WASHINGTON, D.C. — One of the most difficult winter storms to forecast in more than two decades delivered a sharp reminder of how small atmospheric shifts can produce major snowfall differences across the D.C. metro area.
A detailed snowfall review comparing what was predicted vs. what actually fell shows that temperature margins of just 1–2 degrees, a subtle eastward storm track adjustment, and small-scale banding features dramatically altered totals across Washington, D.C., Northern Virginia, and Maryland.
What Was Forecast
The official forecast heading into the event projected:
- 3–6 inches across much of the metro region
- 2–4 inches in southern zones
- “Coating to 2 inches” in lighter areas
- Higher totals in elevated terrain west of the city
Forecasters clearly communicated uncertainty, even outlining boom and bust scenarios:
- 25% chance of 6–12 inches in some areas
- 25% chance of less than 3 inches
The map showed D.C. sitting near a sharp gradient zone — meaning a small wobble could drastically shift snowfall distribution.
What Actually Fell
The observed snowfall map reveals just how tight the gradient became:
- 3–6 inches fell across parts of the western and northern suburbs
- Some isolated spots exceeded 6 inches
- Downtown Washington saw more variability
- Areas west/southwest of Fairfax and parts of downtown & east underperformed
- Several southern areas only received a coating to 1–2 inches
In some neighborhoods, totals matched forecasts closely. Just a few miles away, snowfall dropped off sharply.
That kind of hyper-local variability is typical in marginal setups — but rarely this extreme in such a populated corridor.
Why This Storm Was So Difficult
Forecasters cited several key factors:
1. Marginal Temperatures
Temperatures hovered right near the freezing mark. A difference of 1–2 degrees meant the difference between:
- Efficient snow accumulation
- Wet, compacting snow
- Mixed precipitation
- Or reduced totals altogether
When the thermal profile is that tight, even slight elevation or urban heat differences can impact totals.
2. D.C. Sat Near the Edge of Heaviest Precipitation
Washington was positioned near the gradient between heavier snow bands and lighter precipitation…