[Ips-dsgr] ASWFC Daily Report - 29 April 23 issued 2330 UT on 29 Apr 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sun Apr 30 09:30:58 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 APRIL AND FORECAST FOR 30 APRIL - 02 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 29 Apr:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 29 Apr: 156/110


1B. SOLAR FORECAST
             30 Apr             01 May             02 May
Activity     R1, chance of R2   R1, chance of R2   R1, chance of R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   155/109            150/105            150/105

COMMENT: Solar activity on UT day 29-Apr was at the R0 level, 
with several high level C-class flares. There are currently five 
numbered sunspot regions visible on the solar disk and one unnumbered 
region. AR3288 (S21W30, beta-gamma-delta) is the most magnetically 
complex region and has exhibited trailer spot development over 
the UT day. AR3289 (N20E26, gamma-delta) also showed development 
over 29-Apr. Both AR3288 and AR3289 were responsible for the 
high level C-class flares over the day, with AR3288 responsible 
for the vast majority. AR3291 (N08W26, beta) displayed trailer 
spot development over the UT day. All other sunspot regions are 
stable. An unnumbered sunspot region is visible at N18W36 with 
beta magnetic characteristics. Solar activity is expected to 
be at the R1 level over 30-Apr to 2-May, with a chance of R2. 
A filament eruption is visible in GOES SUVI, SDO and H-Alpha 
imagery from 29/0249UT at around N35E60. An associated northeast 
directed CME is visible in LASCO and STEREO-A imagery from 29/0353UT. 
Modelling suggests this CME has a chance of a glancing impact 
with Earth at 02/1800UT +/- 12 hours. An eruption is visible 
in GOES SUVI, SDO and H-Alpha imagery from 29/0137UT between 
S20-S30 and E10-W35. An associated south directed CME is visible 
in LASCO and STEREO-A imagery from 29/0353UT. Modelling suggests 
this CME has a chance of a glancing impact with Earth at 02/2200UT 
+/- 12 hours. Both of these CMEs are slow and were produced by 
small solar filaments. Any geomagnetic activity due to glancing 
impacts from these CMEs is unlikely to exceed the G1 level. Other 
eruptions were also visible on the solar disk from 29/1221UT 
at around S27E22 and 29/1617UT at around N05W20. No associated 
CME is visible for either of these in currently available coronagraph 
imagery. Further analysis will be performed when more imagery 
is available. The solar wind speed on UT day 29-Apr was elevated, 
ranging from 554 to 720 km/s, and is currently near 580 km/s. 
The peak total interplanetary field strength (IMF, Bt) was 6 
nT and the north-south IMF component (Bz) range was +5 to -6 
nT. A period of sustained Bz from -5 to -6 nT occurred from 29/0900UT 
to 29/1052UT. The solar wind speed is expected to remain elevated 
over 30-Apr, with a decline possible from 1-May onwards as coronal 
hole high speed wind stream effects wane. However, there is a 
chance that a coronal hole in the northern hemisphere will cause 
the solar wind speed to remain elevated over 1-2 May.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 29 Apr: G0

Estimated Indices 29 Apr : A   K           
   Australian Region      13   22343332
      Cocos Island        11   22234321
      Darwin               8   22233221
      Townsville          13   22343332
      Learmonth           18   22344442
      Alice Springs       12   22343322
      Gingin              18   22344442
      Canberra            13   22343332
      Hobart              17   22453332    

Estimated Antarctic Regional K Indices 29 Apr :
      Macquarie Island    38   33665443
      Casey               21   44444332
      Mawson              63   55555675

Observed Regional daily pc3 Indices 29 Apr : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            2   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              32   (Quiet to unsettled)
      Canberra            65   (Active)
      Hobart              63   (Active)

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 29 Apr : A 
           Fredericksburg        15
           Planetary             20                         

Observed AFr/Ap Indices 28 Apr :  A   K
           Fredericksburg        16
           Planetary             22   4523 3433     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
30 Apr    12    G0, chance of G1
01 May    12    G0, chance of G1
02 May    18    G0-G1

COMMENT: Mostly G0 geomagnetic conditions were observed in the 
Australian region on UT day 29-Apr, with an isolated period of 
G1 at Hobart. G0 geomagnetic conditions were observed at Casey, 
mostly G1 conditions with periods of G2 and G3 were observed 
at Mawson and G2 conditions were observed at Macquarie Island. 
G0 geomagnetic conditions, with a chance of G1, are expected 
over 30-Apr to 1-May due to ongoing coronal hole high speed wind 
stream effects. G0-G1 conditions are expected on 2-May due to 
ongoing coronal hole high speed wind stream effects combined 
with the chance of two glancing impacts from CMEs, first observed 
on 29-Apr.

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

PCA Event : No event.

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

COMMENT: Mostly normal HF propagations conditions were observed 
on 29-Apr. Mostly normal HF propagation conditions are expected 
over 30-Apr to 2-May. Shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
29 Apr   100

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 45% during local day.
      Near predicted monthly values during local night.
      Enhanced by 20% after local dawn.
   Niue Island Region:
      Enhanced by 15% during local day.
      Depressed by 15% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Depressed by 35% 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
30 Apr   100    Near to 15% above predicted monthly values
01 May   100    Near to 15% above predicted monthly values
02 May   100    Near to 15% above predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 40 was issued on 
28 April and is current for 28-30 Apr. Maximum usable frequencies 
(MUFs) on UT day 29-Apr in the Australian region were near predicted 
monthly values, with mild enhancements during local day. Spread 
F was observed at Hobart and Canberra during local night hours. 
Sporadic E was observed at Brisbane, Cocos Islands, Hobart, Learmonth 
and Townsville during local night hours. MUFs are expected to 
be near predicted monthly values to 15% enhanced over 30-Apr 
to 2-May. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 28 Apr
       Daily Proton Fluence >1 MeV:   1.9E+05
       Daily Proton Fluence >10 MeV:  2.2E+04
       Daily Electron Fluence >2 MeV: 1.40E+08   (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.9

DSCOVR Satellite Solar Wind Day Averaged Data for 28 Apr
Speed: 656 km/sec  Density:    1.2 p/cc  Temp:   249000 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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