[Ips-dsgr] ASWFC Daily Report - 19 August 26 issued 2330 UT on 19 Aug 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Aug 20 09:30:51 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 AUGUST 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 AUGUST AND FORECAST FOR 20 AUGUST - 22 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Aug: R1
Flares Max Fadeout Freq. Sectors
M1.0 1851UT possible lower E. Asia/Aust.
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Aug: 126/79
1B. SOLAR FORECAST
20 Aug 21 Aug 22 Aug
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 125/78 125/78 125/78
COMMENT: Solar flare activity on UT day 19-Aug was at the R1
level due to an M1.0 flare at 19/1851UT produced by Active Region
(AR) 4513 (N04E75, beta) near the eastern limb. There are currently
four numbered sunspot regions visible on the solar disk and one
unnumbered region. AR 4507 (N05W66, beta) is the largest region
on the disk and has shown decay in its trailer spots. Region
4513 recently rotated over the eastern limb and appears stable.
An unnumbered region recently appeared near S12W41 (beta) and
has shown spot growth. All other regions are either stable or
in decay. Solar flare activity is expected to be at R0-R1 levels
over 20-22 Aug due to the observed flare activity from AR 4513.
S0 solar radiation storm conditions were observed on UT day 19-Aug.
S0 solar radiation storm conditions are expected over 20-22 Aug.
No Earth-directed coronal mass ejections (CMEs) have been observed.
The solar wind speed on UT day 19-Aug was mostly steady, ranging
between 535 and 615 km/s, and is currently near 590 km/s. The
peak total interplanetary magnetic field strength (IMF, Bt) was
10 nT and the north-south IMF component (Bz) range was -8 to
+7 nT. The solar wind speed is expected to remain elevated over
20-22 Aug due to coronal hole high speed wind stream effects
from a northern hemisphere coronal hole.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 Aug: G0
Estimated Indices 19 Aug : A K
Australian Region 12 24342122
Cocos Island 9 24331011
Darwin 12 24342122
Townsville 12 24342122
Learmonth 14 24342223
Alice Springs 11 14342112
Gingin 13 24342222
Canberra 13 13352122
Kennaook Cape Grim 15 24352222
Hobart 15 24352212
Estimated Antarctic Regional K Indices 19 Aug :
Macquarie Island 27 24472211
Casey 17 35431223
Mawson 42 36553265
Observed Regional daily pc3 Indices 19 Aug :
Darwin 2 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 65 (Active)
Canberra 44 (Unsettled)
Hobart 54 (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 19 Aug : A
Fredericksburg 17
Planetary 23
Observed AFr/Ap Indices 18 Aug : A K
Fredericksburg 20
Planetary 25 4532 2254
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Aug 16 G0, chance of G1
21 Aug 12 G0
22 Aug 8 G0
COMMENT: ASWFC Geomagnetic Warning 51 was issued on 19 August
and is current for 19-21 Aug. G1 geomagnetic conditions were
observed at the planetary level on UT day 19-Aug. G0 geomagnetic
conditions were observed in the Australian region, with isolated
local periods of G1 observed at Canberra, Kennaook Cape Grim
and Hobart. G2 geomagnetic conditions were observed in the Antarctic
region, with an isolated period of G3 observed at Macquarie Island.
G0 planetary geomagnetic conditions are expected over 20-22 Aug,
with a chance of G1 on 20-Aug due to coronal hole high speed
wind stream effects.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Aug Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Aug Normal Normal-fair Fair
21 Aug Normal Normal Normal-fair
22 Aug Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 19-Aug were
mostly normal, with some degradations observed in the northern
hemisphere. HF radio propagation conditions are expected to be
normal to fair on 20-Aug, then mostly normal over 21-22 Aug.
Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Aug 71
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Monthly T index:
Month T index
Jul 75
Aug 64
Sep 61
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
20 Aug 70 Near predicted monthly values
21 Aug 70 Near predicted monthly values
22 Aug 70 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 73 was issued on
19 August and is current for 20-22 Aug. Maximum usable frequencies
(MUFs) in the Australian region on UT day 19-Aug were near predicted
monthly values to 20% depressed. Depressions were observed during
local night hours in northern Australian regions. Spread F was
observed at Hobart and Learmonth during local night hours. MUFs
are expected to be near predicted monthly values over 20-22 Aug.
Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Aug
Daily Proton Fluence >1 MeV: 1.6E+06
Daily Proton Fluence >10 MeV: 2.0E+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: B8.6
Solar Wind Day Averaged Data for 18 Aug
Speed: 414 km/sec Density: 10.8 p/cc Temp: 171000 K Bz: 3 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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