[Ips-dsgr] ASWFC Daily Report - 11 August 25 issued 2330 UT on 11 Aug 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Tue Aug 12 09:30:50 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 AUGUST AND FORECAST FOR 12 AUGUST - 14 AUGUST
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 11 Aug:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.7 10/2305UT  possible   lower  West Pacific
  M1.3    0352UT  possible   lower  E. Asia/Aust.
  M1.5    1435UT  possible   lower  South American/
                                    Atlantic
  M1.6    1536UT  possible   lower  South American/
                                    Atlantic

Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Aug: 146/100


1B. SOLAR FORECAST
             12 Aug             13 Aug             14 Aug
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   145/99             140/94             140/94

COMMENT: Solar activity on UT day 11-Aug was at the R1 level 
due to four M-class flares with the largest being a M1.6 at 11/1536UT. 
There are currently eight numbered sunspot regions visible on 
the solar disk and one unnumbered region. AR4168 (N06W93, beta-gamma) 
has recently produced R1 level flares and rotated off the visible 
solar disk. AR4172 (N11W15, beta-gamma) is currently the most 
magnetically complex solar region and has recently grown. Solar 
regions AR4178 (N03W43, beta), AR4174 (S07W71) and AR4179 (S11E57) 
all developed over the UT day. All other sunspot regions are 
either stable or in decay. An unnumbered region has recently 
rotated onto the solar disk near S05E80 (alpha). Solar activity 
is expected to be at R0-R1 levels over 12-14 Aug. S0 solar proton 
conditions were observed on UT day 11-Aug. S0 solar proton conditions 
are expected over 12-14 Aug. Several CMEs were observed, none 
of which are considered geoeffective. A filament eruption was 
observed in SDO304 at 11/1747UT centred near S55W20. Further 
analysis of this eruption will be conducted once coronagraph 
imagery becomes available. The solar wind speed on UT day 11-Aug 
decreased slightly, mostly ranging between 550 km/s to 490 km/s 
and is currently near 530 km/s. The peak total interplanetary 
magnetic field strength (IMF, Bt) was 7 nT and the north-south 
IMF component (Bz) range was -6 nT to +6 nT. The solar wind speed 
is expected to remain elevated with gradual decline over 12-14 
Aug due to waning coronal hole high speed wind stream effects.

-----------------------------------------------------------
2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 11 Aug: G0

Estimated Indices 11 Aug : A   K           
   Australian Region      10   32223322
      Cocos Island         7   222222--
      Darwin              11   32323322
      Townsville          11   32224322
      Learmonth           10   32223322
      Alice Springs       10   322133--
      Gingin              16   323244--
      Canberra            11   222143--
      Kennaook Cape Grim  13   22324422
      Hobart              11   22324322    

Estimated Antarctic Regional K Indices 11 Aug :
      Macquarie Island    41   325565--
      Casey               21   443334--
      Mawson              26   544334--

Observed Regional daily pc3 Indices 11 Aug : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              39   (Quiet to unsettled)
      Canberra            49   (Unsettled)
      Hobart              53   (Unsettled)

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 11 Aug : A 
           Fredericksburg        15
           Planetary             18                         

Observed AFr/Ap Indices 10 Aug :  A   K
           Fredericksburg        17
           Planetary             22   4244 4343     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
12 Aug    16    G0
13 Aug    12    G0
14 Aug    10    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 11-Aug. Mostly G1 geomagnetic conditions were 
observed in the Antarctic region, with a period of G2 conditions 
observed at Macquarie Island. G0 geomagnetic conditions are expected 
over 12-14 Aug.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
12 Aug      Normal         Normal-fair    Fair
13 Aug      Normal         Normal         Normal-fair
14 Aug      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 11-Aug were 
normal to fair. HF radio propagation conditions are expected 
to be mostly normal with fair to normal for high latitudes over 
12-14 Aug. Shortwave fadeouts are possible.

-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
11 Aug    79

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Niue Island Region:
      Enhanced by 35% during local day.
      Enhanced by 40% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Southern Australian Region:
      Depressed by 15% during local day.
      Depressed by 15% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% 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
12 Aug    80    Near predicted monthly values
13 Aug    85    Near predicted monthly values
14 Aug    90    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 75 was issued on 
10 August and is current for 11-12 Aug. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 11-Aug were near predicted 
monthly values to 15-20% depressed. Spread F was observed at 
Hobart, Canberra and Perth during local night hours. MUFs are 
expected to be near predicted monthly values over 12-14 Aug. 
Shortwave fadeouts are possible.

-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 10 Aug
       Daily Proton Fluence >1 MeV:   3.4E+05
       Daily Proton Fluence >10 MeV:  1.9E+04
       Daily Electron Fluence >2 MeV: 9.10E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:10%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.7

DSCOVR Satellite Solar Wind Day Averaged Data for 10 Aug
Speed: 552 km/sec  Density:    2.2 p/cc  Temp:   161000 K  Bz:  -1 nT

(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au



More information about the ips-dsgr mailing list