sleet/hail...
- Thread starter timo
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windingtrailgal
Active member
timo - can we add in the freezing rain as well? I can never seem to understand the difference in all 3 of them.
Thanks
Thanks
Hail: Larger icy pellets (<5mm). Often associated with severe weather situations.
Sleet: snow flakes that have melted and re froze, or mostly frozen rain drops.
Freezing rain: rainfall that freezes upon contact with a surface (trees, gound, etc).
Fascinating stuff.
John, can you tell us which variety of clouds produce each of the above circumstaces. Isn't hail produced by high pressure sitiuations.
Sleet: snow flakes that have melted and re froze, or mostly frozen rain drops.
Freezing rain: rainfall that freezes upon contact with a surface (trees, gound, etc).
Fascinating stuff.
John, can you tell us which variety of clouds produce each of the above circumstaces. Isn't hail produced by high pressure sitiuations.
From the NWS glossary...
<table border="0" cellspacing="0" width="525"><tbody><tr><td width="10">
</td><td><dt>Sleet</dt><dd>(PL) - Sleet is defined as pellets of ice composed of frozen or mostly frozen raindrops or refrozen partially melted snowflakes. These pellets of ice usually bounce after hitting the ground or other hard surfaces. Heavy sleet is a relatively rare event defined as an accumulation of ice pellets covering the ground to a depth of ½" or more.</dd></td></tr></tbody></table> Hail<table border="0" cellspacing="0" width="525"><tbody><tr><td><dd>Showery precipitation in the form of irregular pellets or balls of ice more than 5 mm in diameter, falling from a cumulonimbus cloud.</dd></td></tr></tbody></table>
See: National Weather Service Glossary.
<table border="0" cellspacing="0" width="525"><tbody><tr><td width="10">
</td><td><dt>Sleet</dt><dd>(PL) - Sleet is defined as pellets of ice composed of frozen or mostly frozen raindrops or refrozen partially melted snowflakes. These pellets of ice usually bounce after hitting the ground or other hard surfaces. Heavy sleet is a relatively rare event defined as an accumulation of ice pellets covering the ground to a depth of ½" or more.</dd></td></tr></tbody></table> Hail<table border="0" cellspacing="0" width="525"><tbody><tr><td><dd>Showery precipitation in the form of irregular pellets or balls of ice more than 5 mm in diameter, falling from a cumulonimbus cloud.</dd></td></tr></tbody></table>
See: National Weather Service Glossary.
windingtrailgal
Active member
OK, Glossary Guys - I could have looked that up but I do appreciate that info. (insert respectful smart alleck smiley here)
I think MY question is more how and why do they form so that they ARE different. What atmospheric and metereological conditions are present to make moisture become hail instead of freezing rain instead of sleet instead of snow instead of rain?
Kinda like what hundy stated...
wtg
I think MY question is more how and why do they form so that they ARE different. What atmospheric and metereological conditions are present to make moisture become hail instead of freezing rain instead of sleet instead of snow instead of rain?
Kinda like what hundy stated...
wtg
The answers given were pretty good. Sleet is a cold season event and happens as described above. A raindrop or melted snowflake re-freezes before hitting the ground.
Hail is formed when a water droplet is carried high into the top of a thunderstorm (cumulonimbus) cloud. As it gets higher, the air becomes colder and it freezes. When the hail stone becomes too heavy for the thunderstorm updraft to keep it airborne, it will fall to the ground. A hail stone can sometimes make several rounds of being carried up by the updraft and then falling part way through the cloud, only to be carried up again. Each time it is carried up, it will encounter water vapor that freezes to it and it will grow in size. If you are able to cut a large hail stone in half, you can see the different growth rings on it.
So the main difference is how the precip is formed. Hail ONLY forms within a thunderstorm and sleet ONLY forms when a raindrop or melted snowflake re-freezes as it falls to the surface and before it reaches the surface.
Freezing rain is just simply rain that freezes upon contact with a surface (road, car, power line, tree, etc...) object that is below freezing. Sometimes sleet and freezing rain can happen within the same precip event, but freezing rain is liquid when it falls and then instantly freezes upon contact. Sleet has already frozen.
-John
Hail is formed when a water droplet is carried high into the top of a thunderstorm (cumulonimbus) cloud. As it gets higher, the air becomes colder and it freezes. When the hail stone becomes too heavy for the thunderstorm updraft to keep it airborne, it will fall to the ground. A hail stone can sometimes make several rounds of being carried up by the updraft and then falling part way through the cloud, only to be carried up again. Each time it is carried up, it will encounter water vapor that freezes to it and it will grow in size. If you are able to cut a large hail stone in half, you can see the different growth rings on it.
So the main difference is how the precip is formed. Hail ONLY forms within a thunderstorm and sleet ONLY forms when a raindrop or melted snowflake re-freezes as it falls to the surface and before it reaches the surface.
Freezing rain is just simply rain that freezes upon contact with a surface (road, car, power line, tree, etc...) object that is below freezing. Sometimes sleet and freezing rain can happen within the same precip event, but freezing rain is liquid when it falls and then instantly freezes upon contact. Sleet has already frozen.
-John
windingtrailgal
Active member
John -
Is the circulation of the moisture that forms hail why you see it when there are tornadoes that are either forming of have formed? I mean, is the circulation of the air with the moisture in it the cause tornadoes AND hail?
And thanks for the freezing rain AND sleet combo explanation. That makes sense to me that both being present is what I've seen and why my small brain was confused with which was which - even with good explanations.
Is the circulation of the moisture that forms hail why you see it when there are tornadoes that are either forming of have formed? I mean, is the circulation of the air with the moisture in it the cause tornadoes AND hail?
And thanks for the freezing rain AND sleet combo explanation. That makes sense to me that both being present is what I've seen and why my small brain was confused with which was which - even with good explanations.
In a way it is the circulation of air inside the cloud that causes both hail and tornadoes to sometimes form from the same cloud. To be more precise, it is the severity of the updrafts that cause both the hail and the tornadoes to form. Keep in mind that all thunderstorms do not create hail and tornadoes at the same time. You can have either, both or none occur in an particular thunderstorm.
-John
-John
windingtrailgal
Active member
Thanks, John. I grew up in tornado alley and always remember the hail along with the tornado watches and warnings. But a great explanation and I can actually understand.
wtg
wtg
HuH... Rings around a hail stone...who would of ever thunk that!
Pretty cool, I think.