[TVARC] Propagation Forecast

[w3us at casa-aloha.net]

Received this from fellow PVRC’er and contester extraordinaire Frank Donovan, W3LPL and thought some members might be interested.

My propagation forecast is derived from this morning's NOAA/SWPC
web pages and published five days a week (M-F) in the Daily DX.

Propagation returned to normal on Christmas day and is likely to
remain normal through at least Monday.

160 and 80 meter propagation has been good to east Asia near North
American sunrise. 40 and 30 meter long path propagation to east Asia
has been good near northern hemisphere sunset. Occasional brief
80 meter long path propagation to east Asia near north American sunset
likely for the next few weeks.

Northern hemisphere 30 meter propagation is good from a few hours
before sunrise until a few hours after sunset but spotty during the night
and near local noon. 20 meter propagation continues to be very good
during the day but spotty during the night. 

17 meter daytime propagation has improved because of the increased
sunspot activity despite the long duration of darkness at high northern
latitudes. 15 meter daytime propagation remains less reliable and
shorter in duration. 12 and 10 meter daytime propagation remains spotty,
unreliable and mostly limited to north-south paths and daily southern
hemisphere sporadic-E propagation and less frequent northern hemisphere
sporadic-E.

The solar flux index is expected to remain in the high 80s through the 
end of the year. Two solar regions are on the visible disk, solar region
2794 contains only one sunspot and region 2795 contains nine sunspots.
They are unlikely to cause significant eruptive activity or to increase the
solar flux index through at least Monday. Old solar region 2790 is likely
to rotate over the east limb this weekend but may no longer contain
sunspots.

The north-south component of the interplanetary magnetic field (IMF)
-- the most frequent cause of geomagnetic storms when combined
with the effects of CIRs or coronal mass ejections (CMEs) -- is expected
to remain at background levels at least through at least Monday.

Both hemispheres are in their December-January solstice seasons, the
time of year when geomagnetic activity is weakest and least frequent.
Geomagnetic activity is likely to remain very quiet to quiet (Kp=0 to 2)
through at least Monday. Solar wind speed near Earth is likely to remain at
nominal speeds through at least Monday. The magnetic field strength of
the IMF is likely to remain at nominal strength through at least Monday.
Earth directed solar flares and coronal mass ejections strong enough
to affect HF propagation are unlikely through at least Monday.

Geomagnetic storms will be relatively infrequent during the first 18 to 24
months of solar cycle 25. Geomagnetic storms will be more frequent
and unsettled to active geomagnetic conditions will be more persistent
when solar activity increases later in 2021. Active geomagnetic conditions
caused by weaker coronal hole high speed streams are less frequent
now that we're one year into solar cycle 25 and will be much less
frequent later in cycle 25.

Although northern hemisphere daylength is just one minute longer than
it was on December 21st, sunset is already seven minutes later than it
was three weeks ago as solar noon occurs about 30 seconds later each
day because of the affect of Earth's slightly elliptical orbit.

Happy new year to all!

73
Frank
W3LPL

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