[Ips-dsgr] ASWFC Daily Report - 23 July 25 issued 2332 UT on 23 Jul 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Thu Jul 24 09:32:22 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 JULY AND FORECAST FOR 24 JULY - 26 JULY
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Jul:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Jul: 150/105


1B. SOLAR FORECAST
             24 Jul             25 Jul             26 Jul
Activity     R0, chance of R1   R0, chance of R1   R0, chance of R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   140/94             135/89             130/84

COMMENT: Solar activity on UT day 23-Jul was at the R0 level 
with sporadic, low level C class flares. There are currently 
six numbered sunspot regions and two unnumbered region visible 
on the solar disk. AR4153 (S30E47, beta) showed significant sunspot 
growth over the UT day, whilst AR4149 (N17E21, beta) showed growth 
in its trailer spots. Two unnumbered regions have recently rotated 
onto the solar disk at S11E78 and N09E78 with beta and alpha 
magnetic characteristics respectively. All other regions and 
either stable or in decay. Solar activity is expected to be at 
the R0 level, with a chance of R1 over 24-26 Jul. S0 solar radiation 
storm conditions were observed on UT day 23-Jul. S0 solar radiation 
storm conditions are expected over 24-26 Jul. Multiple faint 
CMEs were observed on 23-Jul. A west directed, faint, partial 
halo CME visible in SOHO and STEREO-A imagery from 23/0824UT 
was possibly associated with a filament eruption visible in SDO 
and GOES SUVI imagery from 24/0300UT at around S10W18. Modelling 
indicates this CME presents the chance of a glancing impact on 
26-Jul at 0900UT +/- 12 hours. There were two other filament 
liftoffs visible on 23-Jul. One from 23/1800UT at around S17E55 
and another from 23/1906 at around S29W07. Both visible in SDO, 
GOES SUVI and H-Alpha imagery. No associated CMEs are visible 
in currently available coronagraph imagery. Further analysis 
will be performed when more imagery is available. The solar wind 
speed increased on 23-Jul UT day and is currently steady. The 
solar wind speed mostly ranged between 430 km/s and 760 km/s 
and is currently at around 700 km/s. The interplanetary magnetic 
field strength is moderately enhanced. The peak total interplanetary 
field strength (IMF, Bt) was 20 nT and the north-south IMF component 
range (Bz) was +14 to -12 nT. The solar wind speed is expected 
to remain elevated on 24-Jul, with the possibility of a slight 
decline on 25-Jul in the second half of the UT day. An increase 
in the solar wind speed is possible on 26-Jul due to the chance 
of a glancing impact from a CME first observed on 23-Jul.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 23 Jul: G0

Estimated Indices 23 Jul : A   K           
   Australian Region      16   23344233
      Cocos Island        10   22233232
      Darwin              14   23334233
      Townsville          13   23334232
      Learmonth           24   33355343
      Alice Springs       16   23344233
      Gingin              23   33255343
      Canberra            16   23245232
      Kennaook Cape Grim  17   23245233
      Hobart              21   23355233    

Estimated Antarctic Regional K Indices 23 Jul :
      Macquarie Island    25   24355433
      Casey               22   44443343
      Mawson              68   76534376

Observed Regional daily pc3 Indices 23 Jul : 
      Darwin               4   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              23   (Quiet to unsettled)
      Canberra            22   (Quiet to unsettled)
      Hobart              55   (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 23 Jul : A 
           Fredericksburg        21
           Planetary             27                         

Observed AFr/Ap Indices 22 Jul :  A   K
           Fredericksburg        16
           Planetary             17   1212 2355     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
24 Jul    20    G0-G1
25 Jul    15    G0, chance of G1
26 Jul    15    G0, chance of G1

COMMENT: ASWFC Geomagnetic Warning 56 was issued on 19 July and 
is current for 22-24 Jul. Mostly G0 geomagnetic conditions were 
observed in the Australian region on UT day 23-Jul, with G1 conditions 
observed at Learmonth, Gingin, Canberra, Kennaook Cape Grim and 
Hobart. G1 conditions were observed at the planetary level. Periods 
of G3 conditions were observed at Mawson with G1 conditions observed 
at Macquarie Island. G0-G1 geomagnetic conditions are expected 
on 24-Jul due to ongoing coronal hole high speed wind stream 
effects. G0 conditions, with a chance of G1 are expected on 25-26 
Jul due to a combination of coronal hole high speed wind stream 
effects and the chance of a glancing impact from a CME first 
observed on 23-Jul.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
24 Jul      Normal         Normal-fair    Fair
25 Jul      Normal         Normal         Normal-fair
26 Jul      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 23-Jul were 
mostly normal. HF conditions are expected to be normal to fair 
for middle to high latitudes over 24-26 Jul due to anticipated 
mild geomagnetic activity induced by a coronal hole high speed 
wind stream and a possible glancing CME impact on 26-Jul.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
23 Jul   110

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
      Depressed by 25% after local dawn.
   Niue Island Region:
      Mostly near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   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
24 Jul   100    Near predicted monthly values
25 Jul   100    Near predicted monthly values
26 Jul   100    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 23-Jul were mostly near predicted monthly values, 
with some mild enhancements in the southern Australian region 
during local night hours. Spread F was observed during local 
night hours at Hobart, Canberra, Brisbane and Townsville. Sporadic 
E was observed at Darwin and slightly at Townsville. MUFs are 
expected to be near predicted monthly values over 24-26 Jul.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 22 Jul
       Daily Proton Fluence >1 MeV:   5.9E+06
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 2.50E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:17%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 22 Jul
Speed: 373 km/sec  Density:    4.9 p/cc  Temp:    53100 K  Bz:   3 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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