[Ips-dsgr] ASWFC Daily Report - 01 December 25 issued 2320 UT on 01 Dec 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Tue Dec 2 10:20:50 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/01 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 01 DECEMBER AND FORECAST FOR 02 DECEMBER - 04 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 01 Dec: R3
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 01 Dec: 196/148
1B. SOLAR FORECAST
02 Dec 03 Dec 04 Dec
Activity R2-R3 R2-R3 R2-R3
Fadeouts Possible Possible Possible
10.7cm/SSN 195/147 195/147 200/152
COMMENT: Solar activity was a the R3 level over the UT day 01-Dec,
generated by an X1.9 flare. Currently, there are nine numbered
sunspot regions, with newly rotated Active Region (AR) 4299 (N23E65,
beta) being associated with the X-class flare. This region appears
to be the same as that of AR4274, from the previous solar rotation.
This region was associated with significant flaring and CME activity.
However, it has decayed significantly since its previous rotation.
AR4294 (S14E41, beta-delta) remains the largest. This region
has shown minor growth over the last 24 hours. AR4297 has fluctuated
in size, but has generally grown in size, spot distribution width
and spot count. All other sunspot regions on the disk are either
stable or in decay. Solar activity is expected to be at the R2-R3
level on 2-4 Dec, due to potential flare activity from both AR4294
and AR4299. Solar radiation storm conditions were at the S0 level
during UT day 01-Dec, and S0 conditions are forecast to continue
over the period 2-4 Dec. There were no Earth-bound Coronal Mass
Ejections observed over the past UT day. Two CMEs were observed,
associated with the X-class flare. Analysis has shown them to
have no Earth directed component. The solar wind environment
on UT day 1-Dec was stable. The solar wind speed ranged from
550 trending to 420 km/s. The peak total interplanetary field
strength (IMF, Bt) was 6 nT and the north-south IMF component
range (Bz) was +3 to -5nT. The solar wind speed is expected to
increase from 3-Dec due to a recurrent coronal hole.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 01 Dec: G0
Estimated Indices 01 Dec : A K
Australian Region 6 22213211
Cocos Island 5 22112211
Darwin 6 21213212
Townsville 7 32213211
Learmonth 9 32223312
Alice Springs 6 21213211
Gingin 9 32213312
Canberra 5 22212211
Kennaook Cape Grim 5 22212211
Hobart 5 22212211
Estimated Antarctic Regional K Indices 01 Dec :
Macquarie Island 8 21133311
Casey 18 44523222
Mawson 17 42323344
Observed Regional daily pc3 Indices 01 Dec :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 11 (Quiet)
Canberra 24 (Quiet to unsettled)
Hobart 12 (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 01 Dec : A
Fredericksburg 10
Planetary 12
Observed AFr/Ap Indices 30 Nov : A K
Fredericksburg 14
Planetary 16 4423 2233
2B. MAGNETIC FORECAST
Date Ap Conditions
02 Dec 8 G0
03 Dec 10 G0
04 Dec 17 G0 - G1
COMMENT: G0 geomagnetic conditions were observed across the Australian
region throughout UT day 01-Dec, with an isolated period of G1
observed at Casey. G0 geomagnetic conditions are expected on
2-3 Dec, with a high speed wind stream from an equatorial coronal
hole expected to connect with the Earth by 4-Dec.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
01 Dec Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
02 Dec Normal Normal Normal
03 Dec Normal Normal Normal-fair
04 Dec Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 01-Dec were
normal. HF conditions are expected to normal over 02-03 Dec,
with normal-fair conditions anticipated on 04-Dec due to geomagnetic
activity from a recurring coronal hole. Frequent HF fadeouts
are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
01 Dec 127
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Niue Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 25% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
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
02 Dec 110 Near to 15% above predicted monthly values
03 Dec 110 Near to 15% above predicted monthly values
04 Dec 90 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 01-Dec were mostly near predicted monthly values.
Niue and Norfolk experienced extended periods of sporadic-E.
MUFs are forecast to continue to be near predicted monthly values
during 01-03 Dec. Shortwave fadeouts are likely on daylight HF
circuits.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 30 Nov
Daily Proton Fluence >1 MeV: 5.3E+06
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 3.50E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:20%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C2.4
DSCOVR Satellite Solar Wind Day Averaged Data for 30 Nov
Speed: 589 km/sec Density: 1.6 p/cc Temp: 167000 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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