[Ips-dsgr] ASWFC Daily Report - 25 May 26 issued 0011 UT on 26 May 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Tue May 26 10:11:11 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 MAY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 MAY AND FORECAST FOR 26 MAY - 28 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 May: 139/93
1B. SOLAR FORECAST
26 May 27 May 28 May
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible Possible Possible
10.7cm/SSN 142/96 145/99 150/105
COMMENT: Solar activity was at the R0 level throughout UT day
25-May, with only low-level C-class flares observed. There are
currently eight sunspot regions on the visible solar disk. Active
regions 4447 (S17E12, beta), and 4450 (N10E48, alpha) showed
slight spot development over the UT day. 4447 was also responsible
for the largest C-class flare of the UT day. No regions currently
visible on the solar disk are particularly large or magnetically
complex. All other regions are either stable or in decay. Solar
flare activity is forecast to be at the R0 level, with a chance
of R1 on 26-May. This is forecast to rise to R0-R1 over 27-28
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. S0 solar radiation storm conditions were observed on
25-May. S0 solar radiation storm conditions are forecast for
26-28 May. No geoeffective coronal mass ejections (CMEs) were
observed over the past 24 hours. A northwest directed CME eruption
is visible in SOHO imagery from 25/2224UT. Limited imagery is
available currently for this CME. Movement behind the northwest
limb is visible in GOES SUVI imagery from 25/2203UT. This CME
is currently considered a far side event and not geoeffective.
The solar wind speed increased slightly over 25-May, mostly ranging
between 320 and 440 km/s. The current solar wind speed is 410
km/s. The interplanetary magnetic field strength (IMF, Bt) peaked
at 9 nT during the UT day, with the north-south component (Bz)
ranging between -7 and +6 nT. The solar wind is expected to remain
at moderate levels over 26-28 May, with the chance of an increase
over 27-28 May due to anticipated recurrent coronal hole high
speed wind stream effects.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 May: G0
Estimated Indices 25 May : A K
Australian Region 4 21111221
Cocos Island 2 11010121
Darwin 4 21111221
Townsville 6 22121222
Learmonth 5 21211222
Alice Springs 4 21111221
Gingin 5 21111222
Canberra 3 11011121
Kennaook Cape Grim 4 11121121
Hobart 4 11021221
Estimated Antarctic Regional K Indices 25 May :
Macquarie Island 5 11133010
Casey 8 33222122
Mawson 20 32233255
Observed Regional daily pc3 Indices 25 May :
Darwin 17 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 4 (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 25 May : A
Fredericksburg 6
Planetary 6
Observed AFr/Ap Indices 24 May : A K
Fredericksburg 7
Planetary 6 1111 2122
2B. MAGNETIC FORECAST
Date Ap Conditions
26 May 8 G0
27 May 10 G0, chance of G1
28 May 10 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region and at the planetary level on 25-May. Mostly G0 conditions
were reported in the Antarctic region, with G1 conditions observed
at Mawson. G0 geomagnetic conditions are expected om 26-May.
G0 conditions, with a chance of G1 are expected over 27-28 May
due to anticipated recurrent coronal hole high speed wind stream
effects.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 May Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 May Normal Normal Normal-fair
27 May Normal Normal Normal-fair
28 May Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were mostly normal during
UT day 25-May. Ionospheric conditions are expected to be mostly
normal over 26-28 May, with the chance of degradations at high
latitudes over the period.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 May 76
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.
Depressed by 15% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
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
26 May 80 Near predicted monthly values
27 May 80 Near predicted monthly values
28 May 80 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were largely near predicted values on UT day 25-May, with
enhanced conditions of up to 15% seen in the southern Australian
region in the last few hours. Spread-F was observed at Brisbane,
Canberra and Hobart during local night hours. MUFs are expected
to remain near predicted monthly values over 26-28 May.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 May
Daily Proton Fluence >1 MeV: 3.5E+06
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 2.00E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:15%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B7.4
DSCOVR Satellite Solar Wind Day Averaged Data for 24 May
Speed: 306 km/sec Density: 2.8 p/cc Temp: 22700 K Bz: -1 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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