SB PROP @ ARL $ARLP029
ARLP029 Propagation de K7RA
QST de W1AW
Propagation Forecast Bulletin 29 ARLP029
From Tad Cook, K7RA
Seattle, WA July 16, 2021
To all radio amateurs
SB PROP ARL ARLP029
ARLP029 Propagation de K7RA
Solar activity declined this week, by a lot, but 6 and 2 meters
yielded exceptional openings. Average daily sunspot number changed
from 55.6 to 21.3, and average daily solar flux dropped from 88.9 to
Geomagnetic indicators were about the same, with average daily
planetary A index at 6.6, although the daily value increased to 14
on Wednesday due to increasing solar wind.
Predicted solar flux is 74 on July 16, 76 on July 17, 74 on July
18-20, 76 on July 21-22, 78 on July 23, 79 on July 24-28, 77 on July
29 through August 1, 75 on August 2, 74 on August 3-9, 73 on August
10-11, 75 on August 12-15, then 79 and 81 and on August 16-17 and 79
on August 18-24.
Predicted planetary A index is 10 on July 16, 5 on July 17-20, 8 on
July 21-22, 5 on July 23 through August 1, 8 on August 2, 5 on
August 3-7, then 12, 16 and 12 on August 8-10, 8 on August 11-12,
and 5 on August 13-28.
Geomagnetic activity forecast for the period July 16 to August 12,
2021 from F.K. Janda, OK1HH.
"Geomagnetic field will be:
quiet on: July 16-18, 25, 30, August 4, 7, 12
quiet to unsettled on: July 20, 23-24, 28-29, August 2, 9
quiet to active on: July 19, 21-22, 31, August 1, 6, 11
unsettled to active: July 26-27, August 3, 5, 8, 10
active to disturbed:- nothing
- Parenthesis means lower probability of activity enhancement.
- The previous prediction of increased geomagnetic field activity
for July 12 was although correct, but the solar wind from the
equatorial coronal hole apparently traveled a longer path, by slower
speed, then expected. That's why it didn't arrive until July 14."
"Propagation crossing low and mid latitudes, the auroral ovals and
polar regions are likely to be normal through Sunday.
"We are in the quiet geomagnetic activity season, only about half as
many geomagnetically disturbed days occur in June and July compared
to the more geomagnetically active equinox seasons.
"Sporadic-E propagation occurs every day during June and July at
mid-latitudes in the northern hemisphere making long distance
propagation up to 15,000 km sporadically available in the 17, 15,
12, 10 and 6 meter bands from sunrise through midnight and
occasionally somewhat later.
"The solar flux index (SFI) is likely to be 75 or less through
Sunday. There are two small active regions on the solar visible disk
with one small sunspot and one tiny sunspot:
"160 and 80 meter propagation from North America to VK/ZL and the
south Pacific is likely to be seasonably normal through Sunday.
"40 meter short path propagation to south Asia at about 0015 UTC is
likely to be normal through Sunday. 40 meter short path propagation
from North America to east Asia after about 0930 UTC is likely to be
normal through Sunday.
"30 meter propagation through the auroral ovals and polar regions is
likely to normal through Sunday. 30 meter propagation always
significantly degraded within a few hours of local noon because of
E-region blanketing of long distance F2 propagation.
"30 meter night time long distance propagation in the northern
hemisphere is likely to improve due to increased ionizing solar
radiation in the northern high latitude regions caused by higher
solar elevation angles and short nights with no source of ionizing
"20 meter daytime and evening propagation through the auroral ovals
and polar regions is likely to be normal through Sunday.
"20 meter northern transpolar propagation within a few hours of
sunrise and sunset is improving with longer duration solar ionizing
radiation on the northern polar region caused by high solar
elevation angles 24 hours per day during the midnight Sun season.
"20 meter long distance propagation is significantly degraded from
mid-morning through late afternoon at low and mid-latitudes in the
northern hemisphere by F1 region midday blanketing of low angle long
distance propagation during the summer.
"20 meter late afternoon, nighttime and early morning long distance
propagation in the northern hemisphere is likely to improve due to
increased ionizing solar radiation in the northern high latitude
regions caused by higher solar elevation angles and short nights
with no source of ionizing solar radiation.
"17 and 15 meter daytime long distance propagation in the northern
hemisphere is likely to improve due to increased ionizing solar
radiation in the northern high latitude regions caused by high solar
elevation angles and long days. 17, 15, 12, 10 and 6 meter
sporadic-E propagation up to 15,000 km is likely to be sporadically
available from sunrise through midnight and occasionally later
through late July.
"Geomagnetic disturbances caused by coronal hole high speed stream
effects are likely to remain mostly brief, minor, and somewhat less
frequent through at least late 2021. The southward oriented (-Bz)
component of the IMF plays a crucial but unpredictable role in
triggering all geomagnetic storms.
"Brief minor to moderate geomagnetic storms may be gradually
triggered when the IMF persists in a southward orientation (-Bz)
with enhanced IMF field strength for several hours coincident with
the effects of an Earth directed coronal hole high speed stream.
"More frequent, longer duration, minor to severe geomagnetic storms
may be triggered suddenly and unpredictably when the IMF persists in
a southward orientation (-Bz) with enhanced IMF field strength for
several hours or more coincident with the effects of an Earth
directed fast CME.
"The solar wind is expected to be at background state through
Sunday. The geomagnetic field is likely to be mostly quiet through
Sunday. Coronal hole high speed stream and CME effects, geomagnetic
storms and solar flares are not likely through Sunday.
"Mid-latitude northern hemisphere sunset is now 5 minutes earlier
and daylength is 19 minutes shorter than it was on the June 21st.
Day length and solar elevation angle in the northern polar region
are slowly declining due to gradually waning summer solstice
James O'Brien, W4AMP, in Dallas, Georgia, wrote:
"A fantastic F2 opening on 6 meters was heard most of the morning of
July 14th here in EM73NV. Rig is Yaesu FT5000MP, amp is Heathkit
SB200 conversion (600 watts), antenna is Cushcraft three element
Yagi at 60 feet.
"Worked EA7L, F4ARU, EB1A, F4GGQ, and I2PJA on SSB. Signals were
strong with QSB. Looking forward to more."
N0JK, from Lawrence, Kansas, wrote:
"Another spot for WP4G on 2M maybe Es July 15.
"2021-07-15 23:19 AA5JF (EM83XL) 144.174.0 FT8 WP4G (FK68WK) 2301 km Tropo? EM83XL<>FK68"
More 6 meter excitement:
"The opening on July 14 2021 from 0930-1900 UTC here in MA yielded
me 7 new countries including Hawaii. Now 49 of 50 for 6M WAS. I
worked OD, 9K, YL, 4X, 5B, SV5. Now at 114 worked and 110 confirmed.
This opening was the best I have ever seen. EU all day long, so many
decodes in FT8 you had to scroll. FT8 on 313 and 323. Signals were
strong and stable, not much QSB. Which made it easier to work. This
day goes down in the books as the best ever opening on the magic
band. 73, Dick, K2KA"
Sent to me and N0JK from Rich, K1HTV:
"Today, July 13, 2010, 2M FT8 operators from the Mid-Atlantic, the
Carolinas, GA, AL, and FL areas as well as some in W9 and W0 land
experienced an extraordinary day in the history of North American
144 MHz propagation.
"As I was driving home from COSTCO, my son Andy, K1RA, who lives
about 10 miles away, came on the local 2M repeater to notify me that
the Pack Rat guys in the Philly area were working into Puerto Rico
on 144.174 FT8. When I arrived home, I swung the beam to the
Caribbean and started working 2M Es.
"So far, here is the 144.174 MHz K1HTV (FM18ap) FT8 log for July 13,
"1518Z NP4BM FK68lm - 1534 miles (2469 km)
1528Z WP4KJJ FK68xf - 1579 miles (2541 km)
1604Z W4AS EL95to - 910 miles (1460 km)
1606Z ZF1EJ EK99jg - 1349 miles (2171 km)
"I thought that I did well until I started seeing spots by KA9CFD in
"NP4BM in FK68lm - 2070 miles (3330 km)
WP4KJJ in FK68xf - 2127 miles (3423 km)
HI3T in FK58ak - 1961 miles (3156 km)
HI8DL in FK58al - 1959 miles (3153 km)
"And then Jon, I saw your even longer distance DX Cluster putouts
for WP4KJJ in FK68xf - 2263 miles (3643 km). Extraordinary! WP4G
in FK68wk - 2249 miles (3619 km).
"It sure looks like it took two separate, well placed highly ionized
patches for this to happen and a PSK Reporter Es MUF map shows the
locations of the two. One was at EM64 and the other patch was at
"The 2m Es opening that I observed from my FM18ap in VA, to Puerto
Rico went from 1518-1558 UTC and then again, briefly from 1630-1633
"The opening to W4AS in EL95 at 1605 UTC only lasted two minutes and
then was gone.
"The opening from FM18ap to ZF1EJ in EK99 started at 1606 UTC and
lasted until 1624 UTC.
"So, it was an incredible 144 MHz propagation day here in NA. I
called a few CQs on 144.200 SSB but had no luck. All of the activity
was on the 144.174 MHz FT8 frequency."
"Bryce Foster, K4NBF, in Mashpee, MA (FN41sp) heard the following
stations on Tuesday, July 13, 2021:
"1255 UTC: 104.3 WZIN 'The Buzz' in Charlotte Amalie, U.S. Virgin
Islands running 44 kW at 1641 miles (2640 km) (1x-Es)
"1956 UTC: 93.7 HILS-FM 'Latidos' in Santo Domingo, Dominican
Republic running 5 kW at 1601 miles (2576 km) (1x-Es)
"2034 UTC: 95.6 'Radio Uno' in Barranquilla, Colombia at 2745 miles
(4417 km). Plus, another unidentified station on 98.6 in
"2040 UTC: 98.7 WUKQ-FM 'La Primera' in Mayaguez, Puerto Rico
running (25 kW) at 1810 miles (2912 km). (2x-Es)."
HI8T, from Dominican Republic, wrote:
"Yesterday July 13, 6 meter band was crowded as 20m, I checked my
radio twice to see if it was really on 6 meters. FT8 Signals were
very loud on 50.313, around 1650 UTC, I switched to the FT8 2m freq
144.174 and worked with very good signal KA9CFD in Illinois, after
him many other stations came in. Later that day I got on my car and
tuned the FM radio and heard 1 radio station from Alabama and one
from Georgia. It seems that Solar Cycle 25 will be full of surprises
and one thing that helps is that with FT8 everybody is captive on
the same frequency."
And finally, I've enjoyed hunting for 10 meter CW propagation
beacons from 28.2-28.3 MHz, sometimes using remote webSDR receivers.
I put up my own beacon (with tremendous help from Vlodymyr, AA7DJ)
last Friday after IARU assigned me a frequency, 28.2833 MHz. K7RA/B
is now running about 5 watts 24x7 from CN87uq with a vertical half
wave dipole. If you hear it, email me a report, or send a QSL card.
A regularly updated comprehensive 10 meter beacon list is at
For more information concerning shortwave radio propagation, see
http://www.arrl.org/propagation and the ARRL Technical Information
Service at http://arrl.org/propagation-of-rf-signals. For an
explanation of numbers used in this bulletin, see
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/.
Instructions for starting or ending email distribution of ARRL
bulletins are at http://arrl.org/bulletins .
Sunspot numbers for July 8 through 14, 2021 were 23, 23, 24, 23, 22,
11, and 23, with a mean of 21.3. 10.7 cm flux was 73.4, 73.8, 74,
73.6, 71.6, 72, and 72.1, with a mean of 72.9. Estimated planetary
A indices were 5, 5, 6, 4, 7, 5, and 14, with a mean of 6.6. Middle
latitude A index was 5, 7, 8, 4, 7, 7, and 10, with a mean of 6.9.