[Ips-dsgr] ASWFC Daily Report - 26 June 26 issued 2330 UT on 26 Jun 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Jun 27 09:30:49 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 JUNE 2026
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: GREEN
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: 163/117
1B. SOLAR FORECAST
27 Jun 28 Jun 29 Jun
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 157/111 158/112 160/114
COMMENT: Solar flare activity was at the R0 level on UT day 26-Jun,
with only C-class flares observed. There are currently five active
sunspot regions on the visible solar disk, with Active Region
(AR) 4478 (S06E48, beta-gamma-delta) being the largest and most
magnetically complex. This region has remained mostly stable
over the last 24 hours. Region 4479 (N17E32, beta) has shown
some growth over the past UT day, with all other regions either
stable or in decay. Solar flare activity is expected to be at
the R0-R1 level over 27-29 Jun, due to the flare potential of
AR 4478. S0 solar radiation storm conditions were observed on
UT day 26-Jun, with the solar proton flux remaining at background
levels. S0 solar radiation storm conditions are expected over
27-29 Jun. No Earth-directed coronal mass ejections (CMEs) were
observed over the past UT day. A south-west-directed CME was
visible in SOHO/LASCO from 26/0200UT, but was determined to be
a far-side event. The solar wind speed was very strong throughout
UT day 26-Jun due to a coronal hole high speed wind stream. The
solar wind speed began the day at 680-710 km/s, and slowly declined
to currently range between 650-680 km/s. The interplanetary magnetic
field strength (IMF, Bt) peaked at 5 nT during the UT day, and
the north-south component (Bz) ranged between -5 and +5 nT over
the UT day. The solar wind speed is expected to remain elevated
on 27-Jun as the high speed wind stream effects continue, with
a decline forecast over 28-29 Jun as the coronal hole moves beyond
a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 Jun: G0
Estimated Indices 26 Jun : A K
Australian Region 8 22212332
Cocos Island 7 21212331
Darwin 8 22212331
Townsville 9 22312332
Learmonth 14 22313532
Alice Springs 8 22212332
Gingin 12 22302442
Canberra 8 22212332
Kennaook Cape Grim 8 22212332
Hobart 8 22212332
Estimated Antarctic Regional K Indices 26 Jun :
Macquarie Island 12 22214431
Casey 22 33323363
Mawson 41 55523266
Observed Regional daily pc3 Indices 26 Jun :
Darwin NA
Townsville 2 (Quiet)
Learmonth 14 (Quiet)
Alice Springs 7 (Quiet)
Gingin 58 (Unsettled)
Canberra 53 (Unsettled)
Hobart 69 (Active)
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 9
Planetary 11
Observed AFr/Ap Indices 25 Jun : A K
Fredericksburg 29
Planetary 25 4543 4343
2B. MAGNETIC FORECAST
Date Ap Conditions
27 Jun 16 G0, chance of G1
28 Jun 12 G0
29 Jun 10 G0
COMMENT: ASWFC Geomagnetic Warning 38 was issued on 25 June and
is current for 25-27 Jun. Geomagnetic conditions in the Australian
region were at the G0 level on UT day 26-Jun, with a G1 interval
observed at Learmonth. G0 conditions were reported at the planetary
level. Periods of G2 were recorded in the Antarctic region. Geomagnetic
conditions are expected to be at the G0 level over 27-29 Jun,
with a chance of G1 on 27-Jun due to an elevated solar wind speed
from a coronal hole high speed wind stream.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 Jun Fair-normal 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-normal
28 Jun Normal Normal Normal-fair
29 Jun Normal Normal Normal-fair
COMMENT: Global high frequency radio propagation conditions were
mostly normal to fair over UT day 26-Jun, with fair to normal
conditions at high latitudes due to ongoing geomagnetic activity.
Normal to fair conditions are expected to persist over 27-Jun
due, with mostly normal conditions forecast over 28-29 Jun. Shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 Jun 87
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.
Enhanced by 20% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 45% during local night.
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
May 67
Jun 68
Jul 65
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
27 Jun 80 Near predicted monthly values
28 Jun 85 Near predicted monthly values
29 Jun 85 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 26-Jun were near predicted values, with enhancements
of up to 45% observed in the northern Australian region. Spread-F
and mild sporadic E were observed at sites on the east coast
of Australia during local night hours, with significant Spread-F
observed in Hobart. MUFs are expected to be mostly near predicted
monthly values over 27-29 Jun. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 Jun
Daily Proton Fluence >1 MeV: 2.1E+06
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 1.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 25 Jun
Speed: 462 km/sec Density: 1.4 p/cc Temp: 43200 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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