[Ips-dsgr] ASWFC Daily Report - 28 April 24 issued 2330 UT on 28 Apr 2024 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Mon Apr 29 09:30:55 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 APRIL 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 APRIL AND FORECAST FOR 29 APRIL - 01 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 Apr:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Apr: 140/94


1B. SOLAR FORECAST
             29 Apr             30 Apr             01 May
Activity     R1, chance R2      R1, chance R2      R1, chance R2 
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   135/89             135/89             130/84

COMMENT: Solar activity on UT day 28-Apr was R0. There are currently 
seven numbered sunspots on the visible solar disk. AR3654 (S06W37, 
beta-gamma-delta) is the largest and most magnetically complex 
region on the solar disk and has shown continued rapid growth 
over UT day 28-Apr. This region produced two C-class flares over 
the UT day. All other sunspot regions are either stable or decaying. 
Solar activity over 29-Apr to 01-May is expected to be at the 
R1 level, with a chance of R2. A south directed CME was observed 
at around 28/0328 UT in SOHO imagery. This CME was the result 
of an erupting filament near the solar limb and is not expected 
to be geo-effective. No other geo-effective CMEs were observed. 
S0 solar radiation storm conditions were observed on 28-Apr. 
S0 solar radiation storm conditions are expected over 29-Apr 
to 01-May. Solar wind speed on UT day 28-Apr ranged from 385 
to 520 km/s and is currently at around 480 km/s. The peak total 
interplanetary field strength (IMF, Bt) was 8 nT and the north-south 
IMF component range (Bz) was +6 to -5 nT. The solar wind speed 
is currently slightly enhanced due to a coronal hole wind stream. 
A long thin coronal hole is just crossing the solar central meridian 
in the northern solar hemisphere extending in solar latitude 
from N50 to S20. This hole is expected to increase the solar 
wind speed from around 01-May.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 28 Apr: G0

Estimated Indices 28 Apr : A   K           
   Australian Region       2   21110001
      Cocos Island         2   22110000
      Darwin               2   -1210002
      Townsville           5   31211012
      Learmonth            3   22211001
      Alice Springs        2   21200001
      Gingin               3   22210000
      Canberra             1   21000001
      Kennaook Cape Grim   2   21100001
      Hobart               2   21100001    

Estimated Antarctic Regional K Indices 28 Apr :
      Macquarie Island     1   22000000
      Casey                8   33331011
      Mawson              12   43321204

Observed Regional daily pc3 Indices 28 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             4   (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 28 Apr : A 
           Fredericksburg         7
           Planetary              7                         

Observed AFr/Ap Indices 27 Apr :  A   K
           Fredericksburg        12
           Planetary             12   3311 4332     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
29 Apr    10    G0
30 Apr     8    G0
01 May    12    G0, chance of G1

COMMENT: G0 geomagnetic conditions were observed in Australian 
and Antarctic regions on UT day 28-Apr. G0 geomagnetic conditions 
are expected over 29-Apr to 01 May. With a change of G1 on 01-May 
due to coronal hole high speed wind streams.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
29 Apr      Normal         Normal         Normal-fair
30 Apr      Normal         Normal         Normal-fair
01 May      Normal         Normal         Normal-fair

COMMENT: HF radio communication conditions were generally normal 
to fair on 28-Apr. HF radio communication conditions are expected 
to be mostly normal over 29-Apr to 01-May, with ongoing mildly 
degraded conditions at high latitudes. Shortwave fadeouts are 
possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
28 Apr   127

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 25% during local night.
   Niue Island Region:
      Near predicted monthly values.
   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
Mar      120
Apr      114
May      115

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
29 Apr   140    Near to 15% above predicted monthly values
30 Apr   140    Near to 15% above predicted monthly values
01 May   135    Near to 15% above predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 42 was issued on 
27 April and is current for 28-30 Apr. Maximum usable frequencies 
(MUFs) in the Australian region were near predicted monthly values 
UT day 28-Apr. Spread F was observed in Hobart and Canberra during 
local nighttime hours. MUFs are expected to be near predicted 
values to 15% enhanced over 29-Apr to 01-May. Shortwave fadeouts 
are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 27 Apr
       Daily Proton Fluence >1 MeV:   9.1E+04
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 1.70E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.8

DSCOVR Satellite Solar Wind Day Averaged Data for 27 Apr
Speed: 419 km/sec  Density:    2.3 p/cc  Temp:   213000 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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