[Ips-dsgr] ASWFC Daily Report - 10 April 25 issued 2330 UT on 10 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Apr 11 09:30:58 AEST 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/10 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 10 APRIL AND FORECAST FOR 11 APRIL - 13 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 10 Apr:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 10 Apr: 153/108


1B. SOLAR FORECAST
             11 Apr             12 Apr             13 Apr
Activity     R1,chance R2       R1,chance R2       R1,chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   155/109            155/109            150/105

COMMENT: Solar activity on UT day 10-Apr was R0. Solar region 
AR4055 (N07W31, beta-gamma-delta) has rapidly grown in the past 
24 hours. Solar region AR4060 (N09E66, beta-gamma) has exhibited 
growth in its leader spots. Previous region of interest AR4048 
(S15W83, beta) has now significantly decayed as it approaches 
the western solar limb and the trailer spots of AR4054 (S12W52, 
beta) have started to decay. The largest flare was a C5.3 flare 
from AR4060 at 10/0752UT. There are currently seven numbered 
sunspot groups on the solar disk. Other regions are small and 
either stable or in decay. Solar activity is expected to be R1, 
chance R2 over 11-13 Apr, primarily due to the possibility of 
isolated flare activity from AR4055 and AR4060. S0 solar radiation 
storm conditions were observed on UT day 10-Apr. S0 solar radiation 
storm conditions are expected over 11-13 Apr. No Earth directed 
CMEs were observed. A north northeast CME was observed from 10/1624UT 
and is considered a far side event. The solar wind environment 
on UT day 10-Apr was moderately enhanced with an overall slow 
declining trend from a recent solar coronal hole wind stream. 
The solar wind speed ranged from 439 km/s to 532 km/s and is 
currently at 450 km/s. The peak total interplanetary field strength 
(IMF, Bt) was 8 nT and the north-south IMF component range (Bz) 
was +6 to -7 nT. Solar wind 27 day recurrence patterns suggest 
that the solar wind will gradually decline over 11-13 Apr.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 10 Apr: G0

Estimated Indices 10 Apr : A   K           
   Australian Region       9   32321223
      Cocos Island         6   22220123
      Darwin               8   32221123
      Townsville           9   32321223
      Learmonth            8   32221223
      Alice Springs        8   32221223
      Gingin              11   32320234
      Canberra             9   32320223
      Kennaook Cape Grim   -   --------
      Hobart              11   32421223    

Estimated Antarctic Regional K Indices 10 Apr :
      Macquarie Island    17   34531223
      Casey               16   43522223
      Mawson              47   55433276

Observed Regional daily pc3 Indices 10 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              18   (Quiet)
      Canberra            14   (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 10 Apr : A 
           Fredericksburg        12
           Planetary             14                         

Observed AFr/Ap Indices 09 Apr :  A   K
           Fredericksburg        22
           Planetary              0   5344 4333     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
11 Apr    18    G0, chance G1
12 Apr    10    G0
13 Apr     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 10-Apr. In the Antarctic region isolated G1-G3 
periods were observed. Generally G0 geomagnetic conditions are 
expected over 11-13 Apr as the mild influence of a coronal hole 
wind stream declines. There is a chance of an isolated G1 period 
on 11-Apr.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions on 10-Apr were generally 
fair to normal, with fair conditions at middle to high latitudes 
early in the UT day. HF conditions are expected to be fair to 
normal on 11-Apr, with fair conditions at high latitudes. HF 
conditions are expected to be normal for 12-13 Apr. Isolated 
fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
10 Apr   136

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20-30%.
   Niue Island Region:
      Enhanced by 25-30%. 
   Northern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Hobart depressed 20-30% early in UT day.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 25% 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
11 Apr   140    Near predicted monthly values to 15% enhanced
12 Apr   140    Near predicted monthly values to 15% enhanced
13 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) in the Australian region on UT day 10-Apr were generally 
near predicted values to 20% enhanced. MUFs at Hobart were depressed 
20-30% during the period 10/0000-0300UT then recovered. Spread-F 
was observed at Hobart and Perth during local night hours. MUFs 
are expected to be near predicted values to 15% enhanced over 
11-13 Apr. Isolated fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 09 Apr
       Daily Proton Fluence >1 MeV:   9.1E+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: C1.6

DSCOVR Satellite Solar Wind Day Averaged Data for 09 Apr
Speed: 499 km/sec  Density:    1.7 p/cc  Temp:   176000 K  Bz:  -3 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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