[Ips-dsgr] ASWFC Daily Report - 13 April 26 issued 2330 UT on 13 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Tue Apr 14 09:30:48 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/13 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 13 APRIL AND FORECAST FOR 14 APRIL - 16 APRIL
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 13 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 13 Apr: 99/46
1B. SOLAR FORECAST
14 Apr 15 Apr 16 Apr
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 100/48 105/54 110/60
COMMENT: Solar flare activity was at the R0 level on UT day 13-Apr,
with no significant solar flares observed. There are currently
four active regions on the visible solar disk, with Active Region
(AR) 4416 (N18W28, beta) being the largest. This region exhibited
a redistribution of minor spots over the past 24 hours, but remained
overall largely stable. AR 4419 (N13E70) has recently rotated
over the eastern limb, and appears stable, with a beta magnetic
classification. All other regions appear stable or in decay.
Solar flare activity is expected to remain at the R0 level through
14-16 Apr. Solar proton conditions remained at the S0 level throughout
UT day 13-Apr. S0 solar proton conditions are expected over 14-16
Apr. A solar eruption was visible on the western limb at 13/1753UT
in SDO/AIA 304 Å imaging, with a subsequent west-directed coronal
mass ejection (CME) visible in SOHO/LASCO at 13/1812UT. Preliminary
analysis suggests this CME is a farside event. However, further
imaging is required to confirm that this event has no geoeffective
component. No other geoeffective CMEs were observed in available
coronagraph imagery over the last 24 hours. The solar wind declined
over UT day 13-Apr, dropping from approximately 500 km/s to 400
km/s across the UT day. The interplanetary magnetic field strength
(IMF, Bt) was largely constant throughout the UT day, peaking
at 6 nT, with the north-south component (Bz) ranging between
-4 and +5 nT. The solar wind is expected to continue a slow declining
trend over 14-16 Apr as the effects of a previous coronal hole
high speed wind stream continue to wane, with possible mild enhancements
in solar wind speed due to a southern coronal hole during this
period.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 13 Apr: G0
Estimated Indices 13 Apr : A K
Australian Region 1 11100100
Cocos Island 1 11110000
Darwin 4 22111111
Townsville 3 22110011
Learmonth 2 12111100
Alice Springs 1 11100001
Gingin 1 11100100
Canberra 0 01100000
Kennaook Cape Grim 1 01100100
Hobart 1 11100100
Estimated Antarctic Regional K Indices 13 Apr :
Macquarie Island 0 01000000
Casey 7 33321101
Mawson 7 33311102
Observed Regional daily pc3 Indices 13 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (Quiet)
Hobart 8 (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 13 Apr : A
Fredericksburg 4
Planetary 5
Observed AFr/Ap Indices 12 Apr : A K
Fredericksburg 7
Planetary 8 2222 212-
2B. MAGNETIC FORECAST
Date Ap Conditions
14 Apr 6 G0
15 Apr 6 G0
16 Apr 6 G0
COMMENT: Geomagnetic conditions in the Australian region were
at the G0 level throughout UT day 13-Apr. G0 conditions were
also observed in the Antarctic region and at the planetary level.
G0 geomagnetic conditions are expected over 14-16 Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
13 Apr Fair Fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
14 Apr Normal Normal Normal-fair
15 Apr Normal Normal Normal-fair
16 Apr Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were fair on UT day 13-Apr,
with some degradations observed at various latitudes at different
times of the UT day due to previous geomagnetic activity. Ionospheric
conditions improved late in the UT day, and are expected to continue
to trend towards normal over 14-16 Apr.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
13 Apr 61
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Depressed by 40% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values 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
14 Apr 80 Near predicted monthly values
15 Apr 80 Near predicted monthly values
16 Apr 80 Near predicted monthly values
COMMENT: Maximum Usable Frequencies (MUFs) in the Australian
region were largely near predicted monthly values on UT day 13-Apr,
with some depressions of up to 20% in the Southern Australian
region during local night hours. Some spread-F was observed in
Hobart and Townsville during local night hours. Ionospheric scintillation
was observed in Darwin over the interval 13/1249-1310UT. Depressions
of up to 40% were observed during local night hours at the Cocos
Islands, with strong sporadic-E also observed. MUFs are expected
to be near predicted values over 14-16 Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 12 Apr
Daily Proton Fluence >1 MeV: 5.1E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 6.10E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B2.2
DSCOVR Satellite Solar Wind Day Averaged Data for 12 Apr
Speed: 507 km/sec Density: 1.6 p/cc Temp: 119000 K Bz: 0 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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