Climate - Moderate
Annual Precipitation - 36.03 Inches
During this period (Sep, Oct, Nov), cool dry polar air begins to compete with the moist tropical air of summer. The "Bermuda High" begins to lose its influence as polar outbreaks become more frequent. Hurricane frequency reaches a maximum in September.
During the winter season the warm Gulf Stream is at its eastern most limit. Cold waters of the Labrador Current are directed southward by the prevailing northerly winds. They replace Gulf Stream waters along the coast of Cape Hatteras and result in depriving the area of the moderating influence of the Gulf Stream. Slow moving cold fronts tend to become stationary near the Gulf Stream during this period. The resulting convergence may produce very strong northeasterly winds, sometimes 40 to 50 knots. Often a series of waves will form on the front east of Hatteras, causing low ceilings, intermittent rain, and strong winds to persist over the area for several days.
The period of March, April, and May is characterized by fewer cold outbreaks and gradual influence of the "Bermuda High". The result is increasingly better weather conditions for the area. Sharp contrasts in the weather often occur late in the season. Pleasant warm days are interrupted by a thrust of cold polar air. Temperatures may fall 20 to 25 degrees, and strong thunderstorms occur along with passages of cold fronts. Winds are predominately from two directions, northwesterly early in the period becoming southerly late in the season.
Frequency of thunderstorm activity reaches a maximum during the summer. Most thunderstorm activity in this area is due to frontal or squall line passage. Cloudiness is at a maximum during the day and minimum at night. June marks the beginning of the hurricane season, however it is not until the middle of August that the probability of hurricanes affecting the Langley area increases to significant levels.