Final answer:
Option D: The weather condition indicated by three dots in the current weather report for Portland, Maine, is drizzle, which is characterized by fine, light droplets.
Step-by-step explanation:
The weather condition signified by three dots in the context of the Portland, Maine radar shading and current weather conditions corresponds to drizzle. In meteorological symbols, different weather phenomena are represented by specific marks or symbols. While rain is typically shown by a series of diagonal lines, snow by asterisk-like symbols, and fog is usually depicted by horizontal lines, drizzle is indicated by a trio of dots. This precipitation is characterized by fine droplets and falls more slowly compared to rain, lasting for extended periods, often resulting in a misty atmosphere. Drizzle is common in coastal areas like Portland, Maine, especially when mild temperatures prevail, as in 49 °F.
The symbol of three dots on the radar shading in Portland, Maine indicates the current weather condition of Fog occurring. These three dots represent foggy weather. Fog is a type of precipitation where tiny water droplets are suspended in the air close to the ground, reducing visibility. It occurs when the air near the ground cools and reaches its dew point, causing the water vapor to condense into small droplets.
In this case, the temperature of 49 °F reported in Portland, Maine, combined with the three dots symbol, suggest foggy weather conditions.