[Ips-dsgr] ASWFC Daily Report - 16 September 26 issued 2330 UT on 16 Sep 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Sep 17 09:30:54 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/16 SEPTEMBER 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 16 SEPTEMBER AND FORECAST FOR 17 SEPTEMBER - 19 SEPTEMBER
STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 16 Sep: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 16 Sep: 100/48
1B. SOLAR FORECAST
17 Sep 18 Sep 19 Sep
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 100/48 100/48 95/41
COMMENT: Solar activity on UT day 16-Sep was R0, with no solar
flares. There are currently three numbered sunspot regions on
the solar disk, however all regions are stable. Solar activity
is expected to be R0 over 17-19 Sep. No CMEs were observed on
UT day 16-Sep. S0 solar radiation storm conditions were observed
on UT day 16-Sep. S0 solar radiation storm conditions are expected
over 17-19 Sep. The solar wind environment on UT day 16-Sep was
mildly disturbed at the beginning of the day due to lingering
effects from the day before, but returned to background levels
over the course of the day. The solar wind speed ranged from
575 to 500 km/s. The peak total interplanetary field strength
(IMF, Bt) was 15 nT and the north-south IMF component range (Bz)
was +8 to -5 nT. The solar wind may become mildly disturbed early
on 17-Sep due to a possible glancing blow from a recent CME,
although this is low confidence. Further enhancements are possible
due to potential coronal hole connections, although it is becoming
less likely they are able to connect with Earth.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 16 Sep: G0
Estimated Indices 16 Sep : A K
Australian Region 6 32223001
Cocos Island 3 31111000
Darwin 8 42223002
Townsville 7 32223012
Learmonth 7 41223001
Alice Springs 7 32223002
Gingin 7 41223001
Canberra 6 32223001
Kennaook Cape Grim 8 32224001
Hobart 8 32224101
Estimated Antarctic Regional K Indices 16 Sep :
Casey 19 55432112
Mawson 17 63323012
Observed Regional daily pc3 Indices 16 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 24 (Quiet to unsettled)
Canberra 19 (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 16 Sep : A
Fredericksburg 14
Planetary 18
Observed AFr/Ap Indices 15 Sep : A K
Fredericksburg 7
Planetary 8 3201 2123
2B. MAGNETIC FORECAST
Date Ap Conditions
17 Sep 16 G0-G1
18 Sep 10 G0
19 Sep 6 G0
COMMENT: ASWFC Geomagnetic Warning 56 was issued on 16 September
and is current for 16-17 Sep. G0 geomagnetic conditions were
observed in the Australian region on UT day 16-Sep. G0-G2 geomagnetic
conditions were observed in the Antarctic region. Mostly G0-G1
geomagnetic conditions are expected on 17-Sep due to the possible
combined effects of a glancing blow from a CME and from a coronal
hole, although this is low confidence. G0 geomagnetic conditions
are mostly expected over 18-19 Sep.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
16 Sep Normal Normal-fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
17 Sep Normal Normal-fair Normal-fair
18 Sep Normal Normal Normal
19 Sep Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 16-Sep were
mostly normal to mildly degraded during local night hours. HF
radio propagation conditions may show a similar pattern on 17-Sep.
HF radio propagation conditions are expected to be mostly normal
over 18-19 Sep.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
16 Sep 60
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 25% during local day.
Enhanced by 15% during local night.
Northern Australian Region:
Mostly near predicted monthly values.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Monthly T index:
Month T index
Aug 66
Sep 62
Oct 60
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
17 Sep 55 Near predicted monthly values/depressed 5 to
15%
18 Sep 65 Near predicted monthly values
19 Sep 70 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 16-Sep were mostly near predicted values. Most
Australian sites were mildly degraded during local dawn hours.
MUFs are expected to be mostly near predicted monthly values
over 17-19 Sep. Further mild degradations are possible during
local dawn hours over the next few days. Should geomagnetic activity
eventuate on 17-Sep due to the combined effects of a CME and
coronal hole, then depressions to MUFs of 15% are possible on
this day.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 15 Sep
Daily Proton Fluence >1 MeV: 6.6E+06
Daily Proton Fluence >10 MeV: 4.2E+04
Daily Electron Fluence >2 MeV: 1.80E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B2.4
Solar Wind Day Averaged Data for 15 Sep
Speed: 401 km/sec Density: 1.4 p/cc Temp: 389000 K Bz: 8 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list