[Ips-dsgr] ASWFC Daily Report - 25 April 25 issued 2330 UT on 25 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Apr 26 09:30:56 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 APRIL AND FORECAST FOR 26 APRIL - 28 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Apr: 164/118
1B. SOLAR FORECAST
26 Apr 27 Apr 28 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 170/124 170/124 165/119
COMMENT: Solar activity on UT day 25-Apr was at the R0 level,
with no significant flaring activity. There are currently twelve
numbered sunspot regions visible on the solar disk and one unnumbered
region. AR4064 (N11W41, beta) is the largest region on the disk
and has decayed over the UT day. AR4077 (S17E62, beta) has exhibited
spot growth over the 24-hour period. AR4074 (S19W64, beta) has
shown mild spot development. An unnumbered region recently appeared
on the disk near N15W42 (beta) and has shown mild spot growth.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be at R0-R1 levels over 26-28 Apr. No
Earth-directed CMEs have been observed. The solar wind speed
on UT day 25-Apr declined, ranging from 440 to 520 km/s and is
currently near 440 km/s. The peak total interplanetary magnetic
field strength (IMF, Bt) was 7 nT and the north-south IMF component
(Bz) range was -2 to +6 nT. The solar wind speed is expected
to decline on 26-Apr, then moderately increase over 27-28 Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Apr: G0
Estimated Indices 25 Apr : A K
Australian Region 1 11100011
Cocos Island 1 11110010
Darwin 4 21211112
Townsville 2 11100112
Learmonth 3 21210111
Alice Springs 2 11100002
Gingin 2 11210011
Canberra 0 01000001
Kennaook Cape Grim 1 11000011
Hobart 1 11000011
Estimated Antarctic Regional K Indices 25 Apr :
Macquarie Island 0 00000020
Casey 9 34321012
Mawson 7 22211104
Observed Regional daily pc3 Indices 25 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 6 (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 25 Apr : A
Fredericksburg 5
Planetary 5
Observed AFr/Ap Indices 24 Apr : A K
Fredericksburg 14
Planetary 13 ---- ----
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Apr 10 G0
27 Apr 15 G0
28 Apr 12 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 25-Apr. G0 geomagnetic conditions
are expected over 26-28 Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Apr Normal Normal Normal-fair
27 Apr Normal Normal Normal-fair
28 Apr Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 25-Apr were
mostly normal. HF radio propagation conditions are expected to
be mostly normal over 26-28 Apr with fair conditions at times
for high latitudes.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Apr 120
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Enhanced by 40% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Enhanced by 20% during local day.
Enhanced by 15% during local night.
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 126
Apr 115
May 113
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
26 Apr 120 Near predicted monthly values
27 Apr 120 Near predicted monthly values
28 Apr 120 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 25-Apr were near predicted monthly values to
20% enhanced in northern Australian regions. Spread F was observed
at Hobart during local night hours. MUFs are expected to be near
predicted monthly values over 26-28 Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Apr
Daily Proton Fluence >1 MeV: 1.6E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 3.20E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Apr
Speed: 506 km/sec Density: 13.2 p/cc Temp: 400000 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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