[RSM] W3LPL forecast thru Thurs/28

Wed Sep 27 01:23:37 EDT 2023

(Does anybody want to continue receiving these forecasts?  Email me. -- Art)

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 27 Sep 2023 01:02:07 -0400 (EDT)
Subject: [PVRC] Propagation crossing low latitudes is likely to be normal
through Wednesday. Propagation crossing mid and high latitudes is likely to
be mostly normal on Wednesday and normal on Thursdayeyh

My propagation forecast derived from today's NOAA/SWPC web pages and twelve
other online sources (the URLs included this forecast) is published five
days a week (M-F) in The Daily DX. All days and times in this forecast are
in UTC (Zulu) time.
NWRA’s Table of Space Weather Indices is updated 40 minutes after every
hour at https://spawx.nwra.com/spawx/env_latest.html

SILSO’s Estimated International Sunspot Number is updated continuously at
https://www.sidc.be/silso/DATA/EISN/EISNcurrent.png

SWPC’s estimated planetary Kp Index is updated every three hours at
https://services.swpc.noaa.gov/images/station-k-index.png

N0NBH’s current HF Band Conditions report is updated regularly at
https://www.hamqsl.com/solar.html Near-real time maps and data about HF
ionospheric propagation are available at https://prop.kc2g.com

Mid-latitude northern hemisphere sunrise is three minutes later and sunset
is six minutes earlier than it was on September 23rd. Sunrise is about two
hours earlier and sunset is about two hours later at the 300 km altitude of
the F2 region than it is at ground level.

Today’s Estimated International Sunspot Number is 164 and is likely to
remain mostly unchanged through Thursday. The sun’s visible disk has three
large, three medium and four tiny active regions containing 79 sunspots
with a total sunspot area of 940 micro-hemispheres (about five times the
surface area of the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

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

Solar wind speed is likely to be mildly elevated at about 450 km/second or
less through Wednesday due to waning CME effects then gradually declining
to less than 400 km/second on Thursday due to CME effects waning to near
background levels.
Mostly quiet conditions are likely on Wednesday with a chance of brief
unsettled to active conditions and a slight chance of brief minor
geomagnetic storm conditions due to waning CME effects. Mostly quiet
geomagnetic conditions are likely on Thursday with a chance of unsettled to
active intervals due to CME effects waning to near background levels.
160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be normal through Wednesday.
40 meter short path propagation from North America to south Asia after
about 2300Z is likely to be mostly normal late Wednesday improving to
normal late Thursday. Short path propagation between North America and east
Asia after about 0900Z is likely to be normal through Thursday.
30 meter propagation crossing the auroral ovals and polar regions is likely
to be mostly below normal on Wednesday improving to normal on Thursday. 30
meter propagation is always mildly to moderately degraded within several
hours of local noon by E-region blanketing of long distance low angle F2
propagation.

20 meter propagation crossing the auroral ovals and polar regions is likely
to be mostly normal on Wednesday improving to normal on Thursday. 20 meter
long distance propagation at low latitudes is usually degraded from several
hours before local solar noon until several hours after local solar noon by
E region blanketing of long distance low angle F2 propagation.

17 and 15 meter propagation crossing the auroral ovals and polar regions is
likely to be mostly normal on Wednesday improving to normal on Thursday. 17
and 15 meter long path propagation from North America to southeast and east
Asia from about 1200Z to at least 1400Z is likely to be normal through
Thursday.

12 and 10 meter long distance daytime propagation is likely to be mostly
normal on Wednesday improving to normal on Thursday. 12 and 10 meter long
path propagation from North America to southeast and east Asia from about
1200Z to at least 1400Z is likely to be normal through Thursday.   We are
in the autumnal equinox season when disturbed geomagnetic conditions are
much more likely than during the solstice seasons.
There is a chance of 6 meter F2 trans-equatorial propagation (TEP) from the
southern tier of U.S. states to South America from late afternoon through
early evening. There is a very slight chance of very brief isolated
propagation via the northern equatorial ionization anomaly from the
southern tier of US states to equatorial Africa and the south Atlantic
(e.g., ZD7 and ZD9) during mid-afternoon. There is a very slight chance of
very brief isolated oblique-TEP from the southern tier of US states to the
south Pacific and VK/ZL during early evening. There is a chance that more
northerly US stations may couple into TEP and oblique-TEP via
geographically focused intervals of mid-latitude sporadic-E and intervals
of mid-latitude F region ionization irregularities. TEP may be
significantly enhanced during the late afternoon through early evening
onset of strong to severe solar flares and geomagnetic storms then
significantly degrading after initial enhancement. See K6MIO’s excellent
article on 6 meter TEP, oblique-TEP, TEP-related and mid-latitude
sporadic-E linking to TEP beginning on page 9 at:
http://www.oh3ac.fi/QEX-2016-11.pdf

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 rientation (-Bz) with
IMF field strength mildly stronger than 5 nanoteslas for at least a few
hours coincident with the effects of an Earth directed CME and solar wind
exceeding 500 km/second.   The Penticton 10.7 cm solar flux index is likely
to be about 165 through Thursday. The solar flux index is updated daily at
1700, 2000 and 2300Z at:
https://www.spaceweather.gc.ca/forecast-prevision/solar-solaire/solarflux/sx-5-flux-en.php

Real time geomagnetic data including Bz orientation, IMF field
strength, solar wind speed and short term k-index forecast are available
at: https://www.swpc.noaa.gov/products/geospace-geomagnetic-activity-plot

Today's three-day GFZ Planetary K Index forecast is updated every three
hours at:
https://spaceweather.gfz-potsdam.de/fileadmin/ruggero/Kp_forecast/forecast_figures/KP_FORECAST_CURRENT.png

Today's SIDC Daily Bulletin on Solar and Geomagnetic Activity is updated
daily at 1230Z at:
https://www.sidc.be/spaceweatherservices/data/ClassicalRWCproducts/meu

Today's SWPC Solar Activity Forecast Discussion is updated daily at 0030Z
and 1230Z at: https://www.swpc.noaa.gov/products/forecast-discussion

Today's Australian Space Forecast Centre Summary and Forecast is updated
daily at 2330Z at: https://www.sws.bom.gov.au/Space_Weather/1/1

Perhaps the most useful HF propagation pages for DXers can be found at:
http://dx.qsl.net/propagation and https://www.solarham.net