Stay Curious. Stay Connected.
MailNewsletters♡Donate Now
Sign up
*Password must be at least 8 characters and contain one uppercase letter, one lowercase letter, one number and one symbol.
Already have an account?
By submitting, you consent that you are at least 18 years of age and to receive information about MPR's or APMG entities' programs and offerings. The personally identifying information you provide will not be sold, shared, or used for purposes other than to communicate with you about MPR, APMG entities, and its sponsors. You may opt-out at any time clicking the unsubscribe link at the bottom of any email communication. View our Privacy Policy.
Sign in to your profile
Forgot Password?
New to MPR News?
Welcome back
to news
for you
Reset Password

Enter the username on file and we'll send you a code to reset your password.

Still require assistance or not sure what your User Name is?
Welcome back
to news
for you
Email Verification

A verification code has been emailed to

Still awaiting the code?
Updraft® - Minnesota Weather News
Paul Huttner

Giant snowflakes fall in the Twin Cities

Go Deeper.

Create an account or log in to save stories.

Like this?

Thanks for liking this story! We have added it to a list of your favorite stories.

[image]

Extreme close up of a stellar dendrite. All photos by Dr. Kenneth Libbrecht at Cal Tech.

Remember the old Dave Letterman joke about hail the size of canned hams?

Well it wasn't that extreme, but there were some pretty big snowflakes at times today in the Twin Cities. Here at the Huttner Weather Lab I observed snow "clumps" about two inches in diameter falling to earth. MPR staffer Chris Worthington reports large snowflakes also fell in downtown St. Paul today. Atmoshperic conditions were just right in the Twin Cities for big flakes today.

[image]

Stellar plate

Giant snowflakes as big as dinner plates have been reported in weather lore. The most credible observations from reliable observers of unusually large snowflakes report a diameter between 2 and 6 inches. William Pike, who is an observer in the British Royal Meteorological service, witnessed 2 to 3 inch diameter flakes in Vancouver, British Columbia. He documented 11 credible reports of giant snowflakes in the Journal of Meteorology in January of 1988. There is a great article in The New York Times about his observations.

[image]

Hollow column

The average snowflake is made up of one or many individual snow crystals. According to snowflake guru Dr. Ken Libbrecht at Cal Tech, the biggest snow crystals in nature are about the size of a pea. Ken is a North Dakota native who has made a career out of his fascination with snowflakes. His work has even been featured on USPS stamps. You can see his amazing images of snow crystals at snowcrystals.com.

[image]

Capped column

It turns out it takes just the right atmospheric conditions to produce big snowflake clusters. The best conditions occur when temperatures in the lowest mile of the atmosphere are just near or above freezing, and winds are relatively light. It may also help to have a slight updraft higher up.

Here's how it works. Normal snow crystals form several thousand feet up. Light updrafts keep them aloft, where they bump into each other and stick together. As they grow, smaller crystals continue to stick to them and they get bigger. Then the weight of the cluster overcomes the updraft and they begin to fall to earth.

The bigger flakes are now falling faster than the tiny snow crystals. As they fall through the slower moving snow crystals they gain mass as the crystals stick, growing even bigger. If the winds are light enough the giant flimsy puffballs can reach the ground intact.

It's amazing what nature can do under just the right conditions.

PH