[Ips-dsgr] ASWFC Daily Report - 13 September 25 issued 2330 UT on 13 Sep 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sun Sep 14 09:30:50 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/13 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 13 SEPTEMBER AND FORECAST FOR 14 SEPTEMBER - 16 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 13 Sep:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 13 Sep: 118/70


1B. SOLAR FORECAST
             14 Sep             15 Sep             16 Sep
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   120/72             115/66             115/66

COMMENT: Solar activity on UT day 13-Sep was R0, with no solar 
flares. There are currently three numbered sunspot regions on 
the solar disk, however there are all either stable or in decay. 
Solar activity is generally expected to be R0 with a chance for 
R1 over 14-16 Sep. 

No Earth-directed CMEs were observed in available 
imagery on UT day 13-Sep. 

S0 solar radiation storm conditions were observed on UT day 13-Sep.
 S0 solar radiation storm conditions are expected over 14-16 Sep.

 The solar wind on UT day 13-Sep was at background levels. 
The solar wind speed ranged from 334 to 382 km/s. The peak
 total interplanetary field strength (IMF, Bt) was 8 nT and the 
north-south IMF component range (Bz) was +5 to -4 nT. The solar 
wind is expected to remain steady for the first half of UT day 
14-Sep, then become enhanced once a large coronal hole connects 
to Earth later in the day. The solar wind is then expected to 
remain enhanced over 15-16 Sep.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 13 Sep: G0

Estimated Indices 13 Sep : A   K           
   Australian Region       3   11211101
      Cocos Island         1   11110000
      Darwin               4   21211102
      Townsville           4   22111111
      Learmonth            4   21211201
      Alice Springs        2   11211001
      Gingin               3   11111201
      Canberra             3   12221001
      Kennaook Cape Grim   4   12221101
      Hobart               4   12221101    

Estimated Antarctic Regional K Indices 13 Sep :
      Macquarie Island     6   11342000
      Casey                4   22221100
      Mawson              17   44322343

Observed Regional daily pc3 Indices 13 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 13 Sep : A 
           Fredericksburg        10
           Planetary             10                         

Observed AFr/Ap Indices 12 Sep :  A   K
           Fredericksburg         9
           Planetary              8   1333 2221     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
14 Sep    13    G0-G1
15 Sep    18    G1-G2
16 Sep    15    G1, chance G2

COMMENT: ASWFC Geomagnetic Warning 68 was issued on 12 September 
and is current for 14-16 Sep. G0 geomagnetic conditions were 
observed in the Australian and Antarctic regions on UT day 13-Sep. 
A coronal hole is expected to connect with the Earth in the second 
half of the day 14-Sep, which may cause periods of G1. G1-G2 
geomagnetic conditions are then expected over 15-16 Sep.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
14 Sep      Normal         Normal         Normal-fair
15 Sep      Normal         Normal-fair    Fair
16 Sep      Normal-fair    Normal-fair    Fair

COMMENT: HF radio propagation conditions on UT day 13-Sep were 
mostly normal to mildly degraded. HF radio propagation conditions 
are expected to be normal on UT day 14-Sep, and become mildly 
degraded over 15-16 Sep due to expected coronal hole activity. 
Conditions are expected to be worse during local night hours.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
13 Sep    77

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 20% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% 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
14 Sep    85    Near predicted monthly values
15 Sep    80    Near predicted monthly values to 10-20% depressed
16 Sep    75    Near predicted monthly values to 10-20% depressed

COMMENT: ASWFC Preliminary HF Communications Warning 83 was issued 
on 12 September and is current for 15-16 Sep. Maximum usable 
frequencies (MUFs) on UT day 13-Sep were mostly near predicted 
values. Sporadic-E was observed in Townsville during local night 
hours and spread-F was observed in Hobart during local dawn hours. 
MUFs are expected to be near predicted values on 14-Sep. MUFs 
may become 10-20% depressed over 15-16 Sep, especially during 
local night hours, due to expected coronal hole activity.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 12 Sep
       Daily Proton Fluence >1 MeV:   4.3E+04
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 3.20E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B5.3

DSCOVR Satellite Solar Wind Day Averaged Data for 12 Sep
Speed: 387 km/sec  Density:    3.4 p/cc  Temp:    26400 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



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