TZUTC: -0600   
   MSGID: 344.fidonet-ls_arrl@1:2320/33 28551437   
   PID: Synchronet 3.19c-Win32 master/d1dfc9c1b Dec  7 2022 MSC 1929   
   TID: SBBSecho 3.15-Win32 master/d1dfc9c1b Dec  7 2022 MSC 1929   
   BBSID: TBOLT   
   CHRS: ASCII 1   
      
   SB PROP @ ARL $ARLP007   
   ARLP007 Propagation de K7RA   
      
   ZCZC AP07   
   QST de W1AW    
   Propagation Forecast Bulletin 7  ARLP007   
   From Tad Cook, K7RA   
   Seattle, WA  February 17, 2023   
   To all radio amateurs   
      
   SB PROP ARL ARLP007   
   ARLP007 Propagation de K7RA   
      
   At 0725 UTC on February 15 the Australian Space Weather Forecasting   
   Centre issued a geomagnetic disturbance warning: "A CME impact   
   occurred around 2200 UTC on February 14. Bz has been southward for   
   the majority of time since impact and there is a chance of G1   
   geomagnetic conditions."   
      
   Bz is the north-south direction of the Interplanetary Magnetic Field   
   (IMF).   
      
   They predicted a disturbance for February 15-16.   
      
   They issued a new warning on February 17 at 0206 UTC:   
      
   "A partial halo CME observed on 15-Feb is due to impact Earth's   
   magnetosphere late on 17-Feb or early 18-Feb UTC. G1 geomagnetic   
   conditions are expected on 18-Feb, with a slight chance of G2.   
      
   "INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS   
   EJECTION FROM 17-19 FEBRUARY 2023."   
      
   For the latest geomagnetic conditions, I prefer this source:   
      
   https://www.swpc.noaa.gov/products/planetary-k-index   
      
   More on the IMF:   
      
   https://bit.ly/3E6IZ15   
      
   Many sunspots appeared over this reporting week (February 9-15) with   
   three new sunspot groups on February 9, one more on February 10, two   
   more on February 11, another on February 12 and three more on   
   February 13. Finally, there was one more yesterday, Thursday,   
   February 16.   
      
   Recent sunspot images:   
      
   https://www.spaceweather.com/images2023/12feb23/hmi1898.gif   
      
   That one is for February 12. To see February 13, just change the   
   12feb23 string to 13feb23, and so on, for any other date.   
      
   Average daily sunspot numbers increased from 95.1 to 182.4, and   
   average daily solar flux from 155.9 to 196.4.   
      
   Geomagnetic activity also rose, with average daily planetary A index   
   going from 11.7 to 13.7, and middle latitude numbers from 7.6 to   
   10.7.   
      
   The most active days were at the beginning and end of the week, with   
   planetary A index at 21 on February 9 and 29 on February 15. On   
   those two days the college A index at Fairbanks, Alaska was 33 and   
   46. The quietest day was Monday, February 13 when the planetary A   
   index was 4.   
      
   The outlook for the next month seems modest, with predicted solar   
   flux at 155, 160, 155, 145 and 135 on February 17-21, 125 on   
   February 22-23, 130 on February 24-26, 140 on February 27 to March   
   1, 145 on March 2-3, then 150, 155 and 165 on March 4-6, 180 on   
   March 7-13, 170 on March 14-15, 160 on March 16-18, and 150 on March   
   19, 140 on March 20-21, and 135 on March 22-25.   
      
   Predicted planetary A index is 22, 30, 12, 8 and 12 on February   
   17-21, 10 on February 22-24, then 5, 5 and 8 on February 25-27,   
   another 5, 5, and 8 on February 28 through March 2, then 5, 5 and 16   
   on March 3-5, then 18, 15 and 8 on March 6-8, and 5 on March 9-20,   
   then 10 on March 21-23, and 5, 5 and 8 on March 24-26, and another   
   5, 5 and 8 on March 27-29.   
      
   Weekly Commentary on the Sun, the Magnetosphere, and the Earth's   
   Ionosphere - February 16, 2023, from F.K. Janda, OK1HH.   
      
   "On February 11, we observed a seemingly dangerous sunspot group   
   AR3217, whose magnetic field had a beta-gamma-delta configuration,   
   in which large flares are often observed, up to X-class flares   
   accompanied by CMEs. This is what we saw at 1548 UTC, while extreme   
   UV radiation ionized the upper part of the Earth's atmosphere.   
   Direct result was the Dellinger effect, which disrupted shortwave   
   communications over all of South America.   
      
   "But this particular eruption did not create a CME. Another   
   explosion did. Five hours before the X eruption, a magnetic filament   
   appeared in the northern hemisphere of the Sun, which spewed a CME   
   into space. Thereafter we were expecting an Earth impact on   
   Valentine's Day, February 14. This was a fairly accurate prediction   
   because the Earth's intervention occurred just one day later, on   
   February 15. It was not a direct hit, only a weak G1 class   
   geomagnetic storm developed.   
      
   "On February 15 a magnetic filament eruption near the solar equator   
   and another CME heading towards Earth was observed. We can expect an   
   arrival on February 17-18, again as a weak G1 class geomagnetic   
   storm, perhaps intensifying to a mild G2 class storm on February 18.   
   Further we can expect to see more M-class solar flares in the next   
   few days. Also, an X-class flare is not out of the question. In   
   addition, the AR3226 sunspot group with an unstable magnetic field,   
   is directly facing the Earth."   
      
   Impossible but dramatic solar image:   
      
   https://bit.ly/3Ib3eMp   
      
   Spaceweather.com warns:   
      
   "GEOMAGNETIC STORM WATCH: Photographers, warm up your cameras. A CME   
   is heading for Earth, and it could spark an unusually good display   
   of Northern Lights when it arrives on Feb. 17-18. NOAA forecasters   
   say that moderate G2-class geomagnetic storms are possible. During   
   such storms, auroras have been seen in the USA as far south as,   
   e.g., New York and Idaho."   
      
   From the Western Washington DX Club email list:   
      
   WT8P posted at 1855 UTC on February 16:   
      
   "6M FT8 open to central and SA At 1845 UTC, LU9AEA (Argentina) and   
   TG9AJR (Guatemala) on FT8, 50.313 MHz."   
      
   W7YED posted at 1939 UTC, February 16:   
      
   "I was able to pick up 5 new ones on 6m in the space of about 20   
   minutes.  Nice opening!   
      
   "TI, CX, CE, LU, TG were all between +3 and -18."   
      
   A story about "vicious solar storms":   
      
   https://bit.ly/3S8g7uV   
      
   Aurora on Valentine's Day:   
      
   https://bit.ly/3YUvsSb   
      
   A video last week from Dr. Tamitha Skov, WX6SWW:   
      
   https://youtu.be/Igfp_EK73Xk   
      
   This weekend is the CW portion of the ARRL International DX Contest.   
   For details see: https://www.arrl.org/arrl-dx .   
      
   Send your tips, reports, observations, questions and comments to   
   k7ra@arrl.net. When reporting observations, don't forget to tell us   
   which mode you were operating.   
      
   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 February 9 through 15, 2023 were 150, 190, 209,   
   197, 185, 206, and 140, with a mean of 182.4. 10.7 cm flux was   
   214.9, 207.8, 209.5, 199.7, 189.2, 179.7, and 173.7, with a mean of   
   196.4. Estimated planetary A indices were 21, 16, 11, 7, 4, 8, and   
   29, with a mean of 13.7. Middle latitude A index was 16, 12, 10, 5,   
   3, 6, and 23, with a mean of 10.7.   
   NNNN   
   /EX   
   --- SBBSecho 3.15-Win32   
    * Origin: The Thunderbolt BBS - Little Rock, Arkansas (1:2320/33)   
   SEEN-BY: 1/120 123 15/0 18/0 50/109 90/1 105/81 106/201 116/17 18   
   SEEN-BY: 116/116 120/340 123/0 10 25 131 170 180 200 525 755 3001   
   SEEN-BY: 135/300 153/7715 154/10 30 40 50 700 218/700 840 220/70 90   
   SEEN-BY: 221/6 222/2 226/17 18 30 227/114 229/110 111 112 113 114   
   SEEN-BY: 229/206 307 317 424 426 428 470 664 700 240/1120 1200 250/1   
   SEEN-BY: 266/512 267/800 275/1000 282/1038 299/6 301/1 113 317/3 320/219   
   SEEN-BY: 322/757 335/364 341/66 342/200 396/45 460/58 467/888 633/267   
   SEEN-BY: 633/280 281 412 416 418 712/620 848 1321 770/1 100 340 772/210   
   SEEN-BY: 772/220 230 2320/0 33 105 304 401 3634/0 12 27 56 57 119   
   SEEN-BY: 4500/1 5001/100 5005/49 5020/715 1042 4441 5030/49 5054/8   
   SEEN-BY: 5058/104 5064/56 5075/128 5083/1 444 5090/958   
   PATH: 2320/33 105 154/10 3634/12 5020/1042 301/1 221/6 218/840   
   PATH: 770/1 712/848 633/280 229/426