[Ips-dsgr] ASWFC Daily Report - 17 May 24 issued 2330 UT on 17 May 2024 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sat May 18 09:30:52 EST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 MAY 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 MAY AND FORECAST FOR 18 MAY - 20 MAY
STATUS INDICATORS SOL:** RED ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 May: R2
Flares Max Fadeout Freq. Sectors
M7.2 2108UT probable lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 17 May: 204/155
1B. SOLAR FORECAST
18 May 19 May 20 May
Activity R1-R2 R1-R2 R1-R2
Fadeouts Probable Probable Probable
10.7cm/SSN 205/156 205/156 205/156
COMMENT: Solar activity on UT day 17-May was at the R2 level
due to an M7.2 flare at 17/2108UT from AR3685 (S14E58, beta).
There are currently twelve numbered sunspot regions visible on
the solar disk. AR3679 (S12E11, beta-gamma) is the most magnetically
complex region and has shown mild growth in its trailer spots.
AR3685 is the largest region on the disk and has shown slight
decay in its intermediate spots. AR3683 (S23W26, beta) has exhibited
spot development over the UT day. Newly numbered AR3686 (S08E71,
beta) recently rotated over the eastern limb and appears stable.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be at R1-R2 levels over 18-20 May. Several
CMEs were observed, but none are considered geoeffective. A partial
halo CME was observed, visible in LASCO C2 coronagraph imagery
from 17/1248UT. This CME is considered a farside event and therefore
not geoeffective. An east-directed CME was observed, visible
in coronagraph imagery from 17/2124UT. This CME is associated
with the M7.2 flare from AR3685. Preliminary modelling indicates
this CME does not contain an Earth-directed component. The solar
wind speed on UT day 17-May increased, ranging from 370 to 495
km/s and is currently near 470 km/s. The peak total interplanetary
field strength (IMF, Bt) was 17 nT and the north-south IMF component
(Bz) range was +13 to -15 nT. A moderate solar wind shock was
observed at 17/1240UT, indicative of a CME arrival. A sustained
period of southward IMF conditions was observed from 17/1423UT
and is ongoing. The solar wind speed is expected to decrease
toward background levels over 18-20 May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 May: G0
Estimated Indices 17 May : A K
Australian Region 16 23123444
Cocos Island 16 13113453
Darwin 13 23123433
Townsville 15 23223434
Learmonth 21 23123554
Alice Springs 14 13123443
Gingin 19 22113455
Canberra 14 13213434
Kennaook Cape Grim 16 13112544
Estimated Antarctic Regional K Indices 17 May :
Macquarie Island 23 23002654
Casey 14 24312343
Mawson 21 23213364
Observed Regional daily pc3 Indices 17 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 0 (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 17 May : A
Fredericksburg 19
Planetary 31
Observed AFr/Ap Indices 16 May : A K
Fredericksburg 19
Planetary 28 2465 4332
2B. MAGNETIC FORECAST
Date Ap Conditions
18 May 22 G1, chance of G2
19 May 8 G0
20 May 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 17-May. G2 planetary geomagnetic conditions
were observed due to a CME arrival. G2 geomagnetic conditions
were observed in the Antarctic region. G1 geomagnetic conditions
are expected on 18-May, with a chance of G2 due to ongoing CME
effects. G0 geomagnetic conditions are expected over 19-20 May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
17 May Normal Normal Normal
PCA Event : 10MeV Proton/PCA Event Began at 1355UT 13/05, Ended at 1410UT 16/05
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
18 May Normal Normal-fair Fair
19 May Normal Normal Normal-fair
20 May Normal Normal Normal-fair
COMMENT: HF radio communication conditions on UT day 17-May were
mostly normal. Mostly normal conditions are expected over 18-20
May, with fair conditions expected at high latitudes on 18-May.
Shortwave fadeouts are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
17 May 137
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 25% during local night.
Niue Island Region:
Enhanced by 25% during local day.
Near predicted monthly values 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.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Apr 125
May 114
Jun 116
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
18 May 135 Near to 15% above predicted monthly values
19 May 135 Near to 15% above predicted monthly values
20 May 135 Near to 15% above predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 53 was issued on
16 May and is current for 16-18 May. Maximum usable frequencies
(MUFs) on UT day 17-May were near predicted monthly values to
20% enhanced in Northern Australia. Spread F was observed at
Hobart during local night hours. MUFs are expected to be near
predicted monthly values to 15% enhanced over 18-20 May. Shortwave
fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 16 May
Daily Proton Fluence >1 MeV: 3.1E+07
Daily Proton Fluence >10 MeV: 1.0E+06
Daily Electron Fluence >2 MeV: 7.30E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C2.2
DSCOVR Satellite Solar Wind Day Averaged Data for 16 May
Speed: 437 km/sec Density: 5.6 p/cc Temp: 83100 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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