[Ips-dsgr] ASWFC Daily Report - 28 July 25 issued 2332 UT on 28 Jul 2025 [SEC=OFFICIAL]

Tue Jul 29 09:32:32 AEST 2025

SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 JULY AND FORECAST FOR 29 JULY - 31 JULY
STATUS INDICATORS SOL:GREEN   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 Jul:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Jul: 145/99

1B. SOLAR FORECAST
             29 Jul             30 Jul             31 Jul
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   145/99             140/94             140/94

COMMENT: Solar activity on UT day 28-Jul was at the R0 level, 
with no significant flaring activity. There are currently eight 
numbered sunspot regions visible on the solar disk. AR4153 (S30W17, 
beta) is the largest region on the disk and has shown mild growth 
in its leader spots, whilst its intermediate and trailer spots 
have decayed. AR4150 (S15W51, beta) has shown mild development 
in its trailer spot. AR4155 (S10E09, beta) has exhibited mild 
spot development in its intermediate spots. AR4161 (S16E65, beta) 
recently rotated over the eastern limb and appears to be growing. 
Newly numbered AR4163 (N19W07, beta) recently appeared on the 
solar disk and has shown mild growth. All other sunspot regions 
are either stable or in decay. Solar activity is expected to 
be at the R0 level, with a chance of R1. S0 solar proton conditions 
were observed on UT day 28-Jul. S0 solar proton conditions are 
expected over 29-31 Jul. No Earth-directed CMEs have been observed. 
The solar wind speed on UT day 28-Jul decreased, ranging from 
365 to 420 km/s and is currently near 370 km/s. The peak total 
interplanetary magnetic field strength (IMF, Bt) was 7 nT and 
the north-south IMF component (Bz) range was -5 to +5 nT. The 
solar wind speed is expected to remain near background levels 
on 29-Jul. There is a chance of an increase in the solar wind 
from 30-Jul due to coronal hole high speed wind stream effects 
from a northern hemisphere coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 28 Jul: G0

Estimated Indices 28 Jul : A   K           
   Australian Region       3   11111121
      Cocos Island         2   11110020
      Darwin               5   12121122
      Townsville           4   12111121
      Learmonth            6   11221231
      Alice Springs        3   02110121
      Gingin               4   01111132
      Canberra             2   01011121
      Kennaook Cape Grim   3   11111121
      Hobart               3   11111121    

Estimated Antarctic Regional K Indices 28 Jul :
      Macquarie Island     2   01101111
      Casey                9   24221132
      Mawson              16   21012264

Observed Regional daily pc3 Indices 28 Jul : 
      Darwin               0   (Quiet)
      Townsville          NA
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               6   (Quiet)
      Canberra            27   (Quiet to unsettled)
      Hobart              23   (Quiet to 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 28 Jul : A 
           Fredericksburg         6
           Planetary              7                         

Observed AFr/Ap Indices 27 Jul :  A   K
           Fredericksburg         5
           Planetary              0   ---- ----     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
29 Jul     5    G0
30 Jul     8    G0
31 Jul     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 28-Jul. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with an isolated period of 
G2 observed at Mawson. G0 geomagnetic conditions are expected 
over 29-31 Jul.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
29 Jul      Normal         Normal         Normal
30 Jul      Normal         Normal         Normal-fair
31 Jul      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 28-Jul were 
mostly normal, with periods of fair conditions at low latitudes. 
HF radio propagation conditions are expected to be mostly normal 
over 29-31 Jul.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
28 Jul    88

Observed Australian Regional MUFs
   Cocos Island Region:
      Mostly near predicted monthly values.
      Depressed by 20% after local dawn.
   Niue Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Depressed by 15% 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
Jun      79
Jul      104
Aug      102

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
29 Jul    85    Near predicted monthly values
30 Jul    85    Near predicted monthly values
31 Jul    85    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 28-Jul were 
near predicted monthly values in southern Australia and 15-20% 
depressed in northern Australia. Spread F was observed at Hobart, 
Darwin and Learmonth during local night hours. MUFs are expected 
to be near predicted monthly values over 29-31 Jul.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 27 Jul
       Daily Proton Fluence >1 MeV:   2.1E+06
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 7.70E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 9%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B8.7

DSCOVR Satellite Solar Wind Day Averaged Data for 27 Jul
Speed: 446 km/sec  Density:    2.7 p/cc  Temp:    28400 K  Bz:   5 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