[Ips-dsgr] ASWFC Daily Report - 03 April 26 issued 2330 UT on 03 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Apr 4 10:30:43 AEDT 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/03 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 03 APRIL AND FORECAST FOR 04 APRIL - 06 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 03 Apr: R1
Flares Max Fadeout Freq. Sectors
M1.3 0756UT possible lower Mid East/Indian
M1.3 1250UT possible lower European
Observed 10.7 cm flux/Equivalent Sunspot Number for 03 Apr: 136/90
1B. SOLAR FORECAST
04 Apr 05 Apr 06 Apr
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 135/89 140/94 140/94
COMMENT: Solar flare activity was at the R1 level on UT day 03-Apr,
with two M1.3 flares observed from Active Region (AR) 4409 (N03E01,
beta-gamma) at 03/0756UT and 03/1250UT. This region is the most
magnetically complex of seven regions on the solar disk, and
has exhibited a redistribution of minor spots over the last 24
hours, but has remained overall stable. All other active regions
are either stable or in decay. Solar flare activity is forecast
to be at the R1 level, with a chance of R2 over the period 04-06
Apr, due to the ongoing flare activity of active region 4409.
Solar radiation storm conditions were at the S0 level on 03-Apr,
with the solar proton flux remaining elevated throughout the
entire UT day. The proton flux peaked at 6.5 pfu at 03/0400UT,
and is at 3.1 pfu at the time of writing. S0 solar
radiation storm conditions, with a slight chance of S1, are expected
for 04-Apr given the elevated solar proton flux. S0 conditions
are expected over 05-06 Apr. No Coronal Mass Ejections (CMEs)
were observed over the last 24 hours in coronagraph imagery.
The solar wind began the UT day elevated, ranging between 610-680
km/s due to ongoing coronal hole high-speed wind stream effects.
A sharp increase in the solar wind speed was observed at 03/1457UT,
due to the impact of a CME first observed at 01/2229UT. The solar
wind then peaked at approximately 800 km/s at 03/1545UT, and
is currently ranging between 680-720 km/s. The interplanetary
magnetic field strength (IMF, Bt) peaking at 14 nT shortly after
the CME arrival at 03/1515UT, with the north-south component
(Bz) ranging between -11 and +5 nT, including an extended southward
period between 03/1503-1800UT. The solar wind will likely remain
elevated over the period 04-06 Apr, due to the ongoing effects
of the CME impact as well as the coronal hole high speed wind
stream, with a slow decline over this period as these effects
gradually subside.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 03 Apr: G1
Estimated Indices 03 Apr : A K
Australian Region 26 33444544
Cocos Island 18 22433533
Darwin 26 33444544
Townsville 25 33443544
Learmonth - --------
Alice Springs 26 33444544
Gingin 35 33444655
Canberra 30 33443555
Kennaook Cape Grim 34 33544555
Hobart 34 33544555
Estimated Antarctic Regional K Indices 03 Apr :
Macquarie Island 64 34555775
Casey 81 45533955
Mawson 78 35555777
Observed Regional daily pc3 Indices 03 Apr :
Darwin 19 (Quiet)
Townsville 9 (Quiet)
Learmonth NA
Alice Springs 14 (Quiet)
Gingin 106 (Major storm)
Canberra 153 (Severe storm)
Hobart NA
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 03 Apr : A
Fredericksburg 28
Planetary 54
Observed AFr/Ap Indices 02 Apr : A K
Fredericksburg 30
Planetary 43 5455 5654
2B. MAGNETIC FORECAST
Date Ap Conditions
04 Apr 33 G1-G2
05 Apr 22 G1
06 Apr 12 G0, chance of G1
COMMENT: ASWFC Geomagnetic Warning 25 was issued on 3 April and
is current for 4 Apr only. Geomagnetic conditions in the Australian
region reached the G1 level on UT day 03-Apr, coinciding with
the arrival of a CME first observed at 01/2229UT. This arrival
was noted by the BOM magnetometer, which registered a weak (19
nT) impulse at 03/1528UT. An isolated period of G2 was recorded
at Gingin Observatory during this time. G1-G3 geomagnetic conditions
were observed in the Antarctic region across UT day 03-Apr, with
a single interval of G5 recorded at Casey. G3 geomagnetic conditions
were observed at the planetary level during the last 24 hours.
G1-G2 geomagnetic conditions are forecast for 04-Apr due to the
combined influence of the CME impact and coronal hole high speed
wind stream. This will decline to G1 conditions on 05-Apr, and
to G0, with a chance of G1 conditions on 06-Apr, as the effects
of these events decline.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
03 Apr Fair Fair-poor Poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
04 Apr Fair Fair Fair-poor
05 Apr Fair-normal Fair-normal Fair
06 Apr Normal-fair Normal-fair Normal-fair
COMMENT: Global ionospheric conditions on UT day 03-Apr were
fair-poor, with poor conditions observed at high latitudes and
in the Australian region due to ongoing geomagnetic activity.
MUFs in the European region were largely near predicted values,
with some depressions due to the geomagnetic activity. Ionospheric
conditions are expected to remain at fair-poor levels over 04-Apr
due to ongoing activity, improving towards normal conditions
over 05-06 Apr. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
03 Apr 65
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 30% during local day.
Near predicted monthly values during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 30% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Mostly near predicted monthly values.
Depressed by 35% after local dawn.
Southern Australian Region:
Depressed by 40% during local day.
Depressed by 20% during local night.
Depressed by 30% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% 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
04 Apr 50 Depressed 20 to 30%/near predicted monthly values
05 Apr 65 Depressed 10 to 15%/near predicted monthly values
06 Apr 80 Near predicted monthly values
COMMENT: ASWFC HF Communications Warning 33 was issued on 3 April
and is current for 4-5 Apr. Maximum Usable Frequencies (MUFs)
in the Southern Australian region were depressed by 20-40% across
the entire UT day 03-Apr due to ongoing geomagnetic activity.
Spread F was observed in Brisbane, Perth, and Hobart, and sporadic-E
was also observed in Hobart, Perth, and Canberra. MUFs in the
Northern Australian region were near monthly predicted values
across the UT day, with some enhancements seen at Niue Island
and the Cocos Islands. MUFs were depressed by up to 15% in the
Antarctic region over the last 24 hours. MUFs are expected to
remain depressed by up to 30% in the Australian region over UT
day 04-Apr, predominantly in the Southern Australian region,
due to the ongoing geomagnetic activity. Conditions are expected
to slowly trend towards predicted monthly values over 05-06 Apr
as this geomagnetic activity eases. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 02 Apr
Daily Proton Fluence >1 MeV: 1.1E+08
Daily Proton Fluence >10 MeV: 1.5E+05
Daily Electron Fluence >2 MeV: 1.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.6
DSCOVR Satellite Solar Wind Day Averaged Data for 02 Apr
Speed: 605 km/sec Density: 3.3 p/cc Temp: 244000 K Bz: -3 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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