[Ips-dsgr] ASWFC Daily Report - 31 December 24 issued 2330 UT on 31 Dec 2024 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Wed Jan 1 10:30:48 AEDT 2025


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 DECEMBER AND FORECAST FOR 01 JANUARY - 03 JANUARY
STATUS INDICATORS SOL:** RED **   MAG:** RED **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Dec:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.0 30/2241UT  possible   lower  East Pacific/
                                    North American
  M1.0    0500UT  possible   lower  E. Asia/Aust.
  M2.0    2151UT  possible   lower  East Pacific/
                                    North American
  M2.7    2219UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Dec: 218/168


1B. SOLAR FORECAST
             01 Jan             02 Jan             03 Jan
Activity     R1-R2, chance R3   R1-R2, chance R3   R1-R2, chance R3
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   210/161            200/152            200/152

COMMENT: Solar activity on UT day 31-Dec was at the R1 level 
due to an M1.0 flare at 31/0500UT and a triple-peaked M2.9 flare 
at 31/2250UT. There are currently eight numbered sunspot regions 
visible on the solar disk and two unnumbered regions. AR3932 
(S15W68, alpha) was responsible for the first M-class flare of 
the UT day, but has since decayed and rotated off the visible 
solar disk. AR3936 (N14W67, beta) was responsible for the triple-peaked 
M2.7 flare and has shown some spot decay on 31-Dec. AR3944 (S14E38, 
beta) showed spot development over the UT day. All other numbered 
regions are either stable or in decay. An unnumbered region is 
visible on the solar disk at S12W22 with beta magnetic characteristics. 
Another unnumbered region has rotated onto the solar disk at 
around S13E78 with beta magnetic characteristics. Solar activity 
is expected to be at R1-R2 levels with a chance of R3 over 01-03 
Jan. S0 solar radiation storm conditions were observed on UT 
day 31-Dec. S0 solar radiation storm conditions are expected 
over 01-03 Jan. Several narrow CMEs were observed over the UT 
day, but none are considered to be geoeffective. The solar wind 
speed was steady at around 350 km/s before a shock was observed 
at 31/1547UT. This shock is due to an impact from a CME first 
observed on 29-Dec. The wind speed jumped to around 485 km/s 
due to this impact and has remain moderate but variable since 
then. The current wind speed is around 445 km/s. The peak total 
interplanetary field strength (IMF, Bt) was 26 nT and the north-south 
IMF component range (Bz) was +17 to -18 nT. A sustained period 
of southward Bz was observed from 31/1815UT until 31/2210UT. 
The solar wind speed is expected to remain enhanced due to the 
recent CME impact until a further impact on 01-Jan. The solar 
wind speed is expected to be moderately elevated over 02-03 Jan, 
with the possibility of another enhancement on 03-Jan due to 
a glancing impact from a CME first observed on 31-Dec.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 31 Dec: G1

Estimated Indices 31 Dec : A   K           
   Australian Region      13   12221533
      Cocos Island         9   12111433
      Darwin              12   11121533
      Townsville          14   12221543
      Learmonth           14   11221534
      Alice Springs       12   11221533
      Gingin              11   12220434
      Canberra             9   11210433
      Kennaook Cape Grim   -   --------
      Hobart              10   12221433    

Estimated Antarctic Regional K Indices 31 Dec :
      Macquarie Island    10   12321432
      Casey               33   56532443
      Mawson              16   34322433

Observed Regional daily pc3 Indices 31 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               2   (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 31 Dec : A 
           Fredericksburg         9
           Planetary             16                         

Observed AFr/Ap Indices 30 Dec :  A   K
           Fredericksburg         7
           Planetary              5   0221 1112     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
01 Jan    25    G0-G1, chance G2
02 Jan     8    G0
03 Jan    10    G0

COMMENT: ASWFC Geomagnetic Warning 78 was issued on 29 December 
and is current for 31 Dec to 1 Jan. G1 geomagnetic conditions 
were observed in the Australian region on UT day 31-Dec. Mostly 
G0 geomagnetic conditions were observed in the Antarctic region, 
with G2 conditions observed at Casey. G0-G1 geomagnetic conditions, 
with a chance of G2 are expected on 01-Jan due an anticipated 
CME impact combined with ongoing CME impact effects. G0 conditions 
are expected over 02-03 Jan.

-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
31 Dec      Normal-fair    Normal-fair    Fair-poor      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
01 Jan      Fair           Fair           Fair-poor
02 Jan      Fair-normal    Fair-normal    Fair-poor
03 Jan      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions were generally normal 
to fair, with fair to poor conditions observed at high latitudes. 
Degraded HF radio propagation conditions are expected over 01-02 
Jan due to anticipated geomagnetic activity. A recovery towards 
mostly normal conditions is expected on the second half of 02-Jan, 
to 03-Jan. Shortwave fadeouts are possible.

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


Date   T index
31 Dec   136

Observed Australian Regional MUFs
   Cocos Island Region:
      Mostly near predicted monthly values.
      Enhanced by 30% after local dawn.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Depressed by 25% after local dawn.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Nov      127
Dec      117
Jan      114

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
01 Jan   125    Near predicted monthly values
02 Jan   125    Near predicted monthly values
03 Jan   145    Near to 15% above predicted monthly values

COMMENT: ASWFC Preliminary HF Communications Warning 150 was 
issued on 29 December and is current for 31 Dec to 2 Jan. ASWFC 
SWF HF Communications Warning 151 was issued on 31 December and 
is current for 31 Dec to 2 Jan. Maximum usable frequencies (MUFs) 
in the Australian region on UT day 31-Dec were near predicted 
monthly values with depressions of up to 25% observed in the 
northern Australian region after local dawn. Sporadic-E at low 
frequencies was common at most sites at various hours. MUFs are 
expected to be near predicted monthly values to 15% depressed 
over 01-02 Jan, due to anticipated geomagnetic activity. MUFs 
are expected to be near predicted monthly values on 03-Jan. Shortwave 
fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 30 Dec
       Daily Proton Fluence >1 MeV:   2.4E+06
       Daily Proton Fluence >10 MeV:  2.4E+04
       Daily Electron Fluence >2 MeV: 3.20E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C3.7

DSCOVR Satellite Solar Wind Day Averaged Data for 30 Dec
Speed: 337 km/sec  Density:    2.5 p/cc  Temp:    30200 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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