[Ips-dsgr] ASWFC Daily Report - 16 May 26 issued 2330 UT on 16 May 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun May 17 09:30:50 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/16 MAY 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 16 MAY AND FORECAST FOR 17 MAY - 19 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 16 May: R1
Flares Max Fadeout Freq. Sectors
M1.9 1612UT possible lower South American/
Atlantic
M1.9 1742UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 16 May: 109/59
1B. SOLAR FORECAST
17 May 18 May 19 May
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible Possible Possible
10.7cm/SSN 105/54 106/55 110/60
COMMENT: Solar flare activity on UT day 16-May was at the R1
level due to an M1.9 flare at 16/1612UT and an M1.9 flare at
16/1742UT. There are currently three numbered sunspot regions
visible on the solar disk and three unnumbered regions. AR4436
(N20W24, alpha) and AR4435 (N22W81, beta) were responsible for
the first and second M-class flares of the day respectively.
AR4436 appears stable, whilst AR4435 has rotated off the solar
disk. AR4438 (N19W69, beta) is in decay. An unnumbered region
has developed on the disk at around N05E28 and two unnumbered
regions have rotated on to the disk at around N15E70 and N04E70
respectively. All three have beta magnetic complexity. Solar
flare activity is expected to be at the R0 level over 17-19 May,
with a chance of R1. S0 solar proton conditions were observed
on UT day 16-May. S0 solar proton conditions are expected over
17-19 May. A north-directed CME is visible in SOHO imagery and
STEREO-A imagery from 16/1648UT. This CME is associated with
an eruption on the solar disk at around N17W16 from 16/1612UT,
visible in SDO, GOES SUVI and H-Alpha imagery. Modelling of this
CME suggests an impact with Earth on 18-May at around 1700UT
+/- 10 hours. Several other CMEs were observed on 16-May, but
none are considered geoeffective. The solar wind speed was elevated
over the UT day 16-Mar, mostly ranging between 575 and 820 km/s
interplanetary magnetic field strength (IMF, Bt) was 15 nT and
the north-south IMF component (Bz) range was -8 to +8 nT. The
solar wind speed is expected to remain elevated on 17-May. A
further enhancement is expected on 18-May due to a CME first
observed on 16-May. Elevated solar wind conditions are expected
to persist over 19-May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 16 May: G0
Estimated Indices 16 May : A K
Australian Region 15 43432322
Cocos Island 12 33332322
Darwin 16 43432332
Townsville 17 43443322
Learmonth 19 44433333
Alice Springs 15 43432322
Gingin 18 44433332
Canberra 19 43532422
Kennaook Cape Grim 20 43543322
Hobart 22 44542422
Estimated Antarctic Regional K Indices 16 May :
Macquarie Island 44 55664532
Casey 22 44443433
Mawson 95 77554776
Observed Regional daily pc3 Indices 16 May :
Darwin 23 (Quiet to unsettled)
Townsville 6 (Quiet)
Learmonth 37 (Quiet to unsettled)
Alice Springs 19 (Quiet)
Gingin 143 (Severe storm)
Canberra 117 (Major storm)
Hobart 148 (Severe storm)
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 16 May : A
Fredericksburg 27
Planetary 38
Observed AFr/Ap Indices 15 May : A K
Fredericksburg 22
Planetary 35 2233 5546
2B. MAGNETIC FORECAST
Date Ap Conditions
17 May 15 G0, chance of G1
18 May 22 G1, chance of G2
19 May 16 G0-G1
COMMENT: Mostly G0 geomagnetic conditions were observed in the
Australian region on 16-May. G1 conditions were observed at Canberra,
Kennaook Cape Grim and Hobart. G2 conditions were observed at
the planetary level. G2-G3 conditions were observed in the Antarctic
region. G0 geomagnetic conditions are expected on 17-May, with
a chance of G1 as high speed wind stream effects calm down. G1
conditions, with a chance of G2 are expected on 18-May and G0-G1
conditions are expected on 19-May due to an anticipated CME impact
in the second half of 18-May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
16 May Normal Normal-fair Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
17 May Normal Normal Normal-fair
18 May Normal Normal-fair Fair
19 May Normal Normal-fair Fair
COMMENT: Global ionospheric conditions were mostly normal to
fair over UT day 16-May, with some degraded conditions observed
at higher latitudes in the northern hemisphere. Mostly normal
conditions are expected on 17-May and for the majority of 18-May.
Mild degradations are possible from late on 18-May through 19-May
due to anticipated geomagnetic activity.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
16 May 64
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.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 25% during local day.
Near predicted monthly values during local night.
Depressed by 25% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 25% 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
17 May 60 Near predicted monthly values
18 May 55 Near predicted monthly values/depressed 5 to
15%
19 May 55 Near predicted monthly values/depressed 5 to
15%
COMMENT: Maximum Usable Frequencies (MUFs) were near predicted
monthly values in the northern Australian region, with depressions
of up to 25% observed in the southern Australian region. Significant
spread-F and sporadic E were observed at Hobart during local
night hours. MUFs are expected to be near predicted monthly values
over 17-18 May, with depressions of up to 15% expected possible
from late on 18-May through 19-May due to anticipated geomagnetic
activity,
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 15 May
Daily Proton Fluence >1 MeV: 3.3E+06
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 1.20E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B3.9
DSCOVR Satellite Solar Wind Day Averaged Data for 15 May
Speed: 560 km/sec Density: 4.7 p/cc Temp: 266000 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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