Sunday, July 10, 2011

Thunderheads snuff more wildfires and warning signs in the tropics



Sunday, July 11, 2011


We have come a long way in about three weeks when we had about 180 fires in a 50 mile radius of Jacksonville. Florida was literally on fire as you can see above. It was so bad folks could not even get out to the pool and some walked their cats and dogs indoors at the nearest pet shopping center and even in their homes. Now compare that to the map below this morning!




We can breathe much easier with only 29 wildfires reported across the area. The air is thick, hazy, and hot today but most of us our smoke-free with the exception of areas near Waycross and the Okefenokee Swamp. Your glasses fog up when you go outside and it feels like a steam bath but it is much easier to take than the stranglehold the smoke had over the area. You can thank those afternoon soakers that have been moving through and we are not done yet! Today we have another friendly front moving our way. It is unusual to have a cold front hold together this far south. Fronts usually stall out in the Carolinas this time of year but over the next couple of days what is left of this front will slowly washout over our area helping to snuff out more wildfires.




This front will be a triggering mechanism to help fire up some showers and thunderstorms. Looking at the atmospheric profile this morning I still do not think it is a good set-up for severe weather. The temperatures in nature's attic are heating up which will not allow the thunderstorms to build too high. There could be a few tops near 35,000 feet but not much higher. By thunderstorm standards in Florida that is quite small and really we would classify these thunderstorms as weaker thundershowers.

The severe storms that swept through a couple weeks ago had tops near 50,000 feet with some cooler air to work with. I do not see that happening today. Remember the taller the thunderstorm the better chance of severe weather.

But do not let your guard down on the roadways. Yesterday we had numerous issues on highway 301 in Bryceville with two inches of rain in an hour. Kingsland, Georgia had a quick inch of rain with many reports of accidents. Today once again the big threat will be heavy downpours and some flood advisories like we saw yesterday. The storms will move from the northwest and drift southeast. Do not be surprised once again if some areas pick up 2 weeks worth of rain in 2 hours. Most of the activity will be this afternoon, although this morning a few storms could pop in nature's soup.


As always lightning will be a threat like we saw yesterday although again with warmer air aloft it will hold down the number of ice crystal collisions in the cloud. But just one bolt of lightning can change your life and this brings us to the weather question of the day. When is it safe to go swimming after a storm passes. Did you guess 30 minutes? Why and what if you have an indoor swimming pool? Is it safe to swim? Nancy wrote me with this question and here was my response.


If you have a large indoor pool it should be treated like an outdoor pool when it comes to lightning safety. Lightning travels from the ground up and loves to travel through plumbing. So I advice folks not to take showers, baths, wash dishes, and this includes indoor swimming.

When you see or hear the first rumble of thunder you will want to clear the pool and then wait 30 minutes after the storm has passed before going back in the water since lightning travels up to 10 miles outside the main cumulonimbus cloud.

If you count to 10 seconds after seeing the flash of lightning to when you hear the thunder roar this means the storm is two miles away. You always divide the time from the bright flash to nature’s rumbling roar by two. This tells you how close the lightning strike was to you. The 30 minute rule ensures the main storm is more than 10  miles away which means you can safely swim indoors and outdoors!

This was a great question and please keep sending them in! My e-mail is mprangley@firstcoastnews.com. Thanks ahead of time. I love this stuff especially since it can really make a difference in keeping people safe!


Yes, we will have some good swimming weather today but remember the earlier the better and remember not to wait to get out of the pool or ocean. When the thunder roars head indoors and if you see it flee it! Most people are struck by lightning when it is not raining. Also remember that convertible cars even with the roof up offer no protection from lightning. Today you want to leave the convertibles home. What happens is the metal shell of your car protects you from lightning in what is called the bird cage efffect. If you do not have that  metal above your head you are putting yourself in danger. Cars are safe during thunderstorms but convertibles are not, that is the bottom line.

 


Make sure to join me tonight and I will track more storms with you and talk about another unusual summer front coming our way by late week that will once again increase our rain chances. But this one may need to be watched a little closer because sometimes you can get tropical development along these stalled frontal boundaries with the right ingredients. Today's front is in an unfavorable sheared environment as you can see above. But this can change in a hurry now that we are getting later in July.

Today is the actual 15th anniversary of Bertha bringing in big surf and deadly rip currents to Jacksonville Beach where one person drowned. It luckily stayed just off the Florida coast. But Wilmington was not so lucky where it hit with 100 mph winds. This is a good reminder to prepare now! It does still look like a busy season. Not just because we have near record warmth in the Atlantic Ocean but take a look at this graph!

The latest long-range computer models that tried to kill off the La Nina were in fact wrong. It looks like we will have a strengthening La Nina for the rest of the summer and thus less wind shear and a more favorable environment for hurricanes in the Atlantic basin. Make sure prepare and the good news is that your First Coast News Hurricane Tracking charts are now available at area Mc Donald's! It includes your all-important safety checklists and even what to do with your pets. I think you will enjoy it and find it most informative. You have a great day. I better get to church so I can get back and track more Florida storms with you this afternoon! Take care.

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