[Ips-dsgr] ASWFC Daily Report - 26 June 25 issued 2330 UT on 26 Jun 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Jun 27 09:30:54 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 JUNE 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 JUNE AND FORECAST FOR 27 JUNE - 29 JUNE
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 Jun: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Jun: 117/69
1B. SOLAR FORECAST
27 Jun 28 Jun 29 Jun
Activity R0, chance R1 R0, chance R1 R0, chance R1
Fadeouts Possible Possible Possible
10.7cm/SSN 125/78 130/84 135/89
COMMENT: Solar activity on UT day 26-Jun was R0, with no solar
flares. There are currently five numbered sunspot regions on
the solar disk. AR4122 (N13E42, beta) has grown over the past
day, but is still a relatively small region. All other sunspot
regions are either stable or in decay. Solar activity is expected
to be R0 with a small chance for R1 over 27-29 Jun.
A large filament near the northwestern solar limb partially erupted
over the course of the day yesterday, associated with a slow CME
directed northwest. This CME is not expected to be geoeffective.
No other CMEs were observed on UT day 26-Jun.
S0 solar radiation storm conditions were observed on UT day 26-Jun.
S0 solar radiation storm conditions are expected over 27-29 Jun.
The solar wind environment on UT day 26-Jun was mildly perturbed
due to ongoing connection to two coronal holes. The solar wind speed
ranged from 529 to 849 km/s and is currently near 700 km/s. The peak
total interplanetary field strength (IMF, Bt) was 16 nT and the
north-south IMF component range (Bz) was +10 to -9 nT. The solar
wind is expected to be enhanced on 27-Jun, beginning to return to
background conditions on 28-Jun although still likely to be elevated
due to the coronal holes.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 Jun: G0
Estimated Indices 26 Jun : A K
Australian Region 14 33323333
Cocos Island 11 33323222
Darwin 17 34423333
Townsville 14 33323333
Learmonth 17 34323343
Alice Springs 14 33323333
Gingin 18 34333343
Canberra 15 33333333
Kennaook Cape Grim 15 33333333
Hobart 15 -3333333
Estimated Antarctic Regional K Indices 26 Jun :
Macquarie Island 38 33356644
Casey 21 44334433
Mawson 73 45654677
Observed Regional daily pc3 Indices 26 Jun :
Darwin 32 (Quiet to unsettled)
Townsville 15 (Quiet)
Learmonth 37 (Quiet to unsettled)
Alice Springs 25 (Quiet to unsettled)
Gingin 141 (Severe storm)
Canberra 102 (Major storm)
Hobart 114 (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 26 Jun : A
Fredericksburg 17
Planetary 24
Observed AFr/Ap Indices 25 Jun : A K
Fredericksburg 0
Planetary 0 2122 3344
2B. MAGNETIC FORECAST
Date Ap Conditions
27 Jun 20 G0-G1, chance G2
28 Jun 17 G0-G1
29 Jun 12 G0
COMMENT: ASWFC Geomagnetic Warning 48 was issued on 26 June and
is current for 26-27 Jun. G0 geomagnetic conditions were observed
in the Australian region on UT day 26-Jun. G0-G3 geomagnetic
conditions were observed in the Antarctic region. G0-G1 geomagnetic
conditions are expected over 27-28 Jun due to ongoing coronal
hole activity. Due to the fast solar wind speeds in particular,
there may be a chance for G2 today.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 Jun Fair Normal-fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
27 Jun Normal-fair Normal-fair Fair
28 Jun Normal-fair Normal-fair Normal-fair
29 Jun Normal Normal Normal-fair
COMMENT: HF radio propagation conditions were mostly normal on
UT day 26-Jun, with depressions over South America and some enhancements
in the northern hemisphere. HF radio propagation conditions are
expected to be mildly degraded, particularly during local night
hours, over 27-29 Jun due to ongoing coronal hole activity, but
improving by the end of the period.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 Jun 86
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Depressed by 25% after local dawn.
Niue Island Region:
Depressed by 15% during local day.
Depressed by 35% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 25% over the UT day.
Monthly T index:
Month T index
May 94
Jun 109
Jul 107
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
27 Jun 75 20 to 30% below predicted monthly values
28 Jun 65 20 to 30% below predicted monthly values
29 Jun 65 20 to 30% below predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 26-Jun were near predicted values to 20% depressed.
Spread-F was observed in Brisbane, Hobart and Perth during local
night hours. Conditions in Darwin were degraded. MUFs are expected
to be near predicted values to 20-30% depressed over 27-29 Jun
due to ongoing coronal hole activity.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 Jun
Daily Proton Fluence >1 MeV: 5.3E+05
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 2.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B4.8
DSCOVR Satellite Solar Wind Day Averaged Data for 25 Jun
Speed: 427 km/sec Density: 4.8 p/cc Temp: 107000 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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