[Ips-dsgr] ASWFC Daily Report - 11 July 25 issued 2332 UT on 11 Jul 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Jul 12 09:32:19 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 JULY AND FORECAST FOR 12 JULY - 14 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 11 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Jul: 132/86
1B. SOLAR FORECAST
12 Jul 13 Jul 14 Jul
Activity R1 R1 R1
Fadeouts Possible Possible Possible
10.7cm/SSN 135/89 135/89 135/89
COMMENT: Solar activity on UT day 11-Jul was R0, with no significant
flare activity observed. Solar regions AR4138 (N29W10, beta),
AR4139 (N22E26, beta), AR4140 (S14E77, beta) produced C class
flare activity with the largest flare a C8.0 at 11/1709UT from
region AR4138. Solar region AR4136 (N19E43, beta-gamma-delta)
whilst being the largest and most magnetically complex region
produced little X-ray flare activity and may now be in initial
decay, with growth in penumbral area in its trailer spots and
decay in its small intermediate spots. Smaller solar region AR4139
showed rapid growth over the past 24 hours. All other sunspot
regions are either stable or in decay. There are currently six
numbered solar regions on the visible solar disk. A 20 degree
long solar filament located at N25W05 visible in GONG H-alpha
imagery slowly disappeared during the interval 10/1800-11/0400UT,
with minor motion visible in SDO 193 imagery. Solar activity
is expected to be R1 over 12-14 Jul. No Earth directed CMEs were
observed on UT day 11-Jul. No CME appeared to be associated with
the very slow on disk filament lift off. A southeast CME was
observed from 11/0924UT associated with southeast limb plasma
eruptions and is not considered to be Earth directed. In STEREO-A
a sequence of south southwest CMEs were observed over the past
24 hours that could not be correlated to on disk activity. S0
solar radiation storm conditions were observed on UT day 11-Jul.
S0 solar radiation storm conditions are expected over 12-14 Jul.
A large coronal hole is in the southern solar hemisphere with
a narrow transequatorial northward extension of this hole now
west of the solar central meridian. The solar wind speed increased
on 11-Jul due to a possible combination of a very weak CME arrival
from a recent north directed filament eruption and the Earth's
entry into a coronal hole wind stream, with an abrupt increase
in wind speed observed at 11/0440UT. The solar wind speed ranged
from 475 to 340 km/s, and is currently at 445 km/sec. The total
interplanetary field strength (IMF, Bt) was 13 nT and the north-south
IMF component range (Bz) was +11 to -11 nT. The IMF Bz component
was mildly southward 11/0500-1000UT. The solar wind is expected
to remain moderately enhanced today due to the ongoing influence
of the coronal hole wind stream.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 11 Jul: G0
Estimated Indices 11 Jul : A K
Australian Region 10 22233232
Cocos Island 8 23232122
Darwin 11 22233233
Townsville 9 22233222
Learmonth 12 22333233
Alice Springs 10 22233232
Gingin 13 22343133
Canberra 8 12233222
Kennaook Cape Grim 10 11243232
Hobart 10 11243232
Estimated Antarctic Regional K Indices 11 Jul :
Macquarie Island 15 01354232
Casey 10 13332132
Mawson 19 04443334
Observed Regional daily pc3 Indices 11 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 7 (Quiet)
Hobart 25 (Quiet to unsettled)
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 11 Jul : A
Fredericksburg 15
Planetary 18
Observed AFr/Ap Indices 10 Jul : A K
Fredericksburg 6
Planetary 6 1111 1111
2B. MAGNETIC FORECAST
Date Ap Conditions
12 Jul 16 G0-G1
13 Jul 19 G1. chance G2
14 Jul 16 G0-G1
COMMENT:
ASWFC Geomagnetic Warning 53 was issued on 11 July and is current
for 11-12 Jul.
Observations:
G0 geomagnetic conditions were observed in the Australian region on
UT day 11-Jul. G0-G1 conditions were observed in the Antarctic region.
Forecast:
G1 periods are possible over 12-14 Jul due to the influence of a
coronal hole wind stream. There is a chance for a very weak CME arrival
on 13-Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
11 Jul Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
12 Jul Normal Fair-normal Fair
13 Jul Normal Fair-normal Fair
14 Jul Normal Normal Fair-normal
COMMENT: HF radio propagation conditions on UT day 11-Jul were
fair to normal. HF radio propagation conditions are expected
to be fair at middle to high latitudes over 12-13 Jul, due to
an anticipated mild increase in geomagnetic activity from a coronal
hole wind stream. HF conditions in the polar regions may be poor
at times. Isolated minor shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
11 Jul 76
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20% during local day.
Depressed by 20% during local night.
Depressed by 25% after local dawn.
Niue Island Region:
Depressed by 15% during local day.
Depressed by 35% during local night.
Northern Australian Region:
Depressed by 20% during local day.
Depressed by 20% during local night.
Depressed by 25% after local dawn.
Southern Australian Region:
Depressed 15% to near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jun 79
Jul 104
Aug 102
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
12 Jul 75 Depressed 15 to 20%/near predicted monthly values
13 Jul 75 Depressed 15 to 20%/near predicted monthly values
14 Jul 75 Depressed 15 to 20%/near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 11-Jul were 25% depressed to near predicted
monthly values, with depressed conditions in the the northern
Australian region. Spread F was observed during local night hours
at Townsville, Learmonth, Perth and Hobart. MUFs are expected
to be 15-20% depressed to near predicted monthly values over
12-14 Jul. Degraded HF conditions are expected during local night
hours due to mild geomagnetic activity induced by a coronal hole
wind stream. Isolated minor shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 10 Jul
Daily Proton Fluence >1 MeV: 1.8E+06
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 1.30E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 10 Jul
Speed: 382 km/sec Density: 1.4 p/cc Temp: 39100 K Bz: 1 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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