[Ips-dsgr] ASWFC Daily Report - 16 July 25 issued 2332 UT on 16 Jul 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Thu Jul 17 09:32:24 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/16 JULY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 16 JULY AND FORECAST FOR 17 JULY - 19 JULY
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 16 Jul:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 16 Jul: 152/107


1B. SOLAR FORECAST
             17 Jul             18 Jul             19 Jul
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possi1ble
10.7cm/SSN   125/78             128/81             130/84

COMMENT: Solar activity on UT day 16-Jul was R0, with no significant 
flares. Solar region AR4143 (N23W08, beta) produced the largest 
flare of the day a C5 flare at 16/0358UT. Solar region AR4142 
(N01E25, beta-delta) also produced isolated minor flare activity. 
Solar region AR4143 has rapidly grown and region AR4142 has also 
exhibited some growth. Solar region AR4139 (N22W43, beta) has 
shown a decline in its intermediate spots. Solar region AR4136 
(N19W24, beta) has slightly grown. There are currently eleven 
numbered sunspot regions on the solar disk. Other regions are 
small. Solar activity is expected to be R0-R1 over 17-19 Jul. 
No Earth directed CMEs have been observed. A CME was observed 
from 16/1736UT in LASCO C2 imagery associated with an erupting 
solar prominence on the western solar limb and is not considered 
Earth directed. S0 solar radiation storm conditions were observed 
on UT day 16-Jul. S0 solar radiation storm conditions are expected 
over 17-19 Jul. The solar wind on UT day 16-Jul remained elevated 
and variable due to ongoing coronal hole effects. The solar wind 
speed ranged from 510 to 600 km/s, currently near 580 km/s. The 
peak total interplanetary field strength (IMF, Bt) was 8 nT and 
the north-south IMF component range (Bz) was +6 to -8 nT. The 
IMF Bz component was variable up to 17UT, with a more consistent 
southward orientation during the interval 16/1700-2100UT. The 
solar wind is expected to remain enhanced over 17-18 Jul due 
to ongoing coronal hole effects.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 16 Jul: G0

Estimated Indices 16 Jul : A   K           
   Australian Region      10   23241123
      Cocos Island         6   13221013
      Darwin              10   33231123
      Townsville          11   33241123
      Learmonth           11   23241133
      Alice Springs        9   22241123
      Gingin              12   23240134
      Canberra             9   22241113
      Kennaook Cape Grim  12   22251123
      Hobart               9   22241123    

Estimated Antarctic Regional K Indices 16 Jul :
      Macquarie Island    17   23361013
      Casey               10   33331122
      Mawson              50   55542167

Observed Regional daily pc3 Indices 16 Jul : 
      Darwin               2   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            4   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              32   (Quiet to unsettled)
      Canberra            33   (Quiet to unsettled)
      Hobart              19   (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 16 Jul : A 
           Fredericksburg        11
           Planetary             13                         

Observed AFr/Ap Indices 15 Jul :  A   K
           Fredericksburg         17        
           Planetary              23  4455 3222     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
17 Jul    19    G0, chance G1
18 Jul    17    G0, chance G1
19 Jul    14    G0

COMMENT: ASWFC Geomagnetic Warning 55 was issued on 14 July and 
is current for 15-17 Jul. G0 geomagnetic conditions were observed 
in the Australian region on UT day 16-Jul. G0-G2 geomagnetic 
conditions were observed in the Antarctic region. A period of 
planetary G1 conditions was observed toward the end of the UT 
day. G0, chance G1 geomagnetic conditions are expected over 17-18 
Jul due to ongoing coronal hole effects.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
17 Jul      Normal         Normal-fair    Fair
18 Jul      Normal         Normal-fair    Fair
19 Jul      Normal         Normal-fair    Fair

COMMENT: HF radio propagation conditions on UT day 16-Jul were 
fair to normal. HF radio propagation conditions over 17-19 Jul 
are expected to be fair to normal with fair conditions at middle 
to high latitudes. Isolated minor shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
16 Jul    77

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Depressed by 40% during local night.
      Depressed by 25% after local dawn.
   Niue Island Region:
      Depressed by 15% during local day.
      Depressed by 20% 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.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% 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
17 Jul    80    Depressed 10 to 20%/near predicted monthly values
18 Jul    80    Depressed 10 to 20%/near predicted monthly values
19 Jul    80    Depressed 10 to 20%/near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on 16-Jul were depressed 30% to near predicted values. 
Darwin MUFs were strongly depressed during local night hours. 
Spread F was observed during local night hours. MUFs are expected 
to be 10-20% depressed to near predicted values over 17-19 Jul 
due to ongoing mild geomagnetic activity induce by a coronal 
hole wind stream. Isolated minor fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 15 Jul
       Daily Proton Fluence >1 MeV:   1.3E+06
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 6.30E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 8%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 15 Jul
Speed: 628 km/sec  Density:    0.7 p/cc  Temp:   286000 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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