[Ips-dsgr] ASWFC Daily Report - 31 August 26 issued 2330 UT on 31 Aug 2026 [SEC=OFFICIAL]

Tue Sep 1 09:30:40 AEST 2026

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 AUGUST 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 AUGUST AND FORECAST FOR 01 SEPTEMBER - 03 SEPTEMBER
STATUS INDICATORS SOL:GREEN   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Aug:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Aug: 107/57

1B. SOLAR FORECAST
             01 Sep             02 Sep             03 Sep
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   108/58             106/55             104/53

COMMENT: Solar flare activity on UT day 31-Aug was at the R0 
level, with the largest flare of the day a C2.6 flare at 31/1516UT. 
There are currently two numbered active regions (ARs) on the 
solar disk and two unnumbered regions. AR 4520 (S12W05, beta) 
showed spot development over the UT day, but remains magnetically 
simple. This region was responsible for the largest flare of 
the day. AR 4518 (N08W19, beta) showed spot decay over the UT 
day. Two unnumbered regions are present on the solar disk. One 
has recently developed on the solar disk at around N11W12 and 
the other has rotated on to the solar disk at around N08E85. 
Both of these regions show beta magnetic complexity. Solar activity 
is expected to be at the R0 level over 01-03 Sep. S0 solar radiation 
storm conditions were observed on UT day 31-Aug and are expected 
to persist over 01-03 Sep. No geoeffective CMEs have been observed 
on 31-Aug. A pair of faint, east directed CMEs are visible in 
SOHO coronagraph imagery from 31/0430UT and 31/0724UT. These 
events are associated with coronal movement over the eastern 
limb in GOES SUVI and SDO imagery and are considered far side 
events. The solar wind speed on UT day 31-Aug declined slightly, 
mostly ranging between 400 and 475 km/s and is currently around 
400 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 6 nT and the north-south IMF component range (Bz) +5 
to -5 nT. The solar wind environment is expected to be mostly 
near background conditions over 01-03 Sep. There is the chance 
of a slight increase late on 03-Sep due to a potential impact 
from a CME first observed on 30-Aug.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 31 Aug: G0

Estimated Indices 31 Aug : A   K           
   Australian Region       6   22231111
      Cocos Island         5   22231100
      Darwin               6   22231112
      Townsville           6   23221112
      Learmonth            6   22331110
      Alice Springs        6   13231111
      Gingin               6   22231111
      Canberra             6   12231112
      Kennaook Cape Grim   5   12231111
      Hobart               5   12231111    

Estimated Antarctic Regional K Indices 31 Aug :
      Macquarie Island     9   24241110
      Casey                8   23332111
      Mawson              17   45332231

Observed Regional daily pc3 Indices 31 Aug : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               4   (Quiet)
      Canberra            18   (Quiet)
      Hobart              11   (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 Aug : A 
           Fredericksburg        11
           Planetary             12                         

Observed AFr/Ap Indices 30 Aug :  A   K
           Fredericksburg        13
           Planetary             15   4434 2322     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
01 Sep     7    G0
02 Sep     5    G0
03 Sep     8    G0

COMMENT: G0 geomagnetic conditions were observed at the planetary 
level and in the Australian region on UT day 31-Aug. Mostly G0 
conditions were observed in the Antarctic region, with the exception 
of one period of G1 activity observed at Mawson. G0 geomagnetic 
conditions are expected over 01-03 Sep.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
31 Aug      Normal-fair    Normal-fair    Normal-fair    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
01 Sep      Normal         Normal         Normal
02 Sep      Normal         Normal         Normal
03 Sep      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 31-Aug were 
mostly normal, with some degraded conditions in the northern 
hemisphere over the day. HF radio propagation conditions are 
expected to be mostly normal over 01-03 Sep.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
31 Aug    66

Observed Australian Regional MUFs
   Cocos Island Region:
      No data available during local day.
      No data available during local night.
   Niue Island Region:
      Enhanced by 20% during local day.
      Near predicted monthly values 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
Jul      75
Aug      64
Sep      61

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
01 Sep    65    Near predicted monthly values
02 Sep    65    Near predicted monthly values
03 Sep    65    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 31-Aug were mostly near predicted monthly values, 
with mild depressions observed in the northern Australian region 
during local night hours. Spread-F was observed at Hobart during 
local night hours. MUFs are expected to be mostly near predicted 
monthly values over 01-03 Sep.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 30 Aug
       Daily Proton Fluence >1 MeV:   1.7E+05
       Daily Proton Fluence >10 MeV:  2.1E+04
       Daily Electron Fluence >2 MeV: 1.80E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B4.7

Solar Wind Day Averaged Data for 30 Aug
Speed: 441 km/sec  Density:    5.0 p/cc  Temp:   135000 K  Bz:  -2 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