WARNING: Very dumb WEENIE question.

[Anonymous]

This is concerning snow-to-water ratios. Anybody that knows this can answer but I'm certain wxguy would.

10 to 1

15 to 1

20 to 1

25 to 1

30 to 1

What are the temperatures associated with each of the above listed snow to water ratios?

Thanks in advance, its much appreciated.

Jeb

[Yankeegirl]

Ok... From what i was told, when I was a kid, 1 inch of rain equals 10 inches of snow... Dont know if thats what your lookin for, but theres my input!

[Brent]

Ok... From what i was told, when I was a kid, 1 inch of rain equals 10 inches of snow... Dont know if thats what your lookin for, but theres my input!

That's if the ratio is 10:1

The wetter the snow, the higher the ratio, so 10:1 is wetter than 15:1, 20:1, 25:1, etc.

25 inches would equal an inch of liquid if the ratio was 25:1

To my knowledge there really is no set "scale" for snow ratio, but the colder, usually the drier. Also how dry the atmosphere is can have a big effect.

[wxguy25]

JEB – determining snow to liquid ratio is NOT just about temperatures. That plays a role but there are other processes which are equally important. ALSO storm tracks are critical too.

A clipper which originates in Canada will have the HIGHEST snow: liquid ratio b/c there are fewer supercooled droplets in the cloud (generally a > 10:1 ratio). A storm which develops in the Rockies will have a respectable Snow: liquid ratio; let’s say even 10:1, w/ a more significant concentration of supercooled water. Thirdly, a GOM low would have the LOWEST snow: liquid ratios. < 10:1.

Furthermore, a VERY cold airmass w/ temperatures < -17 C will actually be an inhibiting factor since the predominant crystal type would probably be sector plates instead of dendrites. Plus the deep layer cold air will also cut back on riming which occurs as the Crystals fall into a warmer layer w/ more supercooled water – it collects on the crystal; results in better growth and thusly higher ratios. The cooler the air through a deep layer the LESS riming and aggregation will take place.

DENDRITES (crystal type favored w/ saturated ascent in temperatures of between -12 and -17 C) are the fastest growing crystals and normally produce the BEST snow: liquid ratios.

Aggregation (crystal collisions) will be maximized w/ a near saturated / ISOTHERMAL sounding below H7.

Strong winds can also limit ratios b/c of crystal fracturing.

SO as you can tell there are SEVERAL different ways to get good ratios. It’s not just about temperatures.

BUT…Based on the 1000-500mb thickness method for determining ratios a 10:1 ratio will occur w/ a thickness value of 540 gpm (geopotential meters), a 528 gpm thickness will produce a 17:1 ratio.

Normally the BEST SFC temperature for maximized ratios is ~15 F but it will vary depending on the aforesaid factors.

Hope this covers it for you.

[Anonymous]

There were great posts from everyone in this thread. Thanks a lot wxguy, your input also helped me a lot.