We've already covered the difference between rain and
showers, but what about the other rain terms most often used around here?
Being known for our gray, damp days, we have plenty of
words to try and help give better details on what it might do on a
particular day.
Sprinkles would be something akin to drizzle -- just a
few drops here and there.
As for showers, "isolated" and "spot" showers mean just a couple of
showers spread over a wide area, with shower coverage
less than 30 percent of the forecast area.
"Scattered" showers mean more shower coverage -- maybe 30-60 percent
coverage of the area. "Frequent" or "widespread" showers mean a large r
area of coverage. Since showers are usually
small in size by definition, we might use our every popular "showers and
sunbreaks" forecast, which would mean that in between showers, the sun might
be out.
Hail forms when
rain droplets get pushed higher into the atmosphere by strong upward winds.
As the droplets go higher, it freezes into an ice stone known as hail. It
then becomes heavier, and falls downward, picking up another coating of
raindrops on its way down.
If the updrafts are strong enough, it'll blow the hail back up again,
where the coating freezes, making the hail larger, then falling back
downward. This process repeats until the hail is heavier than the updraft
can support, when it'll finally fall to the ground. The stronger the
updraft, the larger the hail stone will become.
It's said it takes an updraft of 56 mph for a hailstone to become
golf-ball sized. The largest hailstone recorded was 6" wide (weighing 1.7
pounds!) in Coffeyville, Kansas on Sept. 3, 1970.
Winter Precipitation
Freezing rain is caused when you have a warm mass of air in the middle
altitudes between the ground and the cloud deck, followed by a mass of
freezing air near the surface.
When the precipitation falls from the cloud, it will generally be snow.
As it encounters the warm air, it will melt into the usual rain. But right
before it reaches the ground, it enters the below-freezing air and quickly
turns to ice. On impact, it usually freezes to whatever it lands on. That
can turn streets into skating rinks in no time.
Sleet is snow that begins to melt as it reaches the
ground, but doesn't melt completely. This usually happens when it's around
33-35 degrees at the surface.
Flurries are the drizzle equivalent of snow -- very
light snow that isn't strong enough to accumulate.
