[Ips-dhfpr] ASWFC Daily HF Prop Report - 11 May 23 issued 2330 UT on 11 May 2023 [SEC=OFFICIAL]

[Regional Warning Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/11 MAY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (11 MAY) 
Date   T index  Conditions    
11 May   109    Normal         

Flares    Max     Fadeout    Freq.  Sectors
  M2.2    0901UT  possible   lower  Mid East/Indian
  M1.8    1829UT  possible   lower  East Pacific/
                                    North American

MUFs:
   Cocos Island Region:
      Enhanced by 35-40%.
   Niue Island Region:
      Near predicted monthly values.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Near predicted monthly values over the UT day.

PCA Event : 10MeV Proton/PCA Event Began at 2325UT 09/05, Ended at 0350UT 11/05

Monthly T index:
Month  T index
Apr      120
May      87
Jun      88


2. FORECAST (12 MAY - 14 MAY)
Date   T index  Conditions       MUFs                              
12 May    95    Normal-poor      Near predicted monthly values/depressed 
                                 15 to 20%
13 May    65    Poor-normal      Depressed 15 to 20%/near predicted 
                                 monthly values    
14 May    80    Normal           Near predicted monthly values   

COMMENT: ASWFC Preliminary HF Communications Warning 45 was issued 
on 9 May and is current for 11-12 May. Maximum usable frequencies 
(MUFs) on UT day 11-May were near predicted monthly values to 
40% enhanced. Spread-F was observed at Hobart, Canberra and Townsville 
at times during local night hours. MUFs are expected to be initially 
near predicted monthly values to enhanced by 15% for 12-May, 
with southern Australian region MUFs becoming depressed during 
local night hours by up to 20%. Northern Australian region MUFs 
are expected to be mostly near predicted monthly values, with 
the possibility of mild depressions, depending on the strength 
of induced geomagnetic activity from the expected CME arrival 
early on the 12-May. Degraded HF conditions are expected during 
local night hours tonight, followed by depressed ionospheric 
frequencies of support on 13-May. Isolated shortwave fadeouts 
are possible.

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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