[Ips-dsgr] ASWFC Daily Report - 27 April 23 issued 2330 UT on 27 Apr 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Fri Apr 28 09:30:57 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 APRIL AND FORECAST FOR 28 APRIL - 30 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Apr:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.8    1114UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Apr: 141/95


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

COMMENT: Solar activity on UT day 27-Apr was at the R1 level, 
due to a M1.8 flare from AR3288 (S23W02, beta-gamma-delta) at 
27/1114UT. There are currently five numbered sunspot regions 
visible on the solar disk. AR3288 is the most magnetically complex 
region and has exhibited spot development over the UT day, particularly 
in its intermediate spots. AR3289 (N20E42, beta-delta) has increased 
in magnetic complexity. AR3291 (N10W00, beta) has shown spot 
growth over the 24-hour period. All other sunspot regions have 
shown only minor growth. Solar activity is expected to be at 
the R1 level over 28-30 Apr, with a chance of R2. A filament 
eruption was observed, visible in H-alpha imagery at 27/0204UT 
from ~N05E50. A subsequent northeast directed CME was observed 
in LASCO C2 coronagraph imagery at 27/0236UT. Modelling indicates 
only a very slight chance of a glancing impact to Earth. Any 
impact to Earth from this CME is not expected to be significant. 
No other Earth-directed CMEs have been observed. The solar wind 
speed on UT day 27-Apr decreased, ranging from 525 to 680 km/s, 
and is currently near 580 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 8 nT and the north-south IMF component 
(Bz) range was +7 to -7 nT. The solar wind is expected to remain 
elevated over 28-30 Apr due to ongoing coronal hole high speed 
wind stream effects due to an equatorial coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 27 Apr: G0

Estimated Indices 27 Apr : A   K           
   Australian Region      14   33333332
      Cocos Island         9   22232322
      Darwin              11   33232322
      Townsville          15   33333432
      Learmonth           14   33333332
      Alice Springs       12   23332332
      Gingin              15   33343332
      Canberra            13   23333422
      Hobart              18   33443432    

Estimated Antarctic Regional K Indices 27 Apr :
      Macquarie Island    36   24655533
      Casey               24   43433622
      Mawson              69   56543585

Observed Regional daily pc3 Indices 27 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth           11   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              57   (Unsettled)
      Canberra            46   (Unsettled)
      Hobart              54   (Unsettled)

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 27 Apr : A 
           Fredericksburg        16
           Planetary             21                         

Observed AFr/Ap Indices 26 Apr :  A   K
           Fredericksburg        12
           Planetary             14   3322 3343     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
28 Apr    18    G0-G1
29 Apr    10    G0
30 Apr    10    G0

COMMENT: ASWFC Geomagnetic Warning 21 was issued on 27 April 
and is current for 27-28 Apr. G0 geomagnetic conditions were 
observed in the Australian region on UT day 27-Apr. G1-G2 geomagnetic 
conditions were observed in the Antarctic region. G0-G1 geomagnetic 
conditions are expected on 28-Apr due to ongoing coronal hole 
high speed wind stream effects. G0 geomagnetic conditions are 
expected over 29-30 Apr.

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

PCA Event : No event.

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

COMMENT: Mostly normal HF propagations conditions were observed 
on 27-Apr. Mildly degraded HF propagation conditions are possible 
on 28-Apr due to anticipated geomagnetic activity. Mostly normal 
HF propagation conditions are expected over 29-30 Apr.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
27 Apr   112

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values 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      132
Apr      84
May      84

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
28 Apr   115    Near to 15% above predicted monthly values
29 Apr   115    Near to 15% above predicted monthly values
30 Apr   115    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 27-Apr in 
the Australian region were near predicted monthly values to 15% 
enhanced. Strong spread F was observed at Hobart during local 
night hours. MUFs are expected to be near predicted monthly values 
to 15% enhanced over 28-30 Apr.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 26 Apr
       Daily Proton Fluence >1 MeV:   9.9E+05
       Daily Proton Fluence >10 MeV:  2.2E+04
       Daily Electron Fluence >2 MeV: 1.10E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:11%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.5

DSCOVR Satellite Solar Wind Day Averaged Data for 26 Apr
Speed: 527 km/sec  Density:    9.8 p/cc  Temp:   311000 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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