Check out the ACE-HF propagation software - the latest is version 2.05. ACE-HF is propagation forecasting and modeling for Amateur Radio as well as for Shortwave radio Listening and general HF operation. This software is even used by the military and other clients around the world. This software is developed and maintained by the same engineers that keep VOACAP up-to-date. As a result, this software is the most accurate user interface integrated with VOACAP. CHECK IT OUT, TODAY. This software is the most accurate modeling software available, and is endorsed by NW7US. Read the details to find out why.
This website is kept alive by Tomas (NW7US), out of "spare change" (which there's not always enough of), and, by the kind, helpful people who visit this website. Would you like to help me keep this site running 24/7? If you are able to help me keep this website up and running, please: help me keep this site running for everyone... click on this donation button:
There are other ways that you can help me keep this site up and running. Here are a few other ways:
(Use http://hfradio.org/propsupport/prop.rss as your RSS channel url)
This page was rendered on 08-May-24 0448 UTC.
This page was first created as HFRadio.org in the mid 1990s, and morphed here in 1998, by Tomas David Hood (NW7US)
Current Sunspot Cycle 25 Activity ~ Space Weather ~ Shortwave Radio Propagation
Map, Above: Conditions in the D region of the ionosphere have a dramatic effect on high frequency (HF) communications and low frequency (LF) navigation systems. The global D Region Absorption Predictions (D-RAP) depicts the D region at high latitudes where it is driven by particles as well as low latitudes, where photons cause the prompt changes.
Note: At times, images may appear broken or missing, when SDO is working on the AIA/HMI instruments.
Planetary A-index (Ap): 7
| Planetary K-index (Kp):
Solar Wind: 474 km/s at 2.0 protons/cm3, Bz is 0.0 nT
(May 08, 2024 at 0432 UT)
X-ray Solar Flares:
6h hi [X1.0][0133Z 05/08] 24h hi [X1.0][0133Z 05/08]
What is the difference between the CB and Amateur Radio Services, in the USA? Here are some thoughts on the portrayal of the Amateur Radio Service by the Hit TV Series, NCIS, and a clarification of the difference between CB radio and ham radio.
(Skip to timecode 1:33 to bypass the introductory chat and talk about the headset microphone.)
Here is a video introduction to shortwave / HF amateur radio -- what is it that we amateur radio oprators listen to? If you have not yet been introduced to this world, this is a very basic introduction.
If you are using software utilities such as Ace-HF, that require a "smoothed" sunspot number
(Referred to as the SSN), or, the smoothed 10.7-cm Radio Flux Index,
use the following predicted values in this following table:
Predicted SMOOTHED Sunspot Number And Radio Flux Values
With Expected Ranges
YR/MO
Smoothed Sunspot Number
Predicted/High/Low
Smoothed 10.7 cm Radio Flux
Predicted/High/Low
To understand more about the Maximum Usable Frequencies, and related
science, please read the MUF Basics Page.
Global HF Propagation Conditions
Global HF Propagation Conditions for 0400Z on 05 May, 2021
High Latitude: Normal
Middle Latitude: Normal
Low Latitude: Normal
At 0805 UTC, on 9 August 2011, a strong magnitude X6.9 X-ray flare -- the strongest yet in this current solar cycle (Cycle 24) -- erupted on the northwestern solar limb. Here is a HD Movie of the event:
Videos of Interest - Space Weather, Solar Dynamics Observatory, STEREO, and more... from the NW7US YouTube Channel. (Click on the small image to launch the video...)
Video: Voyager Finds Magnetic Foam at Solar Systems Edge
Video: Zoom View of Prominence Eruption and X-Ray Flare - M2.5 Magnitude - June 7 2011
Video: X-Ray Flare, Coronal Mass Ejection, Proton Storm - M2.5 Magnitude - June 7 2011 (Close-up of the video, above)
Video: Stunning Close-up View of M3 X-Ray Flare 24 February 2011
Video: On How NCIS TV Show Maligned Amateur Radio Service (Full UHD Version)
What's the difference between CB and amateur (ham) radio?
Video: June 2011 20-meter (14-Mhz) JT65A Coverage Map of NW7US Radio Signal
The NW7US Current Sunspot and Geophysical Activity Report
The observations, prognastications, and comments by NW7US
NW7US is Tomas David Hood, Propagation and Space Weather Columnist
for CQ Communications
More about Background X-rays
The hard X-ray energy present from the wavelengths of 1 to 8 Angstroms provide the most effective ionizing energy throughout all of the ionospheric layers in our atmosphere. The GEOS satellites measure these wavelengths and the resulting measurements are reported as the "background X-ray level" throughout the day. A daily average is reported, as well.
Just like X-ray flares, the background hard X-ray level is measured in watts per square meter (W/m2), reported using the categories, A, B, C, M, and X. These letters are multipliers; each class has a peak flux ten times greater than the preceding one. Within a class there is a linear scale from 1 to 9.
If one records the daily background X-ray levels for the course of a sunspot cycle, one would discover that the background X-ray levels remained at the A class level during the sunspot cycle minumum. During the rise and fall of a solar cycle, the background X-ray energy levels remained mostly in the B range. During peak solar cycle periods, the background energy reached the C and sometimes even M levels.
Armed with this information, can we discover any clues as to the current status of Sunspot Cycle 24? Below is a graph plotting the background hard X-ray energy reported by the GEOS satellites since the end of Sunspot Cycle 22. Clearly, we see a noticeable rise in Cycle 24 activity. We're seeing the energy mostly in the B level more often, supporting the view that Cycle 24 is alive and moving along toward an eventual sunspot cycle peak in several years.
Overall, the monthly average background 'hard' X-ray level is rising (as seen by the following plot), showing a change from deep solar cycle minimum. We are certainly in the rising phase of Sunspot Cycle 24. While it has been a slow up-tick over the last eighteen months, I expect to see a more rapid rise during mid to late 2011.
Highlights of Solar and Geomagnetic Activity
Covering the period: 29 April - 05 May 2024
Solar activity was at moderate to high levels. Moderate levels were observed on 29 Apr and 01-02 May. High levels were reached on 30 Apr, due in part to an M9.5/2b flare at 30/2346 UTC from Region 3654 (S07, L=134, class/area Fkc/550 on 30 Apr). Region 3654 was the largest and most complex spot group on 28 Apr-01 May, however it was in decay as it approached the SW limb on 01 May. The region produced a total of 11 M-class flares. On 30 Apr, Region 3663 (N26, L=037, class/area Fkc/580 on 05 May) emerged in the NE quadrant, followed by Region 3664 (S19, L=352, class/area Ekc/580 on 05 May) on 01 May. Both regions grew steadily over the following days. Region 3663 produced 17 M-class flares and 3 X-class flares while Region 3664 produced only 5 M-class flares. The three X-class flares included an X1.6/1b at 03/0222 UTC, an X1.3/1b at 05/0601 UTC, and an X1.2/1b at 05/1154 UTC. The X1.6 flare had associated Type II (959 km/s) and IV radio sweeps, a 550 sfu Tenflare and an associated CME first observed in SOHO/LASCO C2 imagery at 03/0248 UTC. Modelling of the event showed a potential glancing blow arriving around 05/1800 UTC. There were two further CME runs of note. Those included an eruption near N13W09 at 29/0909 UTC that displayed a westward flow across GOES 16 SUVI imagery. C2 imagery showed a CME off the NW limb at 29/1248 UTC that was modelled as a potential glancing blow on 03 May around 1500 UTC. Lastly, a CME that was associated with a C3.9 flare at 03/2037 UTC from a plage area in the NE quadrant. The flare had associated Type II (392 km/s) and Type IV radio emissions and a CME first observed in C3 imagery at 03/2218 UTC. Analysis showed a potential glancing blow on 09 May. Other eruptive events associated with radio signatures were observed, but did not produce ejecta determined to be on the Sun-Earth line.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels throughout.
Solar wind parameters began the period under mild positive polarity CH HSS influence solar wind speed was mostly in the 450-500 km/s range and total field around 2-4 nT. Solar wind speed began to diminish to nominal levels on 30 Apr. After 30/1130 UTC, the first of three CMEs were observed. Total field increased to near 14 nT while the Bz component rotated from -9 nT to +13 nT. Solar wind speed continued to decrease to near 350 km/s. The geomagnetic field responded with quiet levels on 29 Apr, followed by quiet to active levels on 30 Apr-01 May. On 02 May, a shock arrival was observed at 02/1317 UTC, indicating the arrival of the second CME. This CME was possibly the one that left the Sun on 29 Apr. The IMF increased to approximately 21 nT and the Bz component shifted southward to -19 nT. Solar wind speed increased initially to near 450 km/s and later to near 510 km/s on 03 May. The geomagnetic field responded with unsettled to G3 (Strong) storm levels on 02 May and quiet to active levels on 03 May. By early on 03 May, the IMF had decreased to nominal levels with solar wind speed slowly returning to background conditions. Nominal conditions returned on 04 May and through the midday on 05 May. Around 05/1500 UTC, another enhancement was observed in the IMF, likely the arrival of the 03 May CME. Total field strength increased gradually to 14 nT while the Bz component reached a southward deflection of -12 nT. Solar wind speed increased to near 380 km/s. The geomagnetic field responded with unsettled to active levels late on 05 May.
Monthly and smoothed sunspot number - The monthly mean sunspot number (blue) and 13-month smoothed monthly sunspot number (red) for the last five cycles. You can see that this current cycle, Cycle 24, is a weak cycle, compared to the last few.
(Click to see actual size)
Daily and monthly sunspot number (last 13 years)
Daily sunspot number (yellow), monthly mean sunspot number (blue), smoothed monthly sunspot number (red) for the last 13 years and 12-month ahead predictions of the monthly smoothed sunspot number:
SC (red dots) : prediction method based on an interpolation of Waldmeier's standard curves; It is only based on the sunspot number series.
CM (red dashes) : method (from K. Denkmayr and P. Cugnon) combining a regression technique applied to the sunspot number series with the aa geomagnetic index used as a precursor (improved predictions during the minimum phase between solar cycles).
(Click to see actual size)
What is 'Space Weather'? Click on these two information slides to view them in full size:
View of numbered sunspot regions and plages (if any)
Source: http://www.solarmonitor.org/.
(Click for large view)
Active sunspot regions, and plages, identified by SIDC
STEREO IMAGES
What is coming
Current View
What was...
Real Time Solor Wind and Aurora:
On 2024 May 08 0444Z: Bz: 0.5 nT
Bx: -3.0 nT | By: 2.3 nT | Total: 3.8 nT
Most recent satellite polar pass:
Centered on // : UTC Aurora Activity Level was at UTC
visit noaa for latest.
This is a video of the simulation from May 27-28, 2011, showing
the Geomagnetic disturbance caused by the solar wind
Outlook:
07 May 2024 10.7-cm Flux: 170 / Ap: 008
08 May 2024 10.7-cm Flux: 169 / Ap: 012
09 May 2024 10.7-cm Flux: 168 / Ap: 008
Forecast:
Solar Flares: M-class flares expected (probability >=50%) Geo-Disturbance: Active conditions expected (A>=20 or K=4) Solar Proton Event: Quiet
Three Day Forecast of Solar and Geomagnetic Activity
(as of 2200Z on 07 Dec 2014)
Solar Forecast:
Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (08 Dec, 09 Dec, 10 Dec).
Geomagnetic Forecast:
The geomagnetic field is expected to be at quiet to minor storm levels on day one (08 Dec), quiet to active levels on day two (09 Dec) and quiet levels on day three (10 Dec).
Forecast of Solar and Geomagnetic Activity
06 May - 01 June 2024
Solar activity is expected to be at moderate to high levels (R1-R3/Minor-Strong) through 12 May as Regions 3663 and 3664 rotate across the visible disk. Low to moderate levels are expected on 12 May-01 Jun.
There is a chance for S1-S2 (Minor-Moderate) solar radiation storm levels on 06-13 May due to the flare potential of Regions 3663 and 3664.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels on 06 May-01 Jun.
Geomagnetic field activity is expected to be at unsettled to G2 (Moderate) storm levels on 06 May due to persistent CME influence. The geomagnetic field is expected to reach unsettled to active levels on 07-09 May, 12-14 May, 23-25 May, 27-28 May, and 31 May-01 Jun due to recurrent CH HSS activity.
Data and images courtesy of IPS Australia, NOAA, NASA, SWPC, SIDC
Layout, analysis, commentary, and certain forecasts and content is Copyright, 2022, Tomas David Hood (NW7US), all rights reserved.
No part, except for the space weather 'banners', may be copied without express permission.