Alan Sealls Weather

01/08/2026

Aloha snow.

01/03/2026

4pm full in

01/03/2026

WORDS OF THE WEEK 💬
Katabatic wind — Most widely used in mountain meteorology to denote a downslope flow driven by cooling at the slope surface during periods of light larger-scale winds; the nocturnal component of the along-slope wind systems.

Read more about katabatic wind through the AMS Glossary: https://bit.ly/3N039kB

Photo credit 📷: National Snow and Ice Data Center (Adapted from Jennifer Matthews, Institute of Geophysics and Planetary Physics)

01/02/2026

January

12/31/2025

simple, yet complex science

12/30/2025

Out of this world

12/29/2025

highlights for 2026

The moon and sun share top billing in 2026. Kicking off the year's cosmic wonders is the moon, drawing the first astronauts to visit in more than 50 years.

12/26/2025

Hanging out at home for the holidays? Turn some downtime into space time. Make a 2026 Moon Phases Calendar, and follow the lunar cycle all year long!

🌖 All you need is a printer, scissors, tape, and a brass fastener: https://www.jpl.nasa.gov/edu/resources/project/make-a-moon-phases-calendar-and-calculator/

12/24/2025

It’s a Christmas crisis of dendritic dimensions- a mutation of meteorological magnitude. This is the time of year when some of us are blanketed with a blizzard of Christmas and Holiday cards featuring snowflakes. ❄️❄️ What joy doth flake of snow bring to those starved of a Norman Rockwell idyllic winter scene? Oft times, something is awry that may get past your eye. I’m referring to artistic renderings of snowflakes that are inaccurate, in a science sort of way. I need to draw your attention to imposter snowflakes.

It's a “snowfake” scam that’s easy to fall for. It’s like being duped by counterfeit thousand-dollar bills. Those are things most of us don’t get our hands on. Ice crystals are frozen water, aka H2O. The basic shape of an ice crystal is a hexagon (6 sides), not an octagon (8 sides). A single ice crystal has symmetry. Ice crystals, just like the ones in your freezer, or on your car or window on a frosty morning, can grow and sprout dendrites along their 6 arms, resulting in ornate hexagons. This you might notice if you scrape some freezer frost, put it on a dark cloth and look at it with a magnifying glass, without letting your hot breath melt it.

Now that you are aware, have some fun with your kids and see how often they can spot the counterfeit snowflake of more or less than 6 sides, on Christmas cards and displays and on TV commercials. With all fairness to designers and graphic artists, I agree that it is easier to draw a snowflake with 4 or 8 sides, and it is true that Fred Flintstone only has 4 fingers on each hand, and no one seems bothered by that.

I’ll be crystal clear, yes, Virginia, there is a hexagonal snowflake, and no two are identical. I know, you’re saying, “Alan, you have a little too much time on the five fingers of your hands.” To that, I offer a frosty stare.

This “Imposter snowflake” is an excerpt from my book, Weather Things You Always Wanted to Know, originally published in 2019 in Lagniappe Newspaper.

12/22/2025

12/21/2025

Happy Winter! 10:03am Eastern Time today marked the Winter Solstice, the day of the year when the Earth's northern hemisphere is tilted furthest away from the Sun. This also means that today is the shortest of the year (daylight-wise) for those of us north of the equator.

Will wintry temperatures be in your area? 😬
Visit weather.gov to see.

12/20/2025

New AMS Statement: Dismantling NSF’s National Center for Atmospheric Research would harm public safety and weaken U.S. leadership in weather and climate science.

For over 60 years, NSF NCAR has improved forecasts and early warnings that save lives and reduce disaster impacts. A better path forward is to strengthen, not dismantle, this important institution. AMS is prepared to help.

Read the full statement: https://bit.ly/4q6eChn

[Photo: "Scott's Bluff" by Isaac Schleusche was a finalist in the 2024 AMS Photo contest]