[Ips-dsgr] ASWFC Daily Report - 16 August 25 issued 2330 UT on 16 Aug 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sun Aug 17 09:30:49 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/16 AUGUST 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 16 AUGUST AND FORECAST FOR 17 AUGUST - 19 AUGUST
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 16 Aug:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 16 Aug: 122/75


1B. SOLAR FORECAST
             17 Aug             18 Aug             19 Aug
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   120/72             115/66             110/60

COMMENT: Solar activity on UT day 16-Aug was at the R0 level, 
with no significant flaring activity. There are currently eight 
numbered sunspot regions visible on the solar disk. AR4172 (N11W90, 
beta) has exhibited spot growth over the UT day and is currently 
rotating over the western limb. AR4186 (N07W58, beta) has decayed 
over the 24-hour period. All other sunspot regions are either 
stable or in decay. Solar activity is expected to be at the R0 
level over 17-19 Aug. S0 solar proton conditions were observed 
on UT day 16-Aug. S0 solar proton conditions are expected over 
17-19 Aug. No Earth-directed CMEs have been observed. A small 
filament eruption was observed, visible in H-alpha imagery from 
16/1051UT centred near N18E50. A subsequent associated eastward 
CME was observed, visible in STEREO-A coronagraph imagery from 
16/1123UT. Modelling indicates this CME does not contain a geoeffective 
component. The solar wind speed on UT day 16-Aug decreased, ranging 
from 340 to 390 km/s and is currently near 340 km/s. The peak 
total interplanetary magnetic field strength (IMF, Bt) was 6 
nT and the north-south IMF component (Bz) range was -4 to +3 
nT. The solar wind speed is expected to increase late on 17-Aug 
and remain elevated over 18-19 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 16 Aug: G0

Estimated Indices 16 Aug : A   K           
   Australian Region       3   12110201
      Cocos Island         2   11111100
      Darwin               4   12120211
      Townsville           4   11121212
      Learmonth            3   12120200
      Alice Springs        2   12010200
      Gingin               2   11110200
      Canberra             2   11020201
      Kennaook Cape Grim   3   12110201
      Hobart               2   02110201    

Estimated Antarctic Regional K Indices 16 Aug :
      Macquarie Island     2   01020200
      Casey                7   23321201
      Mawson               5   12221212

Observed Regional daily pc3 Indices 16 Aug : 
      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 16 Aug : A 
           Fredericksburg         6
           Planetary              6                         

Observed AFr/Ap Indices 15 Aug :  A   K
           Fredericksburg        10
           Planetary              7   3222 1121     


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

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 16-Aug. G0 geomagnetic conditions 
are expected on 17-Aug. G0-G1 geomagnetic conditions are expected 
over 18-19 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 
16 Aug      Normal         Normal         Normal-fair    

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 16-Aug were 
mostly normal, with periods of fair conditions at high latitudes. 
HF radio propagation conditions are expected to be mostly normal 
over 17-19 Aug, with fair conditions at high latitudes over 18-19 
Aug.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
16 Aug    93

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 35% 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.
   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
17 Aug    90    Near predicted monthly values
18 Aug    80    Near predicted monthly values
19 Aug    80    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 16-Aug were near predicted monthly values. Spread 
F was observed at Hobart and Perth during local night hours. 
MUFs are expected to be near predicted monthly values over 17-19 
Aug.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 15 Aug
       Daily Proton Fluence >1 MeV:   5.0E+04
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 1.50E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B5.9

DSCOVR Satellite Solar Wind Day Averaged Data for 15 Aug
Speed: 420 km/sec  Density:    2.2 p/cc  Temp:    75500 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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