[RSM] W3LPL weekend propagation forecast

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Fri, 20 Jan 2023 00:42:10 -0500 (EST)
Subject: [PVRC] Propagation is likely to be mostly normal with possible
mild degradations on high latitude paths through early Sunday improving to
normal through late Sunday

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 normal through
Sunday.

Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal with possible mild degradations during local night time hours
through early Sunday improving to normal through late Sunday.

Click *here* <https://services.swpc.noaa.gov/images/station-k-index.png>
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.
Today's solar flux index (SFI) is 226 and is likely to remain about the
same through at least Sunday. The sun’s visible disk has one very large,
two large, two medium and five tiny active regions containing 66 sunspots
with a total sunspot area of 2210 micro-hemispheres (about 11 times the
surface area of the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

160 and 80 meter propagation from North America to VK/ZL and the
south Pacific is likely to be normal through Sunday.

40 meter short path propagation from North America to south Asia at about
0000Z is likely to be mostly normal with possible mild degradations through
early Sunday improving to normal through late Sunday. Short path
propagation from North America to east Asia after about 0800Z is likely to
be mostly normal with possible mild degradations through Sunday. 40 meter
long path propagation from North America to east and southeast Asia after
about 2145Z is likely to be mostly normal through Saturday and normal on
Sunday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with possible mild degradations through early Sunday
improving to normal through late Sunday. 30 meter long path propagation
from North America to east and southeast Asia after about 2145Z likely to
be mostly normal through Saturday and normal on Sunday. 30 meter
propagation is always significantly degraded within a few hours of local
noon by 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 with possible mild
degradations during local night time hours through early Sunday improving
to normal through late Sunday. 20 meter transpolar propagation within a few
hours of sunrise and sunset is likely to be mostly normal with possible
mild degradations during local night time hours through early Sunday
improving to normal through late Sunday.

17 and 15 meter long distance propagation is likely to be mostly normal
with possible mild degradations during local night time hours through early
Sunday improving to normal through late Sunday.

12 and 10 meter long distance propagation is likely to be mostly normal
through early Sunday improving to normal through late Sunday. 12 and 10
meter long path propagation from North America to east Asia from about
1200Z to 1400Z is likely to be mostly normal through Saturday and normal on
Sunday. 12 and 10 meter F2 propagation crossing northern hemisphere
mid-latitudes is likely to be enhanced when the solar flux index is about
120 or higher and geomagnetic activity is quiet to unsettled (K index of 3
or less).

There is a slight chance of brief intervals of 6 meter trans-Atlantic F2
propagation through at least Sunday between 1300 and 1700Z. There is a
slightly better chance of trans-equatorial F2 propagation (TEP) and oblique
TEP from the southern tier of U.S. states mostly to equatorial Africa and
CQ Zone 32 through at least Sunday during mid-afternoon and early evening
at the path mid-point. There is a slight chance that stations at
mid-latitudes may briefly couple into TEP and oblique-TEP via brief
intervals of F2 mid-latitude propagation. See K6MIO’s excellent article on
TEP, oblique-TEP and TEP-related 6 meter propagation beginning on page 66
at: https://k5tra.net/TechFiles/2014%20Central%20States%20whole%20book.pdf

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 (faster than 1000 km per second). Real time geomagnetic data including
Bz orientation, IMF field strength, solar wind speed and short term K Index
forecast are available here:
www.swpc.noaa.gov/products/geospace-geomagnetic-activity-plot

Minor to moderate daytime radio blackouts caused by unpredictable sudden
bursts of X-ray radiation from M-class solar flares are likely through
Sunday with a slight chance of isolated strong X-class flares due to
several active regions on the visible disk capable of producing strong
flares.

Solar wind parameters are likely to be mildly enhanced through early Sunday
due to mild coronal hole high speed stream and possible mild CME effects
improving to slightly enhanced through late Sunday.

Geomagnetic activity is likely to be quiet to unsettled with a chance of
active intervals and a slight chance of brief minor geomagnetic storms
through early Sunday due to mild coronal hole high speed stream effects and
possible mild CME effects improving to mostly quiet through late Sunday.

Mid-latitude northern hemisphere sunset is 27 minutes later and day length
is 28 minutes longer than it was on December 21st.

Click *here* <https://www.spaceweather.gc.ca/solarflux/sx-4-en.php> for today’s
Penticton 10.7 cm solar flux index updated at 1800Z, 2000Z and 2200Z 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