[RSM] W3LPL forecast thru Sunday, Aug 27

[Art Boyars]

From: Frank W3LPL <donovanf at starpower.net>
To: PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Fri, 25 Aug 2023 00:51:06 -0400 (EDT)
Subject: [PVRC] Propagation crossing low and mid latitudes is likely to be
normal through Sunday. Propagation crossing the auroral ovals and polar
regions 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 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 Sunday.



Propagation crossing the auroral ovals and polar regions is likely

to be mostly normal through 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 https://prop.kc2g.com

Mid-latitude northern hemisphere sunrise is 47 minutes later and

sunset is 51 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 57 degrees

north latitude.

Today’s Estimated International Sunspot Number is 69 and is likely

to remain about the same through Sunday. The sun’s visible disk has

one large and five three medium active regions containing 26 sunspots

with a total sunspot area of 950 micro-hemispheres

(about five times 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 Sunday.

Solar wind speed is likely to be mildly elevated at about

400 km/second through Sunday due to isolated, weak, persistent,

but intermittent coronal hole high speed stream effects.

Geomagnetic activity is likely to be mostly quiet to unsettled

with a chance of isolated periods of active geomagnetic conditions

through Sunday due to weak, persistent, but intermittent 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 early Sunday. Short

path propagation between North America and east Asia after about

0930Z is likely to be normal through Sunday.


30 meter propagation crossing the auroral ovals and polar regions

is likely to be mostly normal through 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 propagation crossing the auroral ovals and polar regions

is likely to be mostly normal through 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 propagation crossing the auroral ovals and polar

regions 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 at least 1400Z is likely to be normal through Sunday.

12 and 10 meter long distance daytime propagation is likely to be

mostly normal through 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 at least 1400Z is likely to be normal

through Sunday.


There is a very slight chance through Sunday of very brief isolated

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 very 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

very brief isolated oblique-TEP from the southern tier of US states

to the south Pacific and VK/ZL during late afternoon and early

evening through Sunday. There is a very slight chance that more

northerly US stations 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

144 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