[Ips-dsgr] ASWFC Daily Report - 11 April 25 issued 2331 UT on 11 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Sat Apr 12 09:31:18 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 APRIL AND FORECAST FOR 12 APRIL - 14 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 11 Apr:  R1

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Apr: 170/124


1B. SOLAR FORECAST
             12 Apr             13 Apr             14 Apr
Activity     R0-R1, chance R2   R0-R1, chance R2   R0-R1, chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   160/114            160/114            150/105

COMMENT: Solar activity on UT day 11-Apr was R1, with two M1 
flare from AR4055 (N07W48, beta-gamma), which has shown substantial 
growth in the past day and dominates as the most complex region 
on the disk. AR4058 (N17W51, beta) has shown some minor growth 
over the past day, and all other sunspot regions are either stable 
or in decay. Solar activity is expected to be R0-R1 over 12-14 
Apr, with a chance for R2 from 4055. 

S0 solar radiation storm conditions were observed on UT day 11-Apr.
 S0 solar radiation storm conditions are expected over 12-14 Apr. 

No Earth directed CMEs were observed on UT day 11-Apr. 

The solar wind environment on UT day 11-Apr was steady. The solar 
wind speed ranged from 524 to 387 km/s, but was mostly near 450 km/s 
all day. The peak total interplanetary field strength (IMF, Bt) was 8 nT and the

north-south IMF component range (Bz) was +7 to -7 nT. Earth may 
slowly lose connection with a coronal hole over the next few 
days, and the solar wind speed is expected to be slightly elevated 
but decline to background levels over 12-13 Apr.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 11 Apr: G0

Estimated Indices 11 Apr : A   K           
   Australian Region       9   22222233
      Cocos Island         7   22222123
      Darwin               7   22222132
      Townsville           9   22222233
      Learmonth            8   22222133
      Alice Springs        8   22222232
      Gingin               9   22222233
      Canberra             6   22122222
      Kennaook Cape Grim   -   --------
      Hobart              10   33223222    

Estimated Antarctic Regional K Indices 11 Apr :
      Macquarie Island    15   33244133
      Casey               17   34522233
      Mawson              25   44333255

Observed Regional daily pc3 Indices 11 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             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 11 Apr : A 
           Fredericksburg        13
           Planetary             16                         

Observed AFr/Ap Indices 10 Apr :  A   K
           Fredericksburg        11
           Planetary             17   4342 2234     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
12 Apr    10    G0
13 Apr     8    G0
14 Apr     6    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 11-Apr. G0-G1 geomagnetic conditions were observed 
in the Antarctic region. G0 geomagnetic conditions are expected 
over 12-14 Apr.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on UT day 11-Apr were 
normal to fair, with some degradations at high latitudes. HF 
radio propagation conditions are expected to be generally normal 
over 12-14 Apr, with some mild degradations possible in high 
latitudes.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
11 Apr   132

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 30% during local day.
      Enhanced by 40% during local night.
   Niue Island Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   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
12 Apr   135    Near predicted monthly values to 15% enhanced
13 Apr   140    Near predicted monthly values to 15% enhanced
14 Apr   140    Near predicted monthly values to 15% enhanced

COMMENT: ASWFC SWF HF Communications Warning 36 was issued on 
10 April and is current for 11-13 Apr. Maximum usable frequencies 
(MUFs) on UT day 11-Apr were near predicted values in the Australian 
region. Spread F was observed in Hobart during local dawn hours. 
MUFs are expected to be near predicted values to 15% enhanced 
over 12-14 Apr.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 10 Apr
       Daily Proton Fluence >1 MeV:   3.7E+05
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 1.30E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:12%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 10 Apr
Speed: 472 km/sec  Density:    1.5 p/cc  Temp:   105000 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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