EXPLORE THE REPORTED RESULTS
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02 / ATMOSPHERE LAB
When does the atmosphere
support snow?
Change two regional atmospheric values and explore the dissertation’s Levant-wide Snow-Supporting Environment Indicator (SSEI).
Set the environment
−10 °C15 °C
5,300 m5,900 m
Inputs represent regional atmospheric values, not conditions at a single weather station. Heights are given in metres.
Suitability is not a snowfall forecast. Both regional thresholds must be met: T850 ≤ 5.85 °C and Z500 ≤ 5,621.8 m. These empirical thresholds describe large-scale conditions associated with accumulation, not universal freezing levels. Moisture, local elevation and the full temperature profile still matter.
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03 / INTERACTIVE RESEARCH
Snow in a Warming Levant
Occurrence, Atmospheric Suitability and Winter Cyclones
Ramzi Kandah · MSc Applied Meteorology and Climate
University of Reading · 4 September 2026
THE CENTRAL FINDING
Snow-supporting conditions became less frequent and less persistent.
The evidence for this environmental change is stronger than the evidence for declining snow-event frequency. Overall cyclone frequency showed no significant decline.
THE WIDER PICTURE
+1.22 °CRegional 850 hPa warming
1941–2026
1941–2026
~145 mTerrain-masked WBZ rise
Later analysis · 1941–2026
Later analysis · 1941–2026
85.0%Eligible accumulation pulses
matched to cyclones
matched to cyclones
Warming and cyclone figures: dissertation. WBZ: later terrain-masked analysis. Reanalysis-based results, not live observations.
RESEARCH OVERVIEW
From question to conclusion
01 · Research question
How have Levant snow occurrence, snow-supporting atmospheric environments and their cyclone associations changed? The study separates surface snow diagnostics from atmospheric suitability.
02 · Data and methods
ERA5-Land provides snow-cover diagnostics for 1951–2025 and accumulation pulses for complete winters from 1951 to 2026. ERA5 reconstructs the six-hourly winter SSEI for 1941–2026. Cyclone tracks, AO/NAO indices and wet-bulb-zero height describe the wider atmospheric setting.
03 · Findings and uncertainty
The catalogue contains 1,398 Levant accumulation pulses, without a significant frequency trend under the baseline definition. All three Levant SSEI declines remain significant after accounting for dependence between years. Local Jordanian results are less robust and should not be treated as equivalent to the Levant-wide result.
04 · Limitations and conclusions
Reanalysis snow estimates carry uncertainty, and accumulation-pulse counts depend on detection settings. SSEI characterises regional suitability rather than individual snowfall. Agreement between two ERA5-Land variables is internal consistency, not independent observational validation.