[Ips-dsgr] ASWFC Daily Report - 12 April 26 issued 2330 UT on 12 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Apr 13 09:30:48 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/12 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 12 APRIL AND FORECAST FOR 13 APRIL - 15 APRIL
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 12 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 12 Apr: 99/46
1B. SOLAR FORECAST
13 Apr 14 Apr 15 Apr
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 95/41 90/34 100/48
COMMENT: Solar flare activity was at the R0 level on UT day 12-Apr,
with no significant flare activity observed. The solar regions
currently on the visible solar disk are relatively small. The
largest of these is solar region AR4416 (N19W12, beta) which
continues to grow, though has remained flare quiet. Very small
new solar region AR4417 (S07W87, beta) produced some minor low
level C class flares early in the UT day and is now almost off
disk. Some minor spots have emerged around the larger spot of
solar region AR4415 (S18E22, beta). A new small solar region
appears to be rotating onto the solar disk at solar latitude
N11 on the northeast solar limb. There are currently three numbered
solar regions on the visible solar disk. Solar activity is expected
to be at the R0 level for 13-15 Apr. S0 solar radiation storm
conditions were observed on 12-Apr. S0 solar radiation storm
conditions are expected over 13-15 Apr. No Earth directed coronal
mass ejections (CMEs) were observed. The solar wind speed on
12-Apr was initially strong declining to moderate due to the
reduced influence of coronal holes now located in the western
solar hemisphere. An isolated coronal hole at solar latitude
S35 is across the solar central meridian, although the latitude
of this hole is likely to reduce any effects on the solar wind.
A large isolated coronal hole is visible in the northeast solar
quadrant. The solar wind speed ranged from 450 to 601 km/s and
is currently at 450 km/s. The peak total interplanetary magnetic
field strength (IMF, Bt) was 6 nT and the north-south component
(Bz) range was -4 and +6 nT. Solar wind 27 day recurrence patterns
suggest that the solar wind speed will continue to decline to
background levels during 13-14 Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 12 Apr: G0
Estimated Indices 12 Apr : A K
Australian Region 5 22222111
Cocos Island 4 22111111
Darwin 6 22222122
Townsville 6 22222112
Learmonth 8 22233221
Alice Springs 5 22222111
Gingin 8 12233222
Canberra 6 22132111
Kennaook Cape Grim 7 21233211
Hobart 7 21233211
Estimated Antarctic Regional K Indices 12 Apr :
Macquarie Island 8 21143111
Casey 14 34433121
Mawson 18 34442242
Observed Regional daily pc3 Indices 12 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 37 (Quiet to unsettled)
Canberra 35 (Quiet to unsettled)
Hobart 36 (Quiet to unsettled)
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 12 Apr : A
Fredericksburg 7
Planetary 8
Observed AFr/Ap Indices 11 Apr : A K
Fredericksburg 10
Planetary 12 2433 2221
2B. MAGNETIC FORECAST
Date Ap Conditions
13 Apr 8 G0
14 Apr 6 G0
15 Apr 6 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on 12-Apr. G0 geomagnetic activity was observed in the
Antarctic region. G0 conditions are expected over 13-15 Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
12 Apr Normal Fair-normal Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
13 Apr Normal Normal Normal-fair
14 Apr Normal Normal Normal
15 Apr Normal Normal Normal
COMMENT: HF radio propagation conditions on 12-Apr were fair
to normal. Normal HF conditions expected for 13-15 Apr.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
12 Apr 65
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Depressed by 20% 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 during local day.
Depressed by 30% during local night.
Southern Australian Region:
15% depressed to near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Mar 92
Apr 83
May 81
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
13 Apr 80 Near predicted monthly values
14 Apr 80 Near predicted monthly values
15 Apr 80 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were 30% depressed to near predicted monthly values on
12-Apr. Depressed conditions of up to 30% were observed during
local night hours in the northern Australian region and 15% depressions
were observed at times in the southern Australian region during
the local day. Spread F was observed at Hobart during local night
hours. MUFs are generally expected to be near predicted monthly
values over 13-15 Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 11 Apr
Daily Proton Fluence >1 MeV: 1.0E+06
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 4.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B2.0
DSCOVR Satellite Solar Wind Day Averaged Data for 11 Apr
Speed: 568 km/sec Density: 2.3 p/cc Temp: 178000 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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