[RSM] W3LPL: Mostly normal, maybe brief fadeouts, thru Thurs/29

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Tue, 28 Dec 2021 23:33:27 -0500 (EST)
Subject: [PVRC] Mostly normal propagation with a slight chance of brief
shortwave fadeouts through Thursday

My propagation forecast derived from today's NOAA/SWPC web pages
is published five days a week (M-F) in the Daily DX. All days and times in
this forecast are in UTC (Zulu) time.

Propagation crossing low and mid-latitudes is likely to be mostly normal
through Thursday.

Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal through Thursday with possible minor MUF depressions after
late Wednesday due to coronal hole high speed stream effects.

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 The solar flux index (SFI) is likely to be
about 120 through Thursday.
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. 160 and 80 meter
propagation from North America to Asia is likely to be mostly normal
through Thursday.

40 meter short path propagation from North America to south Asia at about
0100Z is likely to be mostly normal through Thursday. 40 meter short path
propagation from North America to east Asia after about 0730Z 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.

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 and 15 meter long distance propagation is likely to be mostly normal
through Thursday while 12 and 10 meter long distance propagation is likely
to be less reliable and shorter in duration due to winter seasonal effects.

Geomagnetic disturbances *caused by CME and coronal hole high speed*
*stream* effects are likely to remain mostly brief, minor and somewhat less
frequent through at least late 2021. Persistent southward orientation (-Bz)
of the north-south 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 IMF
field strength of about 5 nanoteslas 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 IMF field strength significantly stronger
than 5 nanoteslas for several hours or more *coincident with* the effects
of an Earth directed fast CME. Real time geomagnetic data including Bz
orientation and IMF field strength are available here:
www.swpc.noaa.gov/products/geospace-geomagnetic-activity-plot

Solar wind speed is likely to be slightly enhanced by coronal hole high
speed stream effects through Thursday.

The geomagnetic field likely to be mostly quiet with probable unsettled
intervals with a chance of brief active intervals after an increase in
coronal hole high speed effects late Wednesday.

There is a slight chance of brief short wave fadeouts on the sun facing
side of the Earth through Thursday due to possible M-class flares.

We are in the winter solstice season when geomagnetic storms and active
geomagnetic conditions are about half as likely as during the equinox
seasons.

Mid-latitude northern hemisphere sunset is 5 minutes later and day length
is 2 minutes longer than it was on December 21st. Daytime ionization and
residual nighttime ionization in the northern polar region are very low due
the lack of ionizing solar flux in the northern polar region.

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

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