[RSM] W3LPL: Moderate hi-lat night time degradation thru mid-day Friday

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Thu, 23 Mar 2023 01:26:56 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly normal with moderate
degradations at high latitudes during local night time hours from mid-day
Thursday through mid-day 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.

Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal with moderate degradations at high latitudes during local
night time hours through Friday.

VE3EN’s End-of-Day Solar Report is published daily at 0045Z at:
https://www.solarham.net

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.
Mid-latitude northern hemisphere sunset is three minutes later and day
length is nine minutes longer than it was on March 20th.

The March 23rd daily Estimated International Sunspot Number is 90. Today's
solar flux index (SFI) is 159 and is likely be decline to about 150 on
Friday. The sun’s visible disk has one large, three medium and two tiny
active regions containing 21 sunspots with a total sunspot area of 800
micro-hemispheres (about four times the surface area of the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

There is a slight chance of isolated brief minor radio blackouts on the sun
facing side of the earth through Friday.

Solar wind speed is mildly elevated at about 440 km/second and is likely to
increase to moderately elevated from mid-day Thursday through mid-day
Friday.

Geomagnetic activity is likely to be mostly quiet through mid-day Thursday
with minor to moderate geomagnetic storms developing from mid-day Thursday
through mid-day Friday due to combined CME and coronal hole high speed
stream effects. Unsettled geomagnetic conditions are likely after mid-day
Friday. We are in the vernal equinox season when geomagnetic disturbances
are about 50% more likely than during most of the year.

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 moderately degraded late Thursday and mostly normal
late Friday. Short path propagation from North America to east Asia after
about 0830Z is likely to be normal on Thursday and below normal on Friday.
40 meter long path propagation from North America to southeast Asia at
about 2300Z is likely to be mostly below normal on Thursday and mostly
normal on Friday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with moderate degradations at high latitudes during
local night time hours through Friday. 30 meter long path propagation from
North America to southeast Asia at about 2300Z is likely to be mostly below
normal on Thursday and mostly normal on 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 moderate degradations
at high latitudes during local night time hours through Friday. 20
meter transpolar propagation within a few hours of sunrise and sunset is
likely to be mostly normal with moderate degradations at high latitudes
during local night time hours through mid-day Friday.

17 and 15 meter long distance propagation is likely to be mostly normal
with likely moderate degradations at high latitudes during local night time
hours through Friday.

12 and 10 meter long distance propagation is likely to be mostly normal
with likely moderate degradations at high latitudes during local night time
hours through Friday. 12 and 10 meter long path propagation from North
America to east Asia from about 1200Z to 1400Z is likely to be normal on
Thursday and mostly below normal on Friday. 12 and 10 meter F2 propagation
crossing northern hemisphere mid-latitudes is likely to be enhanced when
the solar flux index is above 120 and geomagnetic activity is quiet to
unsettled (K index of 3 or less).

There is a chance through Friday of trans-equatorial F2 trans-equatorial
propagation (TEP) from the southern tier of U.S. states to South America
from early afternoon through late evening. There is a lesser chance through
Friday of oblique-TEP from the southern tier of U.S. states to VK/ZL and
the south Pacific during mid-afternoon and early evening in the U.S. There
is a lesser chance that U.S. stations at mid-latitudes may briefly couple
into both TEP and oblique-TEP via brief isolated 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 linking 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 700 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

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 https://www.solarham.net

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