[Ips-dsgr] ASWFC Daily Report - 23 April 25 issued 2331 UT on 23 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Apr 24 09:31:08 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 APRIL AND FORECAST FOR 24 APRIL - 26 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 23 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Apr: 167/121
1B. SOLAR FORECAST
24 Apr 25 Apr 26 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 160/114 165/119 165/119
COMMENT: Solar activity on UT day 23-Apr was R0. Solar region
AR4064 (N11W16, beta-gamma) is currently the largest and most
complex region on the visible solar disk. This medium sized region
is growing with intermediate spot development evident. Solar
region AR4070 (S13E31, beta) is also growing, though this region
currently has a more simple bipole magnetic configuration. Solar
region AR4062 (S03W40, alpha) is a stable simple monopole. Other
regions are quite small and magnetically simple. The largest
flare was a C3.9 at 23/1455UT from region AR4064. There are currently
eight numbered sunspot regions on the solar disk, with a small
spot emerging on disk at N12E57. No solar filament eruptions
have been observed. Solar activity is expected to be R0-R1 over
24-26 Apr. No Earth directed CMEs have been observed. A southwest
CME was observed from 23/0800UT and is considered to be far side
due to the lack of any on disk plasma motion/flare activity.
S0 solar radiation storm conditions were observed on UT day 23-Apr.
S0 solar radiation storm conditions are expected over 24-26 Apr.
The solar wind speed was strong with an initial declining trend
then a slight increase toward the end of the UT day and ranged
from 458 km/s to 583 km/s and is currently near 534 km/s. The
peak total interplanetary field strength (IMF, Bt) was 9 nT and
the north-south IMF component range (Bz) was +6 to -4 nT. The
solar wind speed is expected to remain mostly elevated over 24-25
Apr, due to a large coronal hole in the southern solar hemisphere.
Due to the shape of this coronal hole the solar wind speed may
decrease and then subsequently increase again. A small CME impact
is possible on late 24-Apr.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 23 Apr: G0
Estimated Indices 23 Apr : A K
Australian Region 4 12122111
Cocos Island 2 12121000
Darwin 6 22222112
Townsville 6 22222122
Learmonth 5 22222011
Alice Springs 3 11122101
Gingin 4 11222011
Canberra 4 12122101
Kennaook Cape Grim 4 11122111
Hobart 3 11122101
Estimated Antarctic Regional K Indices 23 Apr :
Macquarie Island 7 12143110
Casey 11 34323112
Mawson 12 22343223
Observed Regional daily pc3 Indices 23 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 17 (Quiet)
Alice Springs 0 (Quiet)
Gingin 20 (Quiet)
Canberra 43 (Unsettled)
Hobart 12 (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 23 Apr : A
Fredericksburg 15
Planetary 17
Observed AFr/Ap Indices 22 Apr : A K
Fredericksburg 13
Planetary 13 4332 2233
2B. MAGNETIC FORECAST
Date Ap Conditions
24 Apr 15 G0, chance G1
25 Apr 12 G0, chance G1
26 Apr 10 G0
COMMENT: G0 Geomagnetic conditions were observed in the Australian
and Antarctic region on UT day 23-Apr. G0, chance G1 conditions
are expected over 24-25 Apr due to the ongoing influence of a
coronal hole wind stream and a possible weak glancing blow from
a CME first seen on 22-Apr that may arrive late on 24-Apr.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
23 Apr Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
24 Apr Normal Fair-normal Fair
25 Apr Normal Fair-normal Fair
26 Apr Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 23-Apr were
fair to normal with fair conditions at middle to high latitudes.
HF radio propagation conditions are expected to be over fair
to normal over 24-25 Apr at middle to high latitudes with an
improving trend.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
23 Apr 121
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20-40%.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Mostly 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 126
Apr 115
May 113
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
24 Apr 115 Near predicted monthly values
25 Apr 115 Near predicted monthly values
26 Apr 115 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 23-Apr were near predicted monthly values. Spread
F was observed at Hobart and Canberra during local night hours.
MUFs are expected to be near predicted values over 24-26 Apr.
Degraded HF conditions may be experienced during local night
hours for the southern region Australian during 24-25 Apr.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 22 Apr
Daily Proton Fluence >1 MeV: 3.2E+06
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 2.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 22 Apr
Speed: 619 km/sec Density: 1.8 p/cc Temp: 202000 K Bz: 0 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list