[Ips-dsgr] SWS Daily Report - 24 April 21 issued 2343 UT on 24 Apr 2021

rwc rwc at ips.gov.au
Sun Apr 25 09:43:38 EST 2021


SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 APRIL 2021 BY Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 24 APRIL AND FORECAST FOR 25 APRIL - 27 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** RED **     ION: ** YELLOW **
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1A. SOLAR SUMMARY
Activity 24 Apr:  Low

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Apr:  79/19


1B. SOLAR FORECAST
             25 Apr             26 Apr             27 Apr
Activity     Low to moderate    Low to moderate    Low to moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN    79/19              79/19              78/17

COMMENT: Solar activity was low on UT day 24 April with a C2 
flare from region 2817(on the west Limb) at 23/2312UT. There 
are currently four numbered regions on the visible disk, ARs 
2816, 2818,2819 and 2820. AR2816 showed signs of decay wile AR 
2820 has increased rapidly in area and magnetic complexity(now 
a beta-gamma magnetic class), it has the potential for large 
flares over the next few days. The two other regions remained 
stable and quiet. No Earth directed CMEs were observed in the 
available images. Solar activity is expected to be low for the 
next three UT days, 25-27 April with a chance of an M-class flare 
from region 2820. On UT day 24 April, the solar wind speed remained 
slightly enhanced ~ 400 Km/s due to continued effects from a 
negative polarity Equatorial coronal hole until the arrival of 
the anticipated CME from 22 April at 24/2220UT, when it jumped 
to 500km/s, along with a solar wind shock. The Interplanetary 
Magnetic Field Bz component strengthened following the shock. 
Bz is currently sustaining a southward orientation at -10nT. 
These enhanced solar wind conditions are expected to continue 
over the UT day 25 as the CME passes.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 24 Apr: Quiet to Unsettled

Estimated Indices 24 Apr : A   K           
   Australian Region       7   23231012
      Cocos Island         4   22211002
      Darwin               7   23231012
      Townsville           7   23231012
      Learmonth           10   33332112
      Alice Springs        8   33231012
      Gingin               7   3223210-
      Canberra             7   23231012
      Hobart               9   23242112    

Estimated Antarctic Regional K Indices 24 Apr :
      Macquarie Island    18   33363201
      Casey               13   43332223
      Mawson              32   54443246

Observed Regional daily pc3 Indices 24 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              17   (Quiet)
      Canberra            26   (Quiet to unsettled)
      Melbourne           NA

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 Apr : A 
           Fredericksburg         9
           Planetary              9                         

Observed AFr/Ap Indices 23 Apr :  A   K
           Fredericksburg        15
           Planetary             12   3223 1324     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
25 Apr    30    Active to Minor Storm
26 Apr    20    Active
27 Apr    10    Quiet to Unsettled

COMMENT: SWS Geomagnetic Warning 16 was issued on 24 April and 
is current for 26 Apr only. Quiet to Unsettled geomagnetic conditions 
were observed in the Australian region on UT day 24 April. Quiet 
to storm levels were observed in the Antarctic region. The arrival 
of the CME late in the UT day 24 April will increase geomagnetic 
conditions over the UT day 25 April. Expect active to minor storm 
conditions with possible cases of major storm conditions at higher 
latitudes today 25 April. Active levels with an isolated minor 
storm period for 26 April as CME effects persist.

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

PCA Event : No event.

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

COMMENT: Moderate degradation in HF propagation conditions are 
possible on UT days 25-27 April.

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


Date   T index
24 Apr    24

Observed Australian Regional MUFs
   Cocos Island Region:
      No data available.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Mar      9
Apr      19
May      23

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
25 Apr    -5    Depressed 10 to 30%/near predicted monthly values
26 Apr    -5    Near predicted monthly values/depressed 10 to 
                30%
27 Apr    -5    Near predicted monthly values/depressed 10 to 
                30%

COMMENT: SWS HF Communications Warning 12 was issued on 24 April 
and is current for 25-27 Apr. MUFs in the Australian region on 
UT day 24 April were mostly near predicted monthly values. Minor 
to moderate MUF depressions are possible on UT days 25-27 April 
due to expected rise in geomagnetic activity.

-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 23 Apr
       Daily Proton Fluence >1 MeV:   2.5E+05
       Daily Proton Fluence >10 MeV:  4.3E+04
       Daily Electron Fluence >2 MeV: 5.00E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:23%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B2.3

DSCOVR Satellite Solar Wind Day Averaged Data for 23 Apr
Speed: 397 km/sec  Density:    6.5 p/cc  Temp:    63500 K  Bz:  -2 nT

(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------

Space Weather Services              email: asfc at bom.gov.au
Bureau of Meteorology
PO Box 1386                         WWW: http://www.sws.bom.gov.au
Haymarket NSW 1240  AUSTRALIA       FTP: ftp://ftp-out.sws.bom.gov.au
tel: +61 2 9213 8010                fax: +61 2 9213 8060 

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