Interesting Night Time AM Phenomenon

[radiorob2.0]

A coupe of times I have experienced what could be best described as no skywave. Graveyard signals within fifty miles were present without the interference. Even the directionals that throw little signal my way appeared, it was daytime listening by dark of night. What atmospheric phenomenon or lack there of would cause that condition?

 

[boiseengineer]

The sun's acting up.
http://www.swpc.noaa.gov/NOAAscales/index.html#RadioBlackouts

 

[stormy01]

A couple of times I have experienced what could be best described as no skywave. Graveyard signals within fifty miles were present without the interference. Even the directionals that throw little signal my way appeared, it was daytime listening by dark of night. What atmospheric phenomenon or lack there of would cause that condition?

Perhaps a strong Aurora Borealis? (Which is a by-product of increased Solar Activity)

http://www.solarstorms.org/SRefStorms.html

 

[fybush]

Perhaps a strong Aurora Borealis? (Which is a by-product of increased Solar Activity)

http://www.solarstorms.org/SRefStorms.html

Absolutely. Auroral nights are fascinating on AM - skywave just falls away, and you get to hear groundwave signals from stations that are often otherwise hidden by other co-channel daytime signals.

 

[KR4BD]

Here in Central Kentucky, I can always tell when the Aurora is acting up. When I can not hear any of the 50 KW stations to the North of me like WTAM, WJR, WGN, WLS, WBBM, etc., I know we are experiencing auroral conditions. I usually find Spanish language stations on these frequencies and all other stations to the south of me are very strong. Beside enhancing the Graveyard frequencies, it is a great time to pick off low power, seldom, if ever heard stations on the regional frequencies, too.

 

[schmave]

Here in Central Kentucky, I can always tell when the Aurora is acting up. When I can not hear any of the 50 KW stations to the North of me like WTAM, WJR, WGN, WLS, WBBM, etc., I know we are experiencing auroral conditions. I usually find Spanish language stations on these frequencies and all other stations to the south of me are very strong. Beside enhancing the Graveyard frequencies, it is a great time to pick off low power, seldom, if ever heard stations on the regional frequencies, too.

The last aurora I remember in some detail was 2004. It was fascinating. I work a lot of nights ... is this another big one headed our way? Haven't noticed any difference with the usual skywave powers lately.

 

[MarioMania]

When is it going to happen again??

 

[KR4BD]

It happens periodically. I usually notice it a few times every winter season. We had a night a few weeks ago that was fairly "auroral". When it is EXTREME, it is really bizarre. When conditions are intense, NOTHING can be heard to the North of me via skywave at night. But, conditions to the South of me are greatly enhanced, groundwave AND skywave. A couple years ago, I was hearing MANY very low power stations (under 100 watts) at night from Tennessee, SE Kentucky, Southern West Virginia and many Spanish language stations on all the "clears" (760, 880, 1020, etc.) that are not usually received.

You'll know it when it is happening! I generally scan the AM band every night looking for the unusual to happen....

 

[vibe]

i caught a really low power AM on 690 from WV (from central ma) during one of those events. Can't remember the calls but clearly ID' the station at the time. And on a nite when WSB, WWL, were loud and clear and ESPN 1040 St. Pete was in.

 

[pianoplayer88key]

So how do you tell when we're getting auroral conditions? Also is it possible to experience it as far south as 32°45'40"N latitude where I am about 11-12 miles east of San Diego, CA?
From previous posts in this thread it seems that stations to the north would be weak or non-existent. What about stations to the east? For example, some regularly-received stations to the north of here are 560 KSFO (weak), 580 KMJ (weak), 640 KFI (strong, groundwave), 680 KNBR (strong), 700 KALL (fair), 710 KSPN (strong, groundwave weak daytime, not sure about night with reduction in power), 720 KDWN (strong), 740 KCBS (strong), 780 KKOH (strong), 810 KGO (strong), 830 KLAA (fair, groundwave), 840 KXNT (strong), 870 KRLA (weak to fair, faint groundwave daytime), 890 KDXU (fair to strong), 930 KHJ (fair, weak groundwave daytime), 980 KFWB (fair, faint groundwave daytime), 1000 KOMO (weak, mixing with KCEO), 1020 KTNQ (fair, faint groundwave daytime), 1070 KNX (strong, groundwave), 1110 KDIS (weak + groundwave daytime), 1160 KSL (strong), 1180 KERN (fair), 1200 KYPA (weak to fair), 1320 KTCT (weak), 1530 KFBK (strong), 1560 KNZR (fair), 1580 KBLA (fair, faint groundwave daytime), 1620 KSMH (weak to fair), 1640 KDIA (weak to fair), 1660 KTIQ (weak to fair), 1670 KHPY (fair to strong), 1680 KGED (weak to fair), and 1690 KFSG (weak). If I had auroral conditions, would none of the above stations be receivable, except the groundwave stations like KFI, KSPN (maybe), KLAA, KHJ (maybe), KFWB (maybe), KCEO (without interference from KOMO, unless their groundwave would be too weak to reach me at night), and KNX? (And with KTNQ gone would it bring in something like KCKN or maybe even KDKA?)
Also what about stations to the east - what happens to them during Auroral conditions? Some regulars here include 660 KTNN (strong), 770 KKOB (strong), 850 KOA (strong), 880 KRVN (weak, mixing with others), 910 KGME (weak, if I null local KECR which is difficult with a 70+dBuV signal on the Tecsun PL-606), 960 KKNT (weak to fair), 1060 KDUS (weak), 1110 KFAB (weak, mixing with KDIS), and 1520 KOKC. How would reception of those be affected during Auroral conditions? Would they be about the same, weaker or non-existent, or stronger?