[Ips-dsgr] ASWFC Daily Report - 29 April 25 issued 2330 UT on 29 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Apr 30 09:31:00 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 APRIL AND FORECAST FOR 30 APRIL - 02 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 29 Apr: R1
Flares Max Fadeout Freq. Sectors
M1.7 0513UT possible lower E. Asia/Aust.
M1.3 1003UT possible lower European
M1.6 1057UT possible lower European
Observed 10.7 cm flux/Equivalent Sunspot Number for 29 Apr: 149/104
1B. SOLAR FORECAST
30 Apr 01 May 02 May
Activity R1 R1 R1
Fadeouts Possible Possible Possible
10.7cm/SSN 155/109 160/114 165/119
COMMENT: Solar activity on UT day 29-Apr was at the R1 level.
A very small solar region AR4078 (N15W56, beta) produced two
of the M1 flares and AR4079 (N05E63, beta) the largest on disk
region, contributed a single M1 flare. Trailer spots have now
followed AR4079's large double umbra leader spot onto the disk.
This region is still close to the eastern solar limb making assessment
of the regions development difficult, but there may be slight
development in penumbral area around the leader spot. More minor
C class flares were produced by AR4079 and AR4078, with the largest
C class flare a C5.3 at 29/1505UT from AR4079. The very small
flaring region AR4078 showed initial growth then decay toward
the end of the UT day, unless spot redevelopment occurs further
flare activity seems unlikely from this small region. Solar region
AR4076 (N06E08, alpha) is the second largest on disk region and
consists of a stable single monopole. Other regions are quite
small, of the more notable of these small regions AR4070 (S13W47,
beta) exhibited a mixture of growth and decay and AR4072 (S17W09,
beta) is in overall decay. There are currently eight numbered
sunspot regions visible on the solar disk. All other sunspot
regions are small and either stable or in decay. Solar activity
is expected to be at the R1 level over 30-Apr to 02-May, primarily
due to AR4079. S0 solar radiation storm conditions were observed
on UT day 29-Apr. S0 solar radiation storm conditions are expected
over 30-Apr to 02-May. No Earth directed CMEs have been observed.
However, there was a large data gap during the interval 29/0724-2000UT
in the available LASCO imagery. A northwest directed CME was
in progress at the start of the UT day visible in STEREO-A and
LASCO imagery and is considered a continuation of the northwest
CME observed yesterday, which was assessed as far side. The solar
wind speed on UT day 29-Apr slightly increased, ranging from
350 to 450 km/s and is currently near 450 km/s. The peak total
interplanetary magnetic field strength (IMF, Bt) was 9 nT and
the north-south IMF component (Bz) range was -8 to +8 nT. A small
coronal hole located in the northern solar hemisphere, just west
of the solar central meridian may mildly increase the solar wind
speed during 01-02 May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 29 Apr: G0
Estimated Indices 29 Apr : A K
Australian Region 4 02221111
Cocos Island 4 12211111
Darwin 5 12221121
Townsville 4 02221111
Learmonth 5 12221211
Alice Springs 3 02211111
Gingin 4 02320111
Canberra 2 02210011
Kennaook Cape Grim 3 02220011
Hobart 3 12210011
Estimated Antarctic Regional K Indices 29 Apr :
Macquarie Island 2 01210010
Casey 8 23421012
Mawson 9 13332122
Observed Regional daily pc3 Indices 29 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 0 (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 29 Apr : A
Fredericksburg 6
Planetary 7
Observed AFr/Ap Indices 28 Apr : A K
Fredericksburg 5
Planetary 4 3111 1111
2B. MAGNETIC FORECAST
Date Ap Conditions
30 Apr 9 G0
01 May 15 G0, chance G1
02 May 15 G0, chance G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 29-Apr. G0 geomagnetic conditions
are generally expected over 30-Apr to 02-May, with a mild increase
in geomagnetic activity during 01-02 May due to a coronal hole
wind stream.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
29 Apr Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
30 Apr Normal Normal Normal-fair
01 May Normal Normal Normal-fair
02 May Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 29-Apr were
mostly normal, with fair conditions at middle to high latitudes.
HF radio propagation conditions are expected to be mostly normal
over 30-Apr to 02-May. HF conditions at middle to high latitudes
are expected to fair over 01-02 May due to 27 recurrent geomagnetic
activity patterns. Isolated minor fadeouts possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
29 Apr 119
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Near predicted monthly values.
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
Mar 126
Apr 115
May 113
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
30 Apr 125 Near predicted monthly values
01 May 125 Near predicted monthly values
02 May 125 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 42 was issued on
29 April and is current for 29 Apr to 1 May. Maximum usable frequencies
(MUFs) in the Australian region on UT day 29-Apr were near predicted
monthly values. Spread F was observed at Hobart during local
night hours. MUFs are expected to be near predicted monthly values
over 30-Apr to 02-May. Southern Australian region HF conditions
may become mildly degraded during local night hours 01-02 May.
Isolated minor fadeouts possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 28 Apr
Daily Proton Fluence >1 MeV: 4.4E+05
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 2.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 28 Apr
Speed: 388 km/sec Density: 3.0 p/cc Temp: 53700 K Bz: 3 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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