[Ips-dsgr] ASWFC Daily Report - 04 May 25 issued 2331 UT on 04 May 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon May 5 09:31:42 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/04 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 04 MAY AND FORECAST FOR 05 MAY - 07 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 04 May: Low
Flares: R0
Observed 10.7 cm flux/Equivalent Sunspot Number for 04 May: 159/113
1B. SOLAR FORECAST
05 May 06 May 07 May
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 160/114 160/114 160/114
COMMENT: Solar activity on UT day 04-May was at the R0 level.
There are currently four numbered sunspot regions visible on
the solar disk. AR4079 (N08E04, beta-gamma-delta) is by far the
largest and most magnetically complex region on the disk. AR4079,
AR4081(N07E32, beta) and AR4082 (S12E66, beta) all showed spot
development over the UT day. AR4076 (N06W60, alpha) appeared
stable on 04-May. Solar activity is expected to be at R0-R1 levels
over 05-07 May. S0 solar radiation conditions were observed on
04-May. S0 solar radiation conditions are expected on 05-07 May.
No Earth-directed CMEs were observed on 04-May. The solar wind
speed on UT day 04-May decreased for the first part of the day
before increasing again in the second half. The wind speed mostly
ranged between 530 and 735 km/s and is currently near 680 km/s.
The peak total interplanetary magnetic field strength (IMF, Bt)
was 10 nT and the north-south IMF component (Bz) range was -8
to +8 nT. The solar wind is expected to remain enhanced over
05-07 May due to high speed wind stream effects from a pair of
narrow coronal holes in the western hemisphere. There is a chance
of a decline on 05-06 May, however an additional coronal hole
in the southern hemisphere is expected to enter a geoeffective
position on 06-May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 04 May: G0
Estimated Indices 04 May : A K
Australian Region 17 32424433
Cocos Island 13 22413342
Darwin 18 33424433
Townsville 18 33424433
Learmonth 23 33434543
Alice Springs 14 23323433
Gingin 20 32424444
Canberra 16 22424433
Kennaook Cape Grim 23 22524543
Hobart 17 32424433
Estimated Antarctic Regional K Indices 04 May :
Macquarie Island 36 33636543
Casey 23 45433343
Mawson 69 66543477
Observed Regional daily pc3 Indices 04 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 10 (Quiet)
Canberra 23 (Quiet to unsettled)
Hobart 52 (Unsettled)
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 04 May : A
Fredericksburg 19
Planetary 25
Observed AFr/Ap Indices 03 May : A K
Fredericksburg 20
Planetary 20 5445 3334
2B. MAGNETIC FORECAST
Date Ap Conditions
05 May 12 G0, chance of G1
06 May 18 G0-G1
07 May 15 G0-G1
COMMENT: ASWFC Geomagnetic Warning 35 was issued on 4 May and
is current for 4-6 May. Mostly G0 geomagnetic conditions were
observed in the Australian region on UT day 04-May, with G1 conditions
observed at Kennaook Cape Grim and Learmonth. G1 conditions were
also observed at the planetary level. Mostly G2 conditions were
observed in the Antarctic region, with a period of G3 conditions
observed at Mawson. G0 conditions, with a chance of G1 are expected
on 05-May. G0-G1 conditions are again expected over 06-07 May
due to high speed wind stream effects from a coronal hole in
the southern hemisphere rotating towards a geoeffective position.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
04 May Fair Fair Fair-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
05 May Normal Normal Normal-fair
06 May Normal Normal-fair Fair
07 May Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 04-May were
fair to poor at high and low latitudes, particularly in the northern
hemisphere for the first half of the UT day. Conditions recovered
towards fair to normal in the second half of the day. HF radio
propagation conditions are expected to be mostly normal over
05-07 May, with mild degradations possible at high latitudes
over 05-06 May. Minor shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
04 May 112
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Mostly near predicted monthly values.
Depressed by 30% after local dawn.
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
Apr 123
May 113
Jun 111
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
05 May 100 Near predicted monthly values
06 May 115 Near predicted monthly values
07 May 120 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 04-May were near predicted monthly values. Significant
spread F was observed at Hobart during local night hours and
minor spread F was observed at Canberra. MUFs are expected to
be near predicted monthly values over 05-07 May. Further spread
F is expected at Hobart. There is a chance of mild depressions
in the southern Australian region on 05-06 May. Minor shortwave
fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 03 May
Daily Proton Fluence >1 MeV: 7.9E+06
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 1.60E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:14%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.0
DSCOVR Satellite Solar Wind Day Averaged Data for 03 May
Speed: 723 km/sec Density: 1.0 p/cc Temp: 399000 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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