Public

Is it a good day for radio?

HF conditions in one look, from the HamQSL (N0NBH) solar data.

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Next 7 days

How long does it last?

Nearby ionosphere (measured)

Bands (HamQSL calculated)

Band	Day	Night

The numbers

How often should I check this page?

Different numbers change at very different speeds. The page refreshes itself every 10 minutes, so you can leave it open.

What	Changes	So check it
Solar flux, sunspots	Once a day	Once a day is plenty
A-index	Once a day (yesterday's summary)	Once a day
K-index	Every 3 hours	Every few hours if there's a storm
X-ray (flares)	Any minute; a flare's effect lasts minutes to an hour or two	When signals suddenly vanish in daylight
Nearby ionosphere	Every 15 minutes, and really does change hour by hour	Just before you get on air
7-day forecast	NOAA updates the 3-day part twice a day, the rest weekly	Once a day

A simple routine: look once in the morning for the verdict and the week ahead, then glance at the nearby ionosphere section right before you operate. The biggest changes of any day happen around sunrise and sunset.

Is this relevant here in Australia?

Most of the data comes from US agencies, but most of it describes the Sun, and that's the same for everyone.

Number	Where it's from	Relevant to Australia?
Solar flux, sunspots, X-ray, solar wind, Bz	Measured in Canada, and by satellites watching the Sun	Yes, fully. One Sun. A flare only affects the daylit side of the Earth, though, so a flare at 2 am here barely touches us.
K and A index	Average of magnetometers worldwide, mostly in the northern hemisphere	Mostly. Usually close to the field over Australia, but not always. The Bureau of Meteorology's Australian K index would be more exact (coming).
Band table (Good / Fair / Poor)	HamQSL's formula from flux and K	Only roughly. It knows nothing about where you are or the season, and ignores our summer sporadic E.
Nearby ionosphere	Measured over Canberra or Hobart (whichever is working), each about 630 km from Terang, every 15 minutes	Yes, close enough. Neither is right overhead, but Terang sits between the two and well inside the ~1000 km that a reading holds for. Trust it over the band table.

Is VK3 different from VK1?

Only a little. Terang is about 700 km from Canberra and the ionosphere changes slowly with distance, so most of what this page says for IKARA holds here too. The small differences:

Further south (38°S against Canberra's 35°S): Terang is a little closer to the auroral zone, so a geomagnetic storm bites slightly harder, mostly on 80 and 40 m at night. On a big storm the aurora australis can be visible from the Victorian coast.
Slightly later day: same time zone as Canberra, but the sun rises and sets about 25 minutes later in Terang, so the daily changes run a little later.
Further west: paths to VK6 and Africa are a few hundred km shorter than from VK1.

Further afield it gets more different:

VK4 north and VK8 (towards the equator): the ionosphere is denser, so foF2 and the MUF run higher and the higher bands open more often.
VK7 (Tasmania, just across Bass Strait): further south still, so storms hit harder there than in Terang.
VK6: sunrise and sunset are 2–3 hours later than here, so its daily pattern is shifted.

For a contact, what matters most is the ionosphere at the middle of the path, where the signal bounces. Terang to VK6 bounces over the Great Australian Bight, not over either end.

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