[RSM] W3LPL: Thurs-Fri propagation forecast

[Art Boyars]

I think I've missed a few days.  Sometimes these forecasts arrive out of
sync with my availability.  Here's one for the end of the week. -- Art

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Thu, 19 Jan 2023 02:08:15 -0500 (EST)
Subject: [PVRC] Propagation is likely to be mostly normal with possible
mild degradations on mid and high latitude paths from mid-day Thursday
until early Friday

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 latitudes is likely to be normal through Friday.

Propagation crossing mid-latitudes is likely to be mostly normal through
Friday with possible mild degradations from mid-day Thursday until early
Friday during local night time hours.

Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal through Friday with possible moderate degradations from
mid-day Thursday until early Friday during local night time hours.

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 220 and is likely to remain about the
same through at least Friday. The sun’s visible disk has one very large,
two large, two medium and five tiny active regions containing 64 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 Friday.

40 meter short path propagation from North America to south Asia at about
0000Z is likely to be mostly normal through Friday with possible mild
degradations from late Thursday until early Friday. Short path propagation
from North America to east Asia after about 0800Z is likely to be mostly
normal through Friday. 40 meter long path propagation from North America to
east Asia after about 2130Z is likely to be mostly normal through Friday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with possible mild degradations from mid-day Thursday
until early Friday. 30 meter long path propagation from North America to
east Asia after about 2130Z is likely to be mostly normal through Friday.
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 from mid-day Thursday until early Friday during local night
time hours. 20 meter transpolar propagation within a few hours of sunrise
and sunset is likely to be mostly normal with possible mild degradations
from mid-day Thursday until early Friday during local night time hours.

17 and 15 meter long distance propagation is likely to be mostly normal
through Friday with possible mild degradations from mid-day Thursday until
early Friday during local night time hours.

12 and 10 meter long distance propagation is likely to be mostly normal
through Friday with possible mild degradations from mid-day Thursday until
early Friday during local night time hours. 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 Friday. 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 Friday 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 Friday during mid-afternoon and early evening
at the path mid-point. There is a slight chance that stations at
mid-latitudes may also briefly ouple into TEP and oblique TEP via a brief
intervals of F2 mid-latitude propagation. See K6MIO’s excellent article
about 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
Friday 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 increase to disturbed to moderately
enhanced through Friday due to mild coronal hole high speed stream and
possible mild CME effects.

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 Friday due to mild coronal hole high speed stream effects and
possible mild CME effects.

Mid-latitude northern hemisphere sunset is 25 minutes later and day length
is 24 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