[Ips-dsgr] ASWFC Daily Report - 28 June 26 issued 2330 UT on 28 Jun 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Jun 29 09:30:47 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 JUNE 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 JUNE AND FORECAST FOR 29 JUNE - 01 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 Jun: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Jun: 186/139
1B. SOLAR FORECAST
29 Jun 30 Jun 01 Jul
Activity R0-R1 R0-R1 R0, chance of R1
Fadeouts Possible Possible None expected
10.7cm/SSN 175/129 180/133 175/129
COMMENT: Solar flare activity on UT day 28-Jun was at the R0
level, with a C9.5 flare at 28/2144UT from Active Region (AR)
4475 (S08W33, beta-gamma) the largest observed. This region is
one of six on the visible solar disk, with region 4478 (S06E21,
beta-gamma) remaining the largest. This region has shown some
magnetic simplification and spot redistribution over the past
24 hours. AR 4479 (N17E05, beta-gamma) has shown some growth
over the same period. All other regions on the disk appear stable
or in decay. Solar flare activity is forecast to be at the R0-R1
level on 29-30 Jun, given the size and magnetic complexity of
several regions on the disk. This is forecast to decline to R0,
with a chance of R1 on 01-Jul, as some of the larger regions
show signs of decay and magnetic simplification. S0 solar radiation
storm conditions were observed on UT day 28-Jun, with the solar
proton flux remaining at background levels. S0 solar radiation
storms are forecast over the period 29-Jun to 01-Jul. No significant
geoeffective coronal mass ejections (CMEs) were observed in available
coronagraph imagery over the last 24 hours. Two CMEs were observed
at 28/0400UT and 28/0548UT in SOHO/LASCO, associated with filament
eruptions visible in GOES/SUVI 304A imagery. Both of these CMEs
are not considered geoeffective. The solar wind speed declined
over UT day 28-Jun, starting the day at 530 km/s and currently
ranging between 400 and 430 km/s. The interplanetary magnetic
field strength (IMF, Bt) peaked at 4 nT, with the north-south
component (Bz) ranging between -3 and +3 nT over the UT day.
The solar wind speed is forecast to continue to trend toward
background values on 29-Jun, before rising on 30-Jun due to the
impact of a CME first observed on 26-Jun. The solar wind speed
will remain elevated on 01-Jul due to the ongoing effects of
this CME impact.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 28 Jun: G0
Estimated Indices 28 Jun : A K
Australian Region 2 12110000
Cocos Island 1 11010000
Darwin 2 12100001
Townsville 2 12110001
Learmonth 2 21110000
Alice Springs 2 12110000
Gingin 2 22110001
Canberra 2 12110000
Kennaook Cape Grim 1 11110000
Hobart 1 11010000
Estimated Antarctic Regional K Indices 28 Jun :
Macquarie Island 1 11010000
Casey 4 23210011
Mawson 20 33421055
Observed Regional daily pc3 Indices 28 Jun :
Darwin NA
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 2 (Quiet)
Hobart 2 (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 28 Jun : A
Fredericksburg 9
Planetary 10
Observed AFr/Ap Indices 27 Jun : A K
Fredericksburg 8
Planetary 7 3221 212-
2B. MAGNETIC FORECAST
Date Ap Conditions
29 Jun 8 G0
30 Jun 22 G1
01 Jul 20 G0-G1
COMMENT: Geomagnetic conditions in the Australian region on UT
day 28-Jun were at the G0 level, with G0 conditions also reported
at the planetary scale. Mostly G0 conditions were recorded in
the Antarctic region, with some intervals of G1 reported at Mawson.
G0 conditions are forecast on 29-Jun, rising to G1 conditions
on 30-Jun due to the forecast impact of a CME first observed
on 26-Jun. G0-G1 conditions are forecast for 01-Jul due to the
ongoing effects of this CME impact.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
28 Jun Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
29 Jun Normal Normal Normal-fair
30 Jun Normal Normal Normal-fair
01 Jul Normal-fair Normal-fair Fair
COMMENT: Global high-frequency radio propagation conditions on
UT day 28-Jun were mostly normal, with some mild degradations
observed in the African and South American regions. High-frequency
radio propagation conditions are expected to remain normal over
29-30 Jun, with some mild degradations expected on 01-Jul due
to forecast geomagnetic activity. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
28 Jun 80
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
May 67
Jun 68
Jul 65
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
29 Jun 80 Near predicted monthly values
30 Jun 80 Near predicted monthly values
01 Jul 70 Depressed 10 to 15%/near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were near predicted monthly values on UT day 28-Jun. Significant
Spread-F was present across many locations in the Australian
region during local night hours, including significant spread-F
at Hobart, Brisbane, and Learmonth. MUFs are forecast to continue
to be near predicted values over 29-30 Jun, with depressions
of 10-15% forecast on 01-Jul due to anticipated geomagnetic activity.
Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 27 Jun
Daily Proton Fluence >1 MeV: 7.9E+05
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 1.50E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.4
DSCOVR Satellite Solar Wind Day Averaged Data for 27 Jun
Speed: 528 km/sec Density: 1.6 p/cc Temp: 70800 K Bz: 0 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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