[RSM] W3LPL forecast thru Thurs, June 29

Wed Jun 28 10:08:53 EDT 2023

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 28 Jun 2023 01:48:08 -0400 (EDT)
Subject: [PVRC] Propagation crossing low and mid latitudes is likely to be
normal through Thursday. Propagation crossing the auroral ovals and polar
regions is likely to be mostly normal with a chance of mild degradations
mostly during local night time hours through Thursday

My propagation forecast derived from today's NOAA/SWPC web pages and twelve
other online sources (the URLs are 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 normal through
Thursday.

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 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   prop.kc2g.com
<http://www.prop.kc2g.com/> provides near-real time maps and data about
ionospheric conditions.

Mid-latitude northern hemisphere sunset is one minute later and day length
is one minute shorter 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 above 45 degrees north latitude.

Today’s Estimated International Sunspot Number is 155 and is likely to be
about the same through Thursday. The sun’s visible disk has one very large,
one large, three medium and four tiny active regions containing 51 sunspots
with a total sunspot area of 900 micro-hemispheres (about five times the
surface area of the Earth).
https://www.sidc.be/spaceweatherservices/applications/solarmap

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

The solar wind is moderately elevated at 472 km/second and is likely to
gradually decline to background levels of  400 km/second or less by
Thursday.

Geomagnetic activity is likely to be mostly quiet with possible brief
unsettled intervals and a chance of active intervals through Thursday 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 Thursday.

40 meter short path propagation from North America to south Asia after
0000Z is likely to be mostly normal with a chance of mild degradations
primarily during local night time hours through Thursday. Short path
propagation from North America to east Asia after about 0930Z is likely to
be mostly normal with a chance of mild degradations through Thursday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with a chance of mild degradations primarily during
local night time hours through Thursday. 30 meter propagation is
always mildly to moderately 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 primarily during local night time hours through Thursday. 20
meter transpolar propagation within a few hours of sunrise and sunset is
likely to be mostly normal with a chance of mild degradations primarily
during local night time hours through Thursday. 20 meter long distance
propagation at low and mid latitudes in northern hemisphere is usually
degraded during daylight hours from June through September by E region and
sporadic-E blanketing of long distance F2 propagation.

17 and 15 meter long distance propagation is likely to be mostly normal
with a chance of mild degradations primarily during local night time 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 mostly normal
through Thursday.

12 and 10 meter long distance propagation is likely to be mostly normal
with a chance of mild degradations primarily during local night time hours
through Thursday. 12 and 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
mid-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 occasionally
occurs in the northern hemisphere from early morning through late evening
hours through at least mid-July, but its duration and geographic extent is
both sporadic and unpredictable. 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

We are in the summer solstice season when geomagnetic disturbances are less
severe, shorter duration and occur about half as often as during the
equinox seasons.

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.

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

The Penticton 10.7 cm 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

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   v