[Ips-dsgr] ASWFC Daily Report - 23 March 26 issued 2330 UT on 23 Mar 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Tue Mar 24 10:30:45 AEDT 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 MARCH 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 MARCH AND FORECAST FOR 24 MARCH - 26 MARCH
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Mar: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Mar: 124/77
1B. SOLAR FORECAST
24 Mar 25 Mar 26 Mar
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 125/78 125/78 130/84
COMMENT: Solar flare activity on UT day 23-Mar was R0. Solar
regions AR4392 (S16W73, beta), AR4398 (S15E04, beta), AR4401
(N24E53, beta) and AR4402 (N15E59, beta) produced low level C
class flare activity. A long duration C3.4 flare was observed
at 23/0012UT from AR4392. Solar region AR4401 is growing, AR4398
is showing slight growth and AR4392 showed initial development
then decay in its small surrounding spots. Solar region AR4400
(S10W34, beta-gamma) showed decay in its trailer spots
and slight growth in its leader spots. There are currently seven
numbered sunspots on the solar disk. All other sunspot regions
are either stable or in decay. Space based solar imagery was
limited on 23-Mar with images available up to 23/1244UT. Solar
activity is expected to be R0-R1 over 24-26 Mar. No significantly
Earth directed CMEs were observed. A west directed CME was observed
from 22/2348UT, which appeared to be associated with the long
duration C3.4 flare from AR4392. This CME was modelled to pass
well ahead of the Earth. S0 solar radiation storm conditions
were observed on UT day 23-Mar. An weak enhancement in the solar
proton flux was observed from 23/1400UT possibly in association
with the west directed CME. S0 solar radiation storm conditions
are expected over 24-26 Mar. The solar wind speed on UT day 23-Mar
was enhanced and steady due to a coronal hole wind stream. The
solar wind speed ranged from 615 to 725 km/s and is currently
at 653 km/s. The interplanetary magnetic field strength (IMF,
Bt) was 6 nT and the north-south IMF component range (Bz) was
+4 to -5 nT. The solar wind is expected to remain elevated for
24-Mar and then to gradually decline. There is a slight chance
for a very weak glancing blow CME arrival at 24/2100UT from a
solar filament eruption on 22-Mar. This CME is predominately
directed behind the Earth.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 23 Mar: G0
Estimated Indices 23 Mar : A K
Australian Region 20 33244443
Cocos Island 13 22224432
Darwin - --------
Townsville 17 33244333
Learmonth 21 33245433
Alice Springs 18 33235432
Gingin 21 43244443
Canberra 21 33344443
Kennaook Cape Grim 23 33354443
Hobart 23 33354443
Estimated Antarctic Regional K Indices 23 Mar :
Macquarie Island 42 34566543
Casey 42 54436563
Mawson 62 56544765
Observed Regional daily pc3 Indices 23 Mar :
Darwin NA
Townsville 0 (Quiet)
Learmonth 3 (Quiet)
Alice Springs 0 (Quiet)
Gingin 24 (Quiet to unsettled)
Canberra 11 (Quiet)
Hobart 73 (Active)
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 23 Mar : A
Fredericksburg 20
Planetary 28
Observed AFr/Ap Indices 22 Mar : A K
Fredericksburg 36
Planetary 75 4557 6766
2B. MAGNETIC FORECAST
Date Ap Conditions
24 Mar 24 G0-G1
25 Mar 16 G0, chance G1
26 Mar 12 G0
COMMENT: ASWFC Geomagnetic Warning 19 was issued on 22 March
and is current for 22-24 Mar. G0 geomagnetic conditions were
observed in the Australian region on UT day 23-Mar. G1 planetary
conditions were observed. G2-G3 geomagnetic conditions were observed
in the Antarctic region. An overall declining trend in geomagnetic
activity is expected over the next few days as the recent influence
of a coronal hole wind stream abates. There is a slight chance
for a very weak CME glancing blow arrival late in the UT day
on 24-Mar from a solar filament eruption on 22-Mar.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
23 Mar Normal Fair Poor-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
24 Mar Normal Fair Poor-fair
25 Mar Normal Fair-normal Fair
26 Mar Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 23-Mar were
poor to fair. The Macquarie Island riometer observed frequent
increased absorption of up to 3dB on 23-Mar. A brief period of
increased absorption was observed at Casey, Davis and Mawson
Antarctic riometers at 23/1750UT. HF radio propagation conditions
are expected to fair at middle latitudes and poor to fair at
high latitudes on 24-Mar with a slowly improving trend as recent
geomagnetic activity declines.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
23 Mar 38
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Depressed by 40% during local night.
Niue Island Region:
No data available.
Northern Australian Region:
Enhanced by 20% during local day.
Depressed by 20% during local night.
Southern Australian Region:
Depressed by 30-35%.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Feb 98
Mar 87
Apr 85
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
24 Mar 55 Depressed by 15-20% southern Australian region
25 Mar 70 Depressed 10 to 15%/near predicted monthly values
26 Mar 90 Near predicted monthly values
COMMENT: ASWFC HF Communications Warning 28 was issued on 21
March and is current for 22-24 Mar. Maximum usable frequencies
in the southern Australian region on UT day 23-Mar were depressed
30-35%. In the northern Australian region MUFs were 20% enhanced
during the local day and 20% depressed during the local night.
Spread F was observed during the local night hours at Hobart,
Canberra, Brisbane and Perth. Southern Australian region MUFs
are 20% depressed after local dawn this morning. Northern Australian
region MUFs are currently near predicted monthly values. Southern
Australian region MUFs are expected to be 15-20% depressed during
the local day on 24-Mar. Australian region MUFs are then expected
to gradually recover by 25-26 Mar.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 22 Mar
Daily Proton Fluence >1 MeV: 4.7E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 2.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B4.2
DSCOVR Satellite Solar Wind Day Averaged Data for 22 Mar
Speed: 591 km/sec Density: 2.6 p/cc Temp: 198000 K Bz: -4 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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