Year-to-date rainfall is running about 9 inches below normal for part of the Garden State, causing trees, leaves, and autumn enthusiasts to suffer.

Fall is certainly in the air across the Garden State, as morning temperatures are now dipping into the 50s on a regular basis. And as pumpkin spice and apples populate the stores, you know it's about time for the leaves to begin their annual display of brilliant colors.

But, hold the happiness. Will this year's autumnal foliage live up to expectations?

Autumn Timeline

This year's autumnal equinox falls at 10:21 a.m. on September 22. That is the date and time at which the sun will be directly overhead of the Equator. (Of course, in the world of weather and climate, fall season record-keeping begins September 1.)

Map showing average peak of fall foliage across the U.S. and N.J. (NJ DEP)

Trees start changing colors and dropping leaves as a response to temperatures falling near the frost and freeze marks. On average, New Jersey's brilliant fall colors begin to peak around mid-October in the colder higher elevations of the northwest corner of the state. For the majority of northern and central New Jersey, the foliage peaks, on average, in late October. And the deciduous trees of the Jersey Shore, the Pine Barrens, and South Jersey change by early November.

Fall Foliage Forecast

Usually, I don't believe in seasonal weather forecasting, as the precision and accuracy of long-term predictions is shaky at best. However, this forecast seems incredibly straightforward, as the foliage outlook for fall 2016 will be heavily impacted by the lack of rain in recent weeks and months across the Garden State.

Trees depend on moisture in the soil and root system for leaves to generate precious chlorophyll. It is the chlorophyll that keeps leaves on the trees - when it breaks down, the vivid colors of autumn appear before the leaves ultimately shed to the ground. A lack of chlorophyll leads to less color and quicker dropping.

Drought Monitor for New Jersey, issued September 15, 2016. (National Drought Mitigation Center)

According to the latest U.S. Drought Monitor (published September 15), the entire state of New Jersey is now characterized as Abnormally Dry. Over 65% of New Jersey's land area (encompassing over 81% of New Jersey residents) is already in Moderate Drought.

To put a finer point on the drought, year-to-date precipitation is running 8.98 inches below normal at Newark, and 7.48 inches below normal at Trenton. Atlantic City has actually experienced a surplus of 3 inches above normal in the rain gauge since the beginning of the year. However, the underwhelming summer rainy season has contributed to drought conditions for all but parts of northern, western, and southern New Jersey. (That's an important point - keep reading...)

I suspect New Jersey's drought will drive our fall foliage down one of two paths. Either the colors won't be as vivid (i.e. lots of brown), or the color will last for only a few days before the trees go bare for the winter. I already have leaves and acorns down all over my backyard - it's a sad signal that summer is indeed coming to an end, perhaps even quicker than we'd like.

Any Hope for Pretty Colors?

Despite the glum news about the foliage show, the fall season won't be a total waste.

As the drought map above shows, there are areas of far North Jersey, Hunterdon County, and far South Jersey that have fared slightly better (read: less dry) than the rest of the state. In addition, some trees are more hardy than others, and would be more resilient to a temporary drop in rainfall.

There will absolutely be pockets of brilliant colors in New Jersey this fall - you might just have to look a little harder than usual.

Dan Zarrow is Chief Meteorologist and Acting Chief Arborist for Townsquare Media New Jersey. When he's not raking brightly colored leaves, he provides the latest forecast and realtime weather updates on Facebook and Twitter.