[Ips-dsgr] ASWFC Daily Report - 27 May 26 issued 2330 UT on 27 May 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu May 28 09:30:45 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 MAY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 MAY AND FORECAST FOR 28 MAY - 30 MAY
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 May: 142/96
1B. SOLAR FORECAST
28 May 29 May 30 May
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts None expected None expected None expected
10.7cm/SSN 145/99 142/96 145/99
COMMENT: Solar flare activity on UT day 27-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) 4446 (S13E18, beta) is the largest region
on the disk and has shown decay in its trailer spots. AR 4452
(N09W19, beta) has exhibited spot development over the UT day.
Region 4453 (N09W59, alpha) has shown mild spot growth. Newly
numbered AR 4455 (N14E71, alpha) recently rotated over the eastern
limb and is stable. All other sunspot regions are either stable
or in decay. Solar flare activity is expected to be at the R0
level over 28-30 May, with a chance of R1. S0 solar proton conditions
were observed on UT day 27-May. S0 solar proton conditions are
expected over 28-30 May. No Earth-directed coronal mass ejections
(CMEs) have been observed. The solar wind speed on UT day 27-May
was mostly stable, ranging from 365 to 415 km/s and is currently
near 380 km/s. The peak total interplanetary magnetic field strength
(IMF, Bt) was 7 nT and the north-south IMF component (Bz) range
was -7 to +6 nT. The solar wind speed is expected to mildly increase
on 28-May due to coronal hole high speed wind stream effects
from a small southern hemisphere coronal hole. A further increase
is expected on 29-May due to a northern hemisphere coronal hole.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 May: G0
Estimated Indices 27 May : A K
Australian Region 4 12210212
Cocos Island 3 11110122
Darwin 4 21210112
Townsville 5 22210212
Learmonth 5 1221----
Alice Springs 4 12200212
Gingin 5 11200223
Canberra 5 12310212
Kennaook Cape Grim 5 12310212
Hobart 5 12310212
Estimated Antarctic Regional K Indices 27 May :
Macquarie Island 7 12430201
Casey 9 32312223
Mawson 34 35432237
Observed Regional daily pc3 Indices 27 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (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 27 May : A
Fredericksburg 9
Planetary 11
Observed AFr/Ap Indices 26 May : A K
Fredericksburg 7
Planetary 8 2111 1124
2B. MAGNETIC FORECAST
Date Ap Conditions
28 May 10 G0
29 May 14 G0, chance of G1
30 May 14 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 27-May. Mostly G0 geomagnetic conditions were
observed in the Antarctic region, with isolated periods of G1
and G3 observed at Mawson. G0 planetary geomagnetic conditions
are expected over 28-30 May, with a chance of G1 over 29-30 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
27 May Normal Normal Normal
PCA Event : 10MeV Proton/PCA Event Began at 0010UT 26/05, Ended at 0400UT 26/05
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 May Normal Normal Normal-fair
29 May Normal Normal Normal-fair
30 May Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were mostly normal during
UT day 27-May. Ionospheric conditions are expected to be mostly
normal over 28-30 May, with the chance of degradations at high
latitudes over the forecast period.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 May 87
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Mostly near predicted monthly values.
Enhanced by 40% after local dawn.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% 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
28 May 85 Near predicted monthly values
29 May 75 Near predicted monthly values
30 May 75 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were near predicted monthly values to 20% enhanced on
UT day 27-May. Spread-F was observed at Hobart during local night
hours. MUFs are expected to be near predicted monthly values
over 28-30 May.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 May
Daily Proton Fluence >1 MeV: 2.6E+06
Daily Proton Fluence >10 MeV: 4.2E+05
Daily Electron Fluence >2 MeV: 1.40E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.6
DSCOVR Satellite Solar Wind Day Averaged Data for 26 May
Speed: 399 km/sec Density: 3.8 p/cc Temp: 128000 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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