[Ips-dsgr] ASWFC Daily Report - 24 April 26 issued 2331 UT on 24 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Apr 25 09:31:00 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 APRIL AND FORECAST FOR 25 APRIL - 27 APRIL
STATUS INDICATORS SOL:** RED ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 Apr: R3
Flares Max Fadeout Freq. Sectors
X2.4 0107UT probable all West Pacific
X2.5 0813UT probable all Mid East/Indian
M2.0 0907UT possible lower Mid East/Indian
M1.7 1301UT possible lower European
M6.4 1815UT probable lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Apr: 146/100
1B. SOLAR FORECAST
25 Apr 26 Apr 27 Apr
Activity R2, chance of R3 R2, chance of R3 R1-R2
Fadeouts Probable Probable Probable
10.7cm/SSN 152/107 148/102 145/99
COMMENT: Solar flare activity on UT day 24-Apr was at the R3
level due to an X2.4 flare at 24/0107UT and an X2.5 flare at
24/0813UT. An M6.4 (R2) level flare was also observed at 24/1815UT.
All the above flares were produced by active region (AR) 4419
(N15W80, beta). There are currently six numbered and two unnumbered
sunspot regions visible on the solar disk. AR 4419 appears to
have exhibited some spot growth, though its position close to
the limb limits the reliability of this assessment. AR 4420 (N16E14,
beta-gamma) is the largest region on the disk and has exhibited
growth in its trailer spots over the UT day. Regions 4423 (S07E34,
beta-gamma) and 4424 (N16E43, beta) recently appeared on the
solar disk and have shown spot growth. Two unnumbered regions
are visible near N10W22 (beta) and N04E75 (beta). The first has
shown spot growth, whilst the second recently rotated over the
eastern limb and appears stable. All other sunspot regions are
either stable or in decay. Solar flare activity is expected to
be at the R2 level over 25-26 Apr, with a chance of R3 due to
the ongoing flare activity of region 4419 and the magnetic complexity
of regions 4420 and 4423. Flare activity is expected to reduce
to R1-R2 levels from 27-Apr. S0 solar proton conditions were
observed on UT day 24-Apr. S0 solar proton conditions are expected
over 25-27 Apr, with a chance of S1 due to the western limb location
of flare-active region 4419. No Earth-directed coronal mass ejections
(CMEs) were observed on UT day 24-Apr. Two northwest-directed
CMEs were observed in association with the aforementioned X-class
flares, but modelling indicates that neither is geoeffective.
A filament eruption was observed in H-alpha imagery near S27E58
at 24/1742UT, but no significant CME has been observed in association
with this event. The solar wind speed on UT day 24-Apr mildly
decreased, ranging from 420 to 355 km/s and is currently near
395 km/s. The peak total interplanetary magnetic field strength
(IMF, Bt) was 8 nT and the north-south IMF component (Bz) range
was -8 to +4 nT. A period of sustained southward IMF conditions
began at 24/1630UT and is ongoing. The solar wind speed is expected
to increase on 25-Apr due to a small coronal hole. An additional
increase is expected on 26-Apr due to the arrival of a CME first
observed on 23-Apr. The solar wind is expected to remain elevated
on 27-Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 24 Apr: G0
Estimated Indices 24 Apr : A K
Australian Region 5 21211222
Cocos Island 3 11110122
Darwin 7 22311222
Townsville 7 31111322
Learmonth 7 22-11322
Alice Springs 5 21211212
Gingin 8 21302233
Canberra 4 21101222
Kennaook Cape Grim 6 21112322
Hobart 6 21111322
Estimated Antarctic Regional K Indices 24 Apr :
Macquarie Island 3 10111212
Casey 9 33312222
Mawson 31 42213175
Observed Regional daily pc3 Indices 24 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 4 (Quiet)
Hobart 4 (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 24 Apr : A
Fredericksburg 6
Planetary 7
Observed AFr/Ap Indices 23 Apr : A K
Fredericksburg 7
Planetary 7 2322 1112
2B. MAGNETIC FORECAST
Date Ap Conditions
25 Apr 14 G0, chance of G1
26 Apr 26 G1-G2
27 Apr 14 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
and planetary regions on UT day 24-Apr. Mostly G0-G1 geomagnetic
conditions were observed in the Antarctic region, with an isolated
period of G3 observed at Mawson. G0 planetary geomagnetic conditions
are expected for 25-Apr, with a chance of G1 due to a small coronal
hole. G1-G2 geomagnetic conditions are forecast for 26-Apr due
to the combined effects of the coronal hole high speed wind stream
as well as the arrival of a CME first observed at 23/0512UT.
G0 geomagnetic conditions are expected on 27-Apr, with a chance
of G1.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
24 Apr Fair Fair Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
25 Apr Normal Normal Normal-fair
26 Apr Fair Fair Fair-poor
27 Apr Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were fair to normal on
UT day 24-Apr. Ionospheric conditions in low and mid latitude
regions were generally fair. Ionospheric conditions are expected
to be mostly normal on 25-Apr, before trending toward fair conditions
over 26-27 Apr due to forecast geomagnetic activity. Shortwave
fadeouts are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
24 Apr 60
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 25% during local night.
Northern Australian Region:
Depressed by 15% during local day.
Depressed by 25% during local night.
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
25 Apr 70 Near predicted monthly values
26 Apr 60 Depressed 15%/near predicted monthly values
27 Apr 60 Depressed 15%/near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 41 was issued on
24 April and is current for 24-25 Apr. Maximum Usable Frequencies
(MUFs) in the Australian region were 15-25% depressed on UT day
24-Apr. Spread-F was observed at Townsville. MUFs are expected
to be near monthly predicted values on 25-Apr, with depressions
likely over 26-27 Apr due to forecast geomagnetic activity. Shortwave
fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 23 Apr
Daily Proton Fluence >1 MeV: 2.2E+05
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 1.80E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:14%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 23 Apr
Speed: 443 km/sec Density: 2.0 p/cc Temp: 80900 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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