A freezing fog advisory was issued by the National Weather Service on Tuesday at 2:16 a.m. in effect until 10 a.m. for Eastern Curry County and Josephine County and Jackson County.
"Visibility of less than a quarter of mile in freezing fog," comments the weather service. "Strong valley inversions, very shallow mixing layers of less than 1000 feet, and calm winds are expected throughout the advisory time, especially during the overnight and morning hours. A weak front on Thursday may allow for a brief period of improved mixing and particulate dispersion."
"Low visibility could make driving conditions hazardous. Poor air quality may cause issues for people with respiratory problems," adds the weather service. "If driving, slow down, use your headlights, and leave plenty of distance ahead of you. Persons with respiratory illness should follow their physicians advice for dealing with high levels of air pollution during periods of stagnant air. State air quality agencies highly recommend that no outdoor burning occur and that residential wood burning devices be limited as much as possible. According to state air quality agencies, prolonged periods of stagnant air can hold pollutants close to the ground where people live and breathe. Check with your local burn agency for any current restrictions in your area."
A freezing fog advisory serves as a crucial alert indicating the development of fog concurrent with surface temperatures at or below freezing. During such conditions, the tiny liquid droplets within the fog can swiftly freeze upon contact with surfaces, including vehicles and roadways. This phenomenon significantly elevates the risks associated with driving, boating, flying, and various modes of transportation, often resulting in visibilities dropping to a mile or less.
What is a freezing fog?
Freezing fog, a close cousin to ice, forms the same way as regular fog. Both fog and freezing fog start when the skies are clear, heat radiates into space, and as a result, the Earth's surface cools down. As this cooling progresses, the air's capacity to retain moisture decreases, triggering the condensation of water vapor into minuscule liquid droplets -- the essential components of fog. When this fog forms in sub-zero temperatures, its water droplets remain in liquid form, a phenomenon known as "Supercooling". In essence, supercooling occurs when a liquid, despite being below its freezing point, remains in a liquid state due to the absence of a freezing surface.
When these supercooled droplets encounter surfaces, they undergo a remarkable transformation, crystallizing into delicate ice structures known as rime. This transformation is often visible on vertical surfaces exposed to prevailing winds, as well as on trees, plants, and other elements in the environment. In fact, rime can form on a variety of surfaces, including stairs, railings, sidewalks, roads, and even vehicles.
What is black ice?
Black ice, also known as clear ice, refers to a delicate, nearly invisible layer of glaze ice that forms on various surfaces, especially on roadways. Despite its name, the ice is not black, but possesses exceptional transparency, enabling the underlying black pavement of the road, to remain visible.
The formation of black ice is frequently attributed to freezing fog, which can swiftly coat roadways with this treacherous hazard. Its near-invisibility renders black ice exceptionally perilous, as it poses a significant challenge for road users to detect.
How to stay safe?
When freezing fog blankets your surroundings, the safest course of action may entail avoiding travel if at all possible. If venturing out becomes an inevitability, exercise utmost caution and heed these essential safety guidelines:
High vigilance:
Be vigilant, as freezing fog can give rise to the notorious black ice, which remains elusive and challenging to spot.
Moderate your speed:
Reduce your speed to accommodate potentially icy conditions.
Visibility priority:
Ensure your vehicle is visible to others by using low-beam headlights, which also activate your taillights. If you have fog lights, use them.
Avoid high-beams:
Refrain from using high-beam headlights, as they create glare that impairs your visibility on the road.
Keep a safe distance:
Leave a safe distance between you and the vehicle in front of you to account for sudden stops or changes in the traffic pattern.
Stay in your lane:
To ensure you are staying in the correct lane, use the road's lane markings as a guide.
For those taking to the skies, remember that even a thin layer of ice can form on aircraft surfaces, posing severe risks to flight safety. Ensure that the aircraft is properly treated or equipped with effective de-icing systems before embarking on your journey.
In the realm of freezing fog, knowledge, and vigilance serve as your steadfast allies, empowering you to navigate these meteorological complexities with safety as your main priority.