[Ips-dsgr] ASWFC Daily Report - 22 April 26 issued 2330 UT on 22 Apr 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Apr 23 09:30:52 AEST 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 APRIL 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 22 APRIL AND FORECAST FOR 23 APRIL - 25 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 22 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 22 Apr: 116/68
1B. SOLAR FORECAST
23 Apr 24 Apr 25 Apr
Activity R0, chance of R1 R0, chance of R1 R0, chance of R1
Fadeouts Possible Possible Possible
10.7cm/SSN 120/72 120/72 110/60
COMMENT: Solar flare activity on UT day 22-Apr was at the R0
level, with no M-class or greater flares observed. There are
currently four active regions on the visible solar disk, with
Active Region (AR) 4420 (N16E37, beta-gamma) being the most magnetically
complex. This region has shown growth over the past 24 hours,
and has produced numerous C-class flares. The remaining three
regions appear to be mostly stable or in decay. Solar flare activity
is forecast to be at the R0 level, with a chance of R1 over 23-25
Apr, given the recent growth of AR 4420. S0 solar proton conditions
were observed throughout UT day 22-Apr, with the proton flux
persisting at background levels across the entire UT day. S0
solar proton conditions are forecast for 23-25 Apr. No Earth-directed
coronal mass ejections (CMEs) were observed over the past UT
day. A faint, low velocity, east-directed CME was visible from
22/0736UT, but is not geoeffective. The solar wind speed declined
over 22-Apr, with speeds starting the UT day between 500-550
km/s and declining to 450-480 km/s, as past coronal hole high
speed wind stream effects continued to subside. The interplanetary
magnetic field strength (IMF, Bt) peaked at 6 nT, with the north-south
component (Bz) ranging between -4 and +5 nT. The solar wind speed
is expected to continue to decline over 23-24 Apr, with an increase
expected on 25-Apr as a new coronal hole high speed wind stream
connects with Earth.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 22 Apr: G0
Estimated Indices 22 Apr : A K
Australian Region 1 11011010
Cocos Island 2 11111010
Darwin 4 21121012
Townsville 4 -2122111
Learmonth 2 10022010
Alice Springs 1 01011011
Gingin 2 11021000
Canberra 1 01011000
Kennaook Cape Grim 1 01011010
Hobart 2 11111010
Estimated Antarctic Regional K Indices 22 Apr :
Macquarie Island 1 11011010
Casey 12 35331011
Mawson 12 24232214
Observed Regional daily pc3 Indices 22 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 8 (Quiet)
Canberra 11 (Quiet)
Hobart 18 (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 22 Apr : A
Fredericksburg 6
Planetary 5
Observed AFr/Ap Indices 21 Apr : A K
Fredericksburg 14
Planetary 19 5422 3432
2B. MAGNETIC FORECAST
Date Ap Conditions
23 Apr 8 G0
24 Apr 8 G0
25 Apr 14 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 22-Apr, with G0 conditions also reported at
the planetary level. A single interval of G1 was reported at
Casey station. G0 conditions are forecast for 23-24 Apr, with
G0 geomagnetic conditions, with a chance of G1, expected on 25-Apr
due to an equatorial coronal hole becoming geoeffective.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
22 Apr Fair Fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
23 Apr Fair-normal Fair-normal Fair
24 Apr Normal-fair Normal-fair Fair-normal
25 Apr Normal Normal Normal-fair
COMMENT: Global ionospheric conditions were fair throughout UT
day 22-Apr, with degradations seen in the Australian, Asian,
South African, and European regions. Ionospheric conditions are
forecast to slowly recover from previous geomagnetic activity,
with fair to normal conditions on 23-Apr, trending toward normal
conditions over 24-25 Apr.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
22 Apr 47
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 during local day.
Depressed by 35% during local night.
Depressed by 20% after local dawn.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 25% during local night.
Southern Australian Region:
Depressed by 20% during local day.
Depressed by 25% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Monthly T index:
Month T index
Mar 92
Apr 83
May 81
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
23 Apr 58 Depressed 15 to 20%/near predicted monthly values
24 Apr 65 Near predicted monthly values
25 Apr 75 Near predicted monthly values
COMMENT: ASWFC HF Communications Warning 40 was issued on 22
April and is current for 23 Apr only. Maximum Usable Frequencies
(MUFs) in the Australian region were depressed by 20-25% over
UT day 22-Apr, with MUFs near predicted values during local daylight
hours in the Northern Australian region. Spread-F was observed
in multiple sites in the Southern Australian region. Depressions
of up to 15% were reported in the Antarctic region, with depressions
up to 35% at Niue Island. MUFs are forecast to trend toward predicted
monthly values over 23-Apr, and remain near predicted values
over 24-25 Apr.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 21 Apr
Daily Proton Fluence >1 MeV: 6.4E+05
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 9.40E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:10%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.1
DSCOVR Satellite Solar Wind Day Averaged Data for 21 Apr
Speed: 515 km/sec Density: 2.2 p/cc Temp: 120000 K Bz: -2 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