[Ips-dhfpr] ASWFC Daily HF Prop Report - 11 May 24 issued 2340 UT on 11 May 2024 [SEC=OFFICIAL]

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SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/11 MAY 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (11 MAY) 
Date   T index  Conditions    
11 May   113    Poor-fair      

Flares    Max     Fadeout    Freq.  Sectors
  M1.0    0105UT  possible   lower  West Pacific
  X5.8    0123UT  probable   all    West Pacific
  M1.2    0743UT  possible   lower  Mid East/Indian
  M1.7    0915UT  possible   lower  Mid East/Indian
  M3.1    1018UT  possible   lower  European
  X1.5    1144UT  probable   all    European
  M1.2    2041UT  possible   lower  East Pacific/
                                    North American

MUFs:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 70% during local night.
   Northern Australian Region:
      Depressed by 20% during local day.
      Enhanced by 40% during local night.
      Enhanced by 30% after local dawn.
   Southern Australian Region:
      Depressed by 55% during local day.
      Enhanced by 25% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Proton event in progress, increased absorption observed.

PCA Event : 10MeV Proton/PCA Event Began at 1350UT 10/05, Ended at 0050UT 11/05
 and, 10MeV Proton/PCA Event Began 11 05 2024 0210UT and is in progress
 and, 100MeV Proton/PCA Event Began 11 05 2024 0155UT and is in progress

Monthly T index:
Month  T index
Apr      125
May      114
Jun      116


2. FORECAST (12 MAY - 14 MAY)
Date   T index  Conditions       MUFs                              
12 May   100    Poor-fair        Near predicted monthly values
13 May    70    Poor-fair        15 to 30% below predicted monthly 
                                 values    
14 May    90    Normal-fair      Near predicted monthly values   

COMMENT: ASWFC Preliminary HF Communications Warning 49 was issued 
on 9 May and is current for 10-12 May. ASWFC SWF HF Communications 
Warning 50 was issued on 9 May and is current for 10-12 May. 
Maximum usable frequencies (MUFs) on UT day 11-May were strongly 
depressed by 20-50% during the local day and strongly enhanced 
during local night hours in association with geomagnetic storm 
activity. Strong spread F was observed during local night hours 
for southern Australian region sites. A shortwave fadeout was 
observed 11/0101-0405UT in association with the X5 flare. An 
extended interval of equatorial ionospheric scintillation was 
observed at Darwin, Niue and Weipa 11/1139-2040UT. MUFs are expected 
to be initially near predicted monthly values on 12-May, becoming 
degraded overnight with further ionospheric depressions, though 
not as severe, are likely on 13-May. Frequent shortwave fadeouts 
are expected.

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For an explanation of some of the terms in this report, go to
https://www.sws.bom.gov.au, and follow links to Educational->
Glossary on Solar Terrestrial Terms.

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au