[Ips-dsgr] ASWFC Daily Report - 20 June 26 issued 2330 UT on 20 Jun 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Jun 21 09:30:50 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/20 JUNE 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 20 JUNE AND FORECAST FOR 21 JUNE - 23 JUNE
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 20 Jun: R1
Flares Max Fadeout Freq. Sectors
M1.3 0151UT possible lower West Pacific
M1.0 1500UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Jun: 113/64
1B. SOLAR FORECAST
21 Jun 22 Jun 23 Jun
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 115/66 120/72 120/72
COMMENT: Solar activity on UT day 20-Jun was R1, with M1.3 and
M1.0 class solar flares. The first flare originated from active
region (AR) 4472 (S12E53, beta) and the second flare from a region
behind AR4472, yet to be fully rotate into view and receive a
number. There are currently four numbered sunspot regions on
the disk, all of which are currently stable. Exact assessment
cannot yet be made on the new region due to low visibility, however
solar activity is expected to be R0-R1 over 21-23 June due to
this region.
A slow moving partial halo CME was observed from 20/0212 UT associated
with the M1.3 flare on the eastern limb. This CME is not expected to
impact the Earth. A second CME directed to the solar northeast was
observed shortly after at 0312 UT, but has been assessed as farside
and therefore not Earth-directed. No other CMEs were observed on 20-Jun.
S0 solar radiation storm conditions were observed on UT day 20-Jun.
S0 solar radiation storm conditions are expected over 21-23 Jun.
The solar wind environment on UT day 20-Jun was near background levels.
The solar wind speed ranged from 360-420 km/s. The peak total interplanetary
field strength (IMF, Bt) was 8 nT and the north-south IMF component
(Bz) was +6 to -6 nT. The solar wind environment is expected
to mostly remain near background levels over 21-23 Jun, but weak
coronal hole connection may give way to slightly enhanced wind
speeds by the end of the period.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 20 Jun: G0
Estimated Indices 20 Jun : A K
Australian Region 2 11112010
Cocos Island 1 11111000
Darwin 3 11112011
Townsville 4 11122111
Learmonth 4 21212011
Alice Springs 2 11112010
Gingin 4 22212011
Canberra 1 11011010
Kennaook Cape Grim 2 11112010
Hobart 2 11111010
Estimated Antarctic Regional K Indices 20 Jun :
Macquarie Island 1 00012000
Casey 6 23321110
Mawson 23 53313216
Observed Regional daily pc3 Indices 20 Jun :
Darwin NA
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 0 (Quiet)
Hobart 0 (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 20 Jun : A
Fredericksburg 7
Planetary 8
Observed AFr/Ap Indices 19 Jun : A K
Fredericksburg 9
Planetary 7 3212 2112
2B. MAGNETIC FORECAST
Date Ap Conditions
21 Jun 4 G0
22 Jun 4 G0
23 Jun 8 G0
COMMENT: G0 geomagnetic conditions in the Australian region on
UT day 20-Jun were observed. G0-G1 geomagnetic conditions in
the Antarctic region were observed. G0 geomagnetic conditions
are expected over 21-23 Jun.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
20 Jun Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
21 Jun Normal Normal Normal
22 Jun Normal Normal Normal
23 Jun Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 20-Jun were
mostly normal. HF radio propagation conditions are expected to
be mostly normal over 21-23 Jun. Towards the end of the period
conditions may become mildly degraded due to possible weak coronal
hole connection.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
20 Jun 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 20% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
May 67
Jun 68
Jul 65
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
21 Jun 75 Near predicted monthly values
22 Jun 75 Near predicted monthly values
23 Jun 75 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 54 was issued on
20 June and is current for 20-21 Jun. Maximum usable frequencies
(MUFs) in the Australian region on UT day 20-Jun were mostly
near predicted values. Spread-F was observed in Norfolk Island
and in Hobart during local night hours. MUFs are expected to
be mostly near predicted monthly values over 21-23 Jun.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 19 Jun
Daily Proton Fluence >1 MeV: 2.7E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 2.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B4.5
DSCOVR Satellite Solar Wind Day Averaged Data for 19 Jun
Speed: 399 km/sec Density: 6.2 p/cc Temp: 92600 K Bz: 0 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