[Ips-dsgr] ASWFC Daily Report - 19 June 25 issued 2330 UT on 19 Jun 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Jun 20 09:30:52 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 JUNE 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 JUNE AND FORECAST FOR 20 JUNE - 22 JUNE
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Jun:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Jun: 136/90


1B. SOLAR FORECAST
             20 Jun             21 Jun             22 Jun
Activity     R1                 R1                 R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   135/89             135/89             130/84

COMMENT: Solar activity on UT day 19-Jun was R0. Solar region 
AR4114 (N17W37, beta-gamma) is in decay with intermediate and 
leader spots appearing now more as penumbra with a reduction 
in umbral area, though the region retains its large trailer spot. 
Region AR4114 produced C flare activity, the largest a C7.9 at 
19/0917UT. Adjacent solar region AR4115 (N20W23, beta) has been 
largely stable, with slight decay in small spots above the leader 
spot. This region has a simple open spot configuration. Solar 
region AR4117 (S14E54, beta) showed slight growth in its leader 
spot and slight decay in its southern trailer spot. Region AR4117 
also produced C flare activity with the largest a C5.9 at 19/0651UT. 
This region currently has a more open spot configuration. New 
smaller solar region AR4118 (S14E55, beta) just to the east of 
AR4117 showed slight growth. Other sunspot groups are small. 
There are currently six numbered sunspot groups on the visible 
solar disk. All other sunspots are either stable or in decay. 
A 15 degree long filament at N30E35 was active at around 19/0600UT 
but has not lifted off the disk. Small localised plasma motion 
with possible minor on disk dimming was observed at 19/2148UT 
near small region AR4116 (S13W41, alpha), possibly associated 
with a C4 flare at 19/2134UT. Solar activity is expected to be 
R1 due to AR4114 and AR4117. No significant Earth directed CMEs 
have been observed. In LASCO C2 a southwest CME was observed 
from 19/0236UT. A northwest CME was observed from 19/1112UT and 
a southeast CME was observed from 19/1600UT. None of these CMEs 
could be paired with on disk activity and are presumed to be 
far side events. Subsequent coronagraph imagery will be checked 
for any CME associated with the minor on disk plasma motion observed 
near AR4116, but it is not expected to be significant. S0 solar 
radiation storm conditions were observed on UT day 19-Jun. S0 
solar radiation storm conditions are expected over 20-22 Jun. 
The solar wind environment on UT day 19-Jun was moderately elevated 
with a general overall declining trend. The solar wind speed 
ranged from 570 to 450 km/s, and is currently at 470 km/s. The 
peak total interplanetary field strength (IMF, Bt) was 9 nT and 
the north-south IMF component range was +6 to -7 nT. A brief 
period of mildly southward IMF conditions was observed 19/1750-1910UT, 
along with a slight increase in wind speed. The solar wind has 
been recently moderately elevated due to a large coronal hole 
in the southern solar hemisphere, that has now rotated into the 
southwest solar quadrant. An isolated equatorial coronal hole 
is visible in the eastern solar hemisphere. A weak glancing blow 
CME may possibly arrive early on 20-Jun.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 19 Jun: G0

Estimated Indices 19 Jun : A   K           
   Australian Region       6   22211032
      Cocos Island         5   21211032
      Darwin               7   22212132
      Townsville           6   22211132
      Learmonth            7   32202132
      Alice Springs        6   22101033
      Gingin               9   32201143
      Canberra             4   21100032
      Kennaook Cape Grim   5   21110033
      Hobart               4   21110032    

Estimated Antarctic Regional K Indices 19 Jun :
      Macquarie Island     3   11111022
      Casey               16   34311253
      Mawson              25   53321264

Observed Regional daily pc3 Indices 19 Jun : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             2   (Quiet)
      Hobart               8   (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 19 Jun : A 
           Fredericksburg        11
           Planetary             12                         

Observed AFr/Ap Indices 18 Jun :  A   K
           Fredericksburg        12
           Planetary             11   3223 3224     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
20 Jun    18    G0, chance G1
21 Jun    10    G0
22 Jun     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 19-Jun. G0-G2 geomagnetic conditions were observed 
in the Antarctic region. G0, chance G1 geomagnetic conditions 
are expected on 20 Jun, due to effects from an ongoing coronal 
hole wind stream with the possibility of weak glancing blow CME 
arrival. G0 conditions are expected 21-22 Jun.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 19-Jun were 
fair to normal, with fair conditions ar high latitudes. HF radio 
propagation conditions are expected to be fair to normal at middle 
to high latitudes for 20-Jun with improved HF conditions expected 
over 21-22 Jun.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
19 Jun    87

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
      Depressed by 20% after local dawn.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 30% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Depressed by 10-20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 30% over the UT day.
      Frequent spread F and sporadic E.

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

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
20 Jun    90    Depressed 10 to 15%/near predicted monthly values
21 Jun   100    Near predicted monthly values
22 Jun   100    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on 19-Jun were near predicted monthly values during the 
local day and depressed 10-30% during local night hours. Spread 
F was observed at Canberra and Hobart during local night hours. 
Degraded HF conditions were observed at times in the Antarctic 
region. MUFs are expected to be mildly depressed by 15% to near 
predicted values for 20-Jun and near predicted monthly values 
on 21-22 Jun.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 18 Jun
       Daily Proton Fluence >1 MeV:   1.2E+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: C1.3

DSCOVR Satellite Solar Wind Day Averaged Data for 18 Jun
Speed: 491 km/sec  Density:    9.4 p/cc  Temp:   262000 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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