[RSM] W3LPL forecast thru Thursday, Aug. 24

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 23 Aug 2023 02:13:45 -0400 (EDT)
Subject: [PVRC] Propagation crossing low and mid latitudes, the auroral
ovals and polar regions is likely to be mostly normal with possible mild to
moderate degradations at high latitudes during local night hours through
Thursday

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.

Propagation crossing low latitudes is likely to be mostly normal with
possible mild to moderate degradations during local night hours through
Tuesday.   Propagation crossing mid-latitudes is likely to be normal
through Thursday.   Propagation crossing the auroral ovals and polar
regions is likely to be mostly normal with possible mild to moderate
degradations during local night hours through Thursday.
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
ionospheric conditions are available at https://prop.kc2g.com

Mid-latitude northern hemisphere sunrise is 45 minutes later and sunset  is
46 minutes earlier than it was on June 21st. 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. The sun never sets today on the F2
region north of 57 degrees north latitude.

Today’s Estimated International Sunspot Number is 121 and is likely to
remain about the same through Thursday. The sun’s visible disk has two
large, three medium and three tiny active regions containing 15 sunspots
with a total sunspot area of 700 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 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 400 km/second
through Thursday due to weak, persistent, but intermittent coronal hole
high speed stream effects.

Geomagnetic activity is likely to be mostly quiet to unsettled with a
chance of isolated periods of active geomagnetic conditions through
Thursday due to weak, persistent, but intermittent coronal hole high speed
stream effects.
160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be mostly normal through Thursday.
40 meter short path propagation from North America to south Asia after
0000Z is likely to be mostly normal early Thursday. Short path propagation
between North America and east Asia after about 0930Z is likely to be
mostly normal through Thursday.
30 meter propagation crossing the auroral ovals and polar regions is likely
to be mostly normal with possible mild to moderate degradations during
local night hours through 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 with possible mild to moderate degradations during
local night hours through Thursday. 20 meter long distance propagation at
low and mid latitudes in the northern hemisphere is usually degraded from
several hours before noon until several hours after noon through late
August by E region and sporadic-E 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 with possible mild to moderate degradations
during local night hours through Thursday. 17 and 15 meter long path
propagation from North America to east Asia from about 1200Z to 1400Z is
likely to be normal through Thursday.

12 and 10 meter long distance daytime propagation is likely to be mostly
normal with possible mild to moderate degradations during local night hours
through Thursday. 12 and especially 10 meter long distance propagation
crossing the north Atlantic and north Pacific is degraded by seasonally
lower daytime MUFs due to reduced daytime free electron density in the F2
region through late September. 12 and 10 meter long path propagation from
North America to western Australia from about 1200Z to 1400Z is likely to
be normal through Thursday.
There is a very slight chance through Thursday of very brief isolated 6
meter F2 trans-equatorial propagation (TEP) from the southern tier of U.S.
states to South America and the south Atlantic (e.g., ZD7) from early
afternoon through late evening. There is a very slight chance through
Thursday of very brief isolated propagation via the northern equatorial
ionization anomaly from the southern tier of US states to equatorial Africa
during mid-afternoon.  There is a very slight chance through Thursday of
very brief isolated oblique-TEP from the southern tier of US states to the
south Pacific and VK/ZL during late afternoon and early evening through
Thursday. There is a very slight chance that more northerly US stations may
briefly couple into TEP and oblique-TEP via geographically focused
intervals of mid-latitude sporadic-E propagation. TEP may be enhanced
during the 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

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 CME and solar wind
exceeding 500 km/second.   The Penticton 10.7 cm solar flux index is likely
to remain at about 151 through Thursday and 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