[Ips-dsgr] ASWFC Daily Report - 30 April 23 issued 2330 UT on 30 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Mon May 1 09:30:11 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/30 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 30 APRIL AND FORECAST FOR 01 MAY - 03 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 30 Apr: R1
Flares Max Fadeout Freq. Sectors
M2.4 2028UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 30 Apr: 154/109
1B. SOLAR FORECAST
01 May 02 May 03 May
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 155/109 150/105 145/99
COMMENT: Solar activity on UT day 30-Apr was at the R1 level,
with one M2.4 flare from 30/2011UT produced by an unnamed active
region at around N18E86. There are currently five numbered sunspot
regions visible on the solar disk and one unnumbered region.
AR3288 (S22W41, beta-gamma-delta) and AR3239 (N17E11, beta-delta)
remain the largest and most magnetically complex active regions
on the solar disk, AR3289 was stable over the UT-day whilst AR3288
exhibited decay in its trailer spots. The largest flare of the
UT-day was produced by an unnumbered region visible at N18W86
with beta magnetic characteristics which has recently rotated
onto the solar disk. All other sunspot regions are in decay.
Solar activity is expected to be at the R1 level over 1-3 May,
with a chance of R2. No geoeffective CMEs were observed on 30-Apr.
A northeast directed slow CME is visible in LASCO and STEREO-A
imagery from 30/0136UT. A faint eruption is visible at around
N20E30 in GOES SUVI imagery from 29/1857UT, which may be associated
with this CME. Modelling indicates this CME is not geoeffective.
The M2.4 class flare at 30/2011UT produced an east directed CME,
visible in STEREO-A and LASCO imagery from 30/2053. Preliminary
analysis suggests there is a chance of a glancing impact on 4-May
at 4/0500UT but fother analysis will be performed as more imagery
becomes available. The solar wind speed on UT day 30-Apr declined,
ranging from 627 to 442 km/s, and is currently near 490 km/s.
The peak total interplanetary field strength (IMF, Bt) was 5
nT and the north-south IMF component (Bz) range was +4 to -4
nT. The solar wind speed is expected to slowly decline over 1-3
May as coronal hole high speed wind stream effects wane. There
is a chance for an increase late on UT day 2-May due to the chance
of two glancing impacts from CMEs first observed on 29-May. An
increase may also occur late on UT day 3-May due to high speed
wind stream effects from a coronal hole in the southern hemisphere,
rotating towards a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 30 Apr: G0
Estimated Indices 30 Apr : A K
Australian Region 5 12312101
Cocos Island 3 12211100
Darwin 4 12211102
Townsville 6 12312112
Learmonth 6 22311211
Alice Springs 5 12312101
Gingin 5 22311200
Canberra 4 12302101
Hobart 5 12312201
Estimated Antarctic Regional K Indices 30 Apr :
Macquarie Island 6 12402111
Casey 10 34312211
Mawson 31 65533314
Observed Regional daily pc3 Indices 30 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 16 (Quiet)
Hobart 16 (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 30 Apr : A
Fredericksburg 10
Planetary 11
Observed AFr/Ap Indices 29 Apr : A K
Fredericksburg 18
Planetary 21 4344 4433
2B. MAGNETIC FORECAST
Date Ap Conditions
01 May 8 G0
02 May 12 G0-G1
03 May 10 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 30-Apr. G0 geomagnetic conditions were observed
at Casey and Macquarie Island, G1 conditions, with a period of
G2 were observed at Mawson. G0 geomagnetic conditions are expected
on 1-May, G0-G1 conditions are expected on 2-May due to the chance
of two glancing impacts in the second half of the UT day, from
CMEs first observed on 29-Apr. G0 geomagnetic conditions are
expected on 3-May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
30 Apr Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
01 May Normal Normal Normal-fair
02 May Normal Normal Normal-fair
03 May Normal Normal Normal-fair
COMMENT: Mostly normal HF propagations conditions were observed
on 30-Apr. Mostly normal HF propagation conditions are expected
over 1-3 May. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
30 Apr 100
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 30% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Enhanced by 15% during local day.
Depressed by 20% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Depressed by 20% 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
01 May 105 Near to 15% above predicted monthly values
02 May 105 Near to 15% above predicted monthly values
03 May 105 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 30-Apr in
the Australian region were near predicted monthly values during
local day, with enhancements of up to 20% in the northern Australian
region during local night and depressions of up to 15% in the
southern Australian region during local night. Spread F was observed
at Hobart and Canberra during local night hours. Sporadic E was
observed at Canberra, Brisbane, Hobart and Perth during local
night hours. MUFs are expected to be near predicted monthly values
to 15% enhanced over 1-3 May. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 29 Apr
Daily Proton Fluence >1 MeV: 3.7E+05
Daily Proton Fluence >10 MeV: 2.2E+04
Daily Electron Fluence >2 MeV: 4.00E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:21%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.4
DSCOVR Satellite Solar Wind Day Averaged Data for 29 Apr
Speed: 640 km/sec Density: 0.8 p/cc Temp: 183000 K Bz: -2 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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