[RSM] W3LPL: Mostly normal, improving to normal after mid-day Thursday

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 25 Jan 2023 02:00:22 -0500 (EST)
Subject: [PVRC] Propagation is likely to be mostly normal improving to
normal after mid-day 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 normal through
Thursday.

Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal improving to normal after mid-day Thursday.

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 180 and is likely to remain about the
same through at least Thursday. The sun’s visible disk has one very large,
five medium and three tiny active regions containing 37 sunspots with a
total sunspot area of 1380 micro-hemispheres (about seven 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 Thursday.

40 meter short path propagation from North America to south Asia at about
0000Z is likely to be mostly normal improving to normal after mid-day
Thursday. Short path propagation from North America to east Asia after
about 0800Z is likely to be normal through Thursday. 40 meter long path
propagation from North America to east and southeast Asia after about 2145Z
is likely to be mostly normal improving to normal on Thursday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal improving to normal after mid-day Thursday. 30 meter
long path propagation from North America to east and southeast Asia after
about 2145Z is likely to be mostly normal improving to normal on Thursday.
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 improving to normal after
mid-day Thursday. 20 meter transpolar propagation within a few hours of
sunrise and sunset is likely to be mostly normal improving to normal after
mid-day Thursday.

17 and 15 meter long distance propagation is likely to be mostly normal
improving to normal after mid-day Thursday.

12 and 10 meter long distance propagation is likely to be mostly normal
improving to normal after mid-day Thursday. 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 Thursday. 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).

6 meter trans-Atlantic F2 propagation is not likely through at least
Thursday because of depressed F2 MUFs due to reduced ionizing solar flux.
There is a possibility through Thursday of trans-equatorial F2 propagation
(TEP) from the southern tier of U.S. states to South America from
mid-afternoon through late evening. There is a slight chance through
Thursday of oblique-TEP from the southern tier of U.S. states to equatorial
Africa and CQ Zone 32 during mid-afternoon and early evening at the path
mid-points. There is a chance that U.S. stations at mid-latitudes may
briefly couple into both TEP and oblique-TEP via possible intervals of
mid-latitude sporadic-E propagation. See K6MIO’s excellent article on 6
meter TEP, oblique-TEP, TEP-related and mid-latitude sporadic-E coupling to
TEP 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

There is a slight chance of minor to moderate daytime radio blackouts
caused by unpredictable sudden bursts of X-ray radiation from M-class solar
flares and a slight chance of isolated strong X-class flares due to two
active regions on the visible disk capable of producing strong flares.

Solar wind parameters are likely to be mildly enhanced due to coronal hole
high speed stream effects and possible CME influence then improving after
mid-day Thursday

Geomagnetic activity is likely to be quiet to unsettled with a chance of
isolated active intervals due to coronal hole high speed stream effects and
possible mild CME influence then improving to mostly quiet after mid-day
Thursday. There is a chance of isolated moderate geomagnetic storms through
late Wednesday and a slight chance of isolated moderate geomagnetic storms
through mid-day Thursday.

Mid-latitude northern hemisphere sunset is 32 minutes later and day length
is 35 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