[Ips-dsgr] ASWFC Daily Report - 30 April 26 issued 2330 UT on 30 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri May 1 09:30:46 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/30 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 30 APRIL AND FORECAST FOR 01 MAY - 03 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 30 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 30 Apr: 143/97
1B. SOLAR FORECAST
01 May 02 May 03 May
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 135/89 130/84 128/81
COMMENT: Solar flare activity on UT day 30-Apr was at the R0
level, with only C-class flares observed. There are currently
six numbered sunspot regions visible on the solar disk and two
unnumbered regions. Active Region (AR) 4420 (N16W67, beta) has
exhibited growth in its trailer spots over the UT day. This region
is now approaching the western limb, limiting a definitive assessment
of its magnetic classification. AR 4424 (N17W32, beta) has shown
spot development in its intermediate spots, whilst its trailers
have shown some decay. Region 4429 (S05E38, beta) has shown spot
growth over the UT day. Two unnumbered regions are visible near
N12W15 (beta) and S18E65 (beta). Both unnumbered regions have
shown growth since appearing on the visible disk. All other sunspot
regions are either stable or in decay. Solar flare activity is
expected to be at R0-R1 levels over 01-03 May. S0 solar proton
conditions were observed on UT day 30-Apr. S0 solar proton conditions
are expected over 01-03 May. No Earth-directed coronal mass ejections
(CMEs) have been observed. The solar wind speed on UT day 30-Apr
increased, ranging from 350 to 505 km/s and is currently near
470 km/s. The peak total interplanetary magnetic field strength
(IMF, Bt) was 14 nT and the north-south IMF component (Bz) range
was -12 to +11 nT. Periods of sustained southward IMF conditions
were observed over the intervals 30/1028-1256UT and 30/1909-2134UT.
The solar wind speed is expected to remain elevated on 01-May.
A northern hemisphere coronal hole may influence the solar wind
speed over 02-03 May, though its effects will likely be limited
by its high latitudinal extent.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 30 Apr: G0
Estimated Indices 30 Apr : A K
Australian Region 6 11112223
Cocos Island 5 11112222
Darwin 6 21112223
Townsville 7 21122223
Learmonth 4 21112---
Alice Springs 6 11112223
Gingin 8 21112224
Canberra 6 11022223
Kennaook Cape Grim 6 11122223
Hobart 6 11122223
Estimated Antarctic Regional K Indices 30 Apr :
Macquarie Island 11 10034333
Casey 11 33222233
Mawson 23 33212365
Observed Regional daily pc3 Indices 30 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 0 (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 30 Apr : A
Fredericksburg 8
Planetary 10
Observed AFr/Ap Indices 29 Apr : A K
Fredericksburg 6
Planetary 4 0111 2122
2B. MAGNETIC FORECAST
Date Ap Conditions
01 May 18 G0-G1
02 May 12 G0
03 May 14 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
and planetary regions on UT day 30-Apr. Mostly G0-G1 geomagnetic
conditions were observed in the Antarctic region, with an isolated
period of G2 observed at Mawson. G0-G1 planetary geomagnetic
conditions are expected on 01-May due to the current elevated
solar wind conditions. G0 geomagnetic conditions are expected
over 02-03 May, with a chance of G1 on 03-May due to coronal
hole high speed wind stream effects from a northern hemisphere
coronal hole.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
30 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
01 May Normal Normal-fair Fair
02 May Normal Normal Normal-fair
03 May Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were mostly normal across
UT day 30-Apr, with some degradations observed in the southern
hemisphere. Normal to fair ionospheric conditions are forecast
for 01-03 May. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
30 Apr 77
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 15% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values.
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
01 May 80 Near predicted monthly values
02 May 85 Near predicted monthly values
03 May 85 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 44 was issued on
30 April and is current for 30 Apr to 2 May. Maximum Usable Frequencies
(MUFs) in the Australian region were near predicted monthly values
on UT day 30-Apr. Spread F was observed at Hobart and Canberra
during local night hours. MUFs are expected to be generally near
predicted monthly values over 01-03 May, with mild depressions
possible on 01-May. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 29 Apr
Daily Proton Fluence >1 MeV: 2.8E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 1.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.8
DSCOVR Satellite Solar Wind Day Averaged Data for 29 Apr
Speed: 321 km/sec Density: 3.8 p/cc Temp: 22400 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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