[RSM] W3LPL: Mostly normal thru Thurs/27

[Art Boyars]

From: donovanf at erols.com
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Tue, 26 Oct 2021 23:46:50 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly normal through Thursday
October 27th



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 above normal
through Thursday.

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

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

 The solar flux index (SFI) is likely to be at least 110 through Thursday.
There are six active regions on the visible disk with 35 small to moderate
sized sunspots.
https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg

 160 and 80 meter propagation from North America to VK/ZL and the south
Pacific is likely to be normal through Thursday. 40 meter short path
propagation to south Asia until about 0100Z is likely to be mostly normal
through Thursday. 40 meter short path propagation from North America to
east Asia after about 0800Z is likely to be mostly normal through Thursday.



 30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal through Thursday. 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 long distance night
time propagation is likely to be enhanced by increased night time residual
ionization resulting from significantly increased sunspot activity.



 20 meter daytime and evening propagation through the auroral ovals and
polar regions is likely to be mostly normal through Thursday. 20 meter
transpolar propagation within a few hours of sunrise and sunset is likely
to be mostly normal through Thursday.



 17, 15 and 12 meters are open for long distance and long path propagation
nearly every day due to the effects of significantly increased sunspot
activity. North American stations should look for Asian long path on 17, 15
and 12 meters starting a few hours after sunrise and persisting for at
least several hours. Shorter duration long distance propagation is now
occurring daily on 10 meters.

 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.



 The solar wind is likely to be mostly at background levels with possible
weakly enhanced intervals on Thursday due to coronal hole high speed stream
effects.



 The geomagnetic field is likely to be quiet with possible unsettled
intervals on Thursday due to coronal hole high speed stream effects.
Geomagnetic storms, Earth directed coronal mass ejections and solar flare
effects strong enough to significantly degrade HF propagation are not
likely through Thursday.

 Mid-latitude northern hemisphere sunset is 51 minutes earlier and
daylength is 86 minutes shorter than it was on September 22nd. Daytime
ionization and residual nighttime ionization in the far northern polar
region is rapidly declining due to steadily increasing polar night effects.



Click *here* <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 *here*
<https://spaceweather.gfz-potsdam.de/fileadmin/ruggero/Kp_forecast/forecast_figures/KP_FORECAST_CURRENT.png>
for today’s
three-day GFZ Planetary K Index forecast updated every three hours.

Click *here* <http://sidc.oma.be/products/meu/> for today's SIDC Daily
Bulletin on Solar and Geomagnetic Activity updated at 1230Z daily.

Click *here* <https://www.swpc.noaa.gov/products/forecast-discussion>
for today's
SWPC Solar Activity Forecast Discussion updated at 0030Z and 1230Z daily.

Click *here* <https://www.sws.bom.gov.au/Space_Weather/1/1> for today's
Australian Space Forecast Centre 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