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Understanding HF & VHF propagation conditions using data from N0NBH's HAMQSL Solar Data Panel
Category Radio Blackouts
Use X-Ray
Solar Radiation Storms
Use Proton Flux
Geomagnetic Storms
Use K-Index/K-nT/ Aurora/Solar Wind/Bz
Band Openings
Use Solar Flux (SN)
Electron Alert
Use Electron Flux
Extreme X20 (1 per cycle)
Complete HF blackout on entire sunlit side lasting hours
1.0e+06 (1 per cycle)
Complete HF blackout in polar regions
K=9 (nT=>500) [Aur=10++] (SW=>800) [Bz=-40 -50]
(4 per cycle)
HF impossible. Aurora to 40°. Noise S30+.
200-300 (SN=160-250)
Reliable communications all bands up through 6m
>1.0e+03 Alert
Partial to complete HF blackout in polar regions
Severe X10 (8 per cycle)
HF blackout on most of sunlit side for 1 to 2 hours
1.0e+05 (3 per cycle)
Partial HF blackout in polar regions
K=8 (nT=330-500) [Aur=10+] (SW=700-800) [Bz=-30 -40] (100 per cycle)
HF sporadic. Aurora to 45°. Noise S20-S30.
Strong X1 (175 per cycle)
Wide area HF blackout for about an hour on sunlit side
1.0e+04 (10 per cycle)
Degraded HF propagation in polar regions
K=7 (nT=200-330) [Aur=10] (SW=600-700) [Bz=-20 -30]
(200 per cycle)
HF intermittent. Aurora to 50°. Noise S9-S20.
150-200 (SN=105-160)
Excellent conditions all bands up through 10m w/6m openings
Moderate M5 (350 per cycle)
Limited HF blackout on sunlit side for tens of minutes
1.0e+03 (25 per cycle)
Small effects on HF in polar regions
K=6 (nT=120-200) [Aur=9] (SW=500-600) [Bz=-10 -20]
(600 per cycle)
HF fade higher lats. Aurora to 55°. Noise S6-S9.
120-150 (SN=70-105)
Fair to good conditions all bands up through 10m
<1.0e+03 Active
Degraded HF propagation in polar regions
Minor M1 (2000 per cycle)
Occasional loss of radio contact on sunlit side
1.0e+02 (50 per cycle)
Minor impacts on HF in polar regions
K=5 (nT=70-120) [Aur=8] (SW=400-500) [Bz=0 -10]
(1700 per cycle)
HF fade higher lats. Aurora to 56°. Noise S4-S6.
90-120 (SN=35-70)
Fair conditions all bands up through 15m
<1.0e+02 Active
Minor impacts on HF in polar regions
Active C1 Moderate Flare
Low absorption of HF signals
1.0e+01 Active
Very minor impacts on HF in polar regions
K=3-4 (nT=20-70) [Aur=6-7] (SW=200-400) [Bz=0-+50] Unsettled/Active
Minor HF fade higher lats. Aurora 60-58°. Noise S2-S3.
70-90 (SN=10-35)
Poor to fair conditions all bands up through 20m
<1.0e+01 Normal
No impacts on HF
Normal A1-B9 No/Small Flare
No or very minor impact to HF signals
1.0e+00 Normal
No impacts on HF
K=0-2 (nT=0-20) [Aur=<5] (SW=200-400) [Bz=0-+50] Inactive/Quiet
No impacts on HF. Aurora 67-62°. Noise S0-S2.
64-70 (SN=0-10)
Bands above 40m unusable
<1.0e+00 Normal
No impacts on HF
VHF Conditions
 Aur Lat (Auroral Latitude): Indicates lowest latitude from the current Aurora Activity measurement. Text color coded for low activity, hi-latitude, & mid-latitude.
 Aurora (Northern Auroral Activity): Band Closed = No/Low Auroral activity. High LAT AUR = Auroral activity >60°N. MID LAT AUR = Auroral activity 60° to 30°N.
 EsEU (Sporadic E - Europe): Band Closed = No Sporadic E (ES) activity. High MUF (2M only) = Cond support 2M ES. 50/70/144MHz ES = Respective band open
 EsNA (Sporadic E - North America): Band Closed = No Sporadic E activity. High MUF = Cond support 2M ES. 144MHz ES = Sporadic E reported >140 MHz.
 EME (Earth-Moon-Earth): Current EME degradation. Very Poor (>5.5dB), Poor (4dB), Moderate (2.5dB), Good (1.5dB), Very Good (1dB), Excellent (<1dB).
 Solar Flare Probability: Provides the probability of a solar flare (in %) for the net 24 hours.
 MUF (Max Usable Frequency Bar Color): No Sporadic E (ES) activity / ES reported @ 6M / ES reported @ 4M / Cond support 2M ES / ES reported @ 2M
 MS (Meteor Scatter) Activity Color bar: Provides meteor activity color coded MIN to MAX conditions (see the graph below the bar).

©N0NBH Paul L Herrman 2010
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