Thursday, June 4, 2009

Back into Nature's Soup & Watching for Strong T-Storms

As of noon temperatures are in the lower 80s with dewpoints in the lower 70s and thunderstorms are already erupting across the Florida Big Bend area and moving our way. This morning we did have a few showers around as expected in portions of Baker and Ware Counties but this afternoon I think all of us get in on the action. Yesterday you see the thunderstorm that brought blinding rain to Fruit Cove Middle School. Today we will see a repeat of this with the main threats with these storms continuing to be lightning and heavy downpours. Keep in mind there have been two lightning fatalities across the country over the past few days so even if your weather radio does not go off with a thunderstorm warning take all storms seriously. The lightning fact of the day: Convertible rooftops offer you no protection from storms. You need to find a car with a metal roof because that is what protects you from lightning, not your vehicle's tires. We could have up to 100 lightning strikes per minute by late this afternoon.

I am going to go run some errands and cut my lawn before the rain gets here and then I will be back here on the blog with the latest on the storms, how much rain is on the way, and why the weekend looks like it is in jeopardy based on the latest ensemble runs.

What is an ensemble run? Yes, it is a whole lot different than your community 5K Run and Walk. It is a meteorologist's Zoo Run Run so to speak. Basically meteorologists like to get as many opinions as possible on the the weather by looking at more than a dozen weather models. Each model is based on a different mathematical model with its own assumptions. That is why we have a whole slew of low pressures on the map above all in different locations. While it may look confusing to you it really helps meteorologists cover as many bases as possible. I like looking at up to 20 different models a day. Usually by averaging out what the models are telling you it gives you a good guide to help forecast our weather makers, especially more than 60 hours into the future. Notice on the map above nature's boardroom (ensembles) cuts off another low pressure in western Florida this weekend. This will keep us in nature's soup or that southwest flow.

This means we will have to plan for thunderstorms not just for today but throughout the weekend. It will not be as nice as last weekend that is for sure. This does not mean we will have a total washout and I would still plan on going to the Trot for Tots at Jacksonville Municipal Stadium on Saturday morning. We will just have to remember our lightning safety rules and even beware of a higher risk of severe weather beginning this afternoon. Take a look at why below.

We have some stronger winds aloft moving into Florida over the next few days. Even though wind speeds of 25 to 35 mph does not seem too high at 5,000 feet above the ground it is plenty to crank out wind gusts of 50 to 60 mph. What happens is when thunderstorms tower up to 10 miles high into the atmosphere this wind energy spawns stronger updrafts. For every strong updraft there is a strong downdraft and as rain starts falling it pulls this extra wind energy to the ground at much higher speeds. Yes that wind can gain quite a bit of momentum when it starts from 40,000 and 50,000 feet high in the atmosphere. Many times you can get downburst winds or straightline winds that can cause considerable damage. We have already had flood advisories and severe thunderstorm warnings for Glynn and Camden Counties in Georgia. This trend should continue over the next couple days.

As far as rainfall amounts our modeling data usually does a poor job of handling just how much rain we are going to have especially when it comes to thunderstorms. Back in May most of our models were calling for about 3 to 6 inches of rain. That more than double in many areas. This time around we will not be fooled by the map above. You see one to two inches of rain on the way between now and Sunday. I think it is safe to say a much better average will be 2 to 5 inches of rain with a couple spots up near six inches before things try to dry out a bit by Monday but even that is not a guarantee at this point. Checking out satellite and radar maps are key to tropical forecasting this time of year and you see below why I am bullish on the rain.

I will talk more about our June Outllook for rainfall and tell you why we may have to get used to this pattern over the next few weeks. Be careful out there and thanks for reading.

1 comment:

Anonymous said...

I read the blog every day --just like I did at WLFI :-)

Enjoy those t-storms Mr. Mike!