[Ips-dhfpr] ASWFC Daily HF Prop Report - 17 February 23 issued 2330 UT on 17 Feb 2023 [SEC=OFFICIAL]

[Regional Warning Centre]

SUBJ: ASWFC DAILY HF PROPAGATION REPORT
ISSUED AT 2330UT/17 FEBRUARY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECAST CENTRE
AUSTRALIAN REGION SUMMARY AND FORECAST

1. SUMMARY (17 FEBRUARY) 
Date   T index  Conditions    
17 Feb   111    Normal         

Flares    Max     Fadeout    Freq.  Sectors
  X2.3    2017UT  probable   all    East Pacific/
                                    North American

MUFs:
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 40% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 30% during local night.
      Enhanced by 25% after local dawn.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Near predicted monthly values over the UT day.

PCA Event : No event.

Monthly T index:
Month  T index
Jan      119
Feb      75
Mar      76


2. FORECAST (18 FEBRUARY - 20 FEBRUARY)
Date   T index  Conditions       MUFs                              
18 Feb   100    Fair             Near to 15% above predicted 
                                 monthly values
19 Feb    50    Normal-fair      Depressed 15%/near predicted 
                                 monthly values    
20 Feb    50    Fair-poor        Depressed 15%/near predicted 
                                 monthly values   

COMMENT: ASWFC SWF HF Communications Warning 18 was issued on 
17 February and is current for 18-20 Feb. Maximum usable frequencies 
(MUFs) in the Southern Australian region on 16-Feb were near 
predicted monthly values. MUFs in the Northern Australian region 
on 16-Feb were enhanced by up to 15%, with periods of up to 30% 
enhancements during local night. Spread F was observed at Hobart. 
MUFs are expected to be near predicted monthly values to 15% 
enhanced on 18-Feb. Depressions of up to 15% are expected over 
19-20 Feb due to geomagnetic activity caused by two anticipated 
CME impacts, one on 18-Feb from a CME first observed on 15-Feb 
and one on 19/2200 ± 12 hours from a CME first observed on 18-Feb. 
Shortwave fadeouts are probable.

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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