[RSM] W3LPL: Normal through Friday

Art Boyars artboyars at gmail.com
Thu Oct 7 05:25:42 EDT 2021


From: donovanf at erols.com
To: "''''PVRC''''" <pvrc at mailman.qth.net>
Cc: Bernie at dailydx.com
Bcc:
Date: Thu, 7 Oct 2021 01:05:05 -0400 (EDT)

Subject: [PVRC] Propagation is likely to be normal through Friday October
8th

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

Propagation crossing low and mid latitudes is likely to be normal through
Friday.

Propagation crossing the auroral ovals and polar regions is likely to be
normal through Friday.

Click https://services.swpc.noaa.gov/images/planetary-k-index.gif for
today’s latest estimated planetary Kp Index, updated every three hours.

Click http://www.hamqsl.com/solar.html for N0NBH’s current HF Band
Conditions, updated regularly.

We are in the geomagnetically active autumn equinox season through late
October with about twice as many geomagnetically active days compared to
December, January, June and July caused by the interplanetary magnetic
field (IMF) more frequently persisting in a southward orientation (-Bz).
https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg

The solar flux index (SFI) is likely to be about 82 through Friday. The
sun’s visible disk has two active regions containing one moderate size
sunspot and one tiny sunspot.

160 and 80 meter propagation from North America to VK/ZL and the south
Pacific is likely to be normal through Friday. 40 meter short path
propagation to south Asia at about 0000Z is likely to be normal through
Friday. 40 meter short path propagation from North America to east Asia
after about 0830Z is likely to be normal through Friday.

30 meter propagation through the auroral ovals and polar regions is likely
to be normal through Friday. 30 meter propagation is always significantly
degraded within a few hours of local noon because of E-region blanketing of
long distance F2 propagation. 30 meter nighttime long distance propagation
is likely to be slightly enhanced by increased residual nighttime
ionization caused by slightly increased sunspot activity.

20 meter daytime and evening propagation through the auroral ovals and
polar regions is likely to be normal through Friday. 20 meter transpolar
propagation within a few hours of sunrise and sunset is likely to be normal
through Friday. 20 meter late afternoon, nighttime and early morning long
distance propagation is likely to be slightly enhanced by increased
residual nighttime ionization caused by slightly increased sunspot activity.

17, 15 and less reliable 12 meter daytime long distance and seasonal long
path propagation is likely to be slightly enhanced by slightly increased
sunspot activity. North American stations should look for Asian long path
on 17, 15 and 12 meters starting a few hours after sunrise then persisting
for several hours.

12 and especially 10 meter long distance propagation remains much less
reliable than 15 meter DX propagation.

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
interplanetary magnetic field (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.

Solar wind speed is likely to be mostly near nominal speed with occasional
minor disturbances caused by weak coronal hole high speed stream effects.

The geomagnetic field (GMF) is likely to be quiet with possible unsettled
intervals caused by weak coronal hole high speed stream effects.
Geomagnetic storms, CMEs and solar flare effects strong enough to
significantly degrade HF propagation are not likely through Thursday.

Mid-latitude northern hemisphere sunset is 24 minutes earlier and day
length is 37 minutes shorter than it was on September 22nd. Daytime
ionization and residual nighttime ionization in the northern polar region
is steadily declining following the autumnal equinox.

Click https://www.spaceweather.gc.ca/solarflux/sx-4-en.php for today’s
Penticton 10.7 cm solar flux index updated at 1700Z, 2000Z and 2300Z daily.

Click
https://spaceweather.gfz-potsdam.de/fileadmin/ruggero/Kp_forecast/forecast_figures/KP_FORECAST_CURRENT.png
for
the three-day GFZ Planetary K uIndex forecast updated every three hours.

Click http://sidc.oma.be/products/meu for SIDC’s Daily Bulletin on Solar
and Geomagnetic Activity updated at 1230Z daily.

Click https://www.swpc.noaa.gov/products/forecast-discussion for SWPC’s
Solar Activity Forecast Discussion updated at 0030Z and 1230Z daily.
Intervals.
Click https://www.sws.bom.gov.au/Space_Weather/1/1 for the Australian Space
Forecast Centre’s Summary and Forecast updated at 2330Z daily.

Perhaps the most useful HF propagation pages for DXers can be found at:
http://dx.qsl.net/propagation and http://www.solarham.net


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