[Ips-dsgr] ASWFC Daily Report - 21 June 26 issued 2330 UT on 21 Jun 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Jun 22 09:30:50 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 JUNE 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 JUNE AND FORECAST FOR 22 JUNE - 24 JUNE
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 21 Jun: R2
Flares Max Fadeout Freq. Sectors
M2.6 0246UT possible lower E. Asia/Aust.
M7.0 1929UT probable lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Jun: 128/81
1B. SOLAR FORECAST
22 Jun 23 Jun 24 Jun
Activity R1-R2 R1-R2 R1-R2
Fadeouts Possible Possible Possible
10.7cm/SSN 120/72 120/72 120/72
COMMENT: Solar activity on UT day 21-Jun reached R2, with an
M7 class solar flare (R2) from active region (AR) 4473 (S08E59,
gamma). This region also produced an M2.7 class flare. There
are currently five numbered sunspot regions on the solar disk,
although AR 4473 is the only region which has shown any meaningful
change with instability in its leading spots. Solar flare activity
is expected to be R1-R2 over 22-24 Jun due to 4473.
A slow partial halo CME was observed associated with the M2.7
flare, but is not expected to be geoeffective. Similarly, a partial
halo is associated with the M7 solar flare, but there is not adequate
imagery yet available for a full analysis. Given the location
the CME launched from it is not expected to be significantly
geoeffective, however. No other noteworthy CMEs were observed
on 21-Jun.
S0 solar radiation storm conditions were observed on UT day 21-Jun.
S0 solar radiation storm conditions are expected over 22-24 Jun.
The solar wind environment on UT day 21-Jun was
near background levels. The solar wind speed ranged between 410
to 360 km/s. The peak total interplanetary field strength (IMF,
Bt) was +7 to -6 nT. The solar wind environment is expected to
remain mostly quiet over 22-23 Jun, but wind speeds may begin
to become enhanced by 24-Jun due to several patchy coronal holes.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 21 Jun: G0
Estimated Indices 21 Jun : A K
Australian Region 1 11100010
Cocos Island 0 11000000
Darwin 1 11100000
Townsville 2 12100011
Learmonth 3 22200011
Alice Springs 1 11100000
Gingin 2 12100010
Canberra 0 01000010
Kennaook Cape Grim 1 11000010
Hobart 0 01000010
Estimated Antarctic Regional K Indices 21 Jun :
Macquarie Island 0 00000000
Casey 5 23210021
Mawson 9 23212142
Observed Regional daily pc3 Indices 21 Jun :
Darwin NA
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 6 (Quiet)
Hobart 6 (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 21 Jun : A
Fredericksburg 5
Planetary 5
Observed AFr/Ap Indices 20 Jun : A K
Fredericksburg 8
Planetary 7 3222 2222
2B. MAGNETIC FORECAST
Date Ap Conditions
22 Jun 3 G0
23 Jun 6 G0
24 Jun 12 G0, chance G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region and Antarctic region on UT day 21-Jun. Go geomagnetic
conditions are mostly expected over 22-24 Jun. There is a chance
for an isolated period of G1 on 24-Jun due to coronal hole activity.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
21 Jun Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
22 Jun Normal Normal Normal
23 Jun Normal Normal Normal
24 Jun Normal-fair Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 21-Jun were
mostly normal. HF radio propagation conditions are expected to
be normal over 22-23 Jun, but become mildly degraded by 24-Jun
due to intermittent coronal hole connections with Earth.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
21 Jun 72
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Mostly 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
22 Jun 75 Near predicted monthly values
23 Jun 75 Near predicted monthly values
24 Jun 68 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 55 was issued on
21 June and is current for 21-23 Jun. Maximum usable frequencies
(MUFs) in the Australian region on UT day 21-Jun were mostly
near predicted values. Spread-F was observed in Brisbane during
local night hours. MUFs are expected to be mostly near predicted
monthly values over 22-24 Jun. Some spread-F may be present during
local night and dawn hours on 24-Jun.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 20 Jun
Daily Proton Fluence >1 MeV: 3.2E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 2.60E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.0
DSCOVR Satellite Solar Wind Day Averaged Data for 20 Jun
Speed: 389 km/sec Density: 5.6 p/cc Temp: 69400 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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