[RSM] W3LPL prop forecast thru Sunday. April 16

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Fri, 14 Apr 2023 01:43:11 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be normal at low and mid-latitudes
through Sunday. High latitude propagation is likely to be mostly normal
with a slight chance of mild degradations during local night time hours
through 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 a chance of mild degradations during local night time
hours through Sunday.

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 26 minutes later and day length
is 65 minutes longer than it was on March 20th.
The April 14th daily Estimated International Sunspot Number is 165. Today's
solar flux index (SFI) is 160 and is likely to increase slightly through
Sunday. The sun’s visible disk has two large, four medium and two tiny
active region containing 54 sunspots with a total sunspot area of 580
micro-hemispheres (about three times the surface area of the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

There is a chance of minor to moderate radio blackouts caused by M-class
solar flares through Sunday.

The solar wind is likely to remain at weakly elevated levels of about 400
km/second through Sunday. There is a chance the solar wind may increase
slightly during Saturday due to possible increased coronal hole high speed
stream activity.

Geomagnetic activity is likely to be mostly quiet to unsettled due to mild
coronal hole high speed stream effects. There is a chance of active
geomagnetic activity and a slight chance of a weak geomagnetic storm during
Saturday due to possible increased coronal hole high speed stream activity.
We are in the vernal equinox season when geomagnetic disturbances are about
twice as likely as during the summer and winter solstice seasons.

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 a chance of mild degradations
during local night time hours through Sunday. Short path propagation from
North America to east Asia after about 0900Z is likely to be mostly normal
with a chance of mild degradations during local night time hours through
Sunday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with a chance of mild degradations during local night
time hours through Sunday. 30 meter propagation is always mildly degraded
within a few hours of local noon by E-region blanketing of long distance
low angle F2 propagation.

20 meter daytime and evening propagation through the auroral ovals
and polar regions is likely to be mostly normal with a chance of mild
degradations during local night time hours through Sunday. 20
meter transpolar propagation within a few hours of sunrise and sunset is
likely to be mostly normal with a chance of mild degradations during local
night time hours through Sunday.

17 and 15 meter long distance propagation is likely to be mostly normal
with a chance of mild degradations during local night time hours through
Sunday. 17 and 15 meter long path propagation from North America to east
Asia from about 1200Z to 1400Z is likely to be mostly normal through Sunday
12 and 10 meter long distance propagation is likely to be mostly normal
through 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
Sunday. 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 Sunday of 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 chance through Sunday of oblique-TEP from
the southern tier and western U.S. states to VK/ZL and the south Pacific
from late afternoon through early evening. There is a lesser chance that
stations at mid-latitudes in the U.S. may briefly couple into both TEP and
oblique-TEP via brief geographically focused intervals of mid-latitude
sporadic-E propagation. TEP and oblique-TEP may be enhanced during strong
to severe geomagnetic storms that occur more frequently through late April
during the vernal equinox season. 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 mildly stronger than 5 nanoteslas for several hours
or more coincident with the effects of an Earth directed fast CME (faster
than 700 km/second).

Real time geomagnetic data including Bz orientation, IMF field strength,
solar wind speed and short term k-index forecast are available here:
https://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