Hurricane Winds & The Tale Of The Tape

The power of a CAT 5 Storm – Hurricane Andrew 1992

 

 # 10,096

 

Today is day three of National Hurricane Preparedness Week, and the emphasis is on hurricane winds, the classic (although not always the best) gauge of a hurricane’s power.

 

Hurricanes are measured by the Saffir-Simpson Scale, which bases their strength on sustained wind speeds.   Anything CAT 3 or higher is considered a major hurricane.

Even a CATEGORY 1 storm can spin up tornadoes, or produce wind gusts substantially stronger than their sustained wind speeds.  Older Mobile homes, RVs, and even some conventionally built structures may not withstand a CAT 1 storm. 

 

While storm surge is the greatest concern to those living in low-lying coastal areas, hurricane force winds can extend a hundred miles or more inland during a landfalling hurricane.

 

And while great strides have been made over the past few decades in forecasting the path (out to about 48-72 hrs) of hurricanes, meteorologists are far less able to predict intensity changes of these storms. 

 

Just before landfall in 2004, Hurricane Charlie unexpectedly changed direction and ramped up from a moderate CAT 2 to storm to a major CAT 4 in just three hours, leaving coastal residents no time for evacuations.

 

If you live in vulnerable areas, you need to be aware of your evacuation zone, many of which have been recently revised due to a better understanding of storm surge, flooding, and wind damage risks.

 

Whether you stay, or leave, you’ll probably want to secure your home as best you can before high winds arrive. And this year emergency managers are once again reminding the public of the folly and futility of taping their windows in advance of a hurricane.

 

Up until the 1970s, it was pretty much standard advice to homeowners to tape plate glass windows to keep them from shattering, but that advice was discredited, and has not been part of hurricane prep advice for 30 years.

 

Not only does taping windows provide a false sense of security, it can bind shards of flying glass into larger, and more dangerous, projectiles.

 

Still, the myth hangs on.

 

A video that I’ve highlighted in the past, from the Pinellas County Office of Emergency Management demonstrates just how useless masking, or duct taping your your windows really is during a storm .

And for more on this week’s Hurricane Preparedness campaign, visit the following NOAA website which features videos focusing on each day’s topic.

 

 

And for the first two blogs in this week’s series, you may wish to visit:

 

Storm Surge Monday – Hurricane Preparedness Week

Hurricane Preparedness Week 2015 – Day One

Storm Surge Monday – Hurricane Preparedness Week

 

Crystal Beach, Tx after Hurricane Ike (2008) showing destructive force of storm surge

# 10,088

 

This is day two of 2015’s National Hurricane Preparedness Week and the focus today is on Storm Surge, often the biggest cause of death from these killer storms.  While we usually worry most about the winds surrounding the eye of a hurricane, storm surge is more dependent on the contour of the coast, the storm’s angle of approach, and the forward speed of the storm.

Often the highest surge is well away from where the eye crosses the coastline, which can catch some coastal residents off guard.

 

This year the National Hurricane Center will be introducing a new experimental forecast product designed to warn coastal residents of areas where dangerous storm surges are expected.   Full implementation of this product is not expected until 2017.

 

National Hurricane Center to issue storm surge watch and warning graphic

Beginning with the 2015 hurricane season, NOAA’s National Hurricane Center (NHC) will offer an experimental storm surge watch/warning graphic to highlight those areas along the Gulf and Atlantic coasts of the United States that have a significant risk of life-threatening inundation by storm surge from a tropical cyclone.

The new graphic is designed to introduce the concept of a watch or warning specific to the storm surge hazard. Storm surge is often the greatest threat to life and property from a tropical cyclone, and it can occur at different times and at different locations from a storm’s hazardous winds. In addition, while most coastal residents can remain in their homes and be safe from a tropical cyclone’s winds, evacuations are generally needed to keep people safe from storm surge. Having  separate warnings for these two hazards should provide emergency managers, the media, and the general public better guidance on the hazards they face when tropical cyclones threaten.

(Continue . . . )

 

 

Next  stop, a short video from the NHC (National Hurricane Center), and a NHC description of storm surge, after which I’ll return with a bit more:

Storm Surge vs. Storm Tide

Storm surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tides. Storm surge should not be confused with storm tide, which is defined as the water level rise due to the combination of storm surge and the astronomical tide. This rise in water level can cause extreme flooding in coastal areas particularly when storm surge coincides with normal high tide, resulting in storm tides reaching up to 20 feet or more in some cases.

Storm Surge vs. Storm Tide

 

 

Back in 2011,  in Getting SLOSHed For Hurricane Season I wrote about the Sea, Lake and Overland Surges from Hurricanes computer model that emergency planners use to plan for coastal evacuations.  In order to know in advance how far inland a storm surge or tide will encroach, emergency planners run hundreds of SLOSH models for populated regions along the coast. 

 

They vary the size, intensity, direction, and forward speed of hurricanes in the model in order to determine the worst case impact for each category of storm. Evacuation maps and routes are then generated using this information.

This evacuation map of Pinellas County (St. Petersburg-Clearwater) Florida shows that a storm even as low as a CAT 3 could temporarily cut the southern half of the county off from the north.

 

Of course much depends upon the speed, direction, and point of landfall of the storm, and so not all CAT 3 storms impacting this area would produce this dramatic of an effect.

 

Take it from someone who has experienced more than one of these storm surges first hand . . . if you are asked to evacuate by your local authorities, don’t hesitate.

 

Just do it.

 

For more information on the storm’s effects, and how you should prepare, check back every day this week and visit:

Hurricane Preparedness Week 2015 – Day One

 

# 10,084

 

As a native Floridian who grew up on the coast, lived aboard boats for 15 years, and who had a hurricane tracking map tacked to his bedroom wall at an early age, I’ve a hefty respect for these tropical cyclones.   Below you’ll find a map of the hurricanes that crossed Florida during my youth, in the years between 1954-1972.

As you can imagine, these made quite an impression on me growing up. Donna, in 1960, was particularly memorable as I was six years old, and it put a pretty good-sized oak tree limb across our roof.

While we haven’t seen a major (Cat 3+) hurricane strike the continental United States in nearly 9 years (Wilma, 2005) - and this year’s forecast is calling or a below average season – it only takes one strong hurricane hitting a populated area to make it a very bad year.

 

So I will do what I’ve done every year since I was old enough to comprehend the wisdom of such things.  I will prepare as if this is the year I get hit (again), and urge that others do the same.

 

All this week, as part of National Hurricane Preparedness Week, we’ll be looking at these dangerous storms and how you should prepare for them.  NOAA has a short (1-2 minute) video for each day of this week.

 

 

Hurricane season generally builds slowly, with just a few – usually weaker – storms in June and early July.  But as the Atlantic waters warm, the frequency and strength of these tropical systems grows – reaching their peak in mid-September – and then slowly waning through November.

 

Storms that form in June and early July generally form in the Caribbean, the Gulf of Mexico, or just off the coast of the United States – as did Ana earlier this month.

 

June Tropical Climatology

Credit NOAA

 

While generally weaker, these early season storms can still be quite deadly.

 

In 1972 a weak Hurricane Agnes made landfall in Florida on June 19th, trekked north, and dumped more than a foot of rain across the mid-Atlantic states. Of the 122 deaths associated with this storm, only 9 occurred in Florida where Agnes made landfall. 

The rest - 113 fatalities - were caused by inland fresh water flooding a thousand miles north several days later.

 

The moral? :  You don’t have to live near the coast to be hard hit by a hurricane.

 

When it comes to getting the latest information on hurricanes, your first stop should always be the National Hurricane Center in Miami, Florida. These are the real experts, and the only ones you should rely on to track and forecast the storm.

If you are on Twitter, you should also follow @FEMA, @CraigatFEMA, @NHC_Atlantic, @NHC_Pacific and @ReadyGov.

 

If you haven’t already downloaded the updated Tropical Cyclone Preparedness Guide, now would be an excellent time to do so.

Hurricane Arthur, July Climatology & NHC’s New 5-Day Graphical Forecast

 

# 8803

 

Arthur, a category one hurricane, is expected to pass very close to the outer banks of North Carolina this evening on its trek north.  While most of the worst of the weather will likely remain offshore, areas along the coastline are likely to take a pounding. 

 

Residents in the affected areas should be completing their hurricane preparations now (see Hurricane Preparedness Week: Make A Plan).

 

Storms that form in June and early July generally form in the Caribbean, the Gulf of Mexico, or just off the coast of the United States – as has Arthur. 

June Tropical Climatology

Credit NOAA

As the summer progresses the spawning grounds for Hurricanes moves further east into the warming Atlantic ocean.  But it usually isn’t until  August and September that the Cape Verde basin begins to produce what often turn into the largest and most persistent storms.

July & August Tropical Climatology

 

And the number of storms increases as we get later in the summer, with the peak of activity usually in the first half of September.  Hurricane season lasts through November 30th, however, and so late season storms are always possible.

 

You can find much more on Hurricane Climatology at NOAA’s  Tropical Cyclone Climatology page.

When it comes to getting the latest information on hurricanes, your first stop should always be the National Hurricane Center in Miami, Florida. These are the real pros, and the only ones you should rely on to track and forecast the storm.

• 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.

 

This year the NHC has also introduced a new five-day graphical forecast, showing the areas of the tropics where tropical development is possible (or expected) over the next 120 hours.   Here is how NOAA describes this new feature:

 

Five-Day Graphical Tropical Weather Outlook Introduced

Beginning at 2 p.m. EDT July 1st , NOAA’s National Hurricane Center (NHC) will introduce an experimental five-day Graphical Tropical Weather Outlook (GTWO) to accompany its text Tropical Weather Outlook (TWO).

The new five-day GTWO, available for both the Atlantic and eastern North Pacific basins, will indicate the formation potential of  current and future disturbances during the next five days.

Shaded areas will represent the potential tropical cyclone  formation areas,  color-coded by development likelihood, with yellow representing a low (<30%) chance, orange denoting a medium (30%  to 50%) chance, and red  corresponding to a high (>50%) chance of tropical cyclone formation during the next five days. The location of each current disturbance will be denoted by an “X”. A mouse-over feature will allow users to see the accompanying Outlook text for each system. Clicking on an area will display a graphic showing only that disturbance, which should improve clarity when the forecast genesis areas overlap. Because the new five-day GTWO will tend to be busier than the current 48-hour GTWO, the five-day graphic will not display the locations of existing tropical cyclones.

Here is an example of the new five-day GTWO:

 

 

For now, with the exception of Arthur, the Atlantic Basin and Caribbean are quiet, with no tropical development expected.

Making this 4th of July weekend a good time to go over your hurricane (and other disaster) preparedness plans, making sure you, your family, and your business are prepared to deal with whatever unexpected situation that life, and nature, can throw at you.

 

In addition to the preparedness information you can find on the FEMA and READY.GOV websites, a few of my earlier preparedness blogs include:

 

 When 72 Hours Isn’t Enough

The Gift Of Preparedness: 2013

In An Emergency, Who Has Your Back?

Watching The Tropics

 

 

# 8796

 

While it may not currently look like much on radar or In the satellite photos - a low pressure area that slipped off the South Carolina coastline a few days ago and drifted south over the Gulf Stream  - has now gathered steam, and overnight was declared the first tropical depression of the 2014 Atlantic Hurricane Season.

 

From National Hurricane Center’s  5am discussion:

Numerical guidance shows favorable conditions for intensification with weak shear and developing upper-level outflow over the cyclone during the next 72 hours or so. The official intensity forecast now shows the system becoming a hurricane, which is similar to the latest intensity model consensus.

 

By the time this system reaches the Outer Banks of North Carolina, it could be a Category 1 hurricane. Here is the NHC’s Tropical Storm Force Wind Speed Probabilities over the next 120 hours.   As you can see, most of heaviest winds are forecast to stay offshore.

Nonetheless, this storm has the potential to create life-threatening conditions along the coast, and a Tropical Storm Watch is in effect for the East Coast of Florida from Fort Piece to Flagler Beach.  Watches and warnings will likely be extended northward over the next day or two.

 

While not likely to be a major storm, the forecasting of future intensity changes in tropical systems remains a big challenge. So anyone in its potential path should take the time today to review their hurricane preparedness plans and supplies, with an eye towards such issues as:

 

1. How you will communicate with family & friends during and after a disaster, and where you will meet if you are separated
2. How you will deal with those with specific needs, such as children, the elderly, or those with medical conditions
3. To stockpile ample water, food, any required Rx meds, along with a first aid kit
4. How you will cook, or provide light, or receive emergency radio transmissions if the power is out for days or longer
5. Where you will go if you are told to evacuate – and how you will get there
6. And last, but certainly not least, how you will care for your pets during and after a disaster.

Last month, in Hurricane Preparedness Week: Make A Plan, we discussed these issues.  For more information, Ready.gov has an extensive Hurricane preparedness website, with advice on what to do before, during, and after the storm.

 

If you haven’t already downloaded the updated Tropical Cyclone Preparedness Guide, now would be an excellent time to do so.

When it comes to getting the latest information on hurricanes, your first stop should always be the National Hurricane Center in Miami, Florida. These are the real pros, and the only ones you should rely on to track and forecast the storm.

• 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.

NOAA’s NWS National Hurricane Center in Miami also has a Facebook page, where you can keep up with the latest tropical developments.

The second official information source you should have bookmarked is your local Office of Emergency Management.  Here you’ll be able to access local warnings, flood maps and evacuation information. To find your local one, you can Google or Yahoo search with your county/parish name and the words `Emergency Management’.  

And lastly, if you are on Twitter, you should also follow @FEMA, @CraigatFEMA, @NHC_Atlantic, @NHC_Pacific and @ReadyGov.

June Tropical Climatology

 

Mariner’s Poem On Hurricanes

June too soon.
July stand by.
August look out you must.
September remember.
October all over.

- Published in “Weather Lore” by R. Inwards in 1898

 

# 8694

 

June 1st marks the start of this year’s Atlantic Hurricane season, and while strong June hurricanes are fairly rare, named June storms occur roughly every other year.  The chart above shows that hurricane season begins slowly, reaches a peak in mid-September, and then slowly peters out by December.

 

The strongest recorded June storm was Hurricane Audrey in 1957, the only one known to reach CAT 4 strength. Audrey claimed 550 lives after it made landfall in eastern Texas and western Louisiana. Below are a few notable June Hurricane tracks, including  Audrey.

 

Even tropical storms and weak hurricanes are capable of doing severe damage and taking lives.

 

Hurricane Agnes (1972), which I remember well as the first disaster I worked as a Red Cross volunteer, caused relatively little damage to Florida where it made landfall as a minimal CAT 1 storm. Her impact was was to be far greater more than a 1000 miles inland, where she would generate devastating floods in the days that followed.  

Of the 122 deaths associated with this storm, only 9 occurred in Florida where Agnes made landfall.  The rest - 113 deaths - were due to inland fresh water flooding, with New York and Pennsylvania suffering the highest loses.

 

All of which proves you don’t have to live anywhere near the coastline to be severely impacted by one of these storms.

 

Slow moving tropical storm Allison - in June of 2001 – proved more than deadly producing 55 fatalities and causing in excess of $9 billion in damage to Southeast Texas -  primarily due  to its torrential rains.

 

When hurricanes and tropical storms do form early in the season, they tend to form in the warmer, comparatively shallower waters of the the Gulf of Mexico and Caribbean.  And that sometimes means less warning time.

 

Further out to sea the Atlantic waters are still too cold, and and wind and Saharan dust conditions aloft too unfavorable, to promote much in the way of long-track storm development.

June Climatology

Credit NOAA

 

Which means that while it is very early in the Hurricane season, it isn’t too early to be prepared. Last week we spent a considerable amount of time looking at hurricane preparedness, which you can review by clicking this link. 

 

If you haven’t already downloaded the updated Tropical Cyclone Preparedness Guide, now would be an excellent time to do so.

 

NOAA’s NWS National Hurricane Center in Miami are the real experts in hurricane forecasting, and the only ones you should trust. They also have a Facebook page, where you can keep up with the latest tropical developments.

 

For additional official information you should bookmark your local Office of Emergency Management.  Here you’ll be able to access local warnings, flood maps and evacuation information. To find your local one, you can Google or Yahoo search with your county/parish name and the words `Emergency Management’.  

 

If you are on Twitter, you should also follow @FEMA, @CraigatFEMA, @NHC_Atlantic, @NHC_Pacific and @ReadyGov. 

 

And lastly, a shortcut to my `How To Prepare For Hurricane Season’ post for 2014: Hurricane Preparedness Week: Make A Plan

Hurricane Preparedness Week: Day 7

 

# 8689

 

 
Although I’m having some difficulties (DNS errors) connecting to the NHC or  Hurricanes.gov websites this morning, today is the final day of Hurricane preparedness week, where the topics we’ve discussed over the past 7 days are coalesced into one imperative:

 

Take Action.  Now, before a storm threatens.   And decisively, once a threat becomes apparent.

 

 

 

As Stacey Stewart, senior hurricane specialist at the NHC, states in the video above – you need to be prepared for at least a week without essential services – which means having enough water, food, and essential medications on hand, along with emergency lighting, a battery operated radio, and a good first aid kit.

 

For a more detailed overview on how to prepare for a hurricane, you may wish to revisit Hurricane Preparedness Week: Make A Plan.

 

To encourage residents prepare for hurricane season, this year Florida has instituted a tax holiday on certain certain preparedness supplies for the first week of June.

 

Hurricane Preparedness Sales Tax Holiday May 31 through June 8, 2014
During the holiday, qualifying items related to hurricane preparedness are exempt from sales tax. The holiday begins at 12:01 a.m. on Saturday, May 31, 2014, and ends at 11:59 p.m. on Sunday, June 8, 2014. For more information, see the following:

• A list of qualifying items.

 

If you haven’t already downloaded the updated Tropical Cyclone Preparedness Guide, now would be an excellent time to do so.

 

When it comes to getting the latest information on hurricanes, your first stop should always be the National Hurricane Center in Miami, Florida. These are the real pros, and the only ones you should rely on to track and forecast the storm.

• 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.

NOAA’s NWS National Hurricane Center in Miami also has a Facebook page, where you can keep up with the latest tropical developments.

 

The second official information source you should have bookmarked is your local Office of Emergency Management.  Here you’ll be able to access local warnings, flood maps and evacuation information. To find your local one, you can Google or Yahoo search with your county/parish name and the words `Emergency Management’.  

 

And lastly, if you are on Twitter, you should also follow @FEMA, @CraigatFEMA, @NHC_Atlantic, @NHC_Pacific and @ReadyGov. 

Hurricane Preparedness Week: Make A Plan

 

 

# 8686

 

Over the past few days we’ve looked at some of the hazards presented each year by hurricane season; including such killers as storm surge and high winds.  We’ve also looked at how this year’s forecasting, and NHC warning products, have changed.

Today, the focus is on actually making a plan to deal with these (and other) threats.   You need to decide, long before a hurricane (or any other disaster) strikes:

 

1. How you will communicate with family & friends during and after a disaster, and where you will meet if you are separated
2. How you will deal with those with specific needs, such as children, the elderly, or those with medical conditions
3. To stockpile ample water, food, any required Rx meds, along with a first aid kit  
4. How you will cook, or provide light, or receive emergency radio transmissions if the power is out for days or longer
5. Where you will go if you are told to evacuate – and how you will get there
6. And last, but certainly not least, how you will care for your pets during and after a disaster.

 

It’s a big topic, but luckily I’ve addressed all of these issues in the past. So I would invite you follow the links below to revisit those areas you may need to concentrate on:

 

1. NPM13: Create A Family Communications Plan

2. A Prescription For Any Disaster

3. When 72 Hours Isn’t Enough

4. Instead Of Cursing The Darkness

5. NPM13: When Evacuation Is The Better Part Of Valor

6. NPM11: Disaster Preparedness For Pets

 

For more information, Ready.gov has an extensive Hurricane preparedness website, with advice on what to do before, during, and after the storm.

 

Far too many people mistakenly believe they’ve seen the worst that a hurricane can deliver because they’ve been on the periphery of one of the large storms we’ve seen over the past 20 years.

 

The truth is, we’ve not had a Category 5 storm strike the U.S. mainland since 1992, when Andrew took out a large portion of Homestead, Florida.

Before that you have to go back to 1969, and Hurricane Camille in Mississippi. 

 

The modern benchmark for hurricane disasters is Hurricane Katrina, that devastated New Orleans in 2005.  But that storm was barely a Category 3 storm when it hit land. 

 

As horrific as it was, it could have been worse. . .

 

The lessons of Katrina, Wilma, Ike, Irene and Sandy are that it doesn’t take a category 5 storm to cause major devastation, disruptions, and deaths.  Even tropical storms – such as Allison in 2001 – can prove deadly (55 fatalities, $9 billion in damage).

 

While the storm may last 12 to 24 hours, the aftermath – where power may be out, businesses may be closed, and services may curtailed -  can drag on for weeks.

 

Being prepared to deal with these situations can make a huge difference in how you, and your family, will cope with a disaster like a hurricane, tornado, or even an earthquake.  

 

Here is FEMA Director Craig Fugate with a last word on the subject.

 

Hurricane Preparedness Week: Forecasting Then & Now

 

 

# 8679

 

For those born after 1960, it is probably hard to understand just how vulnerable we used to be to the unannounced arrival of hurricanes and tropical storms.  Before then, we had no `eyes in the skies’ –  weather satellites – to tell us if something was brewing far offshore, and tracking storms was pretty much hit and miss, based on ship’s reports.  

 

All that uncertainty began to change, when on April 1st 1960 Tiros I - the world's first weather satellite - was launched into Earth orbit from Cape Canaveral, Florida.

 

For the first time, we had a `god's eye view' of earth, and while the pictures were grainy, and the resolution laughable by today's standards, we could finally watch how and where hurricanes formed. It was a wondrous day for everyone, except possibly for members of the Flat Earth Society.

The first weather satellite photo from space.

 

It meant we were no longer solely dependent on ship's reports and Hurricane Hunter aircraft to know if disaster lay just beyond the horizon. It meant more than 12 hours warning to prepare for a storm.  And it was a major step in unraveling the mysteries of cyclone genesis.

 

It would take time of course. The first satellite only produced about 1 picture an hour, and then, only during daylight hours. Infrared capability was added in later `birds’.  For those with in interest in how `old school’ forecasting was accomplished, last year I wrote about a legend: Grady Norton: The First Hurricane Forecaster.

 

Three different views from space, taken May 26th, 2011 1345Z – NOAA

Today, our reconnaissance satellites can take 40 pictures an hour, and see right through the clouds and measure rainfall, winds and even sea water temperatures.Add in the power of supercomputers,ocean buoys, hurricane probes, and five decades of new knowledge, and the art of hurricane forecasting has improved tremendously over the past 50 years.

 

 

This year, forecasts will include even more information – particularly for coastal residents – as we discussed on Sunday. This year, the NHC will be issuing enhanced color-coded experimental Potential Storm Surge Flooding Maps showing the locations that could be affected by storm surge based on their (SLOSH) computer models.

 

Of course, all of the advances in forecasting technology are for naught if people don’t use this information to prepare for – and in some cases, get out of the way of – these storms.

 

Which is why tomorrow and Saturday Hurricane Preparedness Week will focus on what you need to do to get ready for the storm.

 

In the meantime, if you haven’t already, now would be a good time to download the updated Tropical Cyclone Preparedness Guide and to think about what hazards your home, and or business, might face if one of these storms pays a visit this summer or fall.

How Not To Be Blown Away By Hurricane Season

Credit  @NHC_Atlantic

 

# 8670

 

Today is day three of Hurricane Preparedness Week, and the emphasis today is on the impact of wind – which can often be destructive hundreds of miles away from where the center of the storm actually passes.  A reminder that the forecast cone is the area where there the center will likely pass, and tells us little about the impacts outside of the cone.

First, as short video from the National Hurricane Center, then I’ll be back with more:

 

 

Hurricanes are measured by the Saffir-Simpson Scale, which bases their strength on sustained wind speeds.   Anything CAT 3 or higher is considered a major hurricane.

 

Even a CATEGORY 1 storm can spin up tornadoes, or produce wind gusts substantially stronger than their sustained wind speeds.  Older Mobile homes, RVs, and even some conventionally built structures may not withstand a CAT 1 storm.

 

And while great strides have been made over the past few decades in forecasting the path (out to about 48-72 hrs) of hurricanes, meteorologists are far less able to predict intensity changes of these storms.

 

Just before landfall in 2004, Hurricane Charlie unexpectedly changed direction and ramped up from a moderate CAT 2 to storm to a major CAT 4 in just three hours, leaving coastal residents no time for evacuations.

 

If you live in vulnerable areas, you need to be aware of your evacuation zone, many of which have been recently revised due to a better understanding of storm surge, flooding, and wind damage risks.

 

Whether you stay, or leave, you’ll probably want to secure your home as best you can before high winds arrive. And this year emergency managers are once again reminding the public of the folly and futility of taping their windows in advance of a hurricane.

 

Up until the 1970s, it was pretty much standard advice to homeowners to tape plate glass windows to keep them from shattering, but that advice was discredited, and has not been part of hurricane prep advice for 30 years.

 

Not only does taping windows provide a false sense of security, it can bind shards of flying glass into larger, and more dangerous, projectiles.

 

Still, the myth hangs on.

 

A video that I’ve highlighted in the past, from the Pinellas County Office of Emergency Management demonstrates just how useless masking, or duct taping your your windows really is during a storm .

Hurricane Preparedness Week: Storm Surge

 

 

 

# 8666

 

This is day two of 2014’s National Hurricane Preparedness Week and the focus today is on Storm Surge, traditionally the biggest cause of death from these killer storms. Having spent a good portion of my life as a liveaboard boater on Florida’s West coast, I can assure you from personal experience that storm surge can be both dramatic, and dangerous.

 

First stop, a short video from the NHC (National Hurricane Center), and a NHC description of storm surge, after which I’ll return with a bit more:

 

Storm Surge vs. Storm Tide

Storm surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tides. Storm surge should not be confused with storm tide, which is defined as the water level rise due to the combination of storm surge and the astronomical tide. This rise in water level can cause extreme flooding in coastal areas particularly when storm surge coincides with normal high tide, resulting in storm tides reaching up to 20 feet or more in some cases.

Storm Surge vs. Storm Tide

 

Back in 2011,  in Getting SLOSHed For Hurricane Season I wrote about the Sea, Lake and Overland Surges from Hurricanes computer model that emergency planners use to plan for coastal evacuations. In order to know in advance how far inland a storm surge or tide will encroach, emergency planners run hundreds of SLOSH models for populated regions along the coast. 

 

 

They vary the size, intensity, direction, and forward speed of hurricanes in the model in order to determine the worst case impact for each category of storm. Evacuation maps and routes are then generated using this information.

This evacuation map of Pinellas County (St. Petersburg-Clearwater) Florida shows that a storm even as low as a CAT 3 could temporarily cut the southern half of the county off from the north.

 

Of course much depends upon the speed, direction, and point of landfall of the storm, and so not all CAT 3 storms impacting this area would produce this dramatic of an effect. But if you are asked to evacuate by your local authorities, don’t hesitate.  

 

Just do it.

 

Which is why, the smart money is on deciding where you will go long before hurricane season arrives.  Public shelters are likely to be uncomfortable and crowded, and should really be your option of last resort.   A better plan is to pre-arrange with family or friends for a place to stay. 

As we discussed yesterday, this year, the NHC will be issuing enhanced color-coded experimental Potential Storm Surge Flooding Maps showing the locations that could be affected by storm surge based on their (SLOSH) computer models.

 

If you haven’t already downloaded the updated Tropical Cyclone Preparedness Guide, now would be an excellent time to do so.