Terry K4RX Said:
.....I heard W9, W1, W2, W3, W5, and northern-W4 giving fine reports, but
nothing
was heard at this qth. If it was spotlight propagation, then the beam never
shined on North Florida.....
Thomas KN4LF Says:
3B9C was propagating into North America via the E layer valley/F layer duct
mechanism. The duct was ruptured "in a manner of speaking" allowing the 3B9C RF
signal to drop into New England and the Mid Atlantic States in a spotlike
appearance.
If you look at the weather map last evening there was a strong extra-tropical
surface-250 mb low off the coast of New England. This winter storm system
produced an upward propagating Internal Buoyancy/Gravity Wave that ruptured the
E layer valley/F layer duct open on the North America end of the path. In the
S.E. states including Florida high pressure is dominant with no mechanism in
place to our east to produce upwardly propagating Internal Buoyancy/Gravity
Waves that would rupture the duct mechanism on a bearing into Florida.
You can see this winter storm system on this weather map at
http://weather.cod.edu/forecast/ETA/etaUS_500_avort_0.gif . Also if you look in
the vicinity of Baja California there is a fledgling new 500 mb
shortwave/vorticity maximum. This next disturbance will rapidly track across
the southern latitudes of the U.S. the next several days and emerge into the
Atlantic in the vicinity of the Carolina's. This will produce an opportunity
for the S.E. U.S. including Florida to be able to work the 3B9C with more
consistency, as the E layer valley/F layer duct mechanism is ruptured on a
bearing into Florida.
You can find more information on Internal Buoyancy/Gravity Waves on my "HF/MF
Propagation Theory Notes" website at http://www.kn4lf.com/kn4lf8.htm .
73 & GUD DX,
Thomas F. Giella, KN4LF
Retired Space & Atmospheric Weather Forecaster
Plant City, FL, USA
Grid Square EL87WX
SKYWARN Observer # HIL-249
SWFWMD Observer #574
PODX 070 PSK31 Member #349
Yaesu FT-840 & PSK31 News Group http://groups.yahoo.com/group/yaesu_ft840
10 & 6 Meter Propagation Beacon Network http://www.PropNET.org
Solar Space Weather & Geomagnetic Data Archive http://www.kn4lf.com/kn4lf5.htm
HF/MF Radio Propagation Theory Notes http://www.kn4lf.com/kn4lf8.htm
160-10 Meter Amateur Radio Resources & More http://www.kn4lf.com
Florida Space & Atmospheric Weather Institute http://www.kn4lf.com/fsawi.htm
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