Weather Spectrum

Latest Official Track (6-26-2012 @ 7PM CDT)


Florida took the brunt of Debby in the form of rain and lots, and lots, of it! Check out this rainfall graphic from the National Weather Service...

Upwards of 20 inches of rainfall for FL over the last 7 days, and, of that, about 10 inches of rain fell from Apalachicola to Jacksonville today alone. That's a departure of 8 inches above normal for many places in Florida.
Debby's death toll remains at 1, due to a tornado in central Florida on Sunday.

Again, the good news is that she's on her way out. We all say, "Good Riddance!"

Of course, it does not stop with Debby. The National Hurricane Center is already watching the next tropical wave in the Atlantic.

It's a very disorganized wave, but it does show signs of a broad circulation. It currently has only a 10% chance of developing into a tropical depression in the next 48 hours, but that chance could increase each day as it works its way westward across the Atlantic. With high pressure dominating the Atlantic and a conducive environment for cyclones, we may be watching this system head into the Caribbean as the 4th of July holiday nears. AND there's another wave right behind it that looks robust as well. We'll just have to wait and see what develops.

In the mean time, high pressure continues to dominate TX. It is HOT. Too HOT!!

Galveston broke another record today - 97 degrees - breaking the previous record of 95 set back in 1875. That's the third consecutive day with a record high. Here's a graphic of Galveston's June normals, extremes, and actual. The three stars indicate the records broken.

Hobby airport also saw its second consecutive day with a record high, 105 degrees.

It's starting to sound like a broken record. Sorry, I really could not resist the urge of the pun. :)

Stay cool, be safe in the heat if you have to be out in it, and enjoy the rest of the week indoors in the A/C if you can.

The models show an upper low developing along the TX coast going into the weekend and rain chances look to increase a bit into the weekend as a result. Will update on this if warranted. Right now it looks like scattered showers and T'Storms will be the nature of the rain chances. It's the typical summertime pattern. Hey, at least it might cool some areas down for a bit!

Thanks for reading.

Stay tuned for updates as Weather Spectrum tracks the tropics and the local weather for ya!

This evening the center of tropical storm Debby is stationary about 115 miles south-southwest of the Apalachicola, FL coastline as of 7:00 PM CDT. Maximum sustained winds are 60 MPH, and the minimum central pressure is 990 MB (29.23 inches). The next full advisory from the NHC will be at 10:00 PM.

Debby is a complicated storm to forecast. As evidenced by the dramatic changes in the official forecast track by the National Hurricane Center. Here is the latest track forecast:

The main reason for the changes is track guidance are the various weather models' trouble reaching a consensus on whether Debby will move north, east, or west. Some models say east, while a couple of reliable models say west. Here is the most recent model run from 1:00 PM CDT:

With this divergence in model consensus, the National Hurricane Center is basically splitting the model output and forecasting an almost due north drift for an eventual landfall on the Florida panhandle. While a westward turn for an eventual landfall closer to Louisiana is not 0%, it does seem less likely after observing Debby's track and analyzing the models.

Right now the steering is weak. There is a trough that is digging down into the Midwest/NE, and normally the trough would "pick up" a tropical system steering it north or northeast, but the turn should be occurring and the system would increase in forward speed. It's currently not doing that. The reason is because there is a ridge of high pressure right behind the trough that is like a wall the storm must go through. That is causing Debby to stall and start a slow drift. The direction of the drift is northward. Further complicating things is an upper low spinning west of the system which is doing two things...shearing the system a bit still (slowing organization and strengthening) and trying to steer the storm northward. So between the trough, the ridge of high pressure, and the upper low they're all causing opposing steering currents and so the storm is wobbling about and moving very slow. As a result, the forecast is very uncertain, but it does look like Debby will remain east of TX when it does make landfall.

Again, the National Hurricane Center expects landfall along the panhandle of Florida some time during the day on Thursday.

As for intensity, Debby will struggle to become a hurricane. There is still quite a bit of wind shear, but it looks to relax even more soon. However, maybe more problematic is the dry air being sucked into the system from the west-southwest. The dry air prevents thunderstorms from forming easily and maintaining themselves long enough to begin the strengthening process. The dry air is visible in the next graphic as the black/bronze color west (to the left) of the system.

Debby is very lopsided, with all of the convection on the east and north sides of the system. She looks pretty ragged overall, but the winds have managed to reach 60 MPH. Only 14 MPH more is needed before we have the second hurricane of the season (Chris was first - out in the open Atlantic last week). However, one last thing that Debby will have to overcome though is the water temperature. Yes, the water is very warm in the Gulf, but the warmest water is right at the surface to a depth of 50 meters or so. After a storm sits in one area, the wave action generated by the strong winds causes the water to get churned up and brings cooler water to the surface. Since hurricanes require warm water to get stronger this is not going to allow for rapid intensification for Debby.

That's good news all the way around.

Florida has received quite a bit of rain as well; some areas up to 6-8 inches so far. Mainly around Tampa.

Visible Satellite of Debby before sunset this evening...

Our weather in the Houston/Galveston area will remain dry and hot for the next few days!

Will keep you updated here as Debby progresses. Please subscribe at the upper right at www.weatherspectrum.com if you would like to receive updates via e-mail.

Thanks for reading!

By now you have surely been hearing all of the news weathermen, weather bloggers, Jim Cantore, and maybe even your own boss, coworker, or private "armchair" meteorologist talk about the tropical wave in the Gulf and the potential for development over the next few days. Some may even have ventured to take guesses on where it may head and how strong it could get. Lets face it. Weather is interesting and its capricious behavior keeps us on our toes; in a good way at times, but not so good at other times. That is even more true for the residents along the Gulf Coast; especially now and over the next several days as this system progress into the central Gulf of Mexico.

Right now, the system is a tangled mess of sheared and scattered thunderstorms huddled around a broad surface low pressure area. It lacks the organization for any robust development and currently there is so much wind shear due to strong upper level winds out of the southwest that even if it was organized enough to become a depression or storm, it would be struggling to stay together. That's really good news. While June is not typically host to very strong hurricanes, they can happen when the conditions all come together. Thankfully, this is not the case for this disturbance.

A visible satellite image from just before sunset this evening showed the exposed "center" of this broad low as a tiny swirl of low level clouds (encircled and just right of the "L") moving slowly northwestward. That swirl is a center of sorts, but this is a broad low and there can be multiple "centers" of low pressure and tiny swirls. So this is not necessarily where something would develop. Although as the wind shear relaxes in the next 48 hours, possibly enough to allow for some slow organization of the system, an enclosed surface low pressure center could develop causing a burst of thunderstorms which would take the system to the level of tropical depression. OR another scenario...The thunderstorms surrounding the broad low could maintain themselves and a new circulation could form beneath them with the same effect...a Tropical Depression. We're likely 48 hours at the very minimum from that happening. With the amount of shear and the disorganized state of the system, it could be Saturday before development, if any, began to really take shape.

This image shows the amount of mid-level shear. For tropical development to occur, the color over the Gulf would have to be more black and blue vs. the orange and yellow that is there now. The bright colors mean that any storms that form and try to organize are effectively blown over by the upper level wind quelling any potential organization of a tropical system. The shear is forecast to subside slowly over the next couple of days. By then, the system will be near the north central portion of the Gulf of Mexico.

Currently, the models differ on where this system may go and its development potential. It's complicated by several factors. 1) Wind shear 2) a trough digging into the Midwest and 3) a ridge of high pressure forming over Texas. Wind shear is covered and so we will talk about the trough.

The trough has the potential to "pick-up" the disturbance and basically steer it away from TX and take it towards and over Florida and out into the western Atlantic where further development is likely and Tropical Storm Debby could form quite easily. Especially with the very warm Gulf Stream current beneath it. However, less likely, the high pressure ridge forming over Texas could potentially block the disturbance from following the trough eastward. That would cause the system to stall, possibly develop into a depression or tropical storm and then move westward in the direction of TX/Mexico. Historically speaking, most troughs are able to pick these weak systems up and take them away from TX. I am leaning towards that solution as well, but only about 70%. There is a small chance of it stalling and turning more westward.

Whatever the case, it will take time for anything substantial to develop out of this rather messy system. It will be a rain maker too. The HPC (Hydrometeorological Prediction Center) is leaning towards the first scenario as well which would take the system, and all of the rain, towards Florida.

Here is a snapshot of the 5 day rainfall accumulation that could be expected should the system go towards Florida.

In 48 more hours, we should have an even clearer picture as to where this system will go.

Assuming the system eventually goes east, we'll be hot and dry in southeast TX. We might get a small ground swell out of it for the surfers, but only if it can at least develop into a depression with sustained winds and convection. Overall, our wave chances are looking pretty nil at the moment.

IF the system should stall and begin to organize in the Gulf, I will update as often as possible with the latest forecast information.

Have a great remainder of the week and weekend! Stay cool!

It's been fairly quiet lately. A few thunderstorms in the mornings along the coastal areas of upper TX coast and LA that move inland into the afternoon hours will continue for the next few days as tropical moisture continues to pump in from the Gulf of Mexico. The resulting chances for rain stay between 10-30% each day until next week when things could get a bit interesting.

By interesting, I'm talking about a potential for some tropical development in the southern Gulf of Mexico or Caribbean near the Yucatan. The time frame for this would be mid-week next week, according to model runs. Of course, trying to guess exactly when and where and how strong this system might be is extremely difficult. It may not even happen, but, because the models have been very consistent, the chances are increasing that some sort of tropical development will occur.

Because of the potential for this to occur, rain chances for our area go up substantially next week. The caveat is that it is still a few days out, and depending on the location of development and movement, changes the precipitation forecasts dramatically, either higher or lower, are expected.

There are many of unknowns for this forecast, but you can still be prepared just in case something does develop that could impact the TX coast. Take this as a chance to get things situated. There is a hurricane preparedness section below this paragraph on the right side of the homepage (http://www.weatherspectrum.com). You can visit the FEMA page directly at http://www.ready.gov/hurricanes. Also, it would be a good idea to take pictures of your belongings that you do not plan to take with you in an evacuation as record for insurance claims should a flood, fire, or significant wind damage occur. This is not just good for hurricane season, but anytime.

As we go into next week, I will be updating more frequently to stay on top of this possible tropical development.

Model snapshot showing tropical feature in the Gulf of Mexico. This is 7 days away and much can change! Stay tuned!

Have a good weekend in the mean time!

Aside from some on and off rain showers going into the weekend, the weather pattern for southeast Texas is pretty uneventful for the foreseeable future. That's not uncommon this time of year (Summer). There are multiple reasons for such a stagnant pattern locally, but the culprit for all of Earth's weather shines on us everyday.

All of the weather on Earth has one main source. That source is the Sun, or, rather, a byproduct of the Sun - Heat. Heat from the Sun is a good thing for us Humans. Without it we would freeze to death. Pretty quickly too. You might be surprised to learn that the average temperature of the entire Earth is 59 degrees Fahrenheit. That's pretty chilly. Of course, here in southeast Texas the average temperature is more like 70 degrees Fahrenheit. Remove the Sun from the equation and suddenly Earth would become a huge frozen ball of nothingness. Therefore, we like the Sun. It keeps Earth, and its inhabitants, nice and comfortable; at least most of the time. I can hear half of Houston grumbling about the heat they've experienced last year and this year. Don't look at me. I certainly did not order such heat.

So, the Sun heats the Earth, but because Earth 1) is round, 2) is covered with water AND land (in different proportions), and 3) spins that causes the amount of absorbed heat energy to be different everywhere. Because of this differential heating we get differences in air (atmospheric) pressure. Pressure differential causes the wind to blow and when the wind blows causing different air masses to collide we get weather! That's the short version. It's much more complex than that, but that's the big picture.

When you think about seasons that have the most volatile weather, you probably think of Fall and Spring. Fall brings cold fronts, cooler temperatures, and thunderstorms that accompany the fronts. Spring gets us to warmer temperatures, but the fronts continue to dip down into Texas and that creates thunderstorms also. Sometimes these storms are severe too. But you don't really get the type of severe storms in Summer or Winter that you do in Fall or Spring. Why? Because the temperature differences in the transition months leading to Winter and Summer are much more dramatic.

Think about it this way. In the Fall, as the Sun shines less in the northern hemisphere, thanks to the Earth's 23.5 degree tilt, there is less heat energy available to heat the land. This causes the North Pole and upper latitudes of the northern hemisphere to begin to rapidly cool. However, here in Texas we still have quite a bit of daylight and heating so we do not cool as fast. The temperature difference causes a rather large pressure differential. To balance, cold air rushes southward in the form of cold fronts. When the cold air collides with the warm moist air over Texas that causes thunderstorms to form. That's because cold air sinks and warm air rises...and it rises even quicker when cold air collides with it. Cold fronts occur all the way through Winter since there is always a difference in temperature between the northern and southern latitudes, but as we get into the "dead" of winter (Jan-Feb) the frequency of frontal passages is slightly reduced and since cold air has settled in over much of Texas by then, the thunderstorm activity drops dramatically. There is still rain from time to time, but there isn't enough instability or moisture in the colder atmosphere to create thunderstorms like there are when there's a good bout of hot, moist, air sitting over Texas. As far as severe weather in the Fall, there is a slight peak of severe weather from about October into late November, but generally it wanes fast due to rapid cooling and drying that results from the cold air intrusion.

When Spring comes around, and the northern hemisphere begins to tilt towards the Sun again, the southern part of the country begins to warm faster than the north and a large pressure differential is created again. Fronts continue diving southward to balance things, but with more gusto since the pressure differential is quite large, and that's when we see tornadoes and severe weather in abundance. Especially across the plains. Then, as we settle into Summer much of the nation is quite warm, if not hot, and the frequency of frontal passages wanes again. Then we are dependent on local processes to give us rain along with an occasional upper low passage or tropical system thrown into the mix.

As a matter of fact, an upper low traversing the state is responsible for the weather today and as we go into the weekend. But once it moves out, then we are again dependent on the sea-breeze to give us some rain from time-to-time. At least until the next upper low or, heaven forbid, tropical system. After all, 11 years ago yesterday, it was tropical storm Allison that left her mark in Houston dumping 37 inches of rain.

Allison is also the only tropical storm whose name was retired from the Atlantic Tropical Storm name lists. Usually retired names are hurricanes that cause substantial damage and/or loss of life. Alison was a record storm, caused multiple billions in damage, and took too many lives in the flooding. Reasons enough to retire the name.

Houston is in the summer pattern again even though it's technically not yet summer (June 20th, 2012). And it's certainly hot. So while we wait for the breaks in the heat and the rain to fall, we head to the beach, have BBQs, and try to stay cool indoors from noon until five in the evening. After being in Omaha, NE for 4.5 years, it is certainly a big change for me!

Hopefully we'll all see at least an inch of rain over the next few days. After that, time will tell.

Before I go, here is a pic at 36,000 feet from a trip to Omaha last weekend. On the edge of space!


Have a great rest of the week and weekend and thanks for reading!