rjr@mgweed.UUCP (Bob Roehrig) (10/04/83)
QST DE W1AW HR PROPAGATION FORECAST BULLETIN NR 40 FROM ARRL HEADQUARTERS NEWINGTON CT OCTOBER 3, 1983 TO ALL RADIO AMATEURS BT THE SOLAR FLUX AVERAGED JUST OVER 109 IN SEPTEMBER, THE LOWEST VALUES SINCE LATE 1947. SOLAR ACTIVITY WAS RISING AFTER THE 20TH, THE TREND CONTINUING INTO EARLY OCTOBER. THE FLUX REACHED 120 ON THE 2ND, THE HIGHEST SINCE THE MIDDLE OF AUGUST. THE SOLAR FLUX RISE REPORTED LAST WEEK IS EXPECTED TO FLATTEN OFF IN THE 120S AND START DOWN ABOUT THE 4TH. THERE WILL BE ANOTHER LOW PERIOD ABOUT THE 7TH TO 20TH. A RISE EXPECTED AT THE END OF OCTOBER SHOULD BRING THE BEST OVERALL PROPAGATION OF THE AUTUMN SEASON TO DATE. ABOVE AVERAGE MAGNETIC FIELD ACTIVITY BEGINNING ABOUT OCTOBER 5, 13, 17, 23 AND 28 WILL CAUSE INCREASED SIGNAL ABSORPTION AND SEVERE FADING OVER PERIODS OF ONE TO THREE DAYS. THE MUF WILL TEND TO PEAK ABOUT OCTOBER 4, 7, 14, 25 AND 29, REACHING ITS HIGH FOR THE MONTH ON THE LAST TWO DATES. AMERICAN SUNSPOT NUMBERS FOR SEPTEMBER 22 THROUGH 28 WERE BETWEEN 39 AND 54 WITH A MEAN OF 46.7 AR DE K9EUI