[Ips-dsgr] ASWFC Daily Report - 31 March 26 issued 2330 UT on 31 Mar 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Apr 1 10:30:44 AEDT 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 MARCH 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 MARCH AND FORECAST FOR 01 APRIL - 03 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 31 Mar: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Mar: 141/95
1B. SOLAR FORECAST
01 Apr 02 Apr 03 Apr
Activity R1-R2 R1-R2 R1-R2
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 145/99 140/94
COMMENT: Solar flare activity on UT day 31-Mar was R0. There
are currently ten Active Regions on the Solar disk. Solar region
AR4409 (N03E44, beta) is the newest region, which has developed
a number of spots in the last 24 hours. AR4303 (N15W09, beta)
has shown some continued east-west separation. AR4404 (N17E10,
beta) has seen the development of a number of smaller spots to
its north. All other sunspot regions are either stable or in
decay. Solar activity is expected to be R1-R2 over 01-Apr to
03-Apr. An Earth directed CME was observed, following an X1.4
flare that occurred on the 30-Mar. It was estimated to arrive
at 31/1600UT +/- 10 hours. Signs of its arrival are yet to be
seen. S0 solar radiation storm conditions were observed on UT
day 31-Mar. S0 solar radiation storm conditions are expected
over 01-Apr to 03-Apr. A coronal hole is visible in the southwest
solar quadrant and is expected to become geoeffective on the
03-Apr. The solar wind speed on UT day 31-Mar saw a gentle decline
from its moderately elevated state, due to an earlier solar wind
stream. The solar wind ranged from 460 to 390 km/s and is currently
at 400 km/s. The peak total interplanetary field strength (IMF,
Bt) was 6 nT and the north-south IMF component range (Bz) was
+5 to -4 nT. The solar wind speed is expected to increase
over the next three days, due to the anticipated arrival of a
CME and then from solar wind influences on the 03-Apr due to
a coronal hole.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 31 Mar: G0
Estimated Indices 31 Mar : A K
Australian Region 4 12122111
Cocos Island 2 11211100
Darwin 6 22222112
Townsville 5 22122112
Learmonth - --------
Alice Springs 5 12122112
Gingin 5 22222210
Canberra 4 12122111
Kennaook Cape Grim 5 12122211
Hobart 5 12122211
Estimated Antarctic Regional K Indices 31 Mar :
Macquarie Island 5 11222310
Casey 11 34332211
Mawson 13 23222315
Observed Regional daily pc3 Indices 31 Mar :
Darwin 4 (Quiet)
Townsville 0 (Quiet)
Learmonth NA
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 2 (Quiet)
Hobart 2 (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 31 Mar : A
Fredericksburg 16
Planetary 30
Observed AFr/Ap Indices 30 Mar : A K
Fredericksburg 11
Planetary 12 3333 3222
2B. MAGNETIC FORECAST
Date Ap Conditions
01 Apr 46 G2-G3
02 Apr 29 G1-G2
03 Apr 29 G1-G2
COMMENT: ASWFC Geomagnetic Warning 22 was issued on 31 March
and is current for 31 Mar to 2 Apr. G0 geomagnetic conditions
were observed in the Australian region on UT day 31-Mar. G0 geomagnetic
conditions were observed in the Antarctic region. An Earth directed
CME was anticipated to arrive at approximately 31/1600UT +/-
10 hours, but has yet to do so. This is expected to give rise
to G2-G3 conditions on 01-Apr, giving way to G1-G2 on 02-Apr.
G1-G2 conditions are expected on the 03-Apr, with a coronal hole
high speed wind stream expected to bolster waning CME effects.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
31 Mar Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
01 Apr Poor Poor Poor
02 Apr Fair Fair-poor Poor
03 Apr Fair Fair-poor Poor
COMMENT: HF radio propagation conditions on UT day 31-Mar were
normal. HF conditions are expected to be degraded during the
next three days at all latitudes, due to a CME anticipated to
now arrive on the 01-Apr, followed by connection with a coronal
hole on the 03-Apr. Isolated fadeouts are possible, due to flaring
activity.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
31 Mar 108
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Niue Island Region:
Enhanced by 15% during local day.
Enhanced by 15% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced 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
Feb 98
Mar 87
Apr 85
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
01 Apr 60 20 to 30% below predicted monthly values
02 Apr 60 20 to 30% below predicted monthly values
03 Apr 60 20 to 30% below predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 30 was issued
on 31 March and is current for 31 Mar to 2 Apr. Maximum usable
frequencies (MUFs) in the Australian region on UT day 31-Mar
were generally near predicted values with enhancements of up
to 15% during local night in the northern Australian region.
Spread F was observed at Hobart during the local night. Sporadic
E was also seen during the first half of the 31-Mar at Niue.
MUFs are expected to be up to 30% depressed over 01-Apr to 03-Apr.
Ionospheric depression is anticipated due to a CME expected to
now arrive on the 01-Apr, followed by connection with a coronal
hole on the 03-Apr. Isolated fadeouts are possible, due to flaring
activity.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 30 Mar
Daily Proton Fluence >1 MeV: 2.9E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 4.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 30 Mar
Speed: 450 km/sec Density: 2.2 p/cc Temp: 124000 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