[Ips-dsgr] ASWFC Daily Report - 27 April 25 issued 2331 UT on 27 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Apr 28 09:31:17 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 APRIL AND FORECAST FOR 28 APRIL - 30 APRIL
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Apr: 156/110
1B. SOLAR FORECAST
28 Apr 29 Apr 30 Apr
Activity R0, chance R1 R0, chance R1 R0, chance R1
Fadeouts None expected None expected None expected
10.7cm/SSN 150/105 145/99 140/94
COMMENT: Solar activity on UT day 27-Apr was at the R0 level,
with several low level C-class flares observed. There are currently
eight numbered sunspot regions visible on the solar disk. AR4070
(S13W23, beta) is the largest region on the disk and has exhibited
spot development in its intermediate spots over the UT day. AR4064
(N11W68, beta) has shown decay 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 28-30 Apr, with a chance
of R1. No Earth-directed CMEs have been observed. The solar wind
speed on UT day 27-Apr declined, ranging from 345 to 435 km/s
and is currently near 385 km/s. The peak total interplanetary
magnetic field strength (IMF, Bt) was 10 nT and the north-south
IMF component (Bz) range was -7 to +8 nT. The solar wind speed
is expected to decline over 28-30 Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Apr: G0
Estimated Indices 27 Apr : A K
Australian Region 3 12110211
Cocos Island 3 12111110
Darwin 6 22211222
Townsville 5 22111222
Learmonth 5 22211220
Alice Springs 3 12210111
Gingin 4 22210210
Canberra 2 02100211
Kennaook Cape Grim 2 12100111
Hobart 3 12100211
Estimated Antarctic Regional K Indices 27 Apr :
Macquarie Island 1 01000110
Casey 7 23321111
Mawson 12 33311234
Observed Regional daily pc3 Indices 27 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (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 27 Apr : A
Fredericksburg 7
Planetary 8
Observed AFr/Ap Indices 26 Apr : A K
Fredericksburg 7
Planetary 7 ---- ----
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Apr 12 G0
29 Apr 8 G0
30 Apr 6 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 27-Apr. G0 geomagnetic conditions
are expected over 28-30 Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Apr Normal Normal Normal-fair
29 Apr Normal Normal Normal-fair
30 Apr Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 27-Apr were
mostly normal. HF radio propagation conditions are expected to
be mostly normal over 28-30 Apr with fair conditions at times
for high latitudes.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 Apr 122
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values 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
28 Apr 125 Near predicted monthly values
29 Apr 125 Near predicted monthly values
30 Apr 125 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 27-Apr were near predicted monthly values to
15% 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 28-30 Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 Apr
Daily Proton Fluence >1 MeV: 5.3E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 5.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.5
DSCOVR Satellite Solar Wind Day Averaged Data for 26 Apr
Speed: 434 km/sec Density: 2.1 p/cc Temp: 101000 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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