First Day Of Fall Tuesday

Tuesday at 5:18 p.m. Eastern, Fall will officially begin for the Northern Hemisphere! In case you missed the previous blog entry, here's another look at what the Autumnal Equinox is:
So at 5:18 p.m. Eastern, the Sun's incoming solar rays will be directly over the Equator as the Earth tilts the Northern Hemisphere away from the most intense solar rays, moving into Fall and Winter. Meanwhile, the Earth's tilt brings the Southern Hemisphere back into the Sun's most intense rays, transitioning to Spring and Summer.

Fall is my favorite season of all. I love the transitional nature of the weather patterns, the changing leaves, and the cooler, shorter days. It may be early in the season still, but Fall color is already showing up through parts of New England and the Upper Midwest. Check it out:

Where you see "Low" color right now, foliage color should be peaking within the next few weeks.


Here is a map of the typical foliage peak times in the U.S.

(Map: Wikipedia Commons)

Colors will not peak in Central Virginia until Late October/Early November. But a few trees are already showing some color here in Richmond, but these are mostly trees that were damaged or stressed earlier this year, and are thus more prone to "peaking" early and losing leaves prematurely.

Chilly This Morning

There was definitely a chill in the air this morning, but it definitely wasn't as cold here as it was in parts of New England. The shades of purple on the map below indicate lows in the lower 30s!

Persistent Clouds

The Commonwealth is divided this Saturday, between plenty of sun in the northern half of the state, and persistent cloud-cover over the southern half closer to the cold front that moved through overnight. This front is associated with an upper-level trough that dug into the Northeast Friday. At the base of this trough, drier air is evident in the water vapor image below, as indicated by the orange-red shades (drier, warmer air from higher up in the atmosphere sinking). Notice that where we have sunny skies today is right where that dry air at the upper-levels is present.