Jerusalem braces for snow: Your hour-by-hour guide

In a rare atmospheric performance, Jerusalem is preparing for what meteorologists are calling a "textbook perfect" snow formation event. While the holy city's stones have witnessed countless winters, this week's forecast presents an unusually pristine set of conditions that allow us to observe—almost in slow motion—the intricate physics behind snowflake formation. For those who have ever wondered how water droplets transform into the crystalline blanket that transforms Jerusalem's ancient landscape, this week offers both a scientific spectacle and a meteorological master class.

The Process Begins

The process starts today (Monday). In the morning hours, with temperatures between 12-15 degrees and humidity at 65-70 percent, the initial evaporation process begins. Water molecules start their upward journey, detaching from ground and ocean surfaces. The kinetic energy of the molecules overcomes their attractive forces, transitioning from liquid to gaseous state.

By afternoon, temperatures rise slightly to 14-16 degrees, with humidity climbing to 75 percent. These conditions allow molecules to continue accumulating in the atmosphere, laying the groundwork for snow formation.

Day-by-Day Progression

Tuesday, 18th February

Phase two begins as temperature gradually drops from 13 to 10 degrees, with humidity rising to 80 percent. During this initial condensation phase, water molecules begin clustering around nucleation cores. First cirrus clouds appear at high altitudes, and molecules undergo compression and deceleration.

Wednesday, 19th February

Temperatures drop to 8-10 degrees with humidity reaching 85 percent. Heterogeneous nucleation begins, with airborne dust particles and salts serving as nucleation cores. Water molecules adhere to these particles, forming microscopic water droplets. Night brings temperatures down to 5-7 degrees with 90 percent humidity.

Thursday, 20th February

Accelerated cooling begins. Morning temperatures range between 3-5 degrees with 95 percent humidity. A cold air mass enters the region, dramatically slowing molecular movement. The first ice nuclei form at high altitudes. Night temperatures approach 0-2 degrees with humidity near 100 percent.

Friday, 21st February

The climax arrives between 2:00 and 6:00 AM, with temperatures between minus one and plus one degree. During the freezing process, water molecules transition directly from gas to solid state, forming hexagonal ice crystals. This chemical-physical process responds to both temperature and atmospheric pressure.

Expected Snowfall Timeline

- Northern Israel: Beginning around 14:00

- Jerusalem: Between 18:00-20:00

- Saturday: Continuing snowfall, temperatures between -2 to 3 degrees

Critical Information

The Meteorological Service notes some uncertainty regarding exact timing and precipitation amounts. Residents should:

- Stock up on food and hot drinks

- Verify heating systems are functioning

- Avoid unnecessary travel

- Stay updated on developments

As Jerusalem braces for this remarkable weather event, we're reminded that even in our age of technological mastery, nature still orchestrates the most impressive shows. While our scientific instruments can track every percentage of humidity and each degree of temperature change, they cannot fully capture the transformative moment when the first snowflakes touch the stones of the Old City.

We will continue to monitor and update on any significant developments in this winter weather system.

Kikar HaShabbat contributed to this article.