[RSM] W3LPL forecast thru Sunday 2023-05-21: Mostly normal

Wed May 17 11:30:43 EDT 2023

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Wed, 17 May 2023 00:58:08 -0400 (EDT)
Subject: [PVRC] Low, mid and high latitude propagation is likely to be
mostly normal through Sunday

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 the auroral ovals and polar
regions is likely to be mostly normal through Sunday.

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 56 minutes later and day length
is 135 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 50 degrees north latitude.

The May 17th Estimated International Sunspot Number is 79. Today's Solar
Flux Index (SFI) is 134 and likely to be about the same through Sunday. The
sun’s visible disk has two medium and five tiny active regions containing
36 sunspots with a total sunspot area of 220 micro-hemispheres (about 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 Friday.

The solar wind is slightly enhanced at about 460 km/second, likely to
gradually decline to ambient levels of less than 400 km/second through
Sunday.

Geomagnetic activity is likely to mostly quiet through Sunday.

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 at about
0000Z is likely to be mostly normal through Sunday. Short path propagation
from North America to east Asia after about 0930Z is likely to be mostly
normal through Sunday.

30 meter propagation through the auroral ovals and polar regions is likely
to be mostly normal through Sunday. 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 through Sunday. 20
meter transpolar propagation within a few hours of sunrise and sunset is
likely to be mostly normal through Sunday.

17 and 15 meter long distance propagation is likely to be mostly normal
through Sunday. 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
Sunday.

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

There is a chance through Sunday 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 Sunday 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 Sunday of
oblique-TEP to the south Pacific and VK/ZL during late afternoon and early
evening through Sunday. There is a slight chance that stations at
mid-latitudes in the U.S. 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