Propagation crossing low and mid latitudes is likely to be normal through Friday. Propagation crossing high latitudes is likely to be mostly normal through midday Friday then normal through late Friday.
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The Thursday April 18th W3LPL propagation forecast derived from today's NOAA/SWPC web pages and 15 other online sources (the URLs at the end of 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.
The 2300Z Penticton 10.7 cm observed solar flux index was 216 and is likely to remain mostly unchanged through Friday.
http://www.spaceweather.gc.ca/foreca...ux/sx-4-en.php
SILSO’s latest Estimated International Sunspot Number was 207 and is likely to remain mostly unchanged through Friday.
https://www.sidc.be/SILSO/DATA/EISN/EISNcurrent.png
The visible solar disk has one large, two medium, seven small and two very small active regions containing 79 sunspots with a total sunspot area of 1150 micro solar hemispheres (about seven times the surface area of the Earth).
www.solarham.net/regions.htm
Solar wind speed is likely to be slightly enhanced at about 400 km/second or less through midday Friday due to effects of multiple weak CMEs then declining to near background levels
https://www.swpc.noaa.gov/phenomena/solar-wind
Geomagnetic activity is likely to be mostly unsettled to active on Thursday due to effects of multiple weak CMEs, improving to mostly quiet to unsettled through midday Friday, and further improving to quiet through late Friday. There is a chance of a minor geomagnetic storm before midday Thursday due to CME effects.
https://www.swpc.noaa.gov/phenomena/...mass-ejections
https://www.swpc.noaa.gov/phenomena/coronal-holes
Minor to moderate radio blackouts on the sunlit side of the Earth caused by M-class solar flares are likely through Friday. There is a slight chance of strong radio blackouts caused by X-class solar flares through Friday.
https://www.swpc.noaa.gov/phenomena/...adio-blackouts
There is a slight chance that minor solar radiation storms may affect HF propagation crossing polar regions through Friday.
https://www.swpc.noaa.gov/phenomena/...adiation-storm
160 and 80 meter propagation from North America to VK/ZL and the South Pacific is likely to be normal through Friday.
40 meter short path propagation from North America to the Middle East and south Asia is likely to be mostly normal after 0000Z Friday. Short path propagation between North America and east Asia after about 0930Z is likely to be mildly degraded on Thursday and normal on Friday.
30 meter propagation crossing the auroral ovals and polar regions is likely to be mostly normal through Friday with a chance of mild degradations early Thursday. 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 Friday with a chance of mild degradations early Thursday.
17 and 15 meter propagation crossing the auroral ovals and polar regions is likely to be mostly normal through Friday with a chance of mild degradations early Thursday. 17 and 15 meter long path propagation from North America to southeast and east Asia from about 1200Z to 1400Z is likely to be mildly degraded on Thursday and normal on Friday.
12 and 10 meter long distance propagation is likely to be mostly normal through Friday with a chance of mild degradations early Thursday. 12 and 10 meter long path propagation from North America to southeast and east Asia from about 1200Z to 1400Z is likely to be mildly degraded on Thursday and normal on Friday. High altitude thermally driven summer winds blowing from the dayside F2 region to the nightside F2 region reduce the volume of neutral molecular oxygen available for daytime ionization causing degraded daytime 12 and 10 meter long distance F2 propagation from late spring through late summer.
There is a very slight chance of brief, isolated, geographically focused 6 meter above-the-MUF trans-Atlantic F2 propagation from about 1400-1600Z between mid-latitude U.S states and western Europe, this propagation may be skewed towards the equator. There is a very slight chance of brief geographically focused 6 meter F2 propagation enhanced by TEP over Africa from the southern tier of US states to the Indian Ocean, equatorial and southern Africa (e.g., 3B8. 3B9, 7Q, D2, FR, V5, ZD7 and ZS) from about 1400-1800Z. There is a chance of F2 trans-equatorial propagation (TEP) from the southern tier of U.S. states to South America from about 2000-0200Z. There is a very slight chance of above-the-MUF F2 propagation enhanced by oblique-TEP from the southern tier of US states to the south Pacific (e.g., 3D2, 5W, E5, FK, VK4, VK9, ZL and ZL7) from about 2100-0100Z. There is a slight chance that more northerly U.S. stations may couple into TEP and oblique-TEP via geographically focused brief intervals of above-the-MUF F2 propagation. TEP may be significantly enhanced from about 2000-0200Z during the initial phase of strong to severe geomagnetic storms then degrading several hours 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
Sustained 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 is sustained in a southward orientation (-Bz) with IMF field strength of about 5 nanoteslas or more for at least a few hours coincident with the influence of a geoeffective coronal hole high speed stream or CME. More frequent, longer duration, minor to severe geomagnetic storms may be triggered suddenly and unpredictably when the IMF is sustained in a southward orientation (-Bz) with IMF field strength of about 5 nanoteslas or more for a period of several hours or more coincident with the influence of a geoeffective CME and solar wind speed of about 500 km/second or more.
Mid-latitude northern hemisphere sunrise is 44 minutes earlier and sunset is 32 minutes later than on March 20th. Sunrise is about two hours earlier and sunset is about two hours later at the altitude of the refracting F2 region. Sunrise is about one hour earlier, and sunset is about one hour later at the altitude of the absorbing D region.
EarthSky’s Sun News is published daily at
earthsky.org/sun/sun-news-activity-solar-flare-cme-aurora-updates
Northwest Research Associate’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 frequently at www.sidc.be/silso/DATA/EISN/EISNcurrent.png
The Penticton 10.7 cm solar flux index is updated daily at 1700, 2000 and 2300Z at:
http://www.spaceweather.gc.ca/foreca...-5-flux-en.php
SWPC’s Estimated Planetary Kp Index is updated every three hours at https://services.swpc.noaa.gov/image...on-k-index.png
UK Met Office’s EUHFORIA solar wind report and forecast is updated daily at https://swe.ssa.esa.int/DOCS/portal_...#1708014964422
UK Met Office’s Solar Flare Forecast is updated daily at
https://swe.ssa.esa.int/web/guest/ukmo-S109c-federated
UK Met Office’s Solar Wind Forecast and CME Arrival Prediction is updated regularly at
https://swe.ssa.esa.int/metoffice-enlil-e-federated
N0NBH’s Current HF Band Conditions Report is updated regularly at
www.hamqsl.com/solar.html
KC2G’s Near-Real-Time Maps and Data about HF propagation are generated every 15 minutes, from near real time data usually only 5 to 20 minutes old at
https://prop.kc2g.com
SWPC’s Real Time 24 hour Geomagnetic Data including Bz orientation, IMF field strength, solar wind speed and near real time 30 minute forecasts are updated frequently at
http://www.swpc.noaa.gov/products/ge...-activity-plot
SIDC’s Daily Bulletin on Solar and Geomagnetic Activity is updated daily at 1230Z at http://www.sidc.be/spaceweatherservi...uct/meu/latest
GFZ-Potsdam’s three-day GFZ Planetary K Index Forecast is updated every three hours at
https://spaceweather.gfz-potsdam.de/...ecast-kp-index
SWPC’s Solar Activity Forecast and Discussion is updated daily at 0030Z and 1230Z at
www.swpc.noaa.gov/products/forecast-discussion
Australian Space Forecast Centre’s Summary and Forecast is updated daily at 2330Z at
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 www.solarham.net
__________________________________________________ _____________
The Thursday April 18th W3LPL propagation forecast derived from today's NOAA/SWPC web pages and 15 other online sources (the URLs at the end of 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.
The 2300Z Penticton 10.7 cm observed solar flux index was 216 and is likely to remain mostly unchanged through Friday.
http://www.spaceweather.gc.ca/foreca...ux/sx-4-en.php
SILSO’s latest Estimated International Sunspot Number was 207 and is likely to remain mostly unchanged through Friday.
https://www.sidc.be/SILSO/DATA/EISN/EISNcurrent.png
The visible solar disk has one large, two medium, seven small and two very small active regions containing 79 sunspots with a total sunspot area of 1150 micro solar hemispheres (about seven times the surface area of the Earth).
www.solarham.net/regions.htm
Solar wind speed is likely to be slightly enhanced at about 400 km/second or less through midday Friday due to effects of multiple weak CMEs then declining to near background levels
https://www.swpc.noaa.gov/phenomena/solar-wind
Geomagnetic activity is likely to be mostly unsettled to active on Thursday due to effects of multiple weak CMEs, improving to mostly quiet to unsettled through midday Friday, and further improving to quiet through late Friday. There is a chance of a minor geomagnetic storm before midday Thursday due to CME effects.
https://www.swpc.noaa.gov/phenomena/...mass-ejections
https://www.swpc.noaa.gov/phenomena/coronal-holes
Minor to moderate radio blackouts on the sunlit side of the Earth caused by M-class solar flares are likely through Friday. There is a slight chance of strong radio blackouts caused by X-class solar flares through Friday.
https://www.swpc.noaa.gov/phenomena/...adio-blackouts
There is a slight chance that minor solar radiation storms may affect HF propagation crossing polar regions through Friday.
https://www.swpc.noaa.gov/phenomena/...adiation-storm
160 and 80 meter propagation from North America to VK/ZL and the South Pacific is likely to be normal through Friday.
40 meter short path propagation from North America to the Middle East and south Asia is likely to be mostly normal after 0000Z Friday. Short path propagation between North America and east Asia after about 0930Z is likely to be mildly degraded on Thursday and normal on Friday.
30 meter propagation crossing the auroral ovals and polar regions is likely to be mostly normal through Friday with a chance of mild degradations early Thursday. 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 Friday with a chance of mild degradations early Thursday.
17 and 15 meter propagation crossing the auroral ovals and polar regions is likely to be mostly normal through Friday with a chance of mild degradations early Thursday. 17 and 15 meter long path propagation from North America to southeast and east Asia from about 1200Z to 1400Z is likely to be mildly degraded on Thursday and normal on Friday.
12 and 10 meter long distance propagation is likely to be mostly normal through Friday with a chance of mild degradations early Thursday. 12 and 10 meter long path propagation from North America to southeast and east Asia from about 1200Z to 1400Z is likely to be mildly degraded on Thursday and normal on Friday. High altitude thermally driven summer winds blowing from the dayside F2 region to the nightside F2 region reduce the volume of neutral molecular oxygen available for daytime ionization causing degraded daytime 12 and 10 meter long distance F2 propagation from late spring through late summer.
There is a very slight chance of brief, isolated, geographically focused 6 meter above-the-MUF trans-Atlantic F2 propagation from about 1400-1600Z between mid-latitude U.S states and western Europe, this propagation may be skewed towards the equator. There is a very slight chance of brief geographically focused 6 meter F2 propagation enhanced by TEP over Africa from the southern tier of US states to the Indian Ocean, equatorial and southern Africa (e.g., 3B8. 3B9, 7Q, D2, FR, V5, ZD7 and ZS) from about 1400-1800Z. There is a chance of F2 trans-equatorial propagation (TEP) from the southern tier of U.S. states to South America from about 2000-0200Z. There is a very slight chance of above-the-MUF F2 propagation enhanced by oblique-TEP from the southern tier of US states to the south Pacific (e.g., 3D2, 5W, E5, FK, VK4, VK9, ZL and ZL7) from about 2100-0100Z. There is a slight chance that more northerly U.S. stations may couple into TEP and oblique-TEP via geographically focused brief intervals of above-the-MUF F2 propagation. TEP may be significantly enhanced from about 2000-0200Z during the initial phase of strong to severe geomagnetic storms then degrading several hours 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
Sustained 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 is sustained in a southward orientation (-Bz) with IMF field strength of about 5 nanoteslas or more for at least a few hours coincident with the influence of a geoeffective coronal hole high speed stream or CME. More frequent, longer duration, minor to severe geomagnetic storms may be triggered suddenly and unpredictably when the IMF is sustained in a southward orientation (-Bz) with IMF field strength of about 5 nanoteslas or more for a period of several hours or more coincident with the influence of a geoeffective CME and solar wind speed of about 500 km/second or more.
Mid-latitude northern hemisphere sunrise is 44 minutes earlier and sunset is 32 minutes later than on March 20th. Sunrise is about two hours earlier and sunset is about two hours later at the altitude of the refracting F2 region. Sunrise is about one hour earlier, and sunset is about one hour later at the altitude of the absorbing D region.
EarthSky’s Sun News is published daily at
earthsky.org/sun/sun-news-activity-solar-flare-cme-aurora-updates
Northwest Research Associate’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 frequently at www.sidc.be/silso/DATA/EISN/EISNcurrent.png
The Penticton 10.7 cm solar flux index is updated daily at 1700, 2000 and 2300Z at:
http://www.spaceweather.gc.ca/foreca...-5-flux-en.php
SWPC’s Estimated Planetary Kp Index is updated every three hours at https://services.swpc.noaa.gov/image...on-k-index.png
UK Met Office’s EUHFORIA solar wind report and forecast is updated daily at https://swe.ssa.esa.int/DOCS/portal_...#1708014964422
UK Met Office’s Solar Flare Forecast is updated daily at
https://swe.ssa.esa.int/web/guest/ukmo-S109c-federated
UK Met Office’s Solar Wind Forecast and CME Arrival Prediction is updated regularly at
https://swe.ssa.esa.int/metoffice-enlil-e-federated
N0NBH’s Current HF Band Conditions Report is updated regularly at
www.hamqsl.com/solar.html
KC2G’s Near-Real-Time Maps and Data about HF propagation are generated every 15 minutes, from near real time data usually only 5 to 20 minutes old at
https://prop.kc2g.com
SWPC’s Real Time 24 hour Geomagnetic Data including Bz orientation, IMF field strength, solar wind speed and near real time 30 minute forecasts are updated frequently at
http://www.swpc.noaa.gov/products/ge...-activity-plot
SIDC’s Daily Bulletin on Solar and Geomagnetic Activity is updated daily at 1230Z at http://www.sidc.be/spaceweatherservi...uct/meu/latest
GFZ-Potsdam’s three-day GFZ Planetary K Index Forecast is updated every three hours at
https://spaceweather.gfz-potsdam.de/...ecast-kp-index
SWPC’s Solar Activity Forecast and Discussion is updated daily at 0030Z and 1230Z at
www.swpc.noaa.gov/products/forecast-discussion
Australian Space Forecast Centre’s Summary and Forecast is updated daily at 2330Z at
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 www.solarham.net
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