[Ips-dsgr] ASWFC Daily Report - 27 July 25 issued 2332 UT on 27 Jul 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Jul 28 09:32:08 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 JULY AND FORECAST FOR 28 JULY - 30 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Jul: 145/99
1B. SOLAR FORECAST
28 Jul 29 Jul 30 Jul
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 145/99 140/94
COMMENT: Solar activity on UT day 27-Jul was at the R0 level,
with several low C-class flares. There are currently nine numbered
sunspot regions on the solar disk and one unnumbered region.
There are no magnetically complex regions currently on the solar
disk and all visible regions have no significant flaring history.
An unnumbered sunspot region has emerged on the solar disk at
around N11E03 with beta magnetic complexity. All sunspot regions
are either stable or in decay. Solar activity is expected to
be at the R0 level, with a chance of R1 over 28-30 Jul. S0 solar
radiation storm conditions were observed on UT day 27-Jul. S0
solar radiation storm conditions are expected over 28-30 Jul.
No Earth directed CMEs were observed on UT day 27-Jul. A faint,
north east directed CME is visible in SOHO and STEREO-A imagery
from 27/1212UT. This CME is likely associated with an eruption
behind the northeast limb, visible in SDO, GOES SUVI and H-Alpha
imagery from 27/1125UT at around N30. This CME is not considered
geoeffective. The solar wind speed on UT day 27-Jul was in decline.
The solar wind speed mostly ranged between 410 km/s and 530 km/s
and is currently at around 415 km/s. The peak total interplanetary
field strength (IMF, Bt) was 11 nT and the north-south IMF component
range (Bz) was +10 to -0 nT. The solar wind speed is expected
to remain near background levels over 28-30 Jul. There is a chance
of an increase on 30-Jul due to high speed wind stream effects
from a coronal hole in the northern hemisphere approaching a
geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Jul: G0
Estimated Indices 27 Jul : A K
Australian Region 2 11120100
Cocos Island 1 11110100
Darwin 4 22120111
Townsville 3 21120111
Learmonth 3 21220110
Alice Springs 1 01110100
Gingin 1 20110000
Canberra 1 01110000
Kennaook Cape Grim 2 11120001
Hobart 2 11120000
Estimated Antarctic Regional K Indices 27 Jul :
Macquarie Island 0 00000000
Casey 6 32311110
Mawson 4 22210111
Observed Regional daily pc3 Indices 27 Jul :
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 27 Jul : A
Fredericksburg 7
Planetary 9
Observed AFr/Ap Indices 26 Jul : A K
Fredericksburg 11
Planetary 12 ---- ----
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Jul 5 G0
29 Jul 5 G0
30 Jul 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 27-Jul. G0 geomagnetic conditions
are expected over 28-30 Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Jul Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Jul Normal Normal Normal
29 Jul Normal Normal Normal
30 Jul Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 27-Jul were
generally normal, with periods of fair conditions in the northern
hemisphere and at high latitudes. HF radio propagation conditions
are expected to be mostly normal over 28-30 Jul.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 Jul 98
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 35% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
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
Jun 79
Jul 104
Aug 102
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
28 Jul 100 Near predicted monthly values
29 Jul 100 Near predicted monthly values
30 Jul 100 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 27-Jul were
mostly near predicted monthly values, with some enhancements
in the northern Australian region during local night. Spread
F was observed at Hobart and Brisbane during local night hours.
MUFs are generally expected to be near predicted monthly values
over 28-30 Jul.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 Jul
Daily Proton Fluence >1 MeV: 5.4E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 1.20E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B7.1
DSCOVR Satellite Solar Wind Day Averaged Data for 26 Jul
Speed: 519 km/sec Density: 1.8 p/cc Temp: 111000 K Bz: 2 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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