Current sunspot cycle activity, space weather, solar storm and geomagnetic conditions and radio propagation forecasts

Current sunspot cycle activity, space weather, solar storm and geomagnetic conditions and radio propagation forecasts

This page was rendered on 19-Jul-21 1647 UTC.
This page was first created in 1998, by Tomas David Hood (NW7US)

Current Sunspot Cycle 24 Activity and Space Weather

Sun Spots: 42 as of 07/18/2021 :: 10.7-cm Flux: 80 SFU
(SFU=Solar Flux Units)

Space Weather Overview Graphic from SWPC

30 Minutes of Dazzling Sun! Ultra-high Definition 4k View

An Intimate View of the Sun, Every Day of 2015 (Year 6 of SDO) UHD 4k

Watch Five Very Intense X-class X-ray Flares Erupt, Back-to-back!
(From the largest sunspot region in 20+ years…)

Check out the X2.7 X-ray Flare (May 5 2015) – ‘Biggest’ of 2015, so far

See highlights of the last five years of the Sun, as seen by SDO

Planetary A-index (Ap): 4 | Planetary K-index (Kp): 1
Solar Wind: 411 km/s at 4.0 protons/cm3, Bz is 0.0 nT
(May 05, 2021 at 0435 UT)

X-ray Solar Flares:
6h hi [B9.7][0656Z 07/18] 24h hi [B9.7][0656Z 07/18]

Background X-ray Level, Last Six Days


Check out the current Aurora Oval and activity.

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


Smoothed Sunspot Number

Smoothed 10.7 cm Radio Flux

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

Geomagnetic Latitude Ranges:
High: 60-90 degrees
Middle: 20-60 degrees
Low: 0-20 degrees

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…)

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.

Background X-ray (1 to 8 Angstrom) Plot

Highlights of Solar and Geomagnetic Activity
Covering the period: 12 – 18 July 2021

Solar activity was at very low to low levels over the period. Very low levels were observed on 12-15 and 17-18 Jul while low levels occurred on 16 Jul due to a pair of C1 flares at 16/0727 UTC and 16/0837 UTC from Region 2843 (S17, L=271, class/area Bxo/030 on 16 Jul). No Earth-directed CMEs were observed.

Other activity of note included two backsided halo CMEs beginning at 15/2136 UTC and at 17/0524 UTC in SOHO/LASCO C2 imagery. The first was a full-halo and the second was a partial-halo just beyond the east limb with a visible EIT wave propagating to the front-side in SDO/AIA 193 imagery. It is not known what region was responsible for those CMEs, however old Regions 2835 (S18, L=053) and 2840 (N27, L=035) were near center disk during the halo CME. Both regions were approaching the eastern limb on 17 Jul when the partial-halo CME occurred.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was normal to moderate levels with a peak flux of 386 pfu observed at 17/1825 UTC.

Geomagnetic field activity ranged from quiet to active levels. The period began with solar wind speed ranging from 295-365 km/s and total field between 2 and 10 nT. By 14/1000 UTC, a rise in total field to near 12 nT occurred followed by an increase in solar wind speed to near 480 km/s as a negative polarity CH HSS became geoeffective. Solar wind speed slowly returned to nominal levels by late on 16 Jul. The geomagnetic field responded with quiet to active levels on 14 Jul and quiet to unsettled levels on 12 and 15 Jul.

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)
Monthly and smoothed sunspot number chart

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)
Daily and monthly sunspot number (last 13 years)

What is ‘Space Weather’? Click on these two information slides to view them in full size:

What is Space Weather? Slide 1 of 2 What is Space Weather? Slide 2 of 2

View of numbered sunspot regions and plages (if any)
(Click for large view)

Active Regions and Plages

Active sunspot regions, and plages, identified by SIDC

SIDC Solar Disc with active regions and plages


STEREO Behind Image
What is coming
SOHO EIT 195 Image
Current View
STEREO Ahead Image
What was…

Real Time Solor Wind and Aurora:

On 2021 Jul 19 1642Z: Bz: -2.8 nT
Bx: -3.5 nT | By: 2.4 nT | Total: 5.1 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

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
19 July – 14 August 2021

Solar activity is expected to be at very low to low levels with a slight chance for M-class flare (R1-R2, Minor-Moderate) activity on 20 Jul-03 Aug with the return of old Regions 2835 and 2840.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels.

Geomagnetic field activity is expected to be at unsettled levels on 21-22 Jul, 02 Aug, 10-11 Aug with active levels on 10 Aug due to CH HSS activity.

Real-time foF2 map from IPS (Ionospheric Prediction Service), Australian Space Weather Agency

foF2 Map from IPS, Australia

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