#MEwx Cold, sun and how snowflakes are formed

Good morning Augusta

A direct, real-time feed from my personal weather station is available for you here.

Today it’s going to be mostly sunny with  highs in the lower 30s. Light and variable winds.

Tonight we’ll have partly cloudy skies with lows in the lower 20s. Light and variable winds, becoming north around 10 mph after midnight.

The readings from my weather instruments are:

Our outdoor temperature is 15.8°F, the humidity is 48%, the Dew Point is -0.4°F and our wind chill is 15.8°F.

The wind direction is East between 1.8 MPH and 7.4 MPH.  

The Relative pressure is 30.44, the Absolute pressure is 30.24 and steady with a weather graphic indicating cold and sun.

Visibility is 10.0 Miles / 16.1 Kilometers with clear skies.

The UV rating is 1 out of 16, Sunrise is 6:37 AM, Sunset is 4:10 PM, Moonrise is 8:40 PM, moonset is 11:23 AM and the moon phase is Waning gibbous. 

The RAW METAR readings from Augusta’s airport are:

METAR KAUG 171153Z AUTO 01005KT 10SM CLR M10/M13 A3052 RMK AO2 SLP342 T11001133 11083 21106 53001

Augusta, ME

We didn’t receive any snow or rain here over the past 24 hours.

How do snowflakes form? Thanks to Weather.gov for the following that I’ve shamelessly copied and pasted here.

Q: How are snowflakes formed? 

A:  A snowflake begins to form when an extremely cold water droplet freezes onto a pollen or dust particle in the sky. This creates an ice crystal. As

the ice crystal falls to the ground, water vapor freezes onto the primary crystal, building new crystals – the six arms of the snowflake.

That’s the short answer.

 

The more detailed explanation is this: 

The ice crystals that make up snowflakes are symmetrical (or patterned) because they reflect the internal order of the crystal’s water molecules as they

arrange themselves in predetermined spaces (known as “crystallization”) to form a six-sided snowflake. 

Ultimately, it is the temperature at which a crystal forms — and to a lesser extent the humidity of the air — that determines the basic shape of the ice

crystal. Thus, we see long needle-like crystals at 23 degrees F and very flat plate-like crystals at 5 degrees F.  

The intricate shape of a single arm of the snowflake is determined by the atmospheric conditions experienced by entire ice crystal as it falls. A crystal

might begin to grow arms in one manner, and then minutes or even seconds later, slight changes in the surrounding temperature or humidity causes the crystal

to grow in another way. Although the six-sided shape is always maintained, the ice crystal (and its six arms) may branch off in new directions. Because

each arm experiences the same atmospheric conditions, the arms look identical. 

Q: So, why are no two snowflakes exactly alike? 

A: Well, that’s because individual snowflakes all follow slightly different paths from the sky to the ground —and thus encounter slightly different atmospheric

conditions along the way. Therefore, they all tend to look unique, resembling everything from prisms and needles to the familiar lacy pattern.