[Ips-dsgr] ASWFC Daily Report - 02 April 25 issued 2330 UT on 02 Apr 2025 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Thu Apr 3 10:30:59 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/02 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 02 APRIL AND FORECAST FOR 03 APRIL - 05 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 02 Apr:  R0

Flares    Max     Fadeout    Freq.  Sectors
  M2.5 01/2231UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 02 Apr: 180/133


1B. SOLAR FORECAST
             03 Apr             04 Apr             05 Apr
Activity     R0-R2, chance R3   R0-R2              R0-R2
Fadeouts     Possible           Probable           Probable
10.7cm/SSN   180/133            180/133            176/130

COMMENT: Solar activity on UT day 2-Apr was R0, with no significant 
solar flares. There are currently seven numbered sunspot regions 
on the solar disk. AR4044 (N17W27, beta) and AR4049 (S31E07, 
beta) have shown some minor growth and maturation. AR4048 (S15E23, 
beta-gamma) dominates as the most complex region on the disk, 
however has been relatively stable in the last day. All other 
sunspot regions are either stable or in decay. Solar activity 
is expected to be R0-R2 over 3-5 Apr, although a chance for isolated 
R3 events is possible from AR4048.

 No significant CMEs were observed on UT day 2-Apr. S1 solar radiation 
storm conditions were observed on UT day 2-Apr, trending towards S0. 
S0-S1 solar radiation storm conditions are expected over 3-5 Apr. 

The solar wind environment on UT day 2-Apr wild mildly perturbed. 
The solar wind speed ranged between 500 and 400 km/s. The peak total 
interplanetary field strength (IMF, Bt) was 12 nT and the north-south 
IMF component range (Bz) was +5 to -10 nT. Bz was oriented southward 
for almost 12 hours on 2-Apr, possibly from the passing by CME on 1-Apr 
and also a small coronal hole now obscured. The solar wind is 
expected to quieten to near background conditions on 3-Apr, but 
may increase due to another small coronal hole over 4-5 Apr, 
likely later in the period.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 02 Apr: G0

Estimated Indices 02 Apr : A   K           
   Australian Region      12   33233133
      Cocos Island         8   22222133
      Darwin              12   33233133
      Townsville          14   33243133
      Learmonth           14   33233243
      Alice Springs       11   32233133
      Gingin              11   32232233
      Canberra            12   22243133
      Kennaook Cape Grim  14   23343133
      Hobart              15   33343133    

Estimated Antarctic Regional K Indices 02 Apr :
      Macquarie Island    25   24464233
      Casey               17   44432233
      Mawson              29   54453344

Observed Regional daily pc3 Indices 02 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               4   (Quiet)
      Canberra             2   (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 02 Apr : A 
           Fredericksburg        17
           Planetary             21                         

Observed AFr/Ap Indices 01 Apr :  A   K
           Fredericksburg         5
           Planetary              0   1010 ----     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
03 Apr    10    G0
04 Apr     8    G0, slight chance G1
05 Apr    14    G0, chance G1

COMMENT: ASWFC Geomagnetic Warning 24 was issued on 1 April and 
is current for 4-5 Apr. G0 geomagnetic conditions were observed 
in the Australian region on UT day 2-Apr. G0-G2 geomagnetic conditions 
were observed in the Antarctic region. Mostly G0 geomagnetic 
conditions are expected over 3-5 Apr, with a chance for G1 at 
the end of the period due to a small coronal hole.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
02 Apr      Normal         Normal-fair    Poor(PCA)      

PCA Event : 10MeV Proton/PCA Event Began at 1425UT 31/03, Ended at 0810UT 02/04

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
03 Apr      Normal         Normal-fair    Normal-fair
04 Apr      Normal         Normal         Normal
05 Apr      Normal         Normal         Fair

COMMENT: HF radio propagation conditions on UT day 2-Apr were 
generally good, especially in the southern hemisphere. Some depressions 
persisted in mid to high latitudes in the northern hemisphere, 
becoming more prominent towards the end of the day. Some polar 
cap absorption may have been experienced HF radio propagation 
conditions are expected to be mostly normal over 3-5 Apr, with 
mild degradations in high latitudes, particularly on 5-Apr.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
02 Apr   153

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 30% during local night.
   Niue Island Region:
      Enhanced by 25% during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values 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
03 Apr   148    About 15% above predicted monthly values to 10% 
                depressed
04 Apr   145    About 15% above predicted monthly values
05 Apr   145    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 33 was issued on 
31 March and is current for 1-3 Apr. Maximum usable frequencies 
(MUFs) on UT day 2-Apr in the Australian region were generally 
near predicted values to 20% enhanced, although some polar cap 
absorption may have been observed at high latitudes. MUFs are 
expected to be initially enhanced on UT day 3-Apr but may be 
on a slightly depressing trend due to prolonged Bz south conditions 
yesterday. Otherwise conditions are expected to remain near predicted 
values to slightly enhanced until the onset of a small coronal 
hole, likely UT day 5-Apr.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 01 Apr
       Daily Proton Fluence >1 MeV:   1.0E+08
       Daily Proton Fluence >10 MeV:  6.0E+06
       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: C1.4

DSCOVR Satellite Solar Wind Day Averaged Data for 01 Apr
Speed: 415 km/sec  Density:    3.2 p/cc  Temp:    58000 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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