[Ips-dsgr] ASWFC Daily Report - 12 April 25 issued 2330 UT on 12 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sun Apr 13 09:30:57 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/12 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 12 APRIL AND FORECAST FOR 13 APRIL - 15 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 12 Apr:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.0 11/2220UT  possible   lower  East Pacific/
                                    North American
  M1.1    0445UT  possible   lower  E. Asia/Aust.
  M1.2    0549UT  possible   lower  E. Asia/Aust.
  M1.0    0719UT  possible   lower  Mid East/Indian
  M2.0    1117UT  possible   lower  European
  M2.7    1143UT  possible   lower  European
  M1.3    1512UT  possible   lower  South American/
                                    Atlantic
  M1.6    2203UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 12 Apr: 165/119


1B. SOLAR FORECAST
             13 Apr             14 Apr             15 Apr
Activity     Low to moderate    Low to moderate    Low to moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   160/114            150/105            150/105

COMMENT: Solar activity on UT day 12-Apr was R1, with several R1 
level events from AR4055 (N07W58, beta-gamma) and one from AR4060 
(N09E36, beta). There are currently six numbered sunspot regions 
on the solar disk. AR4055 has continued showing substantial growth 
over the past day, and maintains being the most complex region 
on the disk. Most other regions in the northern solar hemisphere 
have showed some growth over the past day. Solar activity is 
expected to be R1-R2 over 13-15 Apr.

 Several CMEs wee observed on UT day 12-Apr, however a majority were
 limb or farside events. A filament eruption was observed from 1120 UT
 and was associated with a frontside CME, however it is not expected to 
be geoeffective. Slow and faint CME material can be seen coming off the 
northwest limb from 11/1812 UT onwards, which may be coming from the vicinity 
of AR4055, and this may having a weak but lingering connection 
to Earth from 16-Apr onwards. 

S0 solar radiation storm conditions were observed on UT day 12-Apr. 
S0 solar radiation storm conditions are expected over 13-15 Apr. The solar
 wind environment on UT day 12-Apr was mildly disturbed, likely due 
to ongoing but waning coronal hole effects. The solar wind speed was 
on a slow incline and ranged from 375 to 532 km/s. The peak total interplanetary

field strength (IMF, Bt) was 11 nT and the north-south IMF component 
range (Bz) was +6 to -9 nT. The solar wind environment is expected 
to be mostly steady over 13-15 Apr, although the material slowly 
coming from the northwest of the Sun may have a weak but lingering 
impact from 16-Apr onwards. A small coronal hole remnant may 
cause a brief increase to the solar wind on 14-Apr.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 12 Apr: G0

Estimated Indices 12 Apr : A   K           
   Australian Region      11   32223323
      Cocos Island         6   22221222
      Darwin               8   31222223
      Townsville          11   32133323
      Learmonth           12   32223333
      Alice Springs       10   32222323
      Gingin              13   32223343
      Canberra            10   21233323
      Kennaook Cape Grim   -   --------
      Hobart              12   22233423    

Estimated Antarctic Regional K Indices 12 Apr :
      Macquarie Island    31   31355643
      Casey               13   43332223
      Mawson              31   43443555

Observed Regional daily pc3 Indices 12 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             4   (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 12 Apr : A 
           Fredericksburg        16
           Planetary             20                         

Observed AFr/Ap Indices 11 Apr :  A   K
           Fredericksburg        14
           Planetary             16   4322 3234     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
13 Apr    10    G0
14 Apr     8    G0
15 Apr     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 12-Apr. G0-G2 geomagnetic conditions were observed 
in the Antarctic region. Mostly G0 geomagnetic conditions are 
expected over 13-15 Apr.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 12-Apr were 
normal to fair for most of the day across all latitudes. HF radio 
propagation conditions are expected to be mostly normal over 
13-15 Apr, although mild degradations are possible to continue 
at all latitudes over the period.

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


Date   T index
12 Apr   137

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 15% during local day.
      Enhanced by 35% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
      Enhanced by 25% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Depressed by 30% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% 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
13 Apr   140    Near predicted monthly values to 15% enhanced
14 Apr   140    Near predicted monthly values to 15-20% enhanced
15 Apr   140    Near predicted monthly values to 15-20% enhanced

COMMENT: ASWFC SWF HF Communications Warning 36 was issued on 
10 April and is current for 11-13 Apr. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 12-Apr were near predicted 
values to 20% enhanced, although some moderate depressions were 
observed in the southern region. Spread-F was observed in Hobart. 
MUFs are expected to be near predicted values over 13-15 Ape, 
with enhancements up to 15-20%.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 11 Apr
       Daily Proton Fluence >1 MeV:   3.6E+05
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 1.40E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.4

DSCOVR Satellite Solar Wind Day Averaged Data for 11 Apr
Speed: 452 km/sec  Density:    1.7 p/cc  Temp:   146000 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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