Is It Too Cold to Snow? Exploring Frigid Temps and Snowfall

Exploring the Relationship Between Extreme Cold and Snow

Many people assume that the colder the temperature, the more likely it is to snow. However, the connection between frigid weather and snowfall is more complex than it may initially seem. In some cases, bitterly cold air masses can actually inhibit snow from developing.

How Snow Forms in the Atmosphere

To understand why it can sometimes be too cold to snow, it helps to first examine how snow forms in the clouds above us. Snow originates from tiny supercooled water droplets suspended high in the atmosphere. These droplets need a particle like dust or pollen to condense and freeze upon.

As more droplets collide with this frozen particle, it grows into a snow crystal or snow pellet. Once these frozen precipitation particles become heavy enough, they will fall through the cloud towards the earth's surface.

The Role of Temperature Inversions

In order for snow to reach the ground, the air temperature must also be cold enough to allow snowflakes to fall without melting on the way down. This is where temperature inversions come into play during extreme cold.

A temperature inversion describes when a layer of warm air sits on top of a layer of colder air near the surface. The boundary between these layers acts like a lid, trapping moisture below it. When this happens, snow has a very hard time forming and falling thickly through a warm layer.

Other Impacts of Arctic Air Masses

Frigid arctic air masses typically contain very little moisture compared to warmer air mass options. The combination of dry air and potential for a temperature inversion makes it difficult for widespread heavy snow to occur during an arctic outbreak.

Bitterly cold air also discourages lake effect snowfall. When very cold air moves across the relatively warmer Great Lakes waters, it is less likely to pick up enough moisture to produce significant snow bands downwind.

Extreme Cold Air Outbreaks With and Without Snow

There are times when the ingredients come together to allow bursts of heavy snowfall during extremely cold conditions. However, arctic air outbreaks can also usher in drier weather patterns.

Cold Air Outbreaks With Snow

Snowfall can still occur with an arctic blast if enough moisture is present. Systems like Colorado low pressure areas and nor'easters sometimes bring plenty of moisture to interact with the cold air.

The cold then makes the snow ratios very high. Since cold air cannot hold much moisture compared to warm air, a greater percentage of the moisture that is present can be converted into snowflakes.

Snow totals can really pile up when arctic air combines with a moisture-laden storm system. Places downwind of the Great Lakes also see locally heavier snow bands when moisture gets trapped and cycles over the lakes.

Cold Air Outbreaks Without Snow

When arctic frontal passages are dry, they can prevent snow from falling. Very cold air simply lacks the ability to hold enough moisture, while temperature inversions act like lids that trap any existing moisture below warmer upper layers.

A fresh injection of cold air can also scatter existing clouds, allowing drier conditions to prevail under clearing skies. Sunny yet frigid weather often follows the passage of an arctic cold front.

Impacts on Ice and Freezing Rain

If enough shallow moisture lingers below warmer air with an arctic outbreak, freezing rain or ice can occur. Snow often transitions over to sleet and ice as the cold wedge slides underneath.

Any moisture gets trapped below the inversion boundary layer and remains liquid. But shallow cold air causes it to freeze on contact with the surface, icing over roadways and anything exposed.

How Cold Is Too Cold to Snow?

With all the competing factors involved, determining exact thresholds for when it gets too cold to snow can be difficult. However, there are some general guidelines based on decades of weather observations.

-10F to 0F Air Temperature

Once air temperatures fall below zero degrees Fahrenheit, the atmosphere has a hard time holding enough moisture to produce snowfall at the surface. Light snow showers are still possible, but heavier widespread snow becomes less likely.

Approaching -10F, the lack of moisture really cuts down snow potential. Cloud ceilings often lower while cloud coverage overall decreases, allowing clearing skies.

Below -20F Air Temperature

When air temperatures plummet below -20F without wind factored in, snow chances diminish rapidly. What little moisture remains gets trapped underneath inversions.

Cloud formation becomes quite limited and any flurries or light snow showers tend to scatter apart. Frigid high pressure systems usually bring sunny, dry weather at this extreme cold threshold.

The one exception would be dynamic storm systems able to tap into moisture from the Gulf of Mexico, overrunning the shallower arctic air mass. But even then, snowfall remains confined to narrow bands rather than widespread.

In general, the outlook turns much drier as the mercury plunges below -20F across an area. But wind chill impacts can become dangerous well before reaching such extreme cold.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.