[Ips-dsgr] ASWFC Daily Report - 17 June 25 issued 2330 UT on 17 Jun 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Jun 18 09:30:52 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 JUNE 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 JUNE AND FORECAST FOR 18 JUNE - 20 JUNE
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Jun: R3
Flares Max Fadeout Freq. Sectors
X1.2 2149UT probable all East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Jun: 139/93
1B. SOLAR FORECAST
18 Jun 19 Jun 20 Jun
Activity R1, chance R2-R3 R1, chance R2-R3 R1, chance R2-R3
Fadeouts Possible Possible Possible
10.7cm/SSN 150/105 150/105 150/105
COMMENT: Solar activity on UT day 17-Jun was R3, with an isolated
X1 flare from AR4114 (N16W13, beta-gamma-delta). AR4114 has shown
some changes over the past day, with some of its delta spots
weakening but growing some new delta spots. AR4114 remains the
most complex region on the disk. All other sunspots are either
stable or in decay. Solar activity is expected to be R1 with
a chance for R2-R3 over 18-20 Jun.
Several CMEs were observed on UT day 17-Jun, although no CME has
been confirmed associated with the R3 event at time of writing.
A CME originating from near AR4114 was observed from 0048 UT, and
may have a glancing blow to Earth early on 20-Jun. The other CMEs
are not considered to be geoeffective.
S0 solar radiation storm conditions were observed on UT day 17-Jun.
S0 solar radiation storm conditions are expected over 18-20 Jun.
The solar wind environment on UT day 17-Jun was mostly steady.
The solar wind speed ranged from 525 to 442 km/s. The peak total
interplanetary field strength (IMF, Bt) was 8 nT and the north-south
IMF component range was +7 to -5 nT. The solar wind may become
enhanced on 18-Jun due to stronger connection to the large coronal
hole in the southern solar hemisphere and a graze from a recent CME.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 Jun: G0
Estimated Indices 17 Jun : A K
Australian Region 5 12111222
Cocos Island 3 11111121
Darwin 7 23111223
Townsville 6 22111223
Learmonth 7 12212232
Alice Springs 4 12101122
Gingin 6 12112232
Canberra 4 12111122
Kennaook Cape Grim 4 12111122
Hobart 5 12112221
Estimated Antarctic Regional K Indices 17 Jun :
Macquarie Island 3 11022201
Casey 8 23221123
Mawson 17 24322353
Observed Regional daily pc3 Indices 17 Jun :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 4 (Quiet)
Hobart 2 (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 17 Jun : A
Fredericksburg 8
Planetary 10
Observed AFr/Ap Indices 16 Jun : A K
Fredericksburg 0
Planetary 0 2242 2222
2B. MAGNETIC FORECAST
Date Ap Conditions
18 Jun 16 G0-G1
19 Jun 10 G0-G1
20 Jun 16 G0-G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 17-Jun. G0-G1 geomagnetic conditions were observed
in the Antarctic region. G0-G1 geomagnetic conditions are expected
over 18-20 Jun. A large coronal hole in the southern solar hemisphere
may intermittently connect with Earth over this period, and a
glancing blow from a CME is expected on 18-Jun and again on 20-Jun.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
17 Jun Normal-fair Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
18 Jun Normal-fair Normal-fair Fair
19 Jun Normal-fair Normal-fair Fair
20 Jun Normal-fair Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 17-Jun were
normal during daytime hours but mildly degraded during nighttim
hours, especially for high latitudes. HF radio propagation conditions
are expected to be normal during daytime hours over 18-20 Jun,
but degraded during nighttime hours.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
17 Jun 85
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20% during local day.
Depressed by 20% during local night.
Niue Island Region:
Near predicted monthly values during local day.
Depressed by 40% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 30% during local night.
Depressed by 25% after local dawn.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
May 94
Jun 109
Jul 107
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
18 Jun 85 Near predicted monthly values to 10-20% depressed
19 Jun 85 Near predicted monthly values to 10-20% depressed
20 Jun 85 Near predicted monthly values to 10-20% depressed
COMMENT: ASWFC SWF HF Communications Warning 66 was issued on
16 June and is current for 17-19 Jun. Maximum usable frequencies
(MUFs) in the Australian region were depressed up to 30% during
local night hours. Conditions were normal during daytime hours,
however were heavily degraded during nighttime at most sites.
MUFs are expected to be near predicted values during local daytime
hours, but may experience similar depressions up to 20% during
nighttime over 18-20 Jun.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 16 Jun
Daily Proton Fluence >1 MeV: 1.2E+05
Daily Proton Fluence >10 MeV: 1.7E+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: C2.2
DSCOVR Satellite Solar Wind Day Averaged Data for 16 Jun
Speed: 464 km/sec Density: 2.1 p/cc Temp: 152000 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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