Tag Archive for: hurricane season

Does Wet Spring Portend Intense Hurricane Season?

Does a wetter-than-normal spring say anything about Houston’s chances for a busier-than-normal hurricane season? According to Jeff Linder, Harris County’s meteorologist, the two correlate poorly. In the process of exploring that, I discovered some surprising facts about the intensity and seasonality of rainfall in the region.

So Far, Not So Much Wetter than Normal

“Harris County is running slightly above normal for 2024,” says Lindner. “But much of this can be traced back to the rains in late January.”

“I would likely attribute the winter and early Spring rains more to the El Niño pattern in the eastern and central Pacific,” he added. “They tend to bring above-normal rainfall to the southern plains in the fall, winter, and spring months.”

“As for the upcoming hurricane season, there is little correlation between slightly above average rainfall and any sort of potential activity on the Texas coast. With that said, conditions look highly favorable for an active hurricane season in 2024 including very warm sea surface temperatures throughout the Atlantic basin, the collapse of El Nino and development of La Niña.”

Lindner concluded, “That tends to create increasingly favorable conditions for tropical development, especially in the Caribbean Sea, and a wetter than normal pattern from the coast of Africa into the Caribbean.”

The graphs below explain Lindner’s characterization of the temperature and rainfall as “slightly” above normal as we head into hurricane season.

I pulled them from the climate page for Houston on Weather.gov. The National Weather Service (NWS) shows 35 different reporting stations in the Houston region and gives you nine ways to visualize daily, monthly and yearly data.

As I browsed the site, I discovered two interesting things. When you look at monthly averages:

  • Rainfall totals differ greatly depending on your part of Houston.
  • Seasonality of rainfall also differs depending on your area.

Let’s look at the two variables using data and graphs from the climate page above.

Rainfall YTD vs. Highs, Lows, Averages

Bush Intercontinental Airport received about 21 inches of rain (YTD through May 12). In late January and February, Bush was having the rainiest year on record. But since then, despite very heavy rains to the north, we’ve only beaten the average YTD figures by a slight amount, as Lindner observed.

Meanwhile, Galveston started out with record rainfall. Only in the last two or three weeks did it fall behind the record year (1949). Galveston is still about 50% above its average total YTD.

In Conroe, rainfall totals have flirted all year with the record high year of 1935. They only dipped below average for a week or so in January.

Rainiest Months Vary with Distance from Coast

At Bush Intercontinental Airport, June (#1) and October (#2) are the rainiest months with May ranking #3.

But at Galveston’s Scholes Field, May is the ninth rainiest month and September the wettest. September is the peak of hurricane season.

In Conroe, May is the wettest month.

Spring rains play a larger role in the yearly total the farther north you go. But in Galveston, the totals jump up during hurricane season.

Not too much of a surprise there. Many fronts lose their punch before reaching the coast in the winter and spring months. Likewise, many tropical disturbances lose their punch 90 miles inland during the summer and fall – hurricane season.

What Data Illustrates

This data illustrates that it’s hard to generalize about the weather. You can’t take one storm (or even a series of storms) in one location and posit it as proof of a larger trend. Too many factors govern the weather to do that.

Moreover, my rain gage is reading 142% of the YTD figures from the nearest official gage at IAH just seven miles away.

That’s not uncommon. Sometimes a rain bomb lands on your home. Thunderstorms train over you for hours. Or a front stalls when it reaches your address. Those things can skew your perception of the weather.

That said, all the experts are still warning of a much higher-than-normal hurricane season this year. But for reasons unrelated to local flooding.

Happy Mother’s Day

Let me close this Mother’s Day with some beauty from Mother Nature. The son of a friend captured this image while flying around the storm that slammed north Houston on May 9th. He was at 30,000 feet and the clouds topped out at 70,000 feet as the sun was setting.

Photo courtesy of reader. Used with permission.

The power of the photo above should remind you. If you somehow missed it, we just finished Hurricane Preparedness Week. Have you made your preparations for hurricane season yet?

Posted by Bob Rehak on 5/12/24

2448 Days since Hurricane Harvey

Hurricane Season Above Average So Far

NOAA’s National Hurricane Center issues a monthly Atlantic Tropical Weather Summary during hurricane season. For June 2023, it shows above normal tropical cyclone activity and and above normal accumulated cyclone energy (ACE) for the North Atlantic, Caribbean and Gulf of Mexico.

#4 for Year and Counting

Three named tropical storms (Arlene, Bret, and Cindy) formed in the basin during June. The report also shows an unnamed storm in January, that in retrospect appears to have been tropical in strength.  

Bret brought tropical-storm-force winds to portions of the Lesser Antilles, while Arlene and Cindy remained over open water and did not impact land.  

So far, seasonal activity has been above average based on the 30-year climatology (1991-2020), where a named storm typically forms about once every year in June. 

peak of hurricane season
Timing of hurricanes in the last hundred years shows peak at September 10.

In terms of Accumulated Cyclone Energy (ACE), which measures the strength and duration of tropical storms and hurricanes, activity in the basin so far in 2023 has also been above average compared to the long-term (1991-2020) mean.

Reports on individual cyclones, when completed, are available at the National Hurricane Center website.

Summary Table

Name                       Dates              Max Wind (mph)

———————————————————–

Unnamed STS*                                              

TS Arlene                  1-3 Jun                 40

TS Bret                  19-24 Jun                 70

TS Cindy                22-26 Jun                 60

———————————————————–     

* An unnamed subtropical storm formed in mid January. Exact dates and maximum winds will be provided once the post-storm analysis is complete.

As of this writing on 7/5/23, NHC predicts NO tropical storm activity anywhere in the Atlantic basin for the next seven days.

Predictions Vs. Actual

In May, both NHC and Colorado State University predicted that this tropical storm season would have about normal hurricane activity. Both sources cited conflicting trends as the basis for their predictions. We currently have above-normal sea-surface temperatures throughout most of the Atlantic basin. We also are now under the influence of an El Niño, which tends, in this latitude, to produce wind shear that discourages cyclone formation.

To improve predictions, NOAA has made a number of changes in reporting at the National Hurricane Center. They include new, improved models for hurricane forecasts and storm surge, longer-range hurricane outlooks, an excessive rainfall outlook, inundation mapping down to the street level, and improved data-collection technologies.

Posted by Bob Rehak on 7/5/2023

2136 Days since Hurricane Harvey

NHC Predicts Near Normal Hurricane Season

Hurricane season starts this week. Offsetting factors, some of which would call for an above-normal hurricane season and others of which would call for a below-normal season, led forecasters at the NOAA Climate Prediction Center to split the difference in their seasonal outlook.

They are giving almost equal probabilities to average, above-average, and below-average seasons. But average gets a slight edge. See below.

NOAA predicts 12 to 17 named storms (winds of 39 mph or higher). Of those, 5 to 9 could become hurricanes (winds of 74 mph or higher), including 1 to 4 major hurricanes (category 3, 4 or 5; with winds of 111 mph or higher). NOAA has a 70% confidence in these ranges.

2023 Hurricane Season Names

Below is a list of storm names for this hurricane season.

Source: National Hurricane Center

Competing Factors Make Forecast Difficult

Competing factors both suppress and encourage storm formation.

After three hurricane seasons with La Nina present, NOAA scientists predict a high potential for El Niño to develop this summer. It can suppress Atlantic hurricane activity.

El Niño’s strong winds from the west produce sheer that can discourage tropical storms approaching from the east.

However, favorable conditions include:

  • Above-normal west African monsoon formation that produces some of the stronger and longer-lived Atlantic storms
  • Warmer-than-normal sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea which creates more energy to fuel storm development.
Updated May 29, 2023. For more information, see this page on methodology.

The last two factors have produced more active Atlantic hurricane seasons since 1995, according to NOAA.

New Policies, Models, Technologies Will Improve Future Forecasts

To improve forecasts, NOAA is adopting new policies, forecasting models and technologies this year. Improvements include:

  • In late June, the Hurricane Analysis and Forecast System (HAFS) will become operational. HAFS will become NOAA’s primary hurricane model. Compared to previous models, it improves track forecasts 10-15%.
  • A Probabilistic Storm Surge model upgrade gives forecasters the ability to run the model for two storms simultaneously.
  • The National Hurricane Center’s Tropical Weather Outlook graphics will expand the forecast range from five to seven days.
  • Over the last 10 years, flooding from tropical rainfall was the single deadliest hazard. To give communities more time to prepare, the Weather Prediction Center is also extending the Excessive Rainfall Outlook two days. It will now provide forecasts up to five days in advance. The outlook shows general areas at risk for flash flooding due to excessive rainfall.
  • The National Weather Service will unveil a new generation of forecast flood inundation mapping for portions of Texas in September 2023. These maps will show the extent of flooding at the street level.
  • New small aircraft drone systems, the deployment of additional saildronesunderwater gliders, and WindBorne global sounding balloons will fill critical data gaps and improve hurricane forecast accuracy.
  • Upgrades to the Tropical Atmosphere Ocean buoy array will provide new capabilities, updated instruments, more strategic placement of buoys, and more detailed observations.

NOAA emphasizes that its hurricane forecast is not a landfall forecast. Many storms die at sea and never reach land.

Peak of Season Still Three Months Away, But…

The Climate Prediction Center will update the 2023 Atlantic seasonal outlook in early August, just prior to the historical peak of the season.

peak of hurricane season

Historically, the peak of hurricane season hits on September 10. However, storms can develop any time of year. Interestingly, NHC determined that a subtropical storm formed in the Atlantic Basin in Mid-January 2023.

And minutes after I first posted this story, the National Hurricane Center issued this 7-day outlook. It shows a disorganized area of showers and thunderstorms over the central Gulf of Mexico trying to get organized. But the chances of tropical formation are slim: 10% in the next two days and 20% in the next seven.

So remain alert and prepared.

Posted by Bob Rehak on 5/30/2023

2100 Days since Hurricane Harvey


Hurricane Season Ends!

Hurricane season officially ended yesterday, November 30. 2022 turned out to be an average season, not the above-normal season that was predicted. No storms affected Houston. But Category 4 Ian slammed the West Coast of Florida, killing at least 144 people.

Hurricane Ian as seen from NOAA’s GOES-East satellite on Sept. 27, 2022 at 4:26 p.m. (EDT) in the Gulf of Mexico.

Four U.S. Landfalls

The 2022 season saw four hurricane landfalls in the U.S.:

  • Category 4 Ian with 150 mph maximum sustained winds, tied for the fifth-strongest hurricane ever to landfall in the U.S.
  • Ian made landfall a second time in Georgetown, SC as a Category 1.
  • Category 1 Hurricane Nicole made landfall in north Hutchinson Island, Florida. 
  • Hurricane Fiona made landfall near Punta Tocon, Puerto Rico as a Cat 1. It dumped 27 inches on the island still struggling to recover from Hurricane Maria in 2017. Fiona later intensified to a Cat 4 as it headed north.

Unusual Mid-Season Pause

According to the National Hurricane Center, this unique season was defined by a rare mid-season pause. Scientists suspect the causes were increased wind shear and suppressed atmospheric moisture high over the Atlantic Ocean.

After a quiet August, activity ramped up in September with seven named storms, including the two major hurricanes — Fiona and Ian. The season also included a rare late-season storm with Hurricane Nicole making landfall on November 10 along the east coast of Florida.

Forecasting “Firsts”

National Hurricane Center forecasts were aided by the experimental peak storm surge graphic, which allowed forecasters to more accurately communicate the severity of expected storm surge levels.

Another major first included the successful launch of the Altius 600 small uncrewed aircraft system from a Hurricane Hunter aircraft into the core of Ian hours before its landfall. It discovered 216 mph winds at an altitude of 2,150 feet. 

Why Predictable Storms Still Kill So Many People

USA Today published an exceptionally well-researched and written article by Dinah Boyles Pulver to mark the end of hurricane season. The headline: “Ian was deadliest US storm this year, with at least 144 dead. Why are predictable storms still killing so many people?”

Three major take-aways from this thought-provoking article were:

  • How older people die in disproportionate numbers from hurricanes
  • The difficulty of evacuating densely populated areas.
  • Public policy implications of the two points above.

Disproportionate Harm to Older People

Pulver’s article pointed out that, “The median age of Ian’s victims was 72 in Florida, a haven for retirees. More than 61% of the victims whose ages are known were 65 or over. Nearly half had medical conditions that contributed to their deaths.”

The USA Today analysis found that 60 people drowned and that preexisting medical conditions contributed to at least 30 deaths. At least 85 victims were 65 or older.

People Still Dying Despite Better Forecasts

Part of the problem relates to perceptions of risk. Older people are choosing to live in unsafe areas in ever increasing numbers.

The percentage of Florida’s population over 65 in coastal counties is predicted to jump from 16% to 37% by 2100. Over the past 20 years, the percentage of Florida residents aged 65 and older has increased from 17.6% to 21%. This complicates disaster planning and places extra burdens on first responders.

Pulver quotes Amber Silver, a disaster researcher at the University of Albany, as saying, “We have to look at policy failures. When you have vulnerable people living in vulnerable regions, in vulnerable infrastructure being exposed to these storms, you’re going to continue to have these shocking death counts – particularly among the most vulnerable. Until we address this challenge at a systemic, societal level, it’s not going to get better.”

Difficulty of Evacuation Points to Need for Better Floodplain and Building Regulations

Even with perfect forecasts, evacuation decisions remain difficult. Where do you go if you’re at the tip of a low-lying peninsula like Florida, hundreds of miles from higher ground.

Here in Houston, half of the 120 deaths during Rita in 2005 happened during evacuation attempts. Millions fled the Cat 5 storm bearing down on them with 180 mph winds – just weeks after Katrina destroyed New Orleans. Millions of panicked people created gridlock on the freeways.

Such examples create a powerful argument for focusing on better building and floodplain regulations. That battle is won or lost between storms.

We must focus more on creating survivable structures in survivable locations.

But people seem to like affordable homes with water views and living with the risk right up to minute they can’t.

Regardless, Pulver points out that far fewer people die today than, say in the great Galveston hurricane of 1900, which killed an estimated 8000 people. So, we are making some progress.

Posted by Bob Rehak on 12/1/2022

1920 Days since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

Hurricane Season Starts Today, Plan Now

The 2022 Hurricane Season begins today – June 1. And as if on cue, the National Hurricane Center has already highlighted two areas to monitor.

Five day outlook from National Hurricane Center as of 8am 6/1/22.

Neither storm will threaten the Houston area. But this should serve as a wake up call. If you haven’t already done so, now is the time to prepare your family and home for hurricanes and their impacts. 

Above Average Hurricane Season Predicted

If you’ve lived in the Houston area for a while, you know how devastating the effects of just one hurricane can be. And NOAA predicts this will be an above average season.

It’s not just the rain that threatens us as it did in Harvey. Wind can knock down trees on houses and power lines. Power outages can last weeks, as they did during Hurricane Ike in 2008.

The eye of Ike passed right over the Lake Houston Area and knocked down so many trees that my business lost power for 19 days. At the start of that hurricane season, Butch Standerfer, a State Farm insurance agent in Kingwood, had alerted me to something called “Business Interruption Insurance.” We purchased it and thank God we did. Had it not been for that, the loss of income would have forced my company out of business.

Ike taught me many valuable lessons about planning before the storm, maintaining situational awareness during the storm, and recovery after the storm. Please share this post with your people and those new to the area.

Preparedness Is Key

“Hurricanes are one of nature’s most powerful and destructive natural disasters that we face. It only takes one to change your life,” said Tina Petersen, Harris County Flood Control District Executive Director. 

Preparedness can help minimize damages if a hurricane threatens the area. Here are some tips I’ve gathered from interviewing hundreds of storm victims.

Purchase Flood Insurance:

Harris County Flood Control District recommends that all Harris County residents become informed about their flood risk and have flood insurance no matter where they reside in the county.  Flood insurance accelerates the rebuilding and replacement of personal property and fosters community resiliency as a whole. 

For information on flood insurance, call your agent, visit the National Flood Insurance Program website, or call 1-888-379-9531.   

If you need help finding an insurance provider go to FloodSmart.gov/flood-insurance-provider or call the NFIP at 877-336-2627.

If you’re counting on FEMA or HUD disaster relief aid after a storm to repair your home, don’t.

Insurance is the only thing you can count on. I know people who lived or worked so far from flood threats that they didn’t think they needed insurance. Almost five years after Harvey, they bitterly regret that decision.

Sign Up for Flood Warning System Alerts:

The Harris County Flood Warning System offers an alert feature that lets you subscribe to email and/or text alerts that report near real-time rainfall and water levels. Customize alerts and notifications for bayous and tributaries in your area. The Alert Notification System will tell you how much water is headed your way and when/if flooding is likely.

Know Your Flood Risk:

View Flood Insurance Rate Maps and floodplain maps at FEMA’s National Flood Hazard Layer Viewer.  

You can also learn more about different types of flooding (street, coastal, riverine, flash, etc.) with Harris County Flood Control’s Flood Education Mapping Tool. This site has interactive features that let you view different types of flood threats in your neighborhood. For instance, clicking on the “ponding” button shows you where streets are likely to flood. It’s useful for planning evacuation routes and also when buying homes.

Locations susceptible to ponding near the center of Kingwood from Harris County’s Flood Education Mapping Tool. See reddish brown areas.
Study the Advice of Experts

Visit the Harris County Flood Control District Storm Center webpage or Resource Page to view the District Hurricane Guide, information on Flood Insurance and more.  

Bookmark Trusted Weather Pages:

Bookmark trusted sources of weather information. In addition to the sources above, bookmark the National Hurricane Center and National Weather Service. Traffic to these sites is likely to be so heavy during a hurricane that they will bog down. So know the exact pages you want.

Make Your Plan:

USAA maintains a Natural Disaster Preparation Site for hurricane preparedness checklists. They advise:

  • Have an evacuation plan.
  • Create an emergency kit.
  • Keep your documents safe.
  • Review your health plan.
  • Inventory your belongings.

ReduceFlooding.com has dozens of links that can help you prepare for hurricanes, including special checklists for senior citizens and pets.

Count on Life Without Electricity for Awhile

Even if you don’t flood, the likely loss of electricity for an extended period will create hardships. Imagine not being able to store food, cook, watch TV, recharge your cell phone, access your Internet service, fill your vehicle with gasoline, use air conditioning, take a hot shower, turn on the lights, or use power tools to make repairs.

Plan for all those contingencies now and you should survive.

Posted by Bob Rehak on June 1, 2022

1737 Days after Hurricane Harvey

Preparation Checklists for Hurricane Season

It’s that time of year again. Hurricane season officially starts Tuesday and runs through November 30. Here are checklists that can help you prepare for and recover from hurricanes.

Hurricanes can strike anywhere, anytime. The time to prepare is not when one is bearing down on you. It’s now. When you have time. Supplies are plentiful. Internet access is available. You’re calm. And can think things through.

Any number of agencies offer preparedness guides from Harris County Flood Control to the National Weather Service and your insurance company. I also discovered a site that specializes in preparedness and recovery checklists for hurricanes. It’s PreparednessGuide.org. And it has both general lists and lists tailored to the needs of special groups, such as children, senior citizens, and families with pets.

Rosie the Dog on the Harvey Cruise Line. Photo Courtesy of Denise Faulkner.

They also sent me links to several other special-purpose sites. For instance:

For future reference, you can find these checklists on my Links Page under the Preparedness subhead.

Start reviewing these now. It’s never too early to plan!

Posted by Bob Rehak on 5/30/2021

1370 Days since Hurricane Harvey


Could This Be the Start of Hurricane Season?

After four days of heavy rains, today looked like a respite. This morning’s predictions mentioned another inch or two on Friday and Saturday. But then this the National Hurricane Center posted this within the last few minutes: a warning about what could turn into the season’s first tropical depression. And hurricane season doesn’t officially start for another ten days.

20% chance of formation for yellow area in next two to five days

20% Chance Before Official Start of Season

According to Jeff Lindner, Harris County Meteorologist, “The old complex of thunderstorms that moved off the Texas coast yesterday has festered over the west-central Gulf of Mexico today. While the satellite images look impressive, there appears to be no closed low pressure system at the surface and instead a surface trough extending across the region. Thunderstorms have been weakening this afternoon and there is no new development.”

Radar this morning showed storm festering in Gulf with a stationary trough drawing moisture up through Texas and Lousiana.

“So far this evening,” continued Lindner, “there is a large area of dry air to the west of the feature in the Gulf. The dry air will likely become entrained over time. However, some models show additional development for this feature as it moves generally toward the NW or NNW in the general direction of the Texas and Louisiana coastlines.” 

NHC suggests the yellow feature has a 20% chance of developing into a tropical cyclone over the next 2 days.

National Hurricane Center

This feature could help to enhance rainfall amounts over SE Texas this weekend, but any additional impacts beyond that at this time appear to be minimal, according to Lindner.

Preparedness

This should serve to all that hurricane season begins in ten days. Don’t be caught unprepared. My Links page has many sites with helpful tips. You may also want to take this opportunity to bookmark the National Weather Service, National Hurricane Center, and Harris County Flood Warning System. They offer round the clock updates.

Take some time getting to know them know. During an actual storm, power outages and crowded bandwidth may make leisurely learning difficult.

Two other important sites for this area are the San Jacinto River Authority for Lake Conroe releases/levels and the Coastal Water Authority for Lake Houston levels. At this hour, the Lake Conroe is holding steady while releasing 2665 cubic feet per second. Lake Houston is still rising slightly with the flood gates wide open.

Lake Conroe Dashboard as of 7:30 PM on 5/20/21
Lake Houston as of 7:30PM , 5/20/21.

Posted By Bob Rehak on 5/20/21 Based on Information by NWS, NHC, HCFCD, SJRA, and Coast Water Authority

1360 Days since Hurricane Harvey

Another Above-Average Hurricane Season Predicted

This is the time of year when meteorologists start predicting how many hurricanes we will experience in the Atlantic Basin. Frank Billingsley at Click2Houston.com issued his prediction for an above-average hurricane season Friday. He also predicts that other meteorologists will predict the same. Here’s why.

Official Averages Out of Date

The official window used to calculate the average number of storms has been 1981 to 2010. But when Brian McNoldy of the University of Miami looked at the more recent 30 years from 1991 to 2020, he found an increase in the number of storms. Also, AccuWeather has already come out with its prediction, showing a substantial increase.

Year(s)StormsHurricanesMajor Hurricanes
1981-2010 (Old Average)1263
1991-2020 (New Average)1473
2020 Actual30136
2021 Predicted by AccuWeather16 to 207 to 103 to 5
Sources: Brian McNoldy, AccuWeather, NHC

Other Contributing Factors

Sea-Surface Temperatures

Sea-surface temperatures are slightly above normal for this time of year. Despite the polar outbreak in February which cooled the Gulf somewhat, the Caribbean and Atlantic remain higher than average. See anomaly map below from NOAA’s Climate Prediction Center.

Seven day average as of 4/3/2021
La Niña

Billingsley’s prediction also takes into account La Niña, which is part of ENSO (El Niño Southern Oscillation).

NOAA describes El Niño and La Niña as the warm and cool phases of a recurring climate pattern across the tropical Pacific. The pattern can shift back and forth irregularly every two to seven years, and each phase triggers predictable disruptions of temperature, precipitation and winds.

The El Niño phase usually means fewer hurricanes in the Atlantic.

Typical influence of El Niño on Pacific and Atlantic seasonal hurricane activity. Map by NOAA Climate.gov, based on originals by Gerry Bell.

The La Niña phase usually means more hurricanes in The Atlantic.

Typical influence of La Niña on Pacific and Atlantic seasonal hurricane activity. Map by NOAA Climate.gov, based on originals by Gerry Bell.

Why? In short, the warm, wet air of El Niño in the tropical Pacific produces stronger vertical wind sheer which discourages hurricane formation in the Atlantic. The cool, dry air of La Niña produces less wind sheer which lets hurricanes form more easily.

National Hurricane Center

The real question is: How long will La Niña last? La Niña was strong last year. That meant one of the busiest hurricane seasons ever. (See table above.) But will it fade by the start of this hurricane season or the end? The Texas Water Development Board predicted it would begin to fade after this month. But some models show it lasting through the end of the year.

Bermuda High

AccuWeather predicts three to five hurricanes will make a direct hit on the United States this year. That’s partially due to another factor – the position of the Bermuda High. A weak Bermuda High means storms forming in the Atlantic would most likely aim at the Eastern Seaboard as opposed to coming into the Gulf.

Bottom line, “Be prepared. Anyone who has been through a hurricane can tell you it only takes one.”

Frank Billingsley, Click2Houston.com

Valuable Resources During Hurricane Season

For the full AccuWeather forecast, click here.

Colorado State University’s hurricane forecast comes out next week. It’s one of the most respected in the world.

During the season, the National Hurricane Center provides the most frequent updates of storm activities. They will start issuing tropical updates on May 15. And their reports will have more features than ever this year. See the list of new features including storm surge inundation values, weather forecasts for “blue-water” mariners, wave heights, cumulative maximum winds over 5-days, and more.

Posted by Bob Rehak on 4/3/2021 based on information from Click2Houston, AccuWeather, and NOAA

1313 days since Hurricane Harvey

Today is Statistical Peak of Hurricane Season

According to the National Hurricane Center (NHC), today is the statistical peak of hurricane season in the Atlantic Basin.

Little Known Facts About Hurricanes: Peak of Season

The NHC has a fascinating page on hurricanes and climatology. Here are some interesting facts I gleaned from it.

Source: NHC. Peak of season occurs on September 10.

“The official hurricane season for the Atlantic Basin (the Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico) is from 1 June to 30 November. As seen in the graph above, the peak of the season is from mid-August to late October. However, deadly hurricanes can occur anytime in the hurricane season,” warns the NHC.

Average Number of Storms

Source; NHC

In an average season, we get 11 or 12 named storms, six of which become hurricanes and two or three of which become major hurricanes (category 3 or greater).

Twelve storms would get you to the letter L. But so far this year, we’re already on the R storm. And we have three more months to go in the season.

Points of Origin Tend to Shift by Month

The NHC shows where hurricanes tend to form each month of the season. In the first ten days of September, more hurricanes form in the Gulf than at any other time. The NHC shows a whole series of charts like the one below. It’s interesting to see how they change from period to period.

Source: NHC. Sept. 1-10 and Sept. 11-20 show the greatest number of hurricanes forming in the Gulf.

Note how few storms formed in the Caribbean compared to the period from October 11 to 20.

Compared to September 1-10, note how many more storms formed in the Caribbean during October 11-20.

Track Probabilities Also Shift by Month

The NHC also shows an interesting series of charts that show track probabilities by month. September is the most likely month for storms to track through the Caribbean, into the Gulf and onward to the Texas coast.

Source: NHC
Source: NHC

In stark contrast, during October, storms are most likely to veer east toward Florida and the East Coast.

Strike Density on Western Gulf Coast

Source: NHC

On the Texas Gulf Coast, Galveston has been hit more times than any other county. Harris, Brazoria and Chambers Counties follow closely.

Today’s Five Day Tropical Outlook

As if on cue, the NHC is now tracking seven tropical disturbances (as of 800 AM EDT Thu Sep 10 2020).

The two closest to Texas are highlighted in yellow above. That means they currently have less than a 40% chance of formation.

A large area of disorganized showers and thunderstorms near the Bahamas is forecast to move westward, crossing Florida on Friday and moving into the eastern Gulf of Mexico over the weekend. Upper-level winds are expected to become conducive for some development of this system while it moves slowly west-northwestward over the eastern Gulf of Mexico early next week. Formation chance through 5 days is 30 percent.

Another trough of low pressure has developed over the northeastern Gulf of Mexico and is producing a few disorganized showers and thunderstorms. Some slow development of this system is possible while this system moves westward and then southwestward over the northern and western Gulf of Mexico through early next week. Formation chance through through 5 days is even lower, at 20 percent.

Posted by Bob Rehak on 9/10/2020

1108 Days since Hurricane Harvey

“Above-Average” Hurricane Season Predicted This Year

USA Today has reported that hurricane experts from Colorado State University (CSU) have predicted an above-average hurricane season this year. How much above average? About 140%, they say. In addition, CSU predicts a 69% chance for a MAJOR hurricane (Cat 3, 4 or 5) to strike the mainland U.S.

Warm Atlantic and El Niño Seen as Main Factors

Reasons: unusually warm seawater in the Atlantic and the likely LACK of an El Niño in the Pacific. El Niño in the Pacific usually sets up wind shear that tears apart storms in the Atlantic. Said another way, they help keep tropical storms from developing into full-force hurricanes. But without El Niño, the lack of shear allows more storms to develop and creates active hurricane seasons.

Source: NOAA, From April 2, 2020. Shows most of Atlantic has above-normal sea-surface temps, and that temps immediately offshore the upper Texas and Louisiana Coasts are now 4-5 degrees above normal.

CSU predicts 18 named storms will develop.

AccuWeather released its hurricane season predictions a week earlier. They predict 14-18 names storms. Of those, seven to nine will likely become hurricanes, and two to four are likely to hit the U.S. mainland.

NOAA should issue its forecast in late May.

Hurricane season extends from June 1 to November 30.

March Warmth Unrelated to Hurricane Season

Jeff Lindner, Harris County Flood Control’s meteorologist, says that the unusually warm March that south Texas just experienced (about 8 degrees above normal) will have little effect on tropical storm formation. “There is some correlation with a warm Gulf of Mexico and severe weather and flooding along the Gulf Coast during the spring months. But there is little to no correlation to tropical activity in the Gulf during summer months.”

3-4 Inches of Rain Possible in Next 5 Days

Speaking of Spring rains, Lindner also predicts a stormy weather pattern will set up over our area for the next 5-7 days. He says “some severe weather and heavy rainfall will be possible.”

“Widespread rainfall amounts of 1-2 inches with isolated totals of 3-4 inches will be possible between this afternoon and Saturday,” says Lindner. He predicts the heaviest rainfall across area north of I-10. Storms could train, producing the higher rainfall amounts. But Lindner also adds, “It has been dry of late and the soil can take several inches of rainfall as long as it is not all at once.” So no one is talking about flooding at this point.

NOAA predicts a slight chance of severe storms Friday evening, mostly west of Houston.

Here’s where NOAA predicts the heaviest rains to fall during the next 5 days and what the total accumulations should be.

Posted by Bob Rehak on 4/2/2020

947 Days since Hurricane Harvey