[RSM] W3LPL: Mostly normal propagation is likely through Tuesday July 20th

[Art Boyars]

From: donovanf at erols.com
To: Reflector PVRC <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 19 Jul 2021 00:43:30 -0400 (EDT)
Subject: [PVRC] Mostly normal propagation is likely through Tuesday July
20th

My propagation forecast derived from today's NOAA/SWPC

web pages is published five days a week (M-F) in the Daily DX.



Propagation crossing low and mid latitudes is likely to be normal

through Tuesday.



Propagation crossing the auroral ovals and polar regions is likely

to be mostly normal through Tuesday.



 Click *here* <https://services.swpc.noaa.gov/images/planetary-k-index.gif>
 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.



We are in the quiet geomagnetic activity season, only about half

as many geomagnetically disturbed days occur in June and July

compared to the more geomagnetically active equinox seasons.



Sporadic-E propagation occurs every day during June and July

at mid-latitudes in the northern hemisphere making long distance

propagation up to 15,000 km sporadically available in the

17, 15, 12, 10 and 6 meter bands from sunrise through midnight

and occasionally somewhat later.



The solar flux index (SFI) is likely to be at least 80 through Tuesday.

There are three small active regions on the solar visible disk with

twelve tiny sunspots.

https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg



160 and 80 meter propagation from North America to VK/ZL and

the south Pacific is likely to be seasonably normal through Tuesday.

40 meter short path propagation to south Asia at about 0015Z is

likely to be mostly normal through Tuesday. 40 meter 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 mostly normal through Tuesday. 30 meter propagation

is always significantly degraded within a few hours of local noon

because of E-region blanketing of long distance F2 propagation.

30 meter night time long distance propagation in the norther

 hemisphere is likely to improve due to increased ionizing solar

radiation in the northern high latitude regions caused by increased

sunspot activity, higher solar elevation angles and short nights

with no source of ionizing solar radiation.



20 meter daytime and evening propagation through the auroral

ovals and polar regions is likely to be mostly normal through

Tuesday. 20 meter northern transpolar propagation within a

few hours of sunrise and sunset is improving with longer duration

solar ionizing radiation on the northern polar region caused by

high solar elevation angles 24 hours per day during the midnight

sun season. 20 meter long distance propagation is significantly

degraded from mid-morning through late afternoon at low and

mid-latitudes in the northern hemisphere by F1 region midday

blanketing of low angle long distance propagation during the

summer. 20 meter late afternoon, nighttime and early morning

long distance propagation in the northern hemisphere is likely

to improve due to increased ionizing solar radiation in the northern

high latitude regions caused by increased sunspot activity,

higher solar elevation angles and short nights with no source

of ionizing solar radiation.



17 and 15 meter daytime long distance propagation in the northern

hemisphere is likely to improve due to increased ionizing solar

radiation in the northern high latitude regions caused by increased

sunspot activity, high solar elevation angles and long days.

17, 15, 12, 10 and 6 meter sporadic-E propagation up to 15,000 km

is likely to be sporadically available from sunrise through midnight

and occasionally later through late July.



Geomagnetic disturbances *caused by coronal hole high speed stream*

effects are likely to remain mostly brief, minor and somewhat less

frequent through at least late 2021. The southward oriented (-Bz)

component of the 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 enhanced IMF

field strength 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 enhanced IMF field strength

or several hours or more *coincident with* the effects of an Earth

directed fast CME.



The solar wind is expected to be near background state through

Tuesday. The geomagnetic field is likely to be mostly quiet through

Tuesday. Coronal hole high speed stream and CME effects,

geomagnetic storms and solar flares are not likely through Tuesday.



Mid-latitude northern hemisphere sunset is now 6 minutes earlier

and daylength is 22 minutes shorter than it was on the June 21st.

Daylength and solar elevation angle in the northern polar region

are slowly declining due to gradually waning summer solstice effects.



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 http://www.solarham.net