I woke this morning to a howling wind. The sound is unmistakable. We’re in SoCal, but my ears said winter in New England!
I’m hearing Santa Ana winds. These are dry, often hot winds coming from the east. The official meteorological term is katabatic.
A katabatic wind, from the Greek word katabatikos meaning “to flow downhill”, is the technical name for a drainage wind, a wind that carries high density air from a higher elevation down a slope under the force of gravity. Such winds are sometimes also called fall winds.
As the wind flows downhill it compresses, warms and dries. It picks up speed flowing through canyons and passes. The sound is the same, but the effect is nearly the opposite of the New England howl I’m attuned to.
FOR SAN BERNARDINO AND ORANGE COUNTIES…THE STRONG GUSTY NORTHEAST WINDS WILL DEVELOP SUNRISE WITH HUMIDITIES FALLING TO CRITICAL THRESHOLDS DURING THE MORNING. THE DRYING AND GUSTY WINDS WILL SPREAD SOUTHWARD INTO RIVERSIDE AND SAN DIEGO COUNTIES DURING THE AFTERNOON AND EVENING. – NWS San Diego Area Forecast Discussion
At the moment the temperature is 73° and the dewpoint -8°! The relative humidity is 4%.
The wind sucks the moisture from anything it passes. You would be hard pressed to show visible perspiration today. Santa Ana sneezes are often accompanied by a little blood on the tissue.
This is very dangerous fire weather. We had drizzle a few days ago. Any beneficial effect of that rain is gone. If it’s not green it’s tinder.
Red Flag Warnings are up across Southern California. There will be fires. They will spread.
When a weather feature has its own name, it’s significant! Think Nor’easter.
A few more days of Santa Ana wind will follow.