[Ips-dsgr] ASWFC Daily Report - 26 May 26 issued 2330 UT on 26 May 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed May 27 09:30:51 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 MAY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 MAY AND FORECAST FOR 27 MAY - 29 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 26 May: 141/95
1B. SOLAR FORECAST
27 May 28 May 29 May
Activity R0, chance of R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 150/105 145/99
COMMENT: Solar flare activity on UT day 26-May was at the R0
level, with the largest flare a C9.7 flare at 26/1238UT. There
are currently nine numbered sunspot regions on the visible solar
disk and two unnumbered regions. Active region 4451 was responsible
for the largest flare of the UT day. 4446 was the only numbered
active region to show spot development over the UT day, all other
numbered regions are either stable or in decay. Two unnumbered
regions have developed on the solar disk, with beta magnetic
characteristics. One is at N05W06 and the other is at N08W48.
No regions currently visible on the solar disk are particularly
large or magnetically complex. Solar flare activity is forecast
to be at the R0 level, with a chance of R1 on 27-May. This is
forecast to rise to R0-R1 over 28-29 May as potentially flare-active
regions on the far side of the disk, detected by Solar Orbiter,
rotate onto the front side of the disk. Solar radiation storm
conditions were at the S1 level on 26-May due to a large and
fast far side Coronal Mass Ejection. Solar radiation storm conditions
are expected to be at the S0 level over 27-29 May, with a chance
of S1 on 27-May due to currently elevated high energy proton
conditions. No geoeffective CMEs have been observed on 26-May.
A large and fast partial halo CME, directed to the northwest,
was observed from 25/2224UT. This CME is associated with coronal
movement behind the northwestern limb, visible in GOES SUVI and
SDO imagery from 25/2203UT. This CME is considered a far side
event and not geoeffective. A slow, south directed CME is visible
from 26/1000UT in SOHO and STEREO-A. This CME is considered a
far side event and not geoeffective. The solar wind speed was
largely steady over the UT day 25-Mar with a jump observed at
around 26/1850UT, possibly due to a glancing CME impact. The
wind speed mostly ranged between 360 and 460 m/s . The wind speed
is currently at around 420 km/s. The interplanetary magnetic
field strength (IMF, Bt) peaked at 10 nT during the UT day, with
the north-south component (Bz) ranging between -7 and +8 nT.
The solar wind speed is expected to remain at moderate levels
over 27-29 May, with the possibility of mild enhancements due
to small coronal holes approaching a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 May: G0
Estimated Indices 26 May : A K
Australian Region 3 11100013
Cocos Island 3 11110013
Darwin 3 11100113
Townsville 4 12100113
Learmonth 6 21110114
Alice Springs 3 11100113
Gingin 5 21100024
Canberra 3 11100013
Kennaook Cape Grim 3 10100013
Hobart 3 10100013
Estimated Antarctic Regional K Indices 26 May :
Macquarie Island 1 10000102
Casey 6 22200114
Mawson 25 53340136
Observed Regional daily pc3 Indices 26 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 23 (Quiet to unsettled)
Canberra 15 (Quiet)
Hobart 39 (Quiet to unsettled)
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 May : A
Fredericksburg 6
Planetary 6
Observed AFr/Ap Indices 25 May : A K
Fredericksburg 8
Planetary 8 3222 2223
2B. MAGNETIC FORECAST
Date Ap Conditions
27 May 12 G0, chance of G1
28 May 10 G0
29 May 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region and at the planetary level on 26-May. Mostly G0 conditions
were reported in the Antarctic region, with G2 conditions observed
at Mawson. G0 geomagnetic conditions are expected om 27-May,
with a chance of G1 due to recent solar wind enhancements. G0
conditions are expected over 28-29 May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 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
27 May Normal Normal Normal-fair
28 May Normal Normal Normal-fair
29 May Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were mostly normal during
UT day 26-May. Ionospheric conditions are expected to be mostly
normal over 27-29 May, with the chance of degradations at high
latitudes over the period.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 May 80
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:
Near predicted monthly values.
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
Apr 74
May 71
Jun 68
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
27 May 80 Near predicted monthly values
28 May 80 Near predicted monthly values
29 May 80 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were near predicted values on UT day 26-May. Spread-F
was observed at Hobart during local night hours. MUFs are expected
to remain near predicted monthly values over 27-29 May.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 May
Daily Proton Fluence >1 MeV: 1.3E+06
Daily Proton Fluence >10 MeV: 3.5E+04
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: B9.4
DSCOVR Satellite Solar Wind Day Averaged Data for 25 May
Speed: 358 km/sec Density: 4.8 p/cc Temp: 71800 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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