[Ips-dsgr] ASWFC Daily Report - 11 April 26 issued 2330 UT on 11 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Apr 12 09:30:49 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 APRIL AND FORECAST FOR 12 APRIL - 14 APRIL
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 11 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Apr: 93/38
1B. SOLAR FORECAST
12 Apr 13 Apr 14 Apr
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 95/41 95/41 90/34
COMMENT: Solar flare activity was at the R0 level on UT day 11-Apr,
with no significant flare activity observed. There is currently
no region of significance on the visible solar disk. Recent growth
in small solar region AR4416 (N19E02, beta) has slowed with development
in its trailer spots and redistribution in its leader spots.
A recently emerged very small spot is visible at S08W73. There
are currently three numbered solar regions and one unnumbered
region on the visible solar disk. Other solar regions are stable
or in decay. A 15 degree long thin solar filament extending from
AR4416 to the southwest slowly lifted off during the interval
11/1300-1500UT in GONG H-alpha imagery. Solar activity is expected
to be at the R0 level for 12-14 Apr. S0 solar radiation storm
conditions were observed on 11-Apr. S0 solar radiation storm
conditions are expected over 12-14 Apr. No Earth directed coronal
mass ejections (CMEs) were observed. No CME was observed with
the filament activity near AR4416. The solar wind speed on 11-Apr
was strong and steady due to coronal holes now located in the
western solar hemisphere. Another isolated coronal hole at solar
latitude S35 is crossing the solar central meridian, with the
latitude of this hole likely reducing any effects on the solar
wind. The solar wind ranged from 498 to 597 km/s and is currently
at 588 km/s. The peak total interplanetary magnetic field strength
(IMF, Bt) was 11 nT and the north-south component (Bz) range
was -6 and +7 nT. The solar wind speed is expected to be initially
strong on 12-Apr due to the ongoing influence of solar coronal
hole wind streams, then slowly declining.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 11 Apr: G0
Estimated Indices 11 Apr : A K
Australian Region 10 23332311
Cocos Island 6 22231210
Darwin 11 33332312
Townsville 10 23332311
Learmonth 9 23332310
Alice Springs 10 23332311
Gingin 9 23332310
Canberra 8 23332201
Kennaook Cape Grim 10 23332311
Hobart 10 23332311
Estimated Antarctic Regional K Indices 11 Apr :
Macquarie Island 12 24342300
Casey 14 44432211
Mawson 23 34543343
Observed Regional daily pc3 Indices 11 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 36 (Quiet to unsettled)
Canberra 27 (Quiet to unsettled)
Hobart 22 (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 11 Apr : A
Fredericksburg 15
Planetary 19
Observed AFr/Ap Indices 10 Apr : A K
Fredericksburg 16
Planetary 18 4332 4432
2B. MAGNETIC FORECAST
Date Ap Conditions
12 Apr 12 G0
13 Apr 8 G0
14 Apr 6 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on 11-Apr. G0-G1 geomagnetic activity was observed in
the Antarctic region. Generally G0 conditions are expected over
12-14 Apr as the mild influence of the coronal hole wind stream
slowly declines.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
11 Apr Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
12 Apr Normal Fair-normal Fair
13 Apr Normal Normal Normal
14 Apr Normal Normal Normal
COMMENT: HF radio propagation conditions on 11-Apr were fair
to normal. Fair to normal HF conditions are expected on 12-Apr,
with normal HF conditions expected for 13-14 Apr.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
11 Apr 67
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Depressed by 30% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Southern Australian Region:
Depressed by 15% during local day.
Near predicted monthly values local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 30% 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
12 Apr 75 Depressed 10 to 15%/near predicted monthly values
13 Apr 90 Near predicted monthly values
14 Apr 90 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were 15-20% depressed to near predicted monthly values
on 11-Apr. Spread F was observed at Hobart during local night
hours. MUFs are generally expected to be near predicted monthly
values over 12-14 Apr, with mild depressions possible for the
southern Australian region on 12-Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 10 Apr
Daily Proton Fluence >1 MeV: 8.4E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 3.40E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B3.1
DSCOVR Satellite Solar Wind Day Averaged Data for 10 Apr
Speed: 476 km/sec Density: 4.1 p/cc Temp: 211000 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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