[Ips-dsgr] ASWFC Daily Report - 26 April 25 issued 2331 UT on 26 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Apr 27 09:31:05 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 APRIL AND FORECAST FOR 27 APRIL - 29 APRIL
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Apr: 156/110
1B. SOLAR FORECAST
27 Apr 28 Apr 29 Apr
Activity R0, chance R1 R0, chance R1 R0, chance R1
Fadeouts None expected None expected None expected
10.7cm/SSN 155/109 150/105 145/99
COMMENT: Solar activity on UT day 26-Apr was at the R0 level,
with several low level C-class flares observed. There are currently
ten numbered sunspot regions visible on the solar disk. AR4064
(N11W54, beta) is the largest region on the disk and has shown
decay in its intermediate spots. AR4072 (N06E52, beta) has exhibited
mild growth in its trailer spots. All other sunspot regions are
either stable or in decay. Solar activity is expected to be at
the R0 level over 27-29 Apr, with a chance of R1. Several CMEs
were observed, but none are considered geoeffective. The solar
wind speed on UT day 26-Apr declined, ranging from 395 to 490
km/s and is currently near 400 km/s. The peak total interplanetary
magnetic field strength (IMF, Bt) was 9 nT and the north-south
IMF component (Bz) range was -5 to +6 nT. The solar wind speed
may moderately increase over 27-28 Apr, then decline on 29-Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 Apr: G0
Estimated Indices 26 Apr : A K
Australian Region 4 21121111
Cocos Island 3 22111110
Darwin 4 22121111
Townsville 5 22121112
Learmonth 4 21221110
Alice Springs 3 11121101
Gingin 4 21122110
Canberra 4 12032101
Kennaook Cape Grim 4 11132101
Hobart 5 21132101
Estimated Antarctic Regional K Indices 26 Apr :
Macquarie Island 6 11043000
Casey 11 44322111
Mawson 11 33222224
Observed Regional daily pc3 Indices 26 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 11 (Quiet)
Hobart 11 (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 26 Apr : A
Fredericksburg 7
Planetary 7
Observed AFr/Ap Indices 25 Apr : A K
Fredericksburg 5
Planetary 0 ---- ----
2B. MAGNETIC FORECAST
Date Ap Conditions
27 Apr 15 G0
28 Apr 12 G0
29 Apr 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 26-Apr. G0 geomagnetic conditions
are expected over 27-29 Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
27 Apr Normal Normal Normal-fair
28 Apr Normal Normal Normal-fair
29 Apr Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 26-Apr were
mostly normal. HF radio propagation conditions are expected to
be mostly normal over 27-29 Apr with fair conditions at times
for high latitudes.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 Apr 123
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 35% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 25% 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
27 Apr 125 Near predicted monthly values
28 Apr 125 Near predicted monthly values
29 Apr 125 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 26-Apr were near predicted monthly values to
25% enhanced in northern Australian regions. Spread F was observed
at Hobart during local night hours. Ionospheric scintillation
was observed at Darwin and Weipa over the interval 26/1121-1510UT.
MUFs are expected to be near predicted monthly values over 27-29
Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 Apr
Daily Proton Fluence >1 MeV: 6.4E+05
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 3.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.0
DSCOVR Satellite Solar Wind Day Averaged Data for 25 Apr
Speed: 490 km/sec Density: 1.5 p/cc Temp: 150000 K Bz: 4 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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