ARRL PROPOGATION

SB PROP @ ARL $ARLP029
ARLP029 Propagation de K7RA

ZCZC AP29
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 72.9.

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

“Remark:

  • 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.”

W3LPL wrote:

“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:

https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg

“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 solar radiation.

“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 effects.”

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, 2021

“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 EN40om working:

“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 FL06.

“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 UTC.

“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.”

KA3JAW wrote:

“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 Barranquilla. (2x-Es)

“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 24×7 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 https://www.qsl.net/wj5o/bcn.htm .

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 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/.

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.
NNNN
/EX

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