ARLP025 Propagation de K7VVV:
June 23, 2000

ZCZC AP25
QST de W1AW
Propagation Forecast Bulletin 25 ARLP025
From Tad Cook, K7VVV
Seattle, WA June 23, 2000
To all radio amateurs

SB PROP ARL ARLP025
ARLP025 Propagation de K7VVV

Average solar flux and sunspot numbers rose slightly this week, and geomagnetic indices were lower. Planetary and mid-latitude A indices have been mostly in the single digits. Unfortunately, geomagnetic conditions may be a bit more active for Field Day this weekend. The predicted planetary A index for Friday through Tuesday is 15, 15, 20, 20 and 12, but no major disturbance is likely. Solar flux for the same period is expected to be around 175, 175, 170, 165 and 165, and should begin rising again around July 1. The short term outlook is for flux values to slowly rise and then peak around 200 before the middle of next month.

It looks like the best band will be 40 meters. There is also a possibility of 10 meter sporadic E skip openings during the day.

Sunspot numbers for June 15 through 21 were 261, 252, 211, 250, 194, 219 and 226 with a mean of 230.4. 10.7 cm flux was 202.4, 197.5, 193.1, 187.6, 178.4, 183.7 and 188, with a mean of 190.1, and estimated planetary A indices were 20, 9, 10, 11, 9, 9 and 8, with a mean of 10.9.

NASA has an article this week on a proposed model for better predicting the arrival time of the effects from Coronal Mass Ejections. You can see the NASA article at http://science.nasa.gov/headlines/y2000/ast22jun_1m.htm?list and see more info from a solar physics meeting at http://www.lmsal.com/spd/Press/.

Here is a forecast for this Field Day weekend.

• From the East Coast of the United States to the center of the contiguous 48 states, check 80 meters 0000-1200z (best 0200-0400z), 40 meters all hours, best 0130-0900z with a peak at sunset in the Midwest around 0200z, and weakest 1700-1900z, 20 meters also open all hours, strongest around 2330z, 15 meters possibly open 0630-1400z.
• From the East Coast to the West Coast, 80 meters 0300-1030z (best around 0430z), 40 meters 0100-1200z (best 0430-0900z), 20 meters open around the clock, best 0400-0600z, weakest 1730-2000z, 15 meters possibly open during the early morning.
• From the West Coast to the Midwest, 80 meters 0230-1230z (best 0500-1030z), 40 meters open all hours, strongest 0430-1030z, weakest 1830-2030z, 20 meters open all hours, best 0400-1100z, weakest 1800-2100z. 15 meters could possibly open at any time.