[South Florida DX Association] ARLP008 Propagation de K7RA

[Bill Marx]

 ZCZC AP08
> QST de W1AW  
> Propagation Forecast Bulletin 8  ARLP008
> From Tad Cook, K7RA
> Seattle, WA  February 25, 2005
> To all radio amateurs 
> 
> SB PROP ARL ARLP008
> ARLP008 Propagation de K7RA
> 
> Average daily geomagnetic indices for the week were slightly higher,
> and the average daily sunspot numbers and solar flux were down
> markedly. Average daily sunspot numbers were down nearly 30 points
> to 45.4, and average daily solar flux was down nearly 19 points to
> 97.3. This is compared to the seven days reported at the end of last
> week's Propagation Forecast Bulletin ARLP007.
> 
> A week ago this bulletin mentioned that conditions for last
> weekend's ARRL International DX CW Contest should be fair to good,
> but there was a worry about geomagnetic activity. Mid-latitude
> geomagnetic activity wasn't bad, but polar paths were affected more.
> The planetary A index for February 18-20 was 25, 14 and 12, and the
> high latitude college A index (from Alaska) was 37, 40 and 16. The
> mid latitude A index was moderate, at 14, 8 and 6.
> 
> Jeff Hartley, N8II in West Virginia mentioned in an email that he
> had a blast on 20-meters, despite the somewhat disturbed conditions.
> The beam heading from his place to Japan is 330 degrees, which puts
> it right through the auroral zone. JA stations were weak and
> fluttery. Propagation to Europe was much better (Germany has a 47
> degree beam heading for Jeff), and he worked about 1500 European
> stations.
> 
> Disturbed conditions on HF often portend good propagation on VHF.
> Jon Jones, N0JK of Kansas mentioned Sporadic E skip on 6-meters from
> February 18-23. He and Ken Neubeck, WB2AMU are working on a paper on
> the subject of geomagnetic disturbances and 6-meter E-layer
> propagation. Jon writes, "While aurora activity usually dampens
> regular mid-latitude Es, the day(s) after the aurora subsides may
> see increased Es activity." WB2AMU has written extensively on VHF,
> and has published the books, "Six Meters-A Guide to the Magic Band"
> and "VHF Propagation-A practical guide for radio amateurs."
> 
> N0JK mentioned that the February 20th 6-meter opening lasted from
> 1900z to 0100z, and extended across much of the eastern states and
> southern Canada. He worked two stations in Mexico that day, and
> wrote, "From Kansas, stations in Georgia and Florida were booming in
> for hours." He noted that E-layer openings in late February are
> rare.
> 
> This weekend is the CQ World Wide 160-Meter SSB Contest, and for
> 160-meters we hope for quiet geomagnetic conditions. The latest
> forecast for February 25-27 is for a planetary A index of 15, 20 and
> 20. The Prague Geophysical Institute projects active geomagnetic
> conditions for February 26, and unsettled to active for February 25
> and 27. This is because earth is moving into a solar wind stream
> coming from a coronal hole. Sunspot numbers and solar flux should
> remain quite low. Predicted solar flux for February 25-27 is 80, and
> flux values are not expected to rise above 100 until around March 9,
> and then only slightly.
> 
> If you would like to comment or have a tip, email the author at,
> k7ra at arrl.net.
> 
> For more information concerning propagation and an explanation of
> the numbers used in this bulletin see the ARRL Technical Information
> Service propagation page at,
> http://www.arrl.org/tis/info/propagation.html.
> 
> Sunspot numbers for February 17 through 23 were 51, 46, 51, 60, 33,
> 23 and 54 with a mean of 45.4. 10.7 cm flux was 111.3, 104.2, 98.5,
> 95.7, 94.5, 92.3 and 84.6, with a mean of 97.3. Estimated planetary
> A indices were 6, 25, 14, 12, 8, 4 and 4 with a mean of 10.4.
> Estimated mid-latitude A indices were 7, 14, 8, 6, 4, 3 and 2, with
> a mean of 6.3.
> NNNN
> /EX
> 
>