[Ips-dsgr] ASWFC Daily Report - 24 August 25 issued 2330 UT on 24 Aug 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Mon Aug 25 09:30:48 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 AUGUST AND FORECAST FOR 25 AUGUST - 27 AUGUST
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 Aug:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.3    0836UT  possible   lower  Mid East/Indian

Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Aug: 152/107


1B. SOLAR FORECAST
             25 Aug             26 Aug             27 Aug
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   152/107            152/107            155/109

COMMENT: Solar activity on UT day 24-Aug was at the R1 level, 
due to an M1.3 flare at 24/0836UT from over the eastern limb. 
There are currently six numbered sunspot regions visible on the 
solar disk, however analysis was difficult due to lack of imagery. 
AR4191 (N13E31, beta) is the largest region on the solar disk. 
Newly numbered region AR4194 (N03E15, beta) showed spot development 
over the UT day. All other sunspot regions are either stable 
or in decay. Solar activity is expected to be at R0-R1 levels 
over 25-27 Aug. Solar proton conditions were enhanced but below 
the S1 level on UT day 24-Aug. S0-S1 solar proton conditions 
are expected over 25-27 Aug. No Earth-directed CMEs were observed 
on 24-Aug. A north directed, narrow CME was observed in SOHO 
and STEREO-A imagery from 24/0248UT, there is no clear on disk 
activity associated with this CME and it is not considered geoeffective. 
A northeast directed, narrow CME was oberved in SOHO and STEREO-A 
imagery from 24/1036UT, an eruption behind the solar limb is 
visible in SDO and GOES SUVI imagery from 24/0936UT and is likely 
associated with this CME. This CME is expected to pass behind 
the Earth. The solar wind speed on UT day 24-Aug was mostly steady, 
ranging between 360 to 450 km/s and is currently near 375 km/s. 
The peak total interplanetary magnetic field strength (IMF, Bt) 
was 9 nT and the north-south IMF component (Bz) range was -4 
to +6 nT. The solar wind speed is expected to be mostly steady 
on 25-Aug until a possible increase late in the day due to two 
possible glancing CME impacts. A further increase is expected 
on 26-27 Aug due to high speed solar wind stream effects from 
a northern hemisphere coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 24 Aug: G0

Estimated Indices 24 Aug : A   K           
   Australian Region       2   12100111
      Cocos Island         2   12110110
      Darwin               4   22210112
      Townsville           4   12111112
      Learmonth            2   12110110
      Alice Springs        2   12100111
      Gingin               1   11100010
      Canberra             2   12101000
      Kennaook Cape Grim   2   12101011
      Hobart               2   12101000    

Estimated Antarctic Regional K Indices 24 Aug :
      Macquarie Island     1   12001000
      Casey                8   33311112
      Mawson               9   34210113

Observed Regional daily pc3 Indices 24 Aug : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               4   (Quiet)
      Canberra             2   (Quiet)
      Hobart              13   (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 24 Aug : A 
           Fredericksburg         6
           Planetary              5                         

Observed AFr/Ap Indices 23 Aug :  A   K
           Fredericksburg         7
           Planetary              7   3222 2112     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
25 Aug    12    G0, chance of G1
26 Aug    20    G0, chance of G1
27 Aug    18    G0, chance of G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 24-Aug. G0 geomagnetic conditions, 
with a chance of G1 are expected over 25-27 Aug due to a combination 
of two possible glancing CME impacts late on 25-Aug and high 
speed solar wind stream effects due to a northern hemisphere 
coronal hole, expected to be in a geoeffective location over 
26-27 Aug.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
25 Aug      Normal         Normal         Normal-fair
26 Aug      Normal         Normal-fair    Fair
27 Aug      Normal         Normal-fair    Fair

COMMENT: HF radio propagation conditions on UT day 24-Aug were 
mostly normal. HF radio propagation conditions are expected to 
be mostly normal over 25-27 Aug, with possible degradations, 
mostly at high latitudes, over 26-27 Aug.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
24 Aug    86

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:
      Near predicted monthly values during local day.
      Depressed by 20% 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      88
Aug      96
Sep      93

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
25 Aug    90    Near predicted monthly values
26 Aug    80    Near predicted monthly values
27 Aug    80    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 24-Aug were near predicted monthly values, with 
depressions of up to 20% observed in the northern Australian 
region during local night. Mild spread F was observed at Hobart, 
Perth and Brisbane during local night hours. MUFs are expected 
to be near predicted monthly values over 25-27 Aug, with a chance 
of mild depressions on 26-27 Aug due to possible geomagnetic 
activity.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 23 Aug
       Daily Proton Fluence >1 MeV:   6.9E+05
       Daily Proton Fluence >10 MeV:  8.1E+04
       Daily Electron Fluence >2 MeV: 4.10E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.2

DSCOVR Satellite Solar Wind Day Averaged Data for 23 Aug
Speed: 458 km/sec  Density:    1.3 p/cc  Temp:    77500 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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