Rough Weather

  As I was driving home this evening I noticed a lot of cars coming at me with their lights on.  In Florida, if your wipers are going, you're supposed to have your headlights on.  Most people forget to turn their lights off until they turn off their cars.

  I scanned the horizon for a dark curtain of rain below the clouds, but instead noticed that one tall thunderhead was draped in a gauzy white, sunlit curtain of rain falling from its highest reach.  Ah, there is it.  Someone is getting a sun shower…  Nice.

  By the time I got home, the edge of that curtain of rain was dripping lightly, but steadily, on the house.  

  Then the fun began….

  When the thunderhead producing the rain was met by a gust front moving up from the south, it began to pour heavily.  Edward and I had started grilling chicken for dinner as the rain increased.  Our grill is on the porch, thankfully undercover, so the grill was dry.  As the rain picked up it started to slant to the south.   I turned to Edward, and gestured in the direction of the rain.  But when I turned back, the rain was no longer slanting to the south.  Literally, in a matter of seconds, the rain had shifted from slanting to the south, to slanting to the north. I blinked, Edward said "oh shit".  He'd seen this before, in April 2010.   

  The wind was picking up more and now the rain, which had initially been blowing the other way, was blowing onto the porch and onto the grill, which steamed as the rain now falling on it evaporated.  The trees and plants in the ditch swayed ominously.   

  In April of 2010, a front moved down from the northwest, with heavy rains and strong winds.  As the front made landfall we got a tornado warning.  Radar indicated tornadic activity offshore of Largo, moving east.  Toward the house.  I tried to call Edward from work, but what I didn't know was that lightening had struck the streetlight outside the house 15 minutes earlier.  Our phone line was fried and the power was out.  Edward, with nothing else to do, stood watching it rain out the back window.  First to the north, then to the south then from the east.  All in less than a minute.  Then the tree branches started falling.  A tornado had passed approximately a half mile north of the house.  The rapidly shifting winds were the only indicator Edward had as to what was going on.   

  Tonight, as Edward watched the shifting winds, I got out the computer.  The National Weather Service monitors storm clouds with doppler radar, generating a map called the radial velocity.  Clouds approaching the radar are colored red, while those moving away are colored green.   Usually, between the bright red and green areas, there are fainters colors.  When you see two bright opposing colors side-by-side that usually means bad things.  Tonight, that spot was right over us.   Strangely, there were no tornado warnings, not even a severe thunderstorm warning, only urban flood warnings.  That fit as 20 minutes after it started we had 1.25 inches of rain in our gauge.

  By the time the chicken had finished, the winds had shifted to the north again, and calmed down significantly.  The grill was no longer getting rained on.  The areas of red and green on the radial velocity map had started to separate and moved north and offshore.  It was still raining, but things were much quieter.  

  We finished dinner in peace and continued on with the rest of our evening.  I'm still surprised that not even a severe thunderstorm warning had been issued.  That's the problem with knowing how to read those maps.  They can scare scare the shit out of you.  But mostly, I'm glad there was no damage.  A small branch came down in the back yard, nothing of any significance.  I'll pick it up in the morning when I walk the yard before work.  In the meantime, both of us can't help but wonder about this year's weather.  It seems like this area has seen more then its fair share of tornados and waterspouts.  And we're not done yet.  Hurricane season has begun to stretch it's legs as we approach the peak of the season next week.  Only time will tell if we are in for more rough weather.

Storm Watch...

Thunderheads after Hurricane Ike, 

September 15, 2008

  Tropical Storm Isaac.  He won't be so for long.  If the models are right, he'll leave his tour of the northern Cuban coastline, head out into the Gulf and put on a little "weight", in the form of higher winds.  

  By the time he reaches a level latitude with Tampa, he'll be a strong Category 1, heading north.  I am glad he will be offshore.  But it brings back memories of another storm we watched approach along a similar track.  

  Hurricane Charlie.  

  In 2004, we watched Hurricane Charlie approach the bay area.  He crossed Cuba as a category 1 storm and was predicted to run straight north into Tampa Bay.  While a Category 1 storm is nothing to take lightly, it was not too concerning for us.  In the day before he crossed into the Gulf, we made our preparations.  He was not predicted to get much stronger.  We made ice, put away the outside items and covered the windows in a hurricane film that was supposed to keep the windows from breaking completely out if something struck them.  

  We got up on the morning of Aug 13th confident we were ready.  Little did we know what mother nature had in store for us and Charlie that day.

  Charlie turned out to be an unpredictable storm.  What's more, he exhibited a behavior that scientists at the National Hurricane Center still struggle to explain.  Explosive intensification.  In 48 hours Charlie, a weak Category 1, became a monstrous Category 4 headed straight for Tampa.  We were anything but prepared for what was headed our way.  In the end it was only that same unpredictable nature of Charlie that save our skins when he took a turn to the right and made landfall well south of us.  He made landfall within the predicted zone of impact, the infamous cone of uncertainty.  He is the poster child for why you should not focus on the center line and prepare no matter where you are in the cone.   I would expand that to areas near the cone as well.  Models aren't perfect. 

  So now as we sit, watching Isaac work his way though the Caribbean, and across Cuba, my mind wanders back to Charlie.  In hindsight, we were woefully unprepared for what Charlie would have brought to our area.  Our paltry preparations would have not stood much of a chance again the winds Charlie brought ashore.  We got lucky.  

  All the models predict Isaac will continue on his path north.  We are barely out of the track's cone.  But that doesn't mean I'll let my guard down.  I won't relax until he's at least even with Tampa on his trip north.  And even then the story is not over.  Isaac is taking aim on Atlanta, and DragonCon, where we'll spend Labor Day weekend. 

 It seems that we are destined to be under Isaac's influence, not once but twice.    

Lemon Light...

There was a storm approaching.... The radar was showing bright red just east of us. About 30 minutes ago it started rumbling, quietly at first, then progressively louder. The sun was also setting, and as it did, it got below the edge of the clouds to the west and the whole sky lit up with lemon yellow light. Beautiful and erie at the same time. Greens became richer or darker, depending on the tree or plant or grass. The cedar took on a rich, dark green hue.

I wandered out to the end of the driveway to watch the sky. Off to the east, in the direction of the approaching storm, low scud clouds were standing out against their darker comrades as they raced west. Lightning began to stand out against the darkening sky. The rumbles got louder. From the east, the winds picked up, carrying the telltale signs of approaching rain. Cooler temperatures and the feeling of more moisture in the air. It was time to retreat to the front patio.

The sky began to fade. But then, the sky turned orange. The greens became muted, and the lightning more frequent. It was starting to rain.

I retreated into the house to watch the rest of the storm. We sat in the front room with the lights off. The frequent lightning was strong enough to light up the room in the fading light. You could tell the direction the light was coming from, first to the north, then south. Rumbles answered all the flashes. The computer chimed. EmergencyEmail.org reported rainfall rates of two inches an hour in Pinellas. Urban flood advisories were issued.

The storm has passed now. We didn't get the torrential downpour I thought we would. The thunder has quieted, the lightning dimmed. There is still a lot of rain out there. In an hour or so, the storm will have moved offshore. Lightning may still dance across the sky, but the thunder will be too far away to hear. Outside, the side walk is still wet... proof that a storm had passed by.

Rain!

We got some... a little, well, not very much at all, really, but Rain! It lasted about 5 minutes and probably won't even register in a rain gauge. Tough. We got Rain! And north of us, like two counties north, they actually had flood warnings this afternoon. Famous Florida Thunderstorm in May. Very heavy and very stationary. Lasts 30 minutes, or an hour, and dumps five inches of rain in one spot. That is a you-can't-see-across-the-street heavy rain. A Florida staple. Unfortunately, it's been so long since we had any rain that most of that will probably just run off. The ground is too dry for it to sink in.

But not our rain... we didn't get enough to have it run off. Well, it did rain hard enough to run off the roof. But that's OK. It soaked in around the house. We have to start somewhere. I'll take the small showers.

Big summer thunderstorms start with mini May showers that pass briefly by.