[RSM] W3LPL forecast thru Sunday, July 30

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Fri, 28 Jul 2023 02:24:54 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be above normal through early
Sunday then mildly degrading to mostly normal through late Sunday

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 and mid latitudes is likely to be above normal
through early Sunday, then mildly degrading to normal through late Sunday.
  Propagation crossing the auroral ovals and polar regions is likely to be
normal through early Sunday, then mildly degrading to mostly normal through
late Sunday.
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 prop.kc2g.com
<http://www.prop.kc2g.com/>

Mid-latitude northern hemisphere sunrise is 25 minutes later and sunset is
15 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 50 degrees north latitude.

Thursday’s Estimated International Sunspot Number was 142 and is likely to
remain about the same through Sunday. The sun’s visible disk has two large,
four medium and five tiny active regions containing 44 sunspots with a
total sunspot area of 1010 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 daytime radio blackouts caused by
M-class solar flares through Sunday.

The solar wind is likely to be at mostly background levels of about 350 to
400 km/second through early Sunday, then gradually increasing to about 450
km/second through late Sunday due to coronal hole high speed stream effects.

Geomagnetic activity is likely to be quiet through early Sunday.
Geomagnetic activity is likely to gradually degrade to unsettled to active
after early Sunday due to 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 normal through Sunday.

40 meter short path propagation from North America to south Asia after
0000Z is likely to be normal through Sunday. Short path propagation between
North America and east Asia after about 0930Z is likely to be normal
through Saturday and mostly normal on Sunday.
30 meter propagation crossing the auroral ovals and polar regions is likely
to be normal through early Sunday degrading to mostly normal through late
Sunday. 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 daytime and evening propagation through the auroral ovals and
polar regions is likely to be normal through early Sunday mildly degrading
to mostly normal through late Sunday. 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 daytime and evening propagation through the auroral ovals
and polar regions is likely to be normal through early Sunday mildly
degrading to mostly normal through late Sunday. 17 and 15 meter long path
propagation from North America to east Asia from about 1200Z to 1400Z is
likely to be normal through Saturday degrading to mostly normal on Sunday.

12 and 10 meter long distance daytime propagation is likely to be normal
through early Sunday mildly degrading to mostly normal through late Sunday.
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
Saturday degrading to mostly normal on Sunday.

There is a chance of 6 meter long distance sporadic-E propagation up to
10,000 km in the northern hemisphere from mid-morning through
evening.  Long distance sporadic-E is much less reliable, much more
sporadic and much shorter in duration as we approach the end of most
sporadic-E propagation in mid-August. See K6MIO’s excellent article about 6
meter long distance sporadic-E:
www.qsl.net/wa3mej/Articles/Propagation/6M%20Prop/K6MIO/Extreme%20Range%2050-MHz%20Es-%20East%E2%80%93West%20(EWEE).pdf

There is a very slight chance through Sunday of brief 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 Sunday of 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 Sunday of brief
isolated oblique-TEP to the south Pacific and VK/ZL during late afternoon
and early evening through Sunday. There is a very slight chance that
stations in the lower 48 U.S. states 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 165 through Sunday 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