First fall weekend brings more steamy storms and possible waterspouts!

Saturday, September 24, 2011

Wow! This is how you want to start off your weekend. What a magnificent picture sent in from the beach this morning. The cumulonimbus clouds were casting a shadow and scattering the first rays of sunshine upward since the sun was officially still below the horizon. This is a bittersweet picture if you want a totally dry day today. This phenomenon called crepuscular rays tell us the air is full of water, dust, and salt particles that are in abundance. These condensation nucleii will help form raindrops with daytime heating today over the land areas. I do think the farther west you go today the less the amount of rain while east of I-95 we could once again see some isolated 2 inch rain amounts with flood advisories. Areas that will see the heaviest rain today will include points south and east of downtown Jacksonville. It will not be an all-day rain with most of the storms between 3 p.m. and 7 p.m. so do not cancel your plans but keep an eye to the southwest sky. That is where the storms will be moving from.

Here is one of those spine-tingling pictures sent in showing nature's raw power. Amanda captured this waterspout just offshore Mayport. I estimated wind speeds near 50 mph. Remember this time of year with the ocean temperatures in the 80s and a light and variable wind in a stagnant stormy pattern can quickly pop these phenomena. On Thursday just after 3 p.m. we had numerous boundaries collide over the ocean. There was an east-southeast wind from the ocean meeting a west wind and then add in an outflow boundary from the northwest from developing thunderstorms and you had plenty of twisting and turning in the air and the warm water added to the needed instability. You can also get waterspouts that form from a line of cumulus clouds with flat bases. The Florida Keys have most of their waterspout reports on nice sunny days!

Yesterday, St. Augustine also got in on this waterspout weather pattern. This picture is a bit blurry but you can make out another one of those ominous funnels. Are more on the way? I would not be surprised. We will have to watch those warm ocean waters and thunderstorm boundaries in this active pattern. We may not be done yet because the atmosphere is in a holding pattern with a slow-moving front likely not pushing through until early next week. The good news is that I am not expecting these waterspouts to reach land or move over land. They are being driven solely by the bath ocean water. If you are boating they can cause damage to your boat so always move away from them at a 90 degree angle.

The biggest threats today on land will be localized flooding and lightning. Be careful and remember not to cross roads covered by water. This summer steambath pattern is showing signs of releasing its grip on us by later next week. So while this is the first full autumn weekend it will actually not really feel like it until next weekend. It is this warm, tropical air that we can blame for an occasional burst of rain this weekend. But we should not be complaining. Until the relentless rain started early last week we were off to our driest September since 2003. Jacksonville is still about an inch below normal along with Brunswick. St. Augustine is still about 1.5" to 2" below normal as well especially to the north of the Bridge of Lions. Tonight at 6, 7, and 11 I will tally up some fresh rainfall totals and let you know where those storms are and where they are moving in time for your evening cookouts.

Since it will not feel like autumn until next week here is a nice autumn update from the National Park Service in the stunning Smoky Mountains.

There is just a hint of color in the earliest changing trees at this time. A few sourwoods, dogwoods, maples, and birches are beginning to show a little color, but the mountains are still overwhelmingly green at all elevations. Perhaps more notable now are the fall wildflowers such as cardinal flower, black-eyed Susan, coreopsis, great blue lobelia, skunk goldenrod, southern harebell, ironweed, and a variety of asters. The bright fruits on trees such as dogwoods and shrubs such as hearts-a-bustin are eye-catching now.

Peak fall color this year in the Smokies will be the last two weeks of October into early November. Here in Jacksonville we see most of our brightest leaves from Thanksgiving to the Winter Solstice just before Christmas! Have a great weekend and thanks for reading. Make sure to send in your pictures to weather@firstcoastnews.com. See you soon.