[Ips-dsgr] ASWFC Daily Report - 29 May 25 issued 2330 UT on 29 May 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri May 30 09:30:54 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 MAY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 MAY AND FORECAST FOR 30 MAY - 01 JUNE
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 29 May: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 29 May: 145/99
1B. SOLAR FORECAST
30 May 31 May 01 Jun
Activity R1-R2 R1-R2 R1-R2
Fadeouts Possible Possible Possible
10.7cm/SSN 138/92 135/89 135/89
COMMENT: Solar activity on UT day 29-May was at the R0 level,
with no significant flaring activity. There are currently five
numbered sunspot regions visible on the solar disk. AR4100 (N07E29,
beta-gamma-delta) is the largest region on the disk and has exhibited
spot development over the UT day. AR4099 (S14E15, beta-gamma-delta)
has shown decay in its leader spots and mild growth in its trailer
spots. AR4092 (S14W68, beta) has developed trailer spots over
the 24-hour period. AR4101 (N03E18, beta) has shown spot growth.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be at R1-R2 levels over 30-May to 01-Jun.
No Earth-directed CMEs have been observed. The solar wind speed
on UT day 29-May increased, ranging from 455 to 785 km/s and
is currently near 740 km/s. The increase in solar wind speed
was likely due to Earth's entry into a corotating interaction
region (CIR). The peak total interplanetary magnetic field strength
(IMF, Bt) was 25 nT and the north-south IMF component (Bz) range
was -25 to +13 nT. A sustained period of strongly southward IMF
conditions was observed over the interval 28/2348UT to 29/0101UT.
Several other short periods of southward IMF conditions were
observed over the UT day. The solar wind speed is expected to
remain elevated over 30-May to 01-Jun due to coronal hole high
speed wind stream effects from an equatorial coronal hole.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 29 May: G1
Estimated Indices 29 May : A K
Australian Region 33 53544544
Cocos Island 19 43343433
Darwin 30 53544444
Townsville 25 53444433
Learmonth 36 53554544
Alice Springs 34 53554543
Gingin 44 63554644
Canberra 31 53544543
Kennaook Cape Grim 40 53645544
Hobart 40 43655544
Estimated Antarctic Regional K Indices 29 May :
Macquarie Island 78 54866654
Casey 42 44553565
Mawson 100 75564876
Observed Regional daily pc3 Indices 29 May :
Darwin 9 (Quiet)
Townsville 2 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 6 (Quiet)
Gingin 53 (Unsettled)
Canberra 65 (Active)
Hobart 100 (Minor storm)
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 May : A
Fredericksburg 40
Planetary 69
Observed AFr/Ap Indices 28 May : A K
Fredericksburg 0
Planetary 0 ---- ----
2B. MAGNETIC FORECAST
Date Ap Conditions
30 May 24 G1, chance of G2
31 May 18 G0-G1
01 Jun 12 G0
COMMENT: ASWFC Geomagnetic Warning 39 was issued on 28 May and
is current for 28-30 May. G1 geomagnetic conditions were observed
in the Australian region on UT day 29-May, with isolated periods
of G2 observed at Gingin, Kennaook Cape Grim and Hobart. G3 planetary
geomagnetic conditions were observed. Mostly G2-G3 geomagnetic
conditions were observed in the Antarctic region, with isolated
periods of G4 observed at Mawson and Macquarie Island. Geomagnetic
activity was due to Earth's entry into a corotating interaction
region (CIR). G1 geomagnetic conditions are expected on 30-May,
with a chance of G2 due to the combined effects of a coronal
hole high speed wind stream and ongoing effects from a CIR. G0-G1
geomagnetic conditions are expected on 31-May. G0 geomagnetic
conditions are expected on 01-Jun.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
29 May Normal-fair Normal-fair Fair-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
30 May Normal Normal-fair Fair
31 May Normal Normal-fair Fair
01 Jun Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 29-May were
normal to fair. HF radio propagation conditions are expected
to be normal to fair over 30-May to 01-Jun. Shortwave fadeouts
are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
29 May 96
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 15% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 30% over the UT day.
Monthly T index:
Month T index
Apr 123
May 113
Jun 111
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
30 May 95 Near predicted monthly values
31 May 95 Near predicted monthly values
01 Jun 95 Near predicted monthly values
COMMENT: ASWFC HF Communications Warning 54 was issued on 28
May and is current for 28-30 May. ASWFC SWF HF Communications
Warning 55 was issued on 28 May and is current for 28-30 May.
Maximum usable frequencies (MUFs) in the Australian region on
UT day 29-May were near predicted monthly values to 15-20% depressed.
Spread F was observed at Hobart during local night hours. MUFs
are expected to be near predicted monthly values over 30-May
to 01-Jun. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 28 May
Daily Proton Fluence >1 MeV: 2.5E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 1.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.5
DSCOVR Satellite Solar Wind Day Averaged Data for 28 May
Speed: 511 km/sec Density: 3.5 p/cc Temp: 194000 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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