[Ips-dsgr] ASWFC Daily Report - 13 April 25 issued 2330 UT on 13 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Mon Apr 14 09:30:59 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/13 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 13 APRIL AND FORECAST FOR 14 APRIL - 16 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** RED **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 13 Apr:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.1    0405UT  possible   lower  E. Asia/Aust.
  M2.3    0452UT  possible   lower  E. Asia/Aust.
  M1.0    0652UT  possible   lower  Mid East/Indian
  M1.4    0955UT  possible   lower  Mid East/Indian
  M1.2    1542UT  possible   lower  South American/
                                    Atlantic
  M3.2    1851UT  possible   lower  East Pacific/
                                    North American
  M1.6    2202UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 13 Apr: 164/118


1B. SOLAR FORECAST
             14 Apr             15 Apr             16 Apr
Activity     R1, chance R2      R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   160/114            150/105            140/94

COMMENT: Solar activity on UT day 13-Apr was at the R1 level 
due to an M1.3 flare at 13/0006UT, M1.0 flare at 13/0130UT, M1.1 
flare at 13/0405UT, M2.3 flare at 13/0452UT, M1.0 flare at 13/0652UT, 
M1.4 flare at 13/0955UT, an M1.0 flare at 13/1132UT, M1.2 flare 
at 13/1542UT, an M3.2 flare at 13/1851UT and an M1.6 flare at 
13/2202UT. There are currently five numbered sunspot regions 
visible on the solar disk. AR4055 (N07W73, beta) is the most 
significant sunspot group and was responsible for the vast majority 
of the flares of the UT day, although this region will rotate 
off the solar disk by 15-Apr. AR4060 (N09E23, beta-gamma) showed 
trailer movement over the UT day and is magnetically complex, 
although this region has no history of flaring. All other sunspot 
groups were either stable or in decay. Solar activity is expected 
to be at the R1 level, with a chance of R2 on 14-Apr. R0-R1 level 
activity is expected over 15-16 Apr once AR4055 has rotated off 
the solar disk. S0 solar radiation storm conditions were observed 
on UT day 13-Apr. S0 solar radiation storm conditions are expected 
over 14-16 Apr. A southeast directed CME is visible from 13/0012UT 
in SOHO and STEREO-A imagery. This CME presents the chance of 
a glancing impact on 16-Apr at 0600UT +/- 12 hours, although 
it is likely this CME will combine with the one described below. 
A partial halo CME directed to the south is visible from 13/0812UT 
in SOHO and STEREO-A imagery, although a smaller component of 
the same CME is visible earlier in the day. This CME is associated 
with a filament lift off visible from 13/0449UT in SDO, GOES 
SUVI and H-Alpha imagery. Modelling suggests this CME will impact 
Earth on 15-Apr at 1900UT +/- 12 hours. The solar wind speed 
was in slight decline on 13-Apr. The wind speed mostly ranged 
between 575 km/s and 405 km/s. The current wind speed is around 
420 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 8 nT and the north-south IMF component range (Bz) was 
+4 to -6 nT. Solar wind speed is expected to decline slowly towards 
background levels on 14-Apr. An increase is expected on 15-Apr 
due to an anticipated impact from a CME first observed on 13-Apr. 
A further increase is expected on 16-Apr due to anticipated impacts 
from three CMEs first observed on 12, 13 and 14-Apr, although 
these CMEs may combine for a single impact on 15-Apr.

-----------------------------------------------------------
2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 13 Apr: G0

Estimated Indices 13 Apr : A   K           
   Australian Region      10   32233222
      Cocos Island         7   22223121
      Darwin               9   31233222
      Townsville          10   32233222
      Learmonth           12   32234232
      Alice Springs       11   32233232
      Gingin              13   42234132
      Canberra            10   32233222
      Kennaook Cape Grim   -   --------
      Hobart              11   32243122    

Estimated Antarctic Regional K Indices 13 Apr :
      Macquarie Island    18   33345232
      Casey               13   44322132
      Mawson              43   45533275

Observed Regional daily pc3 Indices 13 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              58   (Unsettled)
      Canberra            30   (Quiet to 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 13 Apr : A 
           Fredericksburg        14
           Planetary             16                         

Observed AFr/Ap Indices 12 Apr :  A   K
           Fredericksburg        13
           Planetary              0   3333 3445     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
14 Apr    10    G0
15 Apr    30    G1-G2
16 Apr    20    G1

COMMENT: ASWFC Geomagnetic Warning 27 was issued on 13 April 
and is current for 16-17 Apr. G0 geomagnetic conditions were 
observed in the Australian region on UT day 13-Apr. Mostly G1 
geomagnetic conditions were observed in the Antarctic region, 
with a period of G3 observed at Mawson. G0 geomagnetic conditions 
are expected on 14-Apr. G1-G2 conditions are expected on 15-Apr 
due to an anticipated impact from a partial halo CME first observed 
on 13-Apr. G1 conditions are expected on 16-Apr due to possible 
further CME impacts combined with ongoing effects from 15-Apr.

-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
13 Apr      Fair-normal    Fair           Poor-fair      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
14 Apr      Normal         Normal         Normal-fair
15 Apr      Fair           Fair           Fair-poor
16 Apr      Normal         Normal-fair    Fair

COMMENT: HF radio propagation conditions on UT day 13-Apr were 
fair to poor for the first half of the day, recovering towards 
fair to normal by the end of the day. HF radio propagation conditions 
are expected to be mostly normal on 14-Apr and for the first 
half of 15-Apr. Degraded conditions are expected from late on 
15-Apr and over 16-Apr due to anticipated geomagnetic activity 
due to several anticipated CME impacts.

-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
13 Apr   112

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 15% during local day.
      Depressed by 35% during local night.
   Niue Island Region:
      Enhanced by 25% during local day.
      Enhanced by 15% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Depressed by 25% during local day.
      Depressed by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.

Monthly T index:
Month  T index
Mar      126
Apr      115
May      113

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
14 Apr   120    Near predicted monthly values
15 Apr   100    Near predicted monthly values/depressed 5 to 
                15%
16 Apr   100    Near predicted monthly values/depressed 5 to 
                15%

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 13-Apr were near predicted values to 15% enhanced 
in the northern Australian region. Depressed conditions of up 
to 25% were observed in the southern Australian region. Spread-F 
was observed in Hobart. MUFs are expected to be near predicted 
monthly values on 14-Apr. Near predicted monthly values to 15% 
depressed conditions are expected over 15-16 Apr.

-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 12 Apr
       Daily Proton Fluence >1 MeV:   4.3E+05
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 5.70E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C3.1

DSCOVR Satellite Solar Wind Day Averaged Data for 12 Apr
Speed: 426 km/sec  Density:    1.9 p/cc  Temp:   113000 K  Bz:  -4 nT

(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au



More information about the ips-dsgr mailing list