[Ips-dsgr] ASWFC Daily Report - 28 May 26 issued 2330 UT on 28 May 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri May 29 09:30:50 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 MAY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 MAY AND FORECAST FOR 29 MAY - 31 MAY
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 28 May: 145/99
1B. SOLAR FORECAST
29 May 30 May 31 May
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts None expected None expected None expected
10.7cm/SSN 142/96 145/99 142/96
COMMENT: Solar flare activity on UT day 28-May was at the R0
level, with several low level C-class flares observed. There
are currently ten numbered sunspot regions visible on the solar
disk. Active Region (AR) 4452 (N09W32, beta-gamma) is the most
magnetically complex region on the disk and has exhibited spot
development over the UT day. AR 4445 (N08W16, alpha) has shown
mild spot growth. Region 4449 (S10E11, beta) has shown mild growth
in its trailer spots. All other sunspot regions are either stable
or in decay. Solar flare activity is expected to be at the R0
level over 29-31 May, with a chance of R1. S0 solar radiation
storm conditions were observed on UT day 28-May. S0 solar radiation
storm conditions are expected over 29-31 May. No Earth-directed
coronal mass ejections (CMEs) have been observed. The solar wind
speed on UT day 28-May increased, ranging from 365 to 460 km/s
and is currently near 450 km/s. The peak total interplanetary
magnetic field strength (IMF, Bt) was 10 nT and the north-south
IMF component (Bz) range was -9 to +9 nT. The solar wind speed
is expected to increase on 29-May due to coronal hole high speed
wind stream effects from a northern hemisphere coronal hole,
then decline over 30-31 May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 28 May: G0
Estimated Indices 28 May : A K
Australian Region 8 12322322
Cocos Island 6 12221222
Darwin 7 12321222
Townsville 9 22322322
Learmonth 10 12322333
Alice Springs 8 12321322
Gingin 8 12222332
Canberra 8 12322322
Kennaook Cape Grim 8 12322322
Hobart 8 12322322
Estimated Antarctic Regional K Indices 28 May :
Macquarie Island 14 01443422
Casey 11 33332222
Mawson 22 34423345
Observed Regional daily pc3 Indices 28 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (Quiet)
Hobart 15 (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 May : A
Fredericksburg 10
Planetary 11
Observed AFr/Ap Indices 27 May : A K
Fredericksburg 12
Planetary 11 2232 1333
2B. MAGNETIC FORECAST
Date Ap Conditions
29 May 14 G0, chance of G1
30 May 12 G0
31 May 10 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and planetary regions on UT day 28-May. Mostly G0 geomagnetic
conditions were observed in the Antarctic region, with an isolated
period of G1 observed at Mawson. G0 planetary geomagnetic conditions
are expected over 29-31 May, with a chance of G1 on 29-May due
to coronal hole high speed wind stream effects from a northern
hemisphere coronal hole.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
28 May Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
29 May Normal Normal Normal-fair
30 May Normal Normal Normal-fair
31 May Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were mostly normal during
UT day 28-May. Ionospheric conditions are expected to be mostly
normal over 29-31 May, with some degradations expected at high
latitudes over the forecast period.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
28 May 88
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 during local day.
Enhanced by 25% during local night.
Enhanced by 25% after local dawn.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Apr 74
May 71
Jun 68
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
29 May 85 Near predicted monthly values
30 May 75 Near predicted monthly values
31 May 80 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were near predicted monthly values to 20% enhanced on
UT day 28-May. Spread-F was observed at Hobart during local night
hours. Ionospheric scintillation was observed at Niue Island
over the interval 28/0907-0925UT. MUFs are expected to be near
predicted monthly values over 29-31 May.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 27 May
Daily Proton Fluence >1 MeV: 9.3E+05
Daily Proton Fluence >10 MeV: 4.8E+04
Daily Electron Fluence >2 MeV: 1.60E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B7.8
DSCOVR Satellite Solar Wind Day Averaged Data for 27 May
Speed: 388 km/sec Density: 3.1 p/cc Temp: 84800 K Bz: -2 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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