[RSM] W3LPL: Prop likely normal thru late Tuesday/5

[Art Boyars]

From: donovanf at erols.com
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 4 Oct 2021 00:40:48 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly normal through late
Tuesday October 5th 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
Tuesday.

 Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal with possible below normal intervals through late Tuesday.

 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).
https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg

 The solar flux index (SFI) is likely to be about 87 through Tuesday. The
sun’s visible disk has two small to mid-size active regions with 11 small
to mid-size sunspots.

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

 30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with possible below normal intervals through Tuesday. 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 enhanced by
increased residual nighttime ionization caused by increased sunspot
activity but degraded by possible below normal intervals through late
Tuesday.

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

 17, 15 and occasional 12 meter daytime long distance and autumnal equinox
long path propagation is likely to be enhanced by increased sunspot activity.
17 and 15 meters are open for long distance and long path propagation
nearly every
day due to increased solar activity and the effects of the autumnal
equinox. 12 meter long distance and long path propagation is steadily
improving but is not as reliable as 15 meters. 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.

 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 near nominal speeds with possible
slightly enhanced wind speed intervals through late Tuesday due to weak
coronal hole high speed stream effects.

 The geomagnetic field is likely to be mostly quiet with possible unsettled
intervals due to weak coronal hole high speed stream effects through late
Tuesday. There is a slight chance of active intervals through late Tuesday.

Geomagnetic storms, CMEs and solar flare effects strong enough to
significantly degrade HF propagation are not likely through late Tuesday.

 Mid-latitude northern hemisphere sunset is 19 minutes earlier and
daylength is 30 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 *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