[RSM] W3LPL prop forecast through Tuesday July 6

[Art Boyars]

From: donovanf at erols.com
To: Radio Club <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 5 Jul 2021 01:29:12 -0400 (EDT)
Subject: [PVRC] Mostly normal propagation is likely through Tuesday July 6th

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 through the auroral ovals and polar regions is likely

to be mostly normal through Tuesday. There is a slight possibility

that isolated below normal intervals may briefly degrade high

latitude propagation through early 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 90 through Tuesday.

Solar active region 2835 decreased in magnetic complexity and

area to 540 micro-hemispheres (1.6 billion square kilometers,

three times the surface area of the Earth). Region 2835 is

significantly improving HF propagation on 30 and 20 meters during

late afternoon, nighttime and early morning hours and 17 and

15 meter propagation from sunrise through early evening. New

active region 2838 produced an X-1.5 class solar flare at 1429Z

Saturday -- the strongest since 2017 -- and rotated off the visible

disk late Sunday.

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 is likely to be mostly

normal at about 0015Z 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 be 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 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 much shorter

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 increased

solar ionizing radiation on the northern polar region caused by

increased sunspot activity and 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 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 increasing sunspot activity, higher solar elevation

angles and much shorter 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 increasing

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 for

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

fast CME.



The solar wind is expected to be weakly enhanced and the

geomagnetic field is likely to be unsettled through early Tuesday

due to mild coronal hole high speed stream effects. Geomagnetic

storms are not likely through Tuesday. There is a slight possibility

of an M-class solar flare from Region 2835 through Tuesday, but

any possible HF propagation effects are likely to be brief and minor.



Mid-latitude northern hemisphere sunset is now 1 minute earlier and

daylength is 4 minutes shorter than it was on the June 21st. Daylength

and solar elevation angle in the northern polar region are slowly

declining through mid-July 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