This article examines a newly issued cold weather advisory from the National Weather Service (NWS) Hanford CA and explains what it means for those in the Sierra Nevada region, especially at higher elevations.
Drawing on decades of field experience in mountain meteorology and public safety, we will break down the specifics of the advisory, clarify the differences between various cold-related alerts, and outline practical steps you can take to reduce risk from dangerous wind chills and hypothermia.
Updated Cold Weather Advisory for the Southern Sierra Nevada
The National Weather Service in Hanford, California has issued an updated cold weather advisory, in effect from early Wednesday morning at 5:33 a.m. through Thursday at 9 a.m.
This advisory highlights a period of significantly colder-than-normal conditions for the higher elevations of the southern Sierra Nevada.
The advisory is not merely a routine winter note; it reflects a pattern of seasonably cold but still hazardous conditions that can be especially dangerous for travelers, backcountry users, and anyone working or recreating above tree line.
Regions Under the Advisory
The affected area includes several key high-elevation zones that are popular with hikers, climbers, and winter recreationists.
Specifically, the advisory covers:
These regions share a common feature: extensive terrain above 9,000 feet, where wind and exposure amplify the impact of cold air masses.
How Cold Will It Get?
At the heart of the advisory is a focus on extremely cold wind chills.
While air temperature is important, it is the combined effect of wind and temperature that poses the greatest risk to human health.
In this event, the NWS expects wind chills to drop to as low as 9 to 10 degrees below zero Fahrenheit at elevations above 9,000 feet.
At these values, even short exposures can become hazardous, particularly if clothing is inadequate or skin is left uncovered.
Why Wind Chill Matters
Wind chill is a measure of how cold it “feels” to the human body, not just the thermometer reading.
As wind increases, it strips away the thin layer of warm air that your body maintains close to the skin, accelerating heat loss. This can significantly increase the risk of hypothermia, a dangerous drop in core body temperature.
Under the conditions described in this advisory, the risk is highest for:
Cold Weather Advisory vs. More Severe Alerts
Public safety messaging around cold weather uses several distinct categories, each indicating a different level of risk.
Understanding these terms is crucial for planning and response.
Cold Weather Advisory
A cold weather advisory signals seasonably cold temperatures or wind chills that are concerning but not extreme.
In other words, conditions are cold enough to be hazardous to health if precautions are ignored, but they are generally manageable with appropriate preparation.
During an advisory like the one currently in effect:
Extreme Cold Warning
An extreme cold warning is a step above an advisory, indicating dangerously low temperatures or wind chills.
In these situations, the recommendation is to avoid going outside unless absolutely necessary.
If you must be outdoors during an extreme cold warning, you should:
Extreme Cold Watch
An extreme cold watch signals that dangerously cold conditions are possible, but not yet imminent or fully certain.
This is a critical time to prepare before conditions deteriorate.
Under an extreme cold watch, recommended actions include:
Protecting Public Safety During Severe Cold
This updated advisory is part of a broader strategy to reduce cold-related injuries and fatalities in mountain environments.
While the current conditions may not yet reach the threshold of an extreme cold warning, the projected wind chills above 9,000 feet are low enough to cause serious health issues without proper care.
By understanding the distinctions between a cold weather advisory, an extreme cold warning, and an extreme cold watch, individuals and organizations can make informed decisions about travel, work, and recreation.
Here is the source article for this story: UPDATE: High Sierra under a cold weather advisory until Thursday morning