[Ips-dsgr] ASWFC Daily Report - 04 August 25 issued 2332 UT on 04 Aug 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Tue Aug 5 09:32:31 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/04 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 04 AUGUST AND FORECAST FOR 05 AUGUST - 07 AUGUST
STATUS INDICATORS SOL:** RED **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 04 Aug:  Moderate

Flares    Max     Fadeout    Freq.  Sectors
  M2.0    0457UT  possible   lower  E. Asia/Aust.

Observed 10.7 cm flux/Equivalent Sunspot Number for 04 Aug: 142/96


1B. SOLAR FORECAST
             05 Aug             06 Aug             07 Aug
Activity     R1, chance R2      R1, chance R2      R1, chance R2
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   145/99             145/99             140/94

COMMENT: Solar activity on UT day 04-Aug was at the R1 level 
due to an M2.0 flare at 04/0457UT, produced by AR4168 (N06E06, 
beta-gamma-delta). There are currently five numbered sunspot 
regions visible on the solar disk. AR4168 has shown spot growth 
over the UT day and become more magnetically complex with possibly 
up to two delta spots. AR4161 (S16W27, beta) and AR4165 (N12E07, 
beta) have both shown some growth over the UT day. All other 
sunspot regions are either stable or in decay. Solar activity 
is expected to be at R1 levels with a chance of R2 over 05-07 
Aug. S0 solar proton conditions were observed on UT day 04-Aug. 
S0 solar proton conditions are expected over 05-07 Aug. A diffuse 
CME was observed in SOHO C2 and STEREO A imagery from 04/0800UT 
and is likely associated with the M2.0 flare produced by solar 
region AR4168 and has been modelled as a possible glancing impact 
on 07/0800UT +/- 12 hours. The solar wind speed on UT day 04-Aug 
mildly decreased, ranging from 530 to 430 km/s and is currently 
near 440 km/s. The peak total interplanetary magnetic field strength 
(IMF, Bt) was 9 nT and the north-south IMF component (Bz) range 
was -7 to +6 nT. The solar wind speed is expected to remain steady 
near background levels over 05-06 Aug before possibly increasing 
from late on the 07 Aug as a coronal hole becomes geoeffective.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 04 Aug: G0

Estimated Indices 04 Aug : A   K           
   Australian Region       5   11222221
      Cocos Island         3   11211210
      Darwin               6   12222222
      Townsville           6   12222222
      Learmonth            6   11222321
      Alice Springs        4   02122211
      Gingin               6   11222321
      Canberra             5   11222211
      Kennaook Cape Grim   6   01223221
      Hobart               5   01223220    

Estimated Antarctic Regional K Indices 04 Aug :
      Macquarie Island     8   00233420
      Casey               16   24332521
      Mawson              26   13332645

Observed Regional daily pc3 Indices 04 Aug : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              15   (Quiet)
      Canberra             2   (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 04 Aug : A 
           Fredericksburg         9
           Planetary              9                         

Observed AFr/Ap Indices 03 Aug :  A   K
           Fredericksburg         9
           Planetary              9   2112 2342     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
05 Aug    10    G0
06 Aug    10    G0
07 Aug    20    G0-G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 04-Aug. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with an isolated period of 
G2 observed at Mawson and G1 at Casey. G0 geomagnetic conditions 
are expected over 05-06 Aug. G0-G1 geomagnetic conditions are
expected on 07 Aug due to combined effects of coronal hole high
speed wind stream and possible glancing CME impact.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
05 Aug      Normal         Normal         Normal-fair
06 Aug      Normal         Normal         Normal-fair
07 Aug      Normal         Normal-fair    Fair

COMMENT: HF radio propagation conditions on UT day 04-Aug were 
mostly normal, with isolated periods of fair conditions at high 
latitudes. HF radio propagation conditions are expected to be 
mostly normal over 05-07 Aug. Shortwave fadeouts are probable.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
04 Aug   100

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 55% during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Mostly near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   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
05 Aug    95    Near predicted monthly values
06 Aug    95    Near predicted monthly values
07 Aug    95    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 72 was issued on 
3 August and is current for 4-6 Aug. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 04-Aug were near predicted 
monthly values. Spread F was observed at Hobart during local 
night hours. MUFs are expected to be near predicted monthly values 
over 05-07 Aug. Shortwave fadeouts are probable.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 03 Aug
       Daily Proton Fluence >1 MeV:   4.8E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 3.00E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 03 Aug
Speed: 436 km/sec  Density:    2.1 p/cc  Temp:    85400 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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