[Ips-dsgr] ASWFC Daily Report - 07 September 25 issued 2330 UT on 07 Sep 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Mon Sep 8 09:30:46 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/07 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 07 SEPTEMBER AND FORECAST FOR 08 SEPTEMBER - 10 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 07 Sep:  R0

Flares    Max     Fadeout    Freq.  Sectors
  M1.2 06/2215UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 07 Sep: 133/87


1B. SOLAR FORECAST
             08 Sep             09 Sep             10 Sep
Activity     R0 chance of R1    R0 chance of R1    R0 chance of R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   135/89             135/89             130/84

COMMENT: Solar activity on UT day 07-Sep was at R0. There are 
currently six numbered sunspot regions visible on the solar disk 
with AR4207 (N29W32, beta-gamma) being the most magnetically 
complex region but showing decay over the UT day. AR4213 (S13E16) 
has shown growth in its leader and intermediates and AR4212 (N11W32, 
alpha) a small region has shown both growth and decay over the 
UT day. All other sunspot regions are either stable or in decay. 
A small solar filament eruption located at S18W50 was observed 
on 07/0426UT with GONG H-alpha imagery with no associated CME. 
Solar activity is expected to be at the R0 Level with a chance 
of R1 over 08-10 Sep. S0 solar radiation storm conditions were 
observed on UT day 07-Sep. S0 solar radiation storm conditions 
are expected over 08-10 Sep. A coronal hole spans across the 
solar disk in the southern solar hemisphere, with most of the 
area of this hole now west of the solar central meridian. No 
earth directed CME's have been observed. The solar wind speed 
on UT day 07-Sep has remained steady ranging from 454 to 630 
km/s and is currently near 514 km/s. The peak total interplanetary 
magnetic field strength (IMF, Bt) was 12 nT and the north-south 
IMF component (Bz) range was 5- to +4nT. The solar wind speed 
is expected to remain elevated and steady due to the wind stream 
from the coronal hole located in the southern solar hemisphere. 
A weak CME arrival that was expected on 07-Sep from a small filament 
eruption on 04-Sep appears to have arrived as an indistinct transient 
in the solar wind parameters during the second half of 06-Sep.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 07 Sep: Quiet

Estimated Indices 07 Sep : A   K           
   Australian Region       1   00000012
      Cocos Island         1   11110010
      Darwin               3   10100023
      Townsville           1   10000012
      Learmonth            2   00110022
      Alice Springs        1   00000012
      Gingin               2   10000022
      Canberra             0   00000002
      Kennaook Cape Grim   1   00000012
      Hobart               1   00000012    

Estimated Antarctic Regional K Indices 07 Sep :
      Macquarie Island     0   00000011
      Casey                4   21221012
      Mawson              10   20000145

Observed Regional daily pc3 Indices 07 Sep : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               0   (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 07 Sep : A 
           Fredericksburg         4
           Planetary              5                         

Observed AFr/Ap Indices 06 Sep :  A   K
           Fredericksburg        17
           Planetary             26   4443 4541     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
08 Sep    15    G0 with a chance of G1
09 Sep    12    G0 with a chance of G1
10 Sep    10    G0 with a chance of G1

COMMENT: ASWFC Geomagnetic Warning 65 was issued on 6 September 
and is current for 6-8 Sep. G0 geomagnetic conditions were observed 
in the Australian region on UT day 07-Sep. In the Antarctic region 
G0-G2 geomagnetic conditions were observed. G0 with a chance 
of G1 are expected on 08-10 Sep due to ongoing coronal hole wind 
stream influence.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
08 Sep      Normal         Normal         Normal-fair
09 Sep      Normal         Normal         Normal-fair
10 Sep      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 07-Sep were 
fair to normal. HF radio propagation conditions are generally 
expected to be mostly normal over 08-10 Sep. Isolated minor shortwave 
fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
07 Sep    92

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:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Aug      96
Sep      92
Oct      90

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
08 Sep   100    Near predicted monthly values
09 Sep   100    Near predicted monthly values
10 Sep   100    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the northern Australian 
region on UT day 07-Sep were near predicted monthly values. Spread 
F was observed at Canberra, Perth Hobart, Niue during local night 
hours. MUFs are generally expected to be near to predicted monthly 
values on 08 Sep with degraded HF conditions during local night 
hours for the southern Australian region. Scintillation was observed 
at Niue on UT day 07 Sep starting at 07:56 and ending on 08:20 
UT 04 Sep. MUFs are expected to be near predicted monthly values 
on 09-10 Sep. Isolated minor shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 06 Sep
       Daily Proton Fluence >1 MeV:   3.3E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 1.50E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.2

DSCOVR Satellite Solar Wind Day Averaged Data for 06 Sep
Speed: 529 km/sec  Density:    2.7 p/cc  Temp:   207000 K  Bz:  -1 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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