[MAMS] Early morning propagation, works

[Dr. Gerald N. Johnson]

Often all it takes is a little breeze of 3 or 4 mph to mix the inversion 
layer that naturally happens overnight because of radiant cooling of the 
earth surface that cools a thin layer of air. Clear skies and calm are 
what allows that surface radiant cooling to cool an air layer. And it 
doesn't take much solar input to cause that light a breeze. To add 
complication for taking advantage, the standard NWS anemometer usually 
stalls at about 3 mph, so 3 mph can be called calm in the weather 
reports but there's air motion enough to destroy temporary temperature 
inversions and fog layers (evidence of that cooled air).

73, Jerry, K0CQ

On 7/6/2011 10:33 AM, Lloyd Ellsworth wrote:
> Early this morning, ran a sked with K8MD EN82bq from AJ EN74at on 2304. Tried to get on as Early as. Got there by 7AM EDT. Local Sunrise was 6:01. Found him right away. By the time I found and fixed a bad ground in the 2304 station TX line, and could transmit back 7:30. The band conditions had faded away. 2M sig went from s7 signals, to under s1 in that period. Happens Early. Happens quick guys. Does not last long. Mark noticed similar observations, listening to the 2304.3 WW8M beacon.
>
>
> So, looking back at Last Saturday July 2 MAD, that was definitely a concern. Early.
>
> This Saturday 7/9, going to try another sked with K8MD, EARLY Saturday AM from AJ. Close to 6AM EDT as I can handle. Likely 2M, 2304, maybe 3.4 and 10 GHz.
>
>
> Note from W8ISS James, suggests he will be on from Lupton EN73 Saturday and Sunday, with 3.4 and 10 GHz. Don't know how the AJ (Empire Mi) to Lupton path might work. Willing to try after Mark.
>
>
> Lake Michigan. Finding now that same weather, as about 4 years ago. Thick Lake fog, but look up, and see clear blue sky. It is not very thick. Under 1,000 ft. 74, calm. Dunes along the Lake are about 500 ft above it. AJ is about 4 miles from the Lake. When the fog was there, good prop. As soon as it started to evaporate. Conditions faded. At that time, 24 GHz signals were stronger than 10 GHz signals. And the 47 GHz signals were better than the 24 GHz signals. It appears that Lake Michigan has warmed up enough now, that the Lake effect propagation is starting to kick in. Been very poor all Spring. Cold Lake, warm wet air. Need to run some 24 and 47 GHz. After talking with Mark, talked across the Lake to W9OSS in Green Bay, on 2M, and signals were extremely strong.
>
>
>
> 73, Lloyd NE8I/r
> EN74 etc
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