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.
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This page was rendered on 02-Apr-23 1923 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): 13
| Planetary K-index (Kp):
Solar Wind: 532 km/s at 4.0 protons/cm3, Bz is 1.0 nT
(Apr 02, 2023 at 1908 UT)
X-ray Solar Flares:
6h hi [C6.7][0249Z 04/01] 24h hi [C6.7][0249Z 04/01]
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: 20 - 26 March 2023
Solar activity reached moderate levels on 20 March due to an isolated M1 flare (R1-Minor) at 20/0148 UTC from Region 3256 (S23, L=010, class/area, Eho/300 on 25 Mar). The large collection of remaining sunspot regions produced nothing higher than C-class flare activity throughout the rest of the reporting period.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit reached moderate levels throughout the reporting period.
On 23-24 March, Earth was impacted by the most significant geomagnetic storm of the current solar cycle. It began as a Strong (G3) geomagnetic storm on 23 March at about 1500 UTC and peaked on 24 March at around 0400 UTC as a Severe (G4) geomagnetic storm. This was the first Severe Geomagnetic Storm since 04 November 2021 (as reported from Potsdam). The storm was significantly stronger than expected. On 22 March, the Space Weather Prediction Center (SWPC) issued G1 and G2 watches for 23 and 24 March respectively. The most likely source of the geomagnetic storm was a long duration solar flare on 20 March at 1534 UTC. SWPC and international partner modeling suggested weak glancing impacts from the 20 March CME. ENLIL modeling parameters were likely degraded due to the unavailability of wide angle coronagraph (SOHO/LASCO C3) or STEREO Ahead imagery. The solar wind environment was significantly disturbed after the CME arrival. Total field strength peaked at 22 nT. The Bz component reflected prolonged southward deviation of -15 to -17 nT for over 14.5 hours. The remainder of the summary period observed unsettled to active geomagnetic levels.
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 2023 Apr 02 1917Z: Bz: -0.9 nT
Bx: 3.3 nT | By: -4.5 nT | Total: 5.6 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: (valid from 1230UT, 02 Apr 2023 until 04 Apr 2023)
Solar Flares: Quiet conditions (<50% probability of C-class flares) Geo-Disturbance: Quiet (A<20 and K<4) Solar Proton Event: Quiet
Comment from the SIDC (RWC Belgium): Over the past 24 hours, the solar flaring activity was at very low levels with only one low C-class flare observed. Currently there are five numbered active regions on the visible side of the solar disk. All of these regions have simple configuration of their photospheric magnetic field (alpha or beta). We expect the solar flaring activity to stay at low levels for the next 24 hours, with a small possibility for C-class flares.
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
27 March - 22 April 2023
Solar activity is expected to be at low levels with a slight chance for (R1-R2, Minor-Moderate) events.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 27 March - 06 April, with moderate levels on 07-22 April.
Geomagnetic field activity is expected to reach G1 (Minor) storm levels on 20-21 April, with active conditions on 31 Mar and 01, 10-11, 16, 18 April in response to recurrent CH HSS influence. Quiet to unsettled levels are anticipated for the remainder of the outlook period.
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.