[RSM] W3LPL: Mostly normal thro Fri/16

[Art Boyars]

From: donovanf at erols.com
To: PVRC Submissions <pvrc at mailman.qth.net>
Cc:
Bcc:
Date: Thu, 15 Jul 2021 00:38:46 -0400 (EDT)
Subject: [PVRC] Mostly normal propagation is likely through Friday July 16th

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 Friday.



Propagation through the auroral ovals and polar regions is likely

to be mostly normal through Friday.



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 75 or less through Friday.

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

one small sunspot and two 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 Friday.

40 meter short path propagation to south Asia is likely to be mostly

normal at about 0015Z Friday. 40 meter short path propagation from

North America to east Asia after about 0930Z is likely to be mostly

normal through Friday.



30 meter propagation through the auroral ovals and polar regions

is likely to mostly normal through Friday. 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 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

Friday. 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 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 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 transition to a quieter background state

through Friday. The geomagnetic field is likely to be unsettled to be

quiet to unsettled through Friday. Geomagnetic storms and CME

effects are not likely through Friday.



Mid-latitude northern hemisphere sunset is now 4 minutes earlier

and daylength is 17 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