I am back. No, I didn't disappear off of the face of the Earth! I am back here now after several days of no blog postings! I apologize for the lack. I had so much I wanted to say over the course of the last 10 days or so, but my computer crashed. I have been in the process of restoring everything as best I could, so please bare with me over the next few days as I continue to work to restore everything. The audio blogs will return in the next day or so, and I hope the sound quality will be even better than before. Thank you! It's good to be back! The blog will be in short form this week, since I'll be doing hurricane preparedness! One more quick note here, next Tuesday, June 1, is the beginning of the 2010 Atlantic Hurricane Season. Therefore, the tropical outlook will return. It will generally be located below the marine forecast, unless there's an active storm heading for the Caribbean or Gulf of Mexico, then it will take precedence over everything else and be moved right to the top. I will also utilize the blog more during hurricane season, as this will allow me to enter new information about the tropical systems as they come out.
Now, before I get to the forecast discussion, I promised you hurricane preparedness, and you will still get the full version. I will have to double up each day this week to make up for the lack of information for last week, so once again please bare with me. This week, the way of May 23-29 is officially known as Hurricane Awareness Week. For the duration of the week, I will providing you with all sorts of helpful information to help you prepare for the upcoming tropical season, which begins in just less than a week now (Tuesday, June 1). The first parts tonight cover, commonly used terms during the tropical season, the list of names for the 2010 hurricane season, and new changes to issued forecast products by the National Hurricane Center effective for the 2010 season.
It is essential to have a better understanding of not only hurricanes, but all tropical systems in general. One way to become more knowledgeable of these meteorological entities is to understand and know the meaning of certain terms we use over the course of the season.
As you know, tropical systems are divided into 3 stages for naming purposes: tropical depression, tropical storm, and hurricane. However, it can be taken further as all of these tropical systems begin from what is known as a tropical wave or tropical disturbance. Let's define each one.
Tropical Disturbance- An area of disorganized low pressure that develops in the Atlantic Basin, that is, the Gulf of Mexico, Caribbean Sea, and Atlantic Ocean. It generally evolves from a persistent area of thunderstorms, and lowering pressures over the Atlantic Basin.
Tropical Depression- An organized low pressure system with organized clouds and thunderstorms. It has sustained surface winds of 38 mph or less.
Tropical Storm- An organized low pressure system with organized clouds and intense rainfall. It has sustained surface winds of 39-73 mph.
Hurricane- The most intense of the tropical cyclones. It produced very heavy rainfall, and sustained surface winds must be at least 74 mph.
Hurricane intensity is measured using the Saffir-Simpson scale. It is broken down into 5 categories.
Category 1 74-95 mph. Minimal damage will result such as downed trees and power lines. Damage to poorly constructed mobile homes is possible. Minor roof damage possible to some well-built homes. Some signs could be damaged. Injury or death to people and animals can occur if debris falls on or hits them. Example of a category 1 storm (Dolly in 2008- South Texas).
Category 2- 96-110 mph. Extensive damage will occur. Examples of this include: Older mobile homes can be completely destroyed by the high winds and flying debris. The risk of death or injury to humans and animals increases. High rise buildings sway, and face the risk of having windows blown out. Example of a category 2 storm (Hurricane Frances in 2004- East Central FL Coast).
Category 3 111-130 mph. Severe damage will occur. Major tree and power line damage occurs often producing prolonged power outages for over a week. Major communications can be cut off for more than a week. Almost all older mobile homes will be completely destroyed. Poorly constructed frame homes can face serious damage. Major roof damage will occur. Signs, fences, and canopies destroyed. Example of a category 3 (Hurricane Rita September 24, 2005- SW Louisiana/SE Texas). Hurricanes of category 3 intensity and above are considered major hurricanes.
Category 4 131-155 mph. Devastating damage. A very high risk of death to humans and animals due to falling and flying debris. Major structural damage to well built homes and offices. Certain demolition of mobile homes and trailers. Power failures will last for weeks due to numerous amount of falling trees and power lines. All major services will be unavailable for quite some time after the storm. Example of a category 4 storm (Hurricane Charley- August 2004- West Central Florida).
Category 5 156 mph or greater. Catastrophic damage. A very high risk to almost near certain death for humans and animals due to falling and flying debris. Major damage to well built structures. Nearly all signs, canopies, and fences will be destroyed. Nearly all trees and power lines will be snapped, uprooted, or downed. Expect utilities and services to be absent for weeks possibly months. Many areas will be uninhabitable, and human suffering will be immense. An example of a category 5 storm (Hurricane Andrew- August 1992, and Hurricane Camille- August 1969 Mississippi).
Other terms of note include:
Storm surge- A rapid rise in ocean height as a hurricane moves inland. More people are killed by the storm surge element than the wind element. The storm surge is extremely destructive to anything and everything in its path, especially if it comes in with a significant speed. You should remember that water is extremely heavy, and a cubic yard of water weighs about 1,700 pounds. The larger the storm, the higher the surge will be. The shape of the continental shelf across the coastal waters is also a contributing factor.
When a tropical system is threatening a portion of coastline, and conditions are imminent within a couple of days certain advisories are issued by the National Hurricane Center.
Tropical Storm Watch- Alert issued when tropical storm conditions are expected within 48 hours for a specific area of the coast.
Tropical Storm Warning- Alert issued when tropical storm conditions are expected within 36 hours for a specific area of the coast.
Hurricane Watch- Alert issued when hurricane conditions are expected for a specific portion of the coastline. It is issued within 48 hours of the anticipated onset of tropical storm force, because the stronger winds will make preparations more difficult to complete.
Hurricane Warning- Alert issued when hurricane conditions are expected for a specific portion of the coastline with 36 hours of the anticipated onset of tropical storm force winds. This is because preparations become more difficult to complete once the winds increase.
Tornadoes are also very common during tropical systems, mainly to the right (East) of the center of circulation.
Tornado- A small-scale, violently rotating column of air extending from the cyclonic motion.
These are the common terms used during the course of a tropical season.
The next section will cover some changes that are being made to the issued forecasts for the 2010 season. This information comes courtesy of the National Hurricane Center in Miami, FL.
First, Watches and warnings for tropical storms and hurricanes along threatened coastal areas will be issued 12 hours earlier than in previous years. Tropical storm watches will be issued when tropical storm conditions are possible along the coast within 48 hours. Tropical storm warnings will be issued when those conditions are expected within 36 hours. Similar increases in lead-time will apply to hurricane watches and warnings.
Secondly, The format of the Tropical Cyclone Public Advisory is changing. The most significant changes are:
The Public Advisory will be organized into sections. Within these sections, keywords will be used to assist the human eye and computer software to find specific information more readily.
The summary section of the advisory will move to the top of the product, immediately following the headline. The summary section will contain more information than it did previously.
Watch and warning information will be organized differently and be presented in list or bullet form.
Thirdly, A summary section, identical to the one found in the Public Advisory, will be added to the Tropical Cyclone Update whenever storm information (e.g., position, intensity, movement, pressure, etc.) changes from the previous Advisory.
Fourth, The genesis forecasts for the risk of tropical cyclone development will be provided to nearest 10 percent, in both the text and graphical Tropical Weather Outlooks. In previous years, only risk categories (low/medium/high) were given.
Fifth, The National Weather Service and its National Hurricane Center will begin using the generic term "post-tropical" to refer to any system that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Post-tropical cyclones can continue to carry heavy rains and strong winds. Some post-tropical cyclones will go on to become fully extratropical, that is, derive their energy from the temperature contrast between warm and cold air masses. Another type of post-tropical cyclone is the "remnant low", a weak system with limited thunderstorm activity and winds of less than tropical storm strength.
Next, The Saffir-Simpson Hurricane Wind Scale will become operational. The scale keeps the same wind speed ranges as the original Saffir-Simpson Scale for each of the five hurricane categories, but no longer ties specific storm surge and flooding effects to each category.
Lastly, The size of the tropical cyclone forecast cone will be adjusted. The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of imaginary circles placed along the forecast track (at 12, 24, 36 hours, etc.). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle. The circle radii defining the cones in 2010 for the Atlantic and eastern North Pacific basins are given in the table below.
For more information log onto www.nhc.noaa.gov....The National Hurricane Center.
Finally, in closing the first part of Hurricane Awareness 2010, here is the list of names for the 2010 Season. I should remind you that names are only used for Tropical Storms and Hurricanes. When a storm is at tropical depression status, it is given a number only. The names alternate, boy,girl, boy, girl, etc. and are recycled every 6 years. For example, the first name on this year's list, Alex, will be used once again in 2016. However, I should also note here that names are retired of the storm was influential. Examples of retired storm names include Rita, Katrina, Wilma, Ike, Ivan, Audrey, Frances, Dennis, Camille, Betsy, & Andrew.
Alex
Bonnie
Colin
Danielle
Earl
Fiona
Gaston
Hermine
Igor
Julia
Karl
Lisa
Matthew
Nicole
Otto
Paula
Richard
Shary
Tomas
Virginie
Walter
There are no storm names for the letter Q, U, X, Y, & Z.
Check back for part 2 tomorrow which will feature what to do before, during, and after the storm, as well as hurricane climatology and history for SW Louisiana.. Part three is on Thursday, and will include the science behind hurricanes, that is, the forecasting aspect. It will also include some predictions for the upcoming season. Even though I don't put numbers on it like some experts do, I will give my thoughts on the upcoming season. If you have any questions or comments please feel free to leave them right here, or you can e-mail me. Now onto the forecast...
SW Louisiana Forecast Discussion...Officially, summer begins in a little less than a month. However, summer is firmly enkindled across the forecast area on this last full week of May. This is typical as you know, our summer is very long, and there will be no relief from the heat until at least September. Tuesday was certainly a day very representative of a normal summer day across the forecast area. We still need some rain, and a lucky few did receive some...Luke Bryan is correct!!! Temperatures have been running a tad above normal, but the pattern is essentially normal at this juncture. Afternoon highs today were well into the 90s, with many locations touching the mid 90s. A less than average scattered of afternoon shower and thunderstorm was present on this Tuesday afternoon as some mid and upper level ridging remained in place. Oddly enough, some shower and thunderstorm activity prevailed well after sunset Tuesday over Acadiana, but most of us have stayed dry. Overall, it will be a quiet night with clear skies and humid conditions in place. Overnight lows will be close to the 70 degree mark.
More of the same weather is expected through the forecast period, including the all important Memorial Day weekend. Day to day variations in the chance for scattered afternoon showers and thunderstorms are expected, as some small scale synoptic features aid in dictating what percentage of the daily dose of cumulus clouds can grow vertically into thunderstorms. Wednesday offers one of the days with at least an average chance of scattered shower and thunderstorm activity. A couple of features will come together to produce this slight increase in coverage from Tuesday. Some minor upper air disturbances moving Eastward away from an MCS over Texas, and an inverted trof over the SE U.S. will retrograde into the forecast area, and create another boundary for showers and thunderstorms to feed off of as the afternoon sea breeze works in. In all, areal coverage should be around 30%. Areas that obtain a direct hit from a thunderstorm could pick up a quick inch or so of much needed rainfall, but someone just down the road will continue to bake in the sun. There's no way of pinpointing exactly where the storms will occur, it's simply an at random proposition. I'd almost say it's like God's version of a lottery! It's just a luck of the draw more or less. With the daytime heating aspect always present, and such a moist air mass in place some of the storms could turn out to be rather robust, but certainly anything severe on a large scale is not likely. A similar temperature scheme is in the offing for Wednesday as well with 90s obtainable in nearly all areas once again. The immediate coast will escape it being 90. Heat index values will be at or near 100 real soon....find a pool!!!
Preliminary Numbers & Zone Forecast:
LCH 70/93 71/93 72/94 0 30 0 30 0 30
LFT 70/94 71/95 71/94 20 30 0 30 0 30
BPT 71/95 71/95 72/95 0 30 0 30 0 30
AEX 68/95 69/95 70/96 0 30 0 30 0 20
POE 68/94 69/95 70/95 0 30 0 30 0 20
ARA 71/92 71/92 71/93 20 30 0 30 0 30
Tonight...Mostly Clear. Low 70. Light SE wind.
Wednesday...Partly Cloudy with a 30% chance of scattered afternoon showers & thunderstorms. High 93. SSE wind 10-15 mph.
Wednesday Night...Mostly Clear after a 20% chance of an evening shower or thunderstorm. Low 71. SSE wind 5-10 mph.
Thursday...Partly Cloudy with a 30% chance of scattered afternoon showers & thunderstorms. High 93. SSE wind 10-15 mph.
Thursday Night...Partly Cloudy. Low 72. SSE wind 5-10 mph.
Friday...Partly Cloudy with a 30% chance of scattered afternoon showers & thunderstorms. High 94. SSE wind 10-15 mph.
Wednesday 5/26/10 Daily Planner
6a.m.
Weather: Clear
Temp: 70
Rain: 0%
Wind: SE 3
9a.m.
Weather: Partly Cloudy
Temp: 78
Rain: 10%
Wind: SSE 9
Noon
Weather: Partly Cloudy
Temp: 87
Rain: 20%
Wind: SSE 13
3p..m.
Weather: Partly Cloudy, Scattered Storms
Temp: 92
Rain: 30%
Wind: SSE 15
6p.m.
Weather: Partly Cloudy, Scattered Storms
Temp: 89
Rain: 20%
Wind: SSE 15
9p.m.
Weather: Mostly Clear
Temp: 82
Rain: 0%
Wind: SSE 5
Drew's 7 Day Outlook
Wednesday
Low: 70
High: 93
Rain: 30%
Wind: SSE 10-15
H.I.: 95-100
Thursday
5-27-10
Low: 71
High: 93
Rain: 30%
Wind: SSE 10-15
H.I.: 96-101
Friday
5-28-10
Low: 72
High: 94
Rain: 30%
Wind: SSE 10-15
H.I.: 95-100
Saturday
5-29-10
High: 91
Rain: 30%
Wind: SSE 10-15
H.I.: 95-100
Sunday
5-30-10
Low: 73
High: 94
Rain: 20%
Wind: SSE 10-15
H.I.: 97-102
Monday
5-31-10
Memorial Day
Low: 74
High: 95
Rain: 20%
Wind: SSE 15-20
H.I.: 98-103
Tuesday
6-1-10
Hurricane Season Begins
Low: 75
High: 93
Rain: 30%
Wind: SSE 15-20
H.I.: 97-102
...Marine Forecast...
Tonight...North winds 5 to 10 knots becoming northeast after midnight. Seas 1 foot. Scattered showers and thunderstorms late in the evening...then isolated showers and thunderstorms after midnight.
Wednesday...East winds 5 to 10 knots. Seas 1 foot. A slight chance of showers and thunderstorms in the morning...then scattered showers and thunderstorms in the afternoon.
Wednesday Night...South winds 5 to 10 knots. Seas 1 foot. A slight chance of showers and thunderstorms.
Thursday...West winds 5 to 10 knots. Seas 1 foot. A slight chance of showers and thunderstorms in the morning...then scattered showers and thunderstorms in the afternoon.
Thursday Night...Southwest winds 5 to 10 knots. Seas 1 foot.
Friday...Southwest winds 5 to 10 knots. Seas 1 to 2 feet. A slight chance of showers and thunderstorms.
Good night and God bless!
-DM-
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