From: "ARRL" <memberlist@arrl.org>

SB PROP @ ARL $ARLP005
ARLP005 The ARRL Solar Report

ZCZC AP05
QST de W1AW
Propagation Forecast Bulletin 5 ARLP005

From ARRL Headquarters

Newington CT February 14, 2025
To all radio amateurs

SB PROP ARL ARLP005
ARLP005 The ARRL Solar Report

NOAA reports a G1 (Minor) geomagnetic Storm Watch has been issued for 14 Feb, 2025. A coronal hole high speed stream is expected to move into a position favorable for enhanced interaction between the high speed stream and Earth's magnetosphere. These enhancements are likely to cause elevated geomagnetic responses, with G1 (Minor) storm levels likely.

From Spaceweather.com [ http://Spaceweather.com ] : Another solar wind

stream is heading for Earth. It is flowing from a canyon-like hole in the
Sun's atmosphere. First contact with the stream on February 14th could cause
a minor G1-class geomagnetic storm with Arctic auroras for Valentine's Day.


The greatest observed 3 hr Kp over the past 24 hours was 4. The greatest expected 3 hr Kp for February 13 to 15 is 4.67.


No Minor S1 or greater solar radiation storms are expected. No significant active region activity favorable for radiation storm production is forecast.


Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at February 13 at 1109 UTC.


Solar activity is expected to be low with a chance for R1 to R2, and Minor to Moderate activity on February 13 to 15.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere - February 13, 2025, by F. K. Janda, OK1HH:


"Total solar activity was highest last October in the current 11-year cycle. Since then, it has been declining, but slowly. This is also true for flare activity. Medium strong solar flares were produced mainly by the active
region of AR3981. Some of these were accompanied by CMEs, none of which hit
the Earth directly, but passed close enough to affect its atmosphere.


"NOAA predicted on February 8 that there was a possibility of G1 class geomagnetic storms on February 10 and 11. The prediction turned out to be fairly accurate - although geomagnetic field activity increased as early as February 9, it was highest on February 10 and was elevated on February 11. Therefore, ionospheric shortwave propagation conditions were at their worst
on 10 February and subsequently improved only very slowly in the following days.


"We now observe a large coronal hole, resembling a canyon, on the Sun, which could be another source of enhanced solar wind. Earth should be hit by it on Valentine's Day, or February 14. The days ahead will also be rather
unsettled, but the active regions now rising near the southeastern limb of
the solar disk will cause an uptick in solar activity, nevertheless, causing improved propagation conditions.


"The good news at the end: at www.solarham.com [ https://www.solarham.com ]
on the bottom left, after an eleven-week hiatus, we can see a map of the
entire Sun, especially the Sun's far side, under the 'Farside Watch' banner.
So the JSOC glitch has been fixed, and after another click on http://jsoc.stanford.edu/data/timed [ http://jsoc.stanford.edu/data/timed ]
we can read more under the heading 'Time-Distance Helioseismic Far-Side Imaging.'"


The latest report from Dr. Tamitha Skov, WX6SWW, can be found online at: https://youtu.be/v5H2QsbiCqo [ https://youtu.be/v5H2QsbiCqo ] .

NNNN
/EX

ARRL The National Association for Amateur Radio(R)
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