[Ips-dsgr] ASWFC Daily Report - 24 December 25 issued 2330 UT on 24 Dec 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Dec 25 10:30:44 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 DECEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 DECEMBER AND FORECAST FOR 25 DECEMBER - 27 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 Dec: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Dec: 134/88
1B. SOLAR FORECAST
25 Dec 26 Dec 27 Dec
Activity R0, chance R1 R0, chance R1 R0-R1
Fadeouts None expected None expected Possible
10.7cm/SSN 150/105 155/109 160/114
COMMENT: Solar flare activity on UT day 24-Dec was at the R0
level, with no significant flaring activity. There are currently
seven numbered sunspot regions visible on the solar disk. AR4317
(N11E24, beta) is the largest region on the disk and has shown
mild decay. Newly numbered AR4321 (S11W08, beta) recently appeared
on the solar disk and has shown rapid spot growth. All other
sunspot regions are either stable or in decay. Solar flare activity
is expected to be at the R0 level over 25-26 Dec, with a chance
of R1. R0-R1 conditions are expected on 27-Dec due to the possible
return of previously flare active region AR4294. S0 solar proton
conditions were observed on UT day 24-Dec. S0 solar proton conditions
are expected over 25-27 Dec. No Earth-directed coronal mass ejections
(CMEs) have been observed. The solar wind speed on UT day 24-Dec
mildly declined, ranging from 615 to 725 km/s and is currently
near 615 km/s. The peak total interplanetary magnetic field strength
(IMF, Bt) was 6 nT and the north-south IMF component (Bz) range
was -6 to +5 nT. The solar wind speed is expected to remain near
current levels over 25-27 Dec due to ongoing coronal hole high
speed wind stream effects.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 24 Dec: G0
Estimated Indices 24 Dec : A K
Australian Region 15 33333333
Cocos Island 11 23233322
Darwin 15 33333333
Townsville 14 33333332
Learmonth 15 33333333
Alice Springs 14 33333323
Gingin 14 33333323
Canberra 13 33332233
Kennaook Cape Grim 17 34343323
Hobart 18 34343333
Estimated Antarctic Regional K Indices 24 Dec :
Macquarie Island 28 34654322
Casey 35 46643334
Mawson 44 45545456
Observed Regional daily pc3 Indices 24 Dec :
Darwin 14 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 47 (Unsettled)
Canberra 67 (Active)
Hobart 106 (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 24 Dec : A
Fredericksburg 19
Planetary 24
Observed AFr/Ap Indices 23 Dec : A K
Fredericksburg 14 3332 3333
Planetary 21 3433 4444
2B. MAGNETIC FORECAST
Date Ap Conditions
25 Dec 14 G0, chance of G1
26 Dec 12 G0, chance of G1
27 Dec 12 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 24-Dec. G1-G2 geomagnetic conditions were observed
in the Antarctic region. G0 geomagnetic conditions are expected
over 25-27 Dec, with a chance of G1 due to ongoing coronal hole
high speed wind stream effects.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
24 Dec Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
25 Dec Normal Normal Normal-fair
26 Dec Normal Normal Normal-fair
27 Dec Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 24-Dec were
mostly normal. HF conditions are expected to be normal to fair
for high latitudes over 25-27 Dec due to ongoing mild geomagnetic
activity, and mostly normal elsewhere. Isolated minor shortwave
fadeouts are possible from 27-Dec.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
24 Dec 103
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
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
25 Dec 100 Near predicted monthly values
26 Dec 100 Near predicted monthly values
27 Dec 100 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 24-Dec were near predicted monthly values. Spread
F was observed at Hobart during local night hours. MUFs are forecast
to be near predicted monthly values over 25-27 Dec. Isolated
minor shortwave fadeouts are possible from 27-Dec.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 23 Dec
Daily Proton Fluence >1 MeV: 8.3E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 1.30E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B7.9
DSCOVR Satellite Solar Wind Day Averaged Data for 23 Dec
Speed: 697 km/sec Density: 2.2 p/cc Temp: 194000 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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