[Ips-dsgr] ASWFC Daily Report - 02 April 26 issued 0010 UT on 03 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Apr 3 11:10:09 AEDT 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/02 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 02 APRIL AND FORECAST FOR 03 APRIL - 05 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
Reissued due to additional remark on the solar proton flux.
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 02 Apr: R1
Flares Max Fadeout Freq. Sectors
M3.5 1816UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 02 Apr: 140/94
1B. SOLAR FORECAST
03 Apr 04 Apr 05 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 140/94 135/89 140/94
COMMENT: Solar flare activity on UT day 02-Apr was R1 due to
an M3.5 flare from solar region AR4404 (N17W17, beta). This region
is showing decay in the number of small spots surrounding its
larger main spot. Recent region of interest AR4405 (S26W05, beta)
continues to slowly decay. Solar region AR4409 (N03E17, beta-gamma)
continues to slowly develop. There are currently ten Active Regions
on the solar disk. All other sunspot regions are either stable
or in decay. A C6.1 flare near region AR4403 (N15W36, beta) with
an associated solar filament eruption located at N17W23 was observed
from 01/2229UT in SDO 304 imagery. A small section of filament
located at N08W15 partially erupted at 01/1404UT in GONG imagery
between solar regions AR4406 (N09W17, beta) and AR4404. Another
larger filament eruption was observed from 02/1802UT located
at N10W20 in association with the M3.5 flare from AR4404. Solar
activity is expected to be R0-R1 over 03-05-Apr. A CME has been
observed with an Earth directed component. A fast northwest CME
was observed from 01/2324UT following the filament eruption at
01/2229UT. Modelling of this event shows the bulk of the CME
passing ahead and above the Earth with a glancing blow arrival
at 03/1400UT +/- 12 hours. A more minor northwest CME was observed
from 02/1418UT, which may be associated with the smaller filament
eruption at 01/1404UT. This minor CME was modelled as an Earth
miss. Another northwest CME was observed from 02/1848UT and has
been paired with the M3.5 flare/filament activity. Modelling
of the CME was conducted with limited imagery and results showed
a low density CME passing in front and above the Earth. S0 solar
radiation storm conditions were observed on UT day 02-Apr, though
the solar proton flux has been steadily rising and is currently
at 4PFU. S0, chance S1 conditions are possible on 03-Apr. S0
solar radiation storm conditions are expected over 04-05-Apr.
The solar origin of the increase in solar proton flux is not
clear. An isolated coronal hole is visible in the south west
solar quadrant just south of the solar equator. Following yesterdays
weak shock arrival the solar wind gradually decreased before
steadily increasing. The solar wind toward/away Phi angle, which
indicates the direction of the interplanetary magnetic field
in the ecliptic plane, suggests the Earth entered the coronal
hole wind stream from the hole now in the southwest solar quadrant
a day earlier than expected, with the Phi angle swinging from
"away/+ve" to "towards/-ve" at 01/2000UT (matching the holes
-ve magnetic polarity), the solar wind speed then steadily increased
and the density steadily decreased. The solar wind speed may
have increased earlier than expected due to the increase in coronal
hole area on this rotation. The solar wind ranged from 427 to
702 km/s and is currently at 690 km/s. The peak total interplanetary
field strength (IMF, Bt) was 17 nT and the north-south IMF component
range (Bz) was +12 to -16nT.The solar wind speed is expected
to remain strong over 03-04 Apr.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 02 Apr: G1
Estimated Indices 02 Apr : A K
Australian Region 25 33444543
Cocos Island 16 32333442
Darwin 26 33444544
Townsville 25 33444543
Learmonth - --------
Alice Springs 25 33444543
Gingin 29 43444553
Canberra 26 23544543
Kennaook Cape Grim 33 33554553
Hobart 32 32555543
Estimated Antarctic Regional K Indices 02 Apr :
Macquarie Island 59 24666753
Casey 29 35444543
Mawson 83 55774675
Observed Regional daily pc3 Indices 02 Apr :
Darwin 4 (Quiet)
Townsville 0 (Quiet)
Learmonth NA
Alice Springs 0 (Quiet)
Gingin 14 (Quiet)
Canberra 49 (Unsettled)
Hobart 108 (Major storm)
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 02 Apr : A
Fredericksburg 31
Planetary 48
Observed AFr/Ap Indices 01 Apr : A K
Fredericksburg 8
Planetary 9 3112 3222
2B. MAGNETIC FORECAST
Date Ap Conditions
03 Apr 35 G1-G2
04 Apr 22 G1
05 Apr 12 G0
COMMENT: ASWFC Geomagnetic Warning 24 was issued on 2 April and
is current for 3-4 Apr. G1 geomagnetic conditions were observed
in the Australian region on UT day 02-Apr. G1-G3 geomagnetic
conditions were observed in the Antarctic region. G2 planetary
conditions were observed. The increase in geomagnetic activity
was due to the Earth entering an coronal hole wind stream a day
earlier than expected. G1-G2 geomagnetic conditions are expected
on 03-Apr due to the current influence of the coronal hole wind
stream and an anticipated glancing blow CME arrival during the
second half of the UT day. G1 conditions expected for 04-Apr
due to ongoing effects of the coronal hole wind stream.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
02 Apr Normal Normal-fair Fair-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
03 Apr Normal Poor-fair Poor
04 Apr Normal Fair-normal Poor-fair
05 Apr Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 02-Apr were
normal to poor, with fair to poor conditions at middle to high
latitudes due to earlier than expected onset of geomagnetic activity
from a coronal hole wind stream. Fair to poor HF conditions are
expected at middle to high latitudes on 03-Apr and generally
fair conditions are expected for 04-Apr with poor conditions
at times at higher latitudes. Isolated minor fadeouts are possible.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
02 Apr 118
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Enhanced by 50% during local day.
Enhanced by 50% during local night.
Enhanced by 25% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 20% during local night.
Southern Australian Region:
Enhanced by 20% during local day.
Enhanced by 25% during local night.
Depressed by 30% after local dawn.
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
03 Apr 50 Depressed 20 to 30%/near predicted monthly values
04 Apr 70 Depressed 10 to 15%/near predicted monthly values
05 Apr 90 Near predicted monthly values
COMMENT: ASWFC HF Communications Warning 32 was issued on 2 April
and is current for 3 Apr only. Maximum usable frequencies (MUFs)
in the Australian region on UT day 02-Apr were enhanced by 15-20%
in the northern Australian region. MUFs in the southern Australian
region were enhanced during the local day and night by 20-25%,
then becoming 30% depressed after local dawn this morning following
overnight geomagnetic activity induced by a coronal hole wind
stream. Southern Australian region MUFs are expected to be depressed
by 30% during the local day today. Northern Australian region
MUFs are expected to remain near predicted monthly values on
03-Apr. Southern Australian region MUFs are expected to be depressed
by to up 15% on 04-Apr. Isolated minor short wave fadeouts are
possible.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 01 Apr
Daily Proton Fluence >1 MeV: 2.1E+07
Daily Proton Fluence >10 MeV: 2.3E+04
Daily Electron Fluence >2 MeV: 6.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.6
DSCOVR Satellite Solar Wind Day Averaged Data for 01 Apr
Speed: 398 km/sec Density: 4.2 p/cc Temp: 76100 K Bz: 0 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list