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

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Wed Dec 25 10:30:49 AEDT 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 DECEMBER AND FORECAST FOR 25 DECEMBER - 27 DECEMBER
STATUS INDICATORS SOL:** RED **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 Dec:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M4.8    0019UT  possible   lower  West Pacific
  M1.0    0211UT  possible   lower  E. Asia/Aust.
  M4.1    0841UT  possible   lower  Mid East/Indian
  M1.1    1410UT  possible   lower  South American/
                                    Atlantic
  M1.3    1634UT  possible   lower  South American/
                                    Atlantic
  M1.1    1824UT  possible   lower  East Pacific/
                                    North American
  M1.0    2029UT  possible   lower  East Pacific/
                                    North American
  M1.2    2234UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Dec: 259/209


1B. SOLAR FORECAST
             25 Dec             26 Dec             27 Dec
Activity     R1-R2, chance R3   R1-R2, chance R3   R1-R2, chance R3
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   260/210            260/210            255/205

COMMENT: Solar activity on UT day 24-Dec was R1, with several 
flares, the largest being M4. The group of sunspots near the 
center disk were responsible for a majority of the flares: AR3928 
(S14W04, beta-gamma), AR3932 (S16E17, beta-gamma) and AR3933 
(S07W03, beta-gamma-delta). All three of these regions have shown 
steady growth over the past day. AR3936 (N13E30, beta) has also 
shown growth over the past day. These four regions are the most 
complex on the disk and may have potential for high level flares 
in the next few days. Solar activity is expected to be R1-R2, 
with a chance for R3 over 25-27 Dec.

 Two CMEs were observed on UT day 24-Dec, directed mostly to the south.
 Both of these CMEs originated from near AR3932 and were relatively slow. 
There may be a weak glancing blow on 28-Dec. 

S0 solar radiation storm conditions were observed on UT day 24-Dec. 
S0 solar radiation storm conditions are expected over 25-27 Dec. 

The solar wind environment on UT day 24-Dec was mostly undisturbed. 
The solar wind speed was on a decline as Earth exits the range from 
a small coronal hole. The solar wind speed ranged from 650 to 462 km/s. 
The peak total interplanetary field strength (IMF, Bt) was 7 nT and the 
north-south IMF component range (Bz) was +6 to -6 nT. The solar wind is 
expected to become disturbed either late on 25-Dec or early 26-Dec due 
to a CME that was first observed on UT day 23-Dec. Effects are 
likely to continue over 26-Dec but begin to return to background 
levels by 27-dec.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 24 Dec: G0

Estimated Indices 24 Dec : A   K           
   Australian Region       8   23212223
      Cocos Island         6   22212122
      Darwin               5   22112212
      Townsville           8   23212213
      Learmonth           10   33222322
      Alice Springs        6   22212212
      Gingin              10   32222323
      Canberra             8   23212223
      Kennaook Cape Grim   8   23212223
      Hobart               9   23212323    

Estimated Antarctic Regional K Indices 24 Dec :
      Macquarie Island     9   23203322
      Casey               31   55633333
      Mawson              22   34334335

Observed Regional daily pc3 Indices 24 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               8   (Quiet)
      Canberra            13   (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 24 Dec : A 
           Fredericksburg         8
           Planetary             10                         

Observed AFr/Ap Indices 23 Dec :  A   K
           Fredericksburg        11
           Planetary             10   3110 2334     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
25 Dec    20    G1-G2
26 Dec    14    G0-G1, chance G2
27 Dec    10    G0, chance G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 24-Dec. G0-G2 geomagnetic conditions were observed 
in the Antarctic region. A CME is expected to arrive either late 
25-Dec or early 26-Dec and induce G1-G2 geomagnetic conditions, 
settling down by 27-Dec.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
25 Dec      Normal         Normal         Normal-fair
26 Dec      Normal         Normal-fair    Fair
27 Dec      Normal         Normal-fair    Normal-fair

COMMENT: HF radio propagation conditions on UT day 24-Dec were 
generally normal, with some mild depressions in the southern 
hemisphere in the first half of the day. HF radio propagation 
conditions are expected to be mostly normal on 25-Dec, before 
becoming mildly degraded on 26-Dec due to anticipated geomagnetic 
activity. Conditions are expected to return to normal on 27-Dec. 
Shortwave fadeouts are possible.

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


Date   T index
24 Dec   132

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 15% 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):
      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
25 Dec   115    Near predicted monthly values
26 Dec   105    Near predicted monthly values to 10-15% depressed
27 Dec   110    Near predicted monthly values to 10-15% depressed

COMMENT: ASWFC SWF HF Communications Warning 148 was issued on 
23 December and is current for 24-26 Dec. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 24-Dec were near predicted 
values. Sporadic-E was observed in most sites during local night 
hours. MUFs are expected to be near predicted values for most 
of 25-Dec. Depressions of 10-15% may commence from early 26-Dec 
due to anticipated geomagnetic activity. Depressions may continue 
into 27-Dec.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 23 Dec
       Daily Proton Fluence >1 MeV:   9.6E+05
       Daily Proton Fluence >10 MeV:  2.5E+05
       Daily Electron Fluence >2 MeV: 4.30E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C2.7

DSCOVR Satellite Solar Wind Day Averaged Data for 23 Dec
Speed: 559 km/sec  Density:    1.6 p/cc  Temp:   240000 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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