[Ips-dsgr] ASWFC Daily Report - 15 August 25 issued 2330 UT on 15 Aug 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sat Aug 16 09:30:49 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/15 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 15 AUGUST AND FORECAST FOR 16 AUGUST - 18 AUGUST
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 15 Aug:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 15 Aug: 123/76


1B. SOLAR FORECAST
             16 Aug             17 Aug             18 Aug
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   125/78             125/78             120/72

COMMENT: Solar activity on UT day 15-Aug was at the R0 level, 
with several C-class flares observed. There are currently ten 
numbered sunspot regions visible on the solar disk. AR4172 (N11W65, 
beta) is the largest region on the disk and has decayed over 
the UT day. This region is now approaching the western limb. 
AR4182 (N10E48, beta) has recently developed a small trailer 
spot. Newly numbered AR4186 (N05W45, beta) recently appeared 
on the solar disk and has shown rapid growth. All other sunspot 
regions are either stable or in decay. Solar activity is expected 
to be at the R0 level over 16-18 Aug, with a chance of R1. S0 
solar proton conditions were observed on UT day 15-Aug. S0 solar 
proton conditions are expected over 16-18 Aug. No Earth-directed 
CMEs have been observed. The solar wind speed on UT day 15-Aug 
decreased, ranging from 365 to 480 km/s and is currently near 
370 km/s. The peak total interplanetary magnetic field strength 
(IMF, Bt) was 6 nT and the north-south IMF component (Bz) range 
was -5 to +4 nT. The solar wind speed is expected to remain near 
background levels on 16-Aug, then increase late on 17-Aug due 
to coronal hole high speed wind stream effects from an equatorial 
coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 15 Aug: G0

Estimated Indices 15 Aug : A   K           
   Australian Region       4   22110121
      Cocos Island         2   11110020
      Darwin               6   32211122
      Townsville           4   22111022
      Learmonth            4   22210121
      Alice Springs        4   22210021
      Gingin               5   22210130
      Canberra             3   22110021
      Kennaook Cape Grim   4   22120121
      Hobart               4   22120121    

Estimated Antarctic Regional K Indices 15 Aug :
      Macquarie Island     4   22220110
      Casey               11   34321131
      Mawson              20   34322354

Observed Regional daily pc3 Indices 15 Aug : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra            18   (Quiet)
      Hobart              15   (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 15 Aug : A 
           Fredericksburg         7
           Planetary              8                         

Observed AFr/Ap Indices 14 Aug :  A   K
           Fredericksburg         13
           Planetary              10  3233 2222     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
16 Aug     6    G0
17 Aug     8    G0
18 Aug    16    G0-G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 15-Aug. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with an isolated period of 
G1 observed at Mawson. G0 geomagnetic conditions are expected 
over 16-17 Aug. G0-G1 geomagnetic conditions are expected on 
18-Aug due to coronal hole high speed wind stream effects from 
an equatorial coronal hole.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
16 Aug      Normal         Normal         Normal
17 Aug      Normal         Normal         Normal-fair
18 Aug      Normal         Normal-fair    Fair

COMMENT: HF radio propagation conditions on UT day 15-Aug were 
mostly normal with periods of fair conditions at high latitudes. 
HF radio propagation conditions are expected to be mostly normal 
over 16-18 Aug, with fair conditions at high latitudes on 18-Aug.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
15 Aug    97

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 20% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% 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
16 Aug    90    Near predicted monthly values
17 Aug    90    Near predicted monthly values
18 Aug    80    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 15-Aug were near predicted monthly values to 
15% enhanced. Spread F was observed at Hobart during local night 
hours. MUFs are expected to be near predicted monthly values 
over 16-18 Aug.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 14 Aug
       Daily Proton Fluence >1 MeV:   9.0E+04
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 1.20E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.4

DSCOVR Satellite Solar Wind Day Averaged Data for 14 Aug
Speed: 460 km/sec  Density:    2.6 p/cc  Temp:    97800 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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