That's not rain on Duluth's weather radar – it's birds

Meteorologists in Duluth were curious what the blue blob on radar was.
Author:
Publish date:
The blue blob on radar is indicative of birds, not rain. 

The blue blob on radar is indicative of birds, not rain. 

It's always fascinating when nature finds a way to light up a weather radar. It could be hundreds of thousands of bugs of bunches of birds, which was the case Tuesday morning along the North Shore of Lake Superior. 

The National Weather Service in Duluth noticed a blob of blue reflectivity on radar on the shoreline from Two Harbors to Duluth, but with clear skies and a rising sun there wasn't any precipitation falling. The radar had actually picked up on birds flying south, specifically seagulls and lake gulls. 

One would immediately imagine thousands of birds flying together to show up on radar as a large, blue blob. But that's not the case. 

"The bird density was about 3-6 birds at a time onscreen all going south," the weather service explained. "Radar returns are based on the diameter of the scatterer to the 6th power. So the birds look like large hail stones, they really light up the display even though there aren't as many as you'd think."

You can see them moving south on radar in this GIF from Jonathan Erdman

The Minnesota DNR says it's commonplace to see all kinds of gulls in Duluth and along North Shore year round. 

"The most easily-seen bird at Gooseberry, Herring Gulls are big, gray-backed gulls with pink legs. They nest on the cliff by the mouth of the river, and they are present year-round, but are not very common in winter. Sometimes other gulls stop here when they see the flock of Herring Gulls. Ring-billed Gulls, which nest in Duluth, sometimes visit here in summer. In winter, northern gulls, such as Glaucous Gulls, Thayer's Gulls, and Iceland Gulls sometimes make brief appearances. Great Black-backed Gulls show up on rare occasions, but their range is expanding from the east, so eventually they may be regular residents on the North Shore."

We featured a similar story involving geese flying over Aberdeen, South Dakota, in March 2018. And in July 2017, a massive mayfly hatch showed up on radar near La Crosse, Wisconsin. 

According to Smithsonian, birds and bugs were first seen on radar during World War II, and they're commonly seen now when birds take flight at night, then landing and resting before sunrise. 

That's appears to be exactly what happened this morning in Duluth. 

Next Up

Screen Shot 2020-11-25 at 7.34.43 AM

Watch: Drunk squirrel in Minnesota captures the world's attention

The squirrel was immediately cut off after nearly tipping over.

Screen Shot 2020-11-25 at 7.15.09 PM

Small town gym refusing to close facing lawsuit from attorney general

The gym is facing a lawsuit and a temporary restraining order to halt their operations.

credit card, payment

Money Gal Coaching: Bouncing back after living your best life

Kelly Blodgett started Money Gal Coaching after paying down nearly $50K in debt in 18 months.

flickr-mall-of-america-mitchell-hirsch-march-2019

When do stores open on Black Friday this year?

Many major retailers will be open Black Friday, some for extended hours.

police tape, crime scene

Man found dead outside home near Cass Lake

The man was reportedly shot outside the property.

Minnesota_Welcome_Sign_-_Minnesota_Welcomes_You_-_Taylors_Falls_(28269804891)

Gov. Walz announces $1M in grants to boost Minnesota tourism

The money will be used for marketing efforts to attract people to Minnesota's hard-hit tourist spots.

coronavirus, ICU

Nov. 25 COVID-19 update: 72 deaths ties Minnesota's single-day high

A COVID-19 update will not be provided on Thanksgiving Day.

Texa-Tonka

Revival to open its fourth Twin Cities location

The fried chicken and smoked meat maestros are moving to St. Louis Park.

Duluth and Case Recreation Center

St. Paul to open two extra temporary shelters for homeless people

Mayor Melvin Carter announced the new shelters will be opened in the event of excess demand.

vote, election

Minnesota once again had the highest election turnout in the country

Amid the COVID-19 pandemic, a record percentage of voters also sent in absentee ballots.

Related

That's not a storm on the radar, it's geese

Migration season has arrived in the midwest.

weather radar

Duluth weather radar down rest of August; Twin Cities next

Hardware upgrades are taking the weather radars out of service for lengthy stretches.

snow, slush (submitted photo, ok to use)

Duluth slobbered on with accumulating slushy snow ... on May 19

Are we sure the Night King didn't defeat Mother Nature and is now ruling the weather?

weather radar

With radar down, here's how to check for storms near Twin Cities

Your typical go-to radar sites might be down for a few weeks.

Bulk of heavy snow arrives for most of MN, rain for the Twin Cities

Another 5-10 inches of snow could fall in parts of Minnesota.

Port of Duluth-Superior

Celebrate the North: The fascinating Port of Duluth-Superior

It's the latest in our ongoing video series celebrating northern Minnesota.

Twin Cities weather radar picks up 'interesting phenomenon'

The bright colors aren't a signature of rain or thunderstorms.