[RSM] W3LPL forecast thru Thursday, July 27

[Art Boyars]

 From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 26 Jul 2023 02:42:07 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly normal through late
Wednesday. Moderately degraded propagation crossing the auroral ovals is
likely during local late Wednesday and early Thursday nighttime hours,
improving to mostly normal before midday 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 normal through Thursday.
  Propagation crossing mid latitudes is likely to be normal through late
Wednesday.  Mildly degraded propagation is likely during local late
Wednesday and early Thursday nighttime hours, improving to normal
before midday Thursday.   Propagation crossing the auroral ovals and polar
regions is likely to be mostly normal through late Wednesday. Moderately
degraded propagation is likely during local late Wednesday and early
Thursday nighttime hours, improving to mostly normal before midday
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 prop.kc2g.com
<http://www.prop.kc2g.com/>

Mid-latitude northern hemisphere sunrise is 22 minutes later and sunset is
12 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 45 degrees north latitude.

Tuesday’s Estimated International Sunspot Number was 134 and is likely to
remain about the same through Thursday. The sun’s visible disk has three
large, three medium and four tiny active regions containing 37 sunspots
with a total sunspot area of 1110 micro-hemispheres (about six 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 Thursday.

The solar wind is likely to be mildly enhanced at about 500km/second or
less through late Wednesday, steadily increasing to moderately elevated
levels of about 500 to 550 km/second through early Thursday due to CME
effects, then gradually declining after midday Thursday to 450 km/second or
less.

Geomagnetic activity is likely to be unsettled to active through midday
Thursday. Isolated minor geomagnetic storm are possible early Thursday due
to CME effects. Geomagnetic activity is likely to improve to quiet to
unsettled after midday Thursday.
160 and 80 meter propagation from North America to VK/ZL and
the South Pacific is likely to be normal through Thursday.

40 meter short path propagation from North America to south Asia after
0000Z is likely to be mostly below 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. Moderately degraded propagation is likely during local
late Wednesday and early Thursday nighttime hours, improving to mostly
normal before midday 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 daytime and evening propagation through the auroral ovals and
polar regions is likely to be mostly normal. Moderately degraded
propagation is likely during local late Wednesday and early Thursday
nighttime hours, improving to mostly normal before midday Thursday. 20
meter long distance propagation at low and mid latitudes in the northern
hemisphere is usually degraded from a several hours before noon until a
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 mostly normal. Moderately degraded
propagation is likely during local late Wednesday and early Thursday
nighttime hours, improving to mostly normal before midday Thursday. 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 Thursday.

12 and 10 meter long distance daytime propagation is likely to be mostly
normal 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 mostly normal through Thursday.

6 meter long distance sporadic-E propagation up to 10,000 km in the
northern hemisphere from early morning through late evening hours 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 Thursday 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 Thursday 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 Thursday of brief
isolated oblique-TEP to the south Pacific and VK/ZL during late afternoon
and early evening through Thursday. 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 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