[Ips-dsgr] ASWFC Daily Report - 27 June 26 issued 2330 UT on 27 Jun 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Jun 28 09:30:52 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 JUNE 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 JUNE AND FORECAST FOR 28 JUNE - 30 JUNE
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 27 Jun: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Jun: 188/141
1B. SOLAR FORECAST
28 Jun 29 Jun 30 Jun
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 175/129 175/129 180/133
COMMENT: Solar flare activity on UT day 27-Jun was at the R0
level, with a C7.4 flare from active region (AR) 4475 (S08W19,
gamma) being the largest flare observed. There are currently
six active sunspot regions on the disk, with AR 4478 (S06E34,
beta‑gamma‑delta) being the largest and most magnetically complex
region. This region showed mild growth over the past UT day.
Both AR 4475 and AR 4479 (N17E18, beta) also showed some growth
over the same period. A new region, numbered 4480, has appeared
at S18E10, exhibiting a beta magnetic classification. The remaining
regions are either stable or in decay. Solar flare activity is
forecast to be at the R0-R1 level over 28-30 Jun, due to the
magnetic complexity of ARs 4475 and 4478. Solar radiation storm
conditions were at the S0 level throughout 27-Jun, and are forecast
to remain at the S0 level through 28-30 Jun. A low-velocity south-directed
coronal mass ejection (CME) was observed from 26/2112UT in SOHO/LASCO,
following a C2.5 flare from AR 4475. Modelling suggests this
CME will have a partial impact with Earth on 30-Jun at 30/1900UT
+/- 10 hours. The solar wind speed declined across 27-Jun as
the effects of a coronal hole high speed wind stream began to
subside. The solar wind speed began the UT day at 650-680km/s,
and slowly declined to between 500 and 530 km/s. The interplanetary
magnetic field strength (IMF, Bt) peaked at 4 nT, with the north-south
component (Bz) ranging between -3 and +3 nT. The solar wind is
expected to continue declining over 28-30 Jun, before rising
late on 30-Jun due to the arrival of the CME first seen on 26-Jun.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Jun: G0
Estimated Indices 27 Jun : A K
Australian Region 2 22101001
Cocos Island 1 11101001
Darwin 2 21101001
Townsville 3 22201011
Learmonth 3 21101012
Alice Springs 2 22101001
Gingin 4 32101012
Canberra 3 22201000
Kennaook Cape Grim 3 22102001
Hobart 2 22101001
Estimated Antarctic Regional K Indices 27 Jun :
Macquarie Island 3 22201000
Casey 5 32211111
Mawson 19 44332135
Observed Regional daily pc3 Indices 27 Jun :
Darwin NA
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 8 (Quiet)
Canberra 17 (Quiet)
Hobart 11 (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 27 Jun : A
Fredericksburg 8
Planetary 9
Observed AFr/Ap Indices 26 Jun : A K
Fredericksburg 13
Planetary 11 3221 233-
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Jun 12 G0
29 Jun 8 G0
30 Jun 16 G0-G1
COMMENT: Geomagnetic conditions in the Australian region on UT
day 27-Jun were at the G0 level. G0 conditions were also recorded
at the planetary level, with an isolated G1 interval reported
in the Antarctic region at Mawson. G0 conditions are forecast
over 28-29 Jun, with G0-G1 geomagnetic conditions forecast for
30-Jun due to the arrival of a CME first observed on 26-Jun.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Jun Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Jun Normal Normal Normal-fair
29 Jun Normal Normal Normal-fair
30 Jun Normal Normal Normal-fair
COMMENT: Global high-frequency radio propagation conditions were
mostly normal on UT day 27-Jun, with some normal to fair conditions
in Northern hemisphere polar regions. Global propagation conditions
are expected to remain mostly normal over 28-30 Jun. Shortwave
fadeouts are possible.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 Jun 89
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 30% during local day.
Near predicted monthly values during local night.
Enhanced by 20% after local dawn.
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
28 Jun 85 Near predicted monthly values
29 Jun 85 Near predicted monthly values
30 Jun 85 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 57 was issued on
27 June and is current for 27-28 Jun. Maximum Usable Frequencies
(MUFs) in the Australian region were near predicted monthly values,
with some enhancements seen at Niue Island. Spread-F was present
across most of the Australian region during local night hours,
including significant spread-F at Hobart. MUFs are forecast to
continue to be near predicted values over 28-30 Jun. Shortwave
fadeouts are possible.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 Jun
Daily Proton Fluence >1 MeV: 1.2E+06
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 5.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 26 Jun
Speed: 506 km/sec Density: 0.6 p/cc Temp: 11100 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