Fw: [NLRS] RE: [Mw] Great Lakes Propagation

Mon, 29 Sep 2003 19:40:06 -0500

The XYL & I were in Copper Harbor early and as Jon points out, the
temperatures were unseasonably hot & humid (lower to mid  90s) on Thursday
and much of Friday.    However, later on Friday afternoon, what must have
been a cold front moved inland off the lake (accompanied by distant
thunderheads/lightning) and the temperature fell nearly 20 degrees in a
matter of 2 to 3 hours.    By dark, the temperature was in the low 70s and
overnight lows in the high 60s...    (Quite a relief for motels that don't
normally need air conditioning.)   Donn's weather observations gathered
during the contest on Saturday reflects far cooler and more moderate
temperatures and a few passing showers.    It's interesting to note the
temperature difference was probably not that great between lake level, mid
lake buoys, and our operating position.

But a fascinating topic none the less....   Donn, thanks for the urls and
information sources to read up on!

73s   Jim    K0KFC

----- Original Message -----
From: <[email protected]>
To: <[email protected]>; <[email protected]>; <[email protected]>;
<[email protected]>
Sent: Monday, September 29, 2003 6:48 PM
Subject: Re: [NLRS] RE: [Mw] Great Lakes Propagation

> I know that during our excellent propagation across Lake Superior that the
> weather buoy that was located pretty close to mid path indicated that its
air
> temperature and its dew point were both 65 degrees F and that the lake
> temperature (at the surface) was also 65 degrees F.   At the same time
"inland" was
> setting new high temperature records in the mid 90's.   This same hot air
must
> have been laying over the Lake at elevation.   I think that its classic
tropo
> ducting with warm "drier" air over cooler moist air where the coolness and
> wetness is provided by the lake.   I would speculate that this propagation
mode is
> not uncommon in July and August over the Great Lakes, perhaps especially
Lake
> Superior as its the coldest of the Great Lakes.
>
> Its all speculation on my part, but the propagation was amazing.
>
> 73, Jon
> W0ZQ
>
>
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