This time of year, the Tennessee Valley often relies on tropical systems for rain. As we head further into fall we see more doses of dry northerly air coming in, so tropical systems become the best way for us to keep our soils moist. This year the tropical season has been fairly active, but the systems have mostly missed North Alabama.
An example of this can be seen in a soil moisture loop posted by NASA SPoRT this week:
This tweet shows how the soils along Hurricane Michael’s path became saturated, while North Alabama soils stayed dry. We’re not facing a severe drought on the horizon; our soils are just drier than we would prefer them to be right now, since fall is the last chance plants get to soak up more moisture before winter. For some plants this is an opportunity to focus on root growth, since they’re pulling their nutrients and moisture away from their leaves (which are falling off).
Right now Huntsville is about an inch behind on monthly rainfall totals, and that’s about how much we need according to the Palmer Drought Index to kick the dry conditions. That puts us under the ‘abnormally dry’ category of the US Drought Monitor:
Tropical moisture coming in from the Eastern Pacific could give us our next shot at catching up on rainfall totals this week. The remnants of Hurricane Willa will travel along the Gulf Coast Wednesday, then slide east toward Florida through Friday. It also spreads clouds and rain into the Tennessee Valley all along the way. You can check up on when rain is expected anytime on our forecast discussion page!