications Warning 117 was
issued on 6 December and is current for 9-10 Dec. Maximum usable
frequencies (MUFs) in the Australian region on UT day 6-Dec were
near predicted values to 20% enhanced. Sporadic-E was common
during local night hours at low latitude sights and along the
east coast of Australia. MUFs are expected to be near predicted
values to 20% enhanced over 7-8 Dec. MUFs are expected to be
near predicted values to 20% depressed on 9-Dec. Sporadic-E is
expected to persist.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 05 Dec
Daily Proton Fluence >1 MeV: 1.7E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 4.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.6
DSCOVR Satellite Solar Wind Day Averaged Data for 05 Dec
Speed: 630 km/sec Density: 1.9 p/cc Temp: 320000 K Bz: 1 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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