[Ips-dsgr] ASWFC Daily Report - 20 June 25 issued 2331 UT on 20 Jun 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sat Jun 21 09:31:24 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/20 JUNE 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 20 JUNE AND FORECAST FOR 21 JUNE - 23 JUNE
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 20 Jun:  High

Flares    Max     Fadeout    Freq.  Sectors
  X1.9 19/2350UT  probable   all    West Pacific
  M1.0    1740UT  possible   lower  South American/
                                    Atlantic

Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Jun: 130/84


1B. SOLAR FORECAST
             21 Jun             22 Jun             23 Jun
Activity     R0-R1, chance R3   R0-R1, chance R3   R0-R1, chance R3
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   130/84             130/84             130/84

COMMENT: Solar activity on UT day 20-Jun was R3, with an isolated 
X1 solar flare at 19/2352 UT from AR4114 (N16W53, beta). AR4117 
(S14E40, beta) also produced an M1 flare. There are currently 
six numbered sunspot regions on the solar disk, however all regions 
are currently stable and have shown little change over the past 
day. Solar activity is expected to be R0-R1 over 21-23 Jun, however 
a chance for isolated R3 events may still be possible, although 
unlikely. 

No Earth-directed CMEs were observed on UT day 20-Jun. 

S0 solar radiation storm conditions were observed on UT day 20-Jun. 
S0 solar radiation storm conditions are expected over 21-23 Jun. 

The solar wind environment on UT day 20-Jun was mostly steady. 
The solar wind speed ranged from 518 to 631 km/s, slightly elevated 
due to coronal hole activity but beginning to decline. The peak 
total interplanetary field strength (IMF, Bt) was 9 nT and the 
north-south IMF component range (Bz) was +7 to -6 nT. The solar 
wind environment is expected to remain at similar levels over 
21-23 Jun, possibly becoming slightly more elevated at the end 
of the period due to further coronal hole activity.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 20 Jun: G0

Estimated Indices 20 Jun : A   K           
   Australian Region       6   12322220
      Cocos Island         4   02221210
      Darwin               8   12322321
      Townsville           7   12322320
      Learmonth            6   12222320
      Alice Springs        6   12322220
      Gingin               6   12222320
      Canberra             6   12322220
      Kennaook Cape Grim   7   12323220
      Hobart               6   12322220    

Estimated Antarctic Regional K Indices 20 Jun :
      Macquarie Island     9   11433210
      Casey               12   33423221
      Mawson              21   45333342

Observed Regional daily pc3 Indices 20 Jun : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               8   (Quiet)
      Canberra             4   (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 20 Jun : A 
           Fredericksburg        11
           Planetary             14                         

Observed AFr/Ap Indices 19 Jun :  A   K
           Fredericksburg        11
           Planetary             12   ---- ----     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
21 Jun    10    G0
22 Jun     8    G0
23 Jun    12    G0

COMMENT: G0 geomagnetic conditions were observed on UT day 20-Jun 
in the Australian region. G0-G1 geomagnetic conditions were observed 
in the Antarctic region. Mostly G0 geomagnetic conditions are 
expected over 21-23 Jun, as the CME from 18-Jun is no longer 
expected to arrive.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
21 Jun      Normal-fair    Normal-fair    Fair
22 Jun      Normal-fair    Normal-fair    Normal-fair
23 Jun      Normal-fair    Normal-fair    Normal-fair

COMMENT: HF radio propagation conditions on UT day 20-Jun were 
mixed. Degraded conditions were observed in the northern hemisphere, 
as well as intermittently in the southern hemisphere. HF radio 
propagation conditions are expected to be similar, with mildly 
degraded conditions expected over 21-23 Jun.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
20 Jun    88

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Depressed by 15% during local day.
      Depressed by 40% during local night.
      Depressed by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
      Depressed by 20% after local dawn.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.

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

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
21 Jun    85    Near predicted monthly values to 20% depressed
22 Jun    85    Near predicted monthly values to 20% depressed
23 Jun    85    Near predicted monthly values to 20% depressed

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 20-Jun were near predicted values to 25% depressed. 
Conditions were especially degraded in the northern Australian 
region near local dawn hours, where sporadic-E was common. MUFs 
are expected to be near predicted values to 20% depressed during 
local night and dawn hours over 21-23 Jun.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 19 Jun
       Daily Proton Fluence >1 MeV:   1.9E+05
       Daily Proton Fluence >10 MeV:  1.8E+04
       Daily Electron Fluence >2 MeV: 3.10E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.6

DSCOVR Satellite Solar Wind Day Averaged Data for 19 Jun
Speed: 504 km/sec  Density:    1.5 p/cc  Temp:   189000 K  Bz:   2 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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