SB PROP @ ARL $ARLP008
ARLP008 Propagation de K7RA
ZCZC AP08
QST de W1AW
Propagation Forecast Bulletin 8 ARLP008
From Tad Cook, K7RA
Seattle, WA February 22, 2019
To all radio amateurs
SB PROP ARL ARLP008
ARLP008 Propagation de K7RA
No sunspots are visible since January 30. The lack of sunspot
activity has persisted for over 3 weeks, as of February 21.
This past week (February 14 to 20) the average daily solar flux was
only marginally higher, rising just barely from 70.4 to 70.6.
Geomagnetic indicators were lower, with average daily planetary A
index declining from 8.1 to 4.9, and average daily mid-latitude A
index (measured at a single magnetometer in Virginia) dropping from
6.1 to 3.9.
One advantage at the bottom of the solar cycle is there is less
geomagnetic activity, which is a benefit for propagation on 160, 80
and 60 meters. The recent issue of ARRL Contest Update mentioned
this, when they talked about the CW weekend last week of the ARRL
International DX Contest: "There are many reports that 160 and 80
meters experienced exceptional propagation. The phone version of
this contest is coming up on March 2."
Also in the same Contest Update is a link to K0NR and his piece
about how VHF has propagation opportunities beyond line-of-sight:
http://www.k0nr.com/wordpress/2019/02/the-myth-of-vhf-line-of-sight/
In the 45 day outlook for solar flux, the current forecast shows
predicted values below 70, for the first time in a few weeks, from
March 1 to 10 and again on March 26 through April 6.
We are approaching the end of the winter season, and the vernal
equinox (first day of spring) happens on Wednesday, March 20. This
suggests better HF conditions. Likewise in the Southern Hemisphere
is the autumnal equinox, a good period for HF propagation.
The 45-day solar flux prediction on February 21 was 71 on February
22 through March 1, 68 on March 2 to 10, 70 on March 11 to 25, and
68 on March 26 through April 7.
Predicted planetary A index is 10 and 8 on February 22 and 23, 5 on
February 24 to 26, then 16, 20, 18, 12 and 8 on February 27 through
March 3, then 5, 8, 5, 8, 10 and 8 on March 4 to 9, 5 on March 10
and 11, then 12 and 10 on March 12 and 13, 5 on March 14 to 17, then
12, 16, 12 and 8 on March 18 to 21, 5 on March 22 to 25, then 15,
18, 18, 12, 8 and 5 on March 26 to 31, then 8, 5, 8, 10, and 8 on
April 1 to 5, and 5 on April 6 and 7.
Geomagnetic activity forecast for the period February 22 til March
20, 2019 from F. K. Janda, OK1HH:
"Geomagnetic field will be
Quiet on February 24 to 26, March 10, 15 and 16
Quiet to unsettled on February 23, March 4 to 7, 9, 11, 18
Quiet to active on February 22, March 3, 8, 12 to 14, 17, 19 and 20
Unsettled to active on February 27, March 2
Active to disturbed on February 28, March 1
Solar wind will intensify on February 22, (28,) March (1 to 3, 6 to
9,) 13 to 15, 20
Parenthesis means lower probability of activity enhancement.
Again there are changes in the configuration of active areas, so the
predictability of the prognoses decreases and their computation is
difficult."
Newsweek article on the solar corona and the next sunspot cycle:
https://bit.ly/2BLeT2W
Regarding the recent unusual (and low) predictions for sunspot
numbers and solar flux seen on the final few pages of NOAA's weekly
preliminary Report and Forecast (see https://bit.ly/2TagxVI) to see
an update we will probably need to wait for the next Space Weather
Workshop in April. The Solar Cycle 25 Prediction Panel meets on
Friday, April 5, 2019.
Wayne Greaves, W0ZW of Farmington, New Mexico wrote in a recent
email, "The level of activity during the ARRL International DX
Contest (CW) last weekend certainly proved to me that you can work
DX at the bottom of the solar cycle. I even made a 10 M contact
with a station in Chile."
The latest forecast from Dr. Skov:
https://youtu.be/EHeO-5URiQU
If you would like to make a comment or have a tip for our readers,
email the author at, k7ra at arrl.net.
For more information concerning radio propagation, see the ARRL
Technical Information Service at
http://arrl.org/propagation-of-rf-signals. For an explanation of
numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere.
An archive of past propagation bulletins is at
http://arrl.org/w1aw-bulletins-archive-propagation. More good
information and tutorials on propagation are at http://k9la.us/.
Monthly propagation charts between four USA regions and twelve
overseas locations are at http://arrl.org/propagation.
Instructions for starting or ending email distribution of ARRL
bulletins are at http://arrl.org/bulletins.
Sunspot numbers for February 14 through 20, 2019 were 0, 0, 0, 0, 0,
0, and 0, with a mean of 0. 10.7 cm flux was 71.4, 70.9, 70.7,
70.1, 69.9, 70.2, and 71, with a mean of 70.6. Estimated planetary
A indices were 10, 4, 3, 4, 7, 3, and 3, with a mean of 4.9.
Estimated mid-latitude A indices were 8, 4, 3, 3, 5, 2, and 2, with
a mean of 3.9.
NNNN
/EX
