[RSM] W3LPL: Mostly normal, isolated mildly degraded intervals, thru Tues/23

[Art Boyars]

From: Frank Donovan <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 22 May 2023 03:39:29 -0400 (EDT)
Subject: [PVRC] Propagation is likely to be mostly normal with isolated
mildly degraded intervals at high latitudes late Tuesday

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 mostly normal
through Tuesday.

Propagation crossing the auroral ovals and polar regions is likely to be
mostly normal with isolated mildly degraded intervals late Tuesday.

VE3EN’s End-of-Day Solar Report is published daily at 0045Z at
https://www.solarham.net

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

Click *here* <https://services.swpc.noaa.gov/images/station-k-index.png>
for today’s
latest planetary Kp Index, updated every three hours.

Click *here* <http://www.hamqsl.com/solar.html> for N0NBH’s current HF Band
Conditions, updated regularly.
Mid-latitude northern hemisphere sunset is 60 minutes later and day length
is 141 minutes longer than it was on March 20th. 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 in the F2
region over Canada above 48 degrees north latitude.

The May 21st Estimated International Sunspot Number is 138. Today's Solar
Flux Index (SFI) is 163 and likely to be about the same through Tuesday.
The sun’s visible disk has two very large, one large, two medium and three
tiny active regions containing 60 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

Minor to moderate daytime radio blackouts caused by M-class solar flares
are likely with a chance of strong X-class solar flares through Tuesday.

The solar wind is moderately enhanced at about 540 km/second, declining to
mildly enhanced at less than 500 km/second through midday Tuesday then
increasing to moderately enhanced at more than 500 km/second late Tuesday.

Geomagnetic activity is likely to quiet to unsettled through midday Tuesday
degrading to active to minor storm conditions late Tuesday.

160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be mostly normal through Tuesday.

40 meter short path propagation from North America to south Asia at about
0000Z is likely to be mostly normal through Tuesday. Short path propagation
from North America to east Asia after about 0930Z is likely to be mostly
normal through Tuesday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal with isolated mildly degraded intervals late Tuesday.
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 isolated mildly
degraded intervals late Tuesday. 20 meter transpolar propagation within a
few hours of sunrise and sunset is likely to be mostly normal with isolated
mildly degraded intervals late Tuesday.

17 and 15 meter long distance propagation is likely to be mostly normal
with isolated mildly degraded intervals late Tuesday. 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 Tuesday.

12 and 10 meter long distance propagation is likely to be mostly normal
with isolated mildly degraded intervals late Tuesday. 12 and 10 meter long
distance propagation crossing the north Atlantic and north Pacific is
degraded by normal seasonally lower MUFs due to reduced free electron
density in the F2 region through mid-September. 12 and 10 meter long path
propagation from North America to east Asia from about 1200Z to 1400Z is
likely to be mostly normal through Tuesday.

There is a chance through Tuesday of 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 slight chance through Tuesday of propagation via the
northern equatorial ionization anomaly from the southern tier of US states
to equatorial Africa during mid-afternoon. There is a slight chance through
Tuesday of oblique-TEP to the south Pacific and VK/ZL during late afternoon
and early evening through Tuesday. There is a slight chance that stations
in the lower 48 U.S. states may briefly couple into TEP and oblique-TEP via
brief geographically focused intervals of mid-latitude sporadic-E or
enhanced F2 propagation. TEP may be enhanced during the onset of strong to
severe geomagnetic storms then degrading significantly 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
faster than 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

Click *here* <https://www.spaceweather.gc.ca/solarflux/sx-4-en.php> for today’s
Penticton 10.7 cm solar flux index updated at 1700Z, 2000Z and 2300Z daily.

Click *here*
<https://spaceweather.gfz-potsdam.de/fileadmin/ruggero/Kp_forecast/forecast_figures/KP_FORECAST_CURRENT.png>
for today’s
three-day GFZ Planetary K Index forecast updated every three hours.

Click *here* <http://sidc.oma.be/products/meu/> for today's SIDC Daily
Bulletin on Solar and Geomagnetic Activity updated at 1230Z daily.

Click *here* <https://www.swpc.noaa.gov/products/forecast-discussion>
for today's
SWPC Solar Activity Forecast Discussion updated at 0030Z and 1230Z daily.

Click *here* <https://www.sws.bom.gov.au/Space_Weather/1/1> for today's
Australian Space Forecast Centre Summary and Forecast updated at 2330Z
daily.
Perhaps the most useful HF propagation pages for DXers can be found at:
http://dx.qsl.net/propagation and https://www.solarham.net

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