ALTOONA, Pa (WTAJ)- The weather Thursday was beautiful! All of Central Pa had plenty of sunshine and a warm afternoon. The average high temperature for this time of the year is 56 degrees. Temperatures made it into the 70s.
The western counties were much warmer than the eastern counties. West of Interstate 99 the temperatures made it into the mid to upper 70s. While east of Interstate 99 the temperatures topped out in the upper 60s to the lower 70s. The reason why the temperatures are so different from east to west is because of the wind.
The wind Thursday was coming out of the southeast. When there is an easterly component to the wind the eastern counties do not warm up as much. Cool moist air from the Atlantic Ocean settles in the valleys, while the warmer and drier air makes it over the mountains. Cool air sinks because it is denser (heavier) than warm air. This phenomenon is called cold-air damming.