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 29-Mar-24 1559 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: 356 km/s at 1.0 protons/cm3, Bz is 0.0 nT
(Mar 29, 2024 at 1542 UT)
X-ray Solar Flares:
6h hi [X1.1][2050Z 03/28] 24h hi [X1.1][2050Z 03/28]
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: 18 - 24 March 2024
Solar activity during the week reached high levels. The largest flare was an X1.1/ 2F at 23/0133 UTC. Region 3614 (N17, L=224, Dso-B/210 on 23 Mar) produced the flare which appeared along a filanment channel to the north of the spot group. A 240 SFU 10cm radio burst and Type II sweep (791 km/s) were observed. The flare was also accompanied by an EUV wave, dimming and post-eruptive arcades visible in GOES SUVI 195 Angstrom imagery. An asymmetric halo cme was first visible in SOHO/LASCO C2 imagery at 23/0048 UTC. Plane of sky measurments averaged from C2 and C3 suggested the CME was moving at 1492 km/s. While Region 3614 produced the largest flare of the week, Region 3615 (S13, L-215, Fkc-BGD/810 on 24 March) was the most prolific. It produced 27 M-class flares during the week, three of which were greater than M5 (R2). The largest was an M7.4, 3B on 20/0736 UTC.
The X1.1 and CME described above triggered a 10 MeV proton event. The 10 MeV flux began rising at 23/0400 UTC, crossed the 10 pfu (S1) threshold at 23/0815 UTC and the 100 pfu (S2) threshold at 23/1405 UTC. The event peaked on 23/1820 UTC at 956 pfu. A second peak of 687 pfu was observed at 24/1230 UTC as the CME described earlier approached.
The greater than 2 MeV electron flux at geosynchronous orbit ranged from normal to moderate levels throughout the week.
Four distinct geomagnetic storms ocurred during the week. The first was associated with a CME arrival at 21/0225 UTC. Bz dipped southward to -12 nt and, and a couple of periods of prolonged southward Bz led to three synoptic periods of minor (G1) geomagnetic storm conditions between 21/1200-2100 UTC. The second even began on 22/2320 UTC Bz shifted southward around 23/0100 UTC and remained there for about 7 hours. This gave rise to two periods of minor (G1) geomagnetic storm conditions between 23/0300-0900 UTC. This activity was most likely a CIR, in advance of a negative polarity coronal hole, based on the density increase and rotation of the Phi angle .Solar wind speed and temperature began rising at the end of the storm activity, suggesting the high-speed stream had become geoeffective. The third storm began with the 23/1800 UTC UTC synoptic period (Kp=5-, G1), peaked during the 2100-0000 UTC synoptic period, reaching Kp=6- (G2), and returned to G1 conditions for the final period from 24/0000 UTC to 24/0300 UTC. The final storm began with the arrival of the CME described in the first paragraph. The interplanetary shock arrived at L1 at 24/1411 UTC and a sudden impulse (377 nT at Meanook Observatory) was detected at 24/1437 UTC. Solar wind speed jumped from the 500-550 km/s high speed stream values to approximately 800 km/s and remained elevated. Bz dipped southward to -27 nT at 24/1510 UTC. Kp ranged from 6+ (G2) moderate storm conditions to 8o (G4) sever conditions between 24/1200-2100 UTC. The severe synoptic period was from 24/1500-1800 UTC. The magnetic cloud appears to have arrived around 24/1826 UTC distinguised by a slow rotation of the Phi angle. Earth was still within the magnetic cloud at the end of this reporting period.
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 Mar 29 1553Z: Bz: 0.4 nT
Bx: -3.0 nT | By: -0.5 nT | Total: 3.1 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:
28 Mar 2024 10.7-cm Flux: 170 / Ap: 006
29 Mar 2024 10.7-cm Flux: 166 / Ap: 005
30 Mar 2024 10.7-cm Flux: 155 / Ap: 008
Forecast:
Solar Flares: M-class flares expected (probability >=50%) Geo-Disturbance: Quiet (A<20 and 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
25 March - 20 April 2024
The threat of high solar activity remains throughout the coming week. Region 3615 (Fkc-BGD) is expected to remain on the visible disk until March 29th-30th. The departure of Region 3615 is anticipated to bring a period of low solar activity with a lingering chance for M flares. Regions 3614 and 3615 are expected to return on April 11th, increasing the potential for moderate to high activity.
Along with the high solar activity, there is a chance for another proton event at geosynchronous orbit, with the greatest threat from Region 3615 until it departs. The threat will decrease until the region returns on April 11th.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at moderate to high levels during the forecast period. The high levels are anticipated between March 28th-31st, and again from 6-8 April in the wake of coronal holes.
The beginning of the forecast period is expected to see strong (G3) geomagnetic conditions declining to mostly quiet conditions after March 26th. Levels will increase to potentially minor (G1) levels with the influence of a coronal hole high speed stream on April 3rd-5th. High speed streams on April 9th-11th and 19th-20th are expected to bring less than minor (G1) storm conditions. The threat of more CMEs and subsequent storms associated with Regions 3614 and 3615, or with new regions that emerge, remains.
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.