[Ips-dsgr] ASWFC Daily Report - 19 May 24 issued 2330 UT on 19 May 2024 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Mon May 20 09:30:46 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 MAY 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 MAY AND FORECAST FOR 20 MAY - 22 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 May:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.9    1344UT  possible   lower  European
  M2.5    1756UT  possible   lower  South American/
                                    Atlantic
  M1.6    2159UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 19 May: 201/153


1B. SOLAR FORECAST
             20 May             21 May             22 May
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   200/152            200/152            200/152

COMMENT: Solar activity on UT day 19-May was at the R1 level 
due to three low level M-class flares, the largest of which was 
an M2.5 flare at 19/1756UT produced by AR3685 (S14E31, beta-delta). 
There are currently nine numbered sunspot regions visible on 
the solar disk. AR3685 is the largest and most magnetically complex 
region on the disk and has exhibited spot development over the 
UT day, particularly in its intermediate spots. AR3679 (S12W19, 
beta-gamma) has shown growth in its trailer spots. AR3683 (S23W56, 
beta) and AR3684 (S06E13, beta) have both shown growth in their 
leader spots. AR3686 (S08E43, beta) has exhibited spot development 
in its trailer spots. All other sunspot regions are either stable 
or in decay. Solar activity is expected to be at R0-R1 levels 
over 20-22 May. Several CMEs were observed, but none are considered 
geoeffective. A low velocity southward CME was observed, visible 
in STEREO-A coronagraph imagery at 19/0123UT. This CME is associated 
with a filament eruption first observed at 18/2048UT. Modelling 
indicates this CME is not geoeffective. Two filament eruptions 
were observed on UT day 19-May, the first at 19/1408UT near N31W27, 
the second at 19/1530UT near N24W60. A northeast-directed CME 
was observed, visible in LASCO C2 coronagraph imagery from 19/1709UT, 
likely associated with the first filament eruption. Modelling 
indicates this CME does not contain an Earth-directed component. 
No CME was observed in association with the second filament eruption. 
The solar wind speed on UT day 19-May was mostly stable, ranging 
from 365 to 430 km/s and is currently near 405 km/s. The peak 
total interplanetary field strength (IMF, Bt) was 10 nT and the 
north-south IMF component (Bz) range was +6 to -9 nT. A sustained 
interval of southward IMF conditions was observed from 19/1200-1800UT. 
The solar wind speed is expected to remain near background levels 
over 20-22 May.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 19 May: G0

Estimated Indices 19 May : A   K           
   Australian Region       4   12122120
      Cocos Island         3   12111120
      Darwin               5   12122121
      Townsville           7   12223221
      Learmonth            5   12122220
      Alice Springs        3   11122110
      Gingin               5   12113220
      Canberra             3   01122111
      Kennaook Cape Grim   4   01123120    

Estimated Antarctic Regional K Indices 19 May :
      Macquarie Island     6   01133220
      Casey                6   22222121
      Mawson              15   24322252

Observed Regional daily pc3 Indices 19 May : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               4   (Quiet)
      Canberra             4   (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 19 May : A 
           Fredericksburg         9
           Planetary             12                         

Observed AFr/Ap Indices 18 May :  A   K
           Fredericksburg        14
           Planetary             15   3434 4322     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
20 May     8    G0
21 May     8    G0
22 May     6    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 19-May. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with an isolated period of 
G1 observed at Mawson. G0 geomagnetic conditions are expected 
over 20-22 May.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
19 May      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
20 May      Normal         Normal         Normal-fair
21 May      Normal         Normal         Normal-fair
22 May      Normal         Normal         Normal

COMMENT: HF radio communication conditions on UT day 19-May were 
mostly normal. Mostly normal HF conditions are expected over 
20-22 May. Shortwave fadeouts are possible.

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


Date   T index
19 May   149

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 65% during local night.
   Niue Island Region:
      Enhanced by 20% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   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
20 May   145    Near to 15% above predicted monthly values
21 May   145    Near to 15% above predicted monthly values
22 May   145    Near to 15% above predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 54 was issued on 
19 May and is current for 20-22 May. Maximum usable frequencies 
(MUFs) on UT day 19-May were near predicted monthly values to 
25% enhanced in Northern Australia. Spread F was observed at 
Hobart during local night hours. Ionospheric scintillation was 
observed at Darwin and Weipa from 19/1142-1610UT. MUFs are expected 
to be near predicted monthly values to 15% enhanced over 20-22 
May. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 18 May
       Daily Proton Fluence >1 MeV:   1.5E+07
       Daily Proton Fluence >10 MeV:  6.6E+04
       Daily Electron Fluence >2 MeV: 2.90E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.5

DSCOVR Satellite Solar Wind Day Averaged Data for 18 May
Speed: 412 km/sec  Density:    2.3 p/cc  Temp:    48000 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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