[Ips-dsgr] ASWFC Daily Report - 18 July 25 issued 2332 UT on 18 Jul 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Jul 19 09:32:26 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 JULY AND FORECAST FOR 19 JULY - 21 JULY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 18 Jul: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Jul: 156/110
1B. SOLAR FORECAST
19 Jul 20 Jul 21 Jul
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 155/109 150/105 150/105
COMMENT: Solar activity on UT day 18-Jul was R0, with no solar
flares. There are currently ten numbered sunspot regions on the
solar disk. AR4136 (N19W53, beta-gamma) shown some overall decay,
although some complexity is developing in it's leading spot.
AR4142 (N01W04, beta) showed maturation although increased in
size. All other sunspot regions are either stable or in decay.
Solar activity is expected to be R0-R1 over 19-21 Jul.
No Earth directed CMEs were observed on UT day 18-Jul.
S0 solar radiation storm conditions were observed on UT day 18-Jul.
S0 solar radiation storm conditions are expected over 19-21 Jul.
The solar wind environment on UT day 18-Jul was mildly elevated but
steady due to ongoing coronal hole effects. The solar wind speed ranged
from 418 to 630 km/s. The peak total interplanetary field strength
(IMF, Bt) was 7 nT and the north-south IMF component range (Bz)
was +6 to -6 nT. The solar wind environment is expected to begin
a slow decline to background conditions over 19-21 Jul.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 18 Jul: G0
Estimated Indices 18 Jul : A K
Australian Region 7 11233211
Cocos Island 5 11123210
Darwin 9 22233222
Townsville 8 22233212
Learmonth 8 12233221
Alice Springs 5 11132211
Gingin 7 12223221
Canberra 5 11132211
Kennaook Cape Grim 6 11232211
Hobart 6 11232211
Estimated Antarctic Regional K Indices 18 Jul :
Macquarie Island 11 11244321
Casey 13 33333232
Mawson 18 43334333
Observed Regional daily pc3 Indices 18 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 4 (Quiet)
Canberra 2 (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 18 Jul : A
Fredericksburg 10
Planetary 12
Observed AFr/Ap Indices 17 Jul : A K
Fredericksburg 14
Planetary 19 4444 4432
2B. MAGNETIC FORECAST
Date Ap Conditions
19 Jul 11 G0
20 Jul 9 G0
21 Jul 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 18-Jul. Mostly G0 geomagnetic
conditions are expected over 19-21 Jul.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
18 Jul Normal-fair Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
19 Jul Normal Normal Normal-fair
20 Jul Normal Normal Normal-fair
21 Jul Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 18-Jul were
mixed, with mild degradations widespread. Enhanced ionospheric
conditions were observed in the southern hemisphere and depression
conditions were observed in the northern hemisphere. Ionospheric
conditions are expected to be mostly normal over 19-21 Jul.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
18 Jul 98
Observed Australian Regional MUFs
Cocos Island Region:
Mostly near predicted monthly values.
Depressed by 20% after local dawn.
Niue Island Region:
Enhanced by 30% during local day.
Enhanced by 30% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 15% 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
19 Jul 82 Depressed 10 to 15%/near predicted monthly values
20 Jul 85 Depressed 10 to 15%/ near predicted monthly values
21 Jul 90 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region were near predicted values to 15% depressed. Conditions
were degraded across all Australian sites during local dusk and
nighttime hours, with significant sporadic-E at many stations.
Scintillation was observed at Niue from 0834 to 0850 UT. MUFs
are expected to be near predicted values to 15% depressed over
19-20 Jul before returning to near normal. Degraded conditions
are likely to ease.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 17 Jul
Daily Proton Fluence >1 MeV: 9.2E+05
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 2.20E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:16%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 17 Jul
Speed: 636 km/sec Density: 0.2 p/cc Temp: 218000 K Bz: -1 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list