[Ips-dsgr] ASWFC Daily Report - 23 June 25 issued 2330 UT on 23 Jun 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Tue Jun 24 09:30:49 AEST 2025


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

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Jun: 122/75


1B. SOLAR FORECAST
             24 Jun             25 Jun             26 Jun
Activity     R0                 R0                 R0
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   120/72             120/72             125/78

COMMENT: Solar activity on UT day 23-Jun was R0, with no significant 
solar flares. Solar regions AR4117 (S14E02, beta) and nearby 
AR4118 (S13E11, beta) have both slightly declined. Solar region 
AR4115 (N20W76, beta) is about to rotate off disk and produced 
a C5 flare at 23/1223UT, which was the largest flare for the 
day. Other regions are very small. There are currently six numbered 
sunspot regions on the solar disk. Solar activity is expected 
to be R0 over 24-26 Jun. No Earth directed CMEs were observed 
in available imagery on UT day 23-Jun. S0 solar radiation storm 
conditions were observed on UT day 23-Jun. S0 solar radiation 
storm conditions are expected over 24-26 Jun. A large equatorial 
coronal hole is currently crossing the solar central meridian. 
The solar wind speed on 23-Jun slightly declined. The solar wind 
speed ranged from 527 to 417 km/s and is currently at 430 km/s. 
The peak total interplanetary field strength (IMF, Bt) was 6 
nT and the north-south IMF component range (Bz) was +5 to -6 
nT. The solar wind environment is expected to become enhanced 
from late 24-Jun and on 25 Jun due to a coronal hole wind stream 
from the equatorial coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 23 Jun: G0

Estimated Indices 23 Jun : A   K           
   Australian Region       4   22121110
      Cocos Island         3   21121100
      Darwin               4   22111111
      Townsville           4   22121111
      Learmonth            5   32111210
      Alice Springs        3   22111100
      Gingin               3   22111110
      Canberra             3   21121100
      Kennaook Cape Grim   4   21121210
      Hobart               3   21121100    

Estimated Antarctic Regional K Indices 23 Jun :
      Macquarie Island     4   21132100
      Casey                7   33221111
      Mawson              29   64333254

Observed Regional daily pc3 Indices 23 Jun : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             7   (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 23 Jun : A 
           Fredericksburg        10
           Planetary             11                         

Observed AFr/Ap Indices 22 Jun :  A   K
           Fredericksburg         8
           Planetary              0   ---- ----     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
24 Jun    18    G0, increasing to G1 late in the UT day
25 Jun    25    G1, chance G2
26 Jun    16    G0, chance G1

COMMENT: ASWFC Geomagnetic Warning 47 was issued on 23 June and 
is current for 24-26 Jun. G0 geomagnetic conditions were observed 
on UT day 23-Jun in the Australian region. G0-G2 geomagnetic 
conditions were observed in the Antarctic region. A coronal hole 
wind stream is expected to induce G1 geomagnetic activity on 
25-Jun.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions were fair to normal 
on UT day 23-Jun. HF radio propagation conditions are expected 
to be normal to fair on 24-Jun, then becoming degraded, particularly 
during local nighttime hours on 25-Jun for middle to high latitudes 
due to anticipated geomagnetic activity induced by a coronal 
hole wind stream.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
23 Jun    74

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
      Depressed by 25% after local dawn.
   Niue Island Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Depressed by 15% during local day.
      Depressed by 30% during local night.
      Depressed by 20% after local dawn.
   Southern Australian Region:
      Depressed by 20% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.
      Sporadic E and spread F frequently observed.

Monthly T index:
Month  T index
May      94
Jun      109
Jul      107

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
24 Jun    90    Depressed 10 to 15%/near predicted monthly values
25 Jun    80    Depressed 10 to 15%/near predicted monthly values
26 Jun    65    Depressed 15 to 20%/near predicted monthly values

COMMENT: ASWFC HF Communications Warning 67 was issued on 21 
June and is current for 22-24 Jun. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 23-Jun were generally 
15 to 30% depressed. Spread F was observed at Canberra, Townsville, 
Hobart and Norfolk Island during local hight hours. Antarctic 
HF conditions were degraded. MUFs are expected to be 10-15% depressed 
to near predicted monthly values 24-25 Jun, with degraded HF 
conditions for the southern Australian region on 25-Jun during 
local night hours due to expected geomagnetic activity from a 
coronal hole wind stream. Southern Australian region MUFs are 
expected to be 15 to 20% depressed on 26-Jun.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 22 Jun
       Daily Proton Fluence >1 MeV:   1.8E+05
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 2.80E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.1

DSCOVR Satellite Solar Wind Day Averaged Data for 22 Jun
Speed: 483 km/sec  Density:    2.0 p/cc  Temp:   152000 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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