11/30/2025 – Today marks the end of the 2025 hurricane season. It was average in terms of the number of storms, but unusual in terms of where they tracked. These three screen captures from the National Hurricane Center tell the story.
2025 Named-Storm Tracks. Only one named storm hit the mainland U.S. – Chantal in early July.And none hit the US Gulf Coast.
This table shows the strength and timing of each.
And this table compares the 2025 season to a 30-year average (1991-2020).
So, the Atlantic basin had one less named storm, two fewer hurricanes, and one more major hurricane than in an average year. But for the most part, they stayed away from the U.S.
Actual Vs. Predicted
For those keeping track, in April, Colorado State University researchers predicted an above-average season with
CSU also predicted the probability of where storms would make landfall. Texas residents, they said, had a 19% chance of being within 50 miles of a major hurricane landfall this season. Those chances increased to 44% for a hurricane and 70% for a named storm. Oops.
All in, I’d say NOAA’s National Hurricane Center predictions came closer to the actual numbers, though neither was very far off.
Actual Vs. Averages
But how did the 2025 season compare to the long-term averages?
Over a 50-year period (1949–2008), the Gulf of Mexico averaged about 3.2 tropical storms per season, 1.6 hurricanes, and ~0.4 major hurricanes.
On a basin-wide (Atlantic + Caribbean + Gulf) basis, typical recent-era (1991–2020) seasons averaged 14 named storms, ~7 hurricanes, and ~3 major hurricanes.
So, the Gulf had far less activity than in an average year. However, basin wide, we came close to the average.
How Unusual Was Gulf This Year?
How unusual is it for the Gulf to have no hurricanes? Over the long term, the probability is about 20%. So it’s unusual, but far from unprecedented. There are multiple historical examples of No-Gulf-Hurricane seasons.
The longest recorded “Gulf hurricane drought” on record lasted 1,080 days (≈ 3 years), from September 2013 until September 2016 — during that period, no hurricanes entered or developed in the Gulf, according to The Weather Channel.
Why does that happen occasionally? It usually reflects unfavorable conditions for storm formation or strengthening in our sub-basin (e.g., upper-level wind shear, atmospheric stability, unfavorable steering currents). But as the map above shows, that does not mean the overall Atlantic or Caribbean is quiet. Storms may still form and even become major hurricanes, but track elsewhere, as Melissa did.
Plan for Worst, Hope for Best
The variability — including periods of many storms — argues for resilience and planning, even if some seasons are quiet. The recent cyclones that struck Sri Lanka and Indonesia make good cases in point.
Deadly floods and landslides in Sri Lanka left at least 153 people dead with hundreds more still missing at this point. According to Reuters, more than 78,000 people have been displaced.
Another cyclone struck Indonesia and killed 435 people. It destroyed tens of thousands of homes and displaced more than 200,000 people. And the cascading effects are just starting. Flooding and landslides disrupt not only homes, but agriculture, transport, and supply chains — with ripple effects on food security, local economies, and displacement.
Posted by Bob Rehak on 11/30/25
3015 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/11/20251130-2025-Hurricane-Tracks.jpg?fit=1100%2C876&ssl=18761100adminadmin2025-11-30 12:31:462025-12-01 09:18:05Average But Unusual 2025 Hurricane Season Ends Today
5/31/25 – The 2025 Hurricane Season starts tomorrow, 6/1/25. But ironically, despite predictions of an above-average season, the federal agencies that help forecast hurricanes, issue warnings, and provide disaster relief are struggling with significant funding, staff and program cuts.
Poignant Letter in New York Times
Michael Lowry, who served as a senior scientist at the National Hurricane Center (NHC), a planning chief at FEMA, and a hurricane expert at the Weather Channel, wrote a poignant letter published in the New York Times today under the headline “A Hurricane Season Like No Other.”
The letter began with an anecdote about data collection from inside Hurricane Milton last year by a Hurricane Hunter crew. The data they collected about “vortex alignment” heralded rapid intensification of the storm. Within 24 hours, it had become the strongest hurricane in 20 years with 180 MPH winds.
Milton as it began intensifying and heading toward the Florida Coast
But there was no surprise on the Florida coast. The forecasts gave “enough time for people in the highest-risk areas to safely evacuate and businesses to prepare for the worst.”
Lowry then segues to budget, staff and program cuts at FEMA, NOAA, NHC, the National Weather Service (NWS), Hurricane Hunters, and more. Some examples:
NWS offices that have lost 60 percent of their staff members, including entire management teams.
Nearly half of NWS local forecast offices are understaffed, with vacancy rates of 20 percent or higher.
Weather balloon launches are down 15 to 20 percent nationwide. The balloons increase forecast confidence and let evacuation orders be made sooner.
New budget documents released Friday propose eliminating NOAA’s research wing, the Office of Oceanic and Atmospheric Research, which lends mission-critical support to the hurricane hunters.
Along the way, Lowry points out that “The National Weather Service costs the average American $4 per year in today’s inflated dollars — about the same as a gallon of milk — and offers an 8,000 percent annual return on investment, according to 2024 estimates.”
“Without the arsenal of tools from NOAA and its 6.3 billion observations sourced each day, the routinely detected hurricanes of today could become the deadly surprise hurricanes of tomorrow,” he says.
Bottom line: Lowry says we’re jeopardizing decades of progress that have increased forecast accuracy and warning times. And that will put more people at risk.
Dizzying Days for FEMA: Cuts and More Cuts
Andrew Rumbach, a Senior Fellow with the Urban Land Institute writes about policies for disaster risk reduction. He wrote a Substack post in early May called “100 Dizzying Days for FEMA.” It details the dismantling of disaster-relief and flood-mitigation capabilities including:
Disbanding key advisory councils that guide FEMA’s work, despite them being established in law. They include the National Advisory Council, the Technical Mapping Advisory Council, and the National Dam Safety Review Board.
A Notice of Funding Opportunity for the Flood Mitigation Assistance (FMA) program for 2025-2026, another major source of funding, was removed.
The administration quietly stopped approving new allocations of funding from the Hazard Mitigation Grant Program (HMGP).
FEMA has withdrawn its participation in the International Code Council (ICC) update process. It provided resources and expertise to help develop building codes that would better protect against floods.
An executive order titled “Achieving Efficiency Through State and Local Preparedness” describes a policy that “State and local governments and individuals play a more active and significant role in national resilience and preparedness.”
Could States Do What FEMA Does?
An article in the June 9 issue of Time Magazine addresses whether states could do what FEMA does. The consensus: it makes more sense to manage disaster response at the federal level. Why? It’s more efficient. If you spread disaster responsibilities among 50 states, you will have a lot of people sitting around a long time between disasters. FEMA can shift people from state to state, disaster to disaster, and keep them busier.
Experts cite the need for reform. But getting rid of the system without a meaningful replacement is likely to cause harm.
My takeaway from the article: Surgeons experience better outcomes with scalpels than cannons.
Erosion of Safety Margins
We live in a time of uncertainty. I’m not sure which is scarier: major hurricanes, a reduction in forecasting capabilities, or the loss of disaster-relief and flood-mitigation assistance.
These cuts will erode safety margins. Sixty million Americans reportedly live in areas regularly impacted by hurricanes.
If you haven’t already completed preparations for hurricane season, check out this NWS page on Hurricane Safety Tips and Preparations. Before someone takes it down to save a buck.
Posted by Bob Rehak on 5/31/25
2832 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/10/Milton.jpg?fit=1000%2C740&ssl=17401000adminadmin2025-05-31 23:17:492025-06-01 10:17:28On Eve of Hurricane Season, NOAA, NWS, NHC, FEMA Struggle with Cuts
1/17/25 – According to the National Oceanic and Atmospheric Administration (NOAA), 2024 was a year for climate records and near records. 2024 was the:
Warmest year in the contiguous United States in 130 years
Third wettest year of the climate record in the contiguous United States
Second worst year for tornadoes (with 1,735 confirmed to date)
Second highest year for billion-dollar weather disasters in 45 years. Twenty-seven cost a total of $182.7 billion (which was the fourth highest price tag on record).
Fourth highest year for hurricanes making landfall in the U.S.
Graphic Recap of 2024’s Most Significant Climate and Weather Events
The maps below come from the NOAA’s National Centers for Environmental Information (NCEI). The first shows significant climate events during 2024.
Billion-Dollar Weather and Climate Disasters
The second map shows the location and dates of the 27 billion-dollar disasters.
NOAA says 2024 ranks second highest for number of billion-dollar disasters in a calendar year, one event behind 2023’s record 28 events. The total annual cost in 2024 – $182.7 billion – may rise by several billion as additional costs from identified events are reported.
Since records began in 1980, the U.S. has sustained 403 separate weather and climate disasters where overall damages/costs reached or exceeded $1 billion. All costs are adjusted to 2024 dollars based on the Consumer Price Index (CPI). The total cost of these 403 events exceeds $2.915 trillion.
Since 1980, the U.S. has experienced an average of nine billion-dollar disasters per year. So 2024 tripled the average.
Seventeen states (Texas, Oklahoma, Minnesota, Wisconsin, Michigan, Indiana, Ohio, Kentucky, Tennessee, West Virginia, Virginia, Pennsylvania, Maryland, New York, Vermont, New Hampshire and Maine) ranked warmest on record while all but two remaining states across the Lower 48 ranked as one of the warmest five years on record.
Annual precipitation for the contiguous U.S. was 31.58 inches, 1.66 inches above average, ranking in the wettest third of the historical record (1895–2024).
The Atlantic basin saw 18 named tropical cyclones and five landfalling hurricanes during 2024—an above-average season. Hurricane Helene was the seventh-most-costly Atlantic hurricane on record.
The tornado count for 2024 was second highest on record behind 2004 (1,817 tornadoes) with at least 1,735 confirmed tornadoes. When looking at EF-2+ tornadoes, 2024 was the most active year since the historic 2011 season.
Be cautious about generalizing about trends from these numbers. Almost every one of the stats references other record years from decades or even a century ago.
Posted by Bob Rehak on 1/17/2025 based on information from NOAA and NCEI
2698 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/01/Disasters-in-2024.png?fit=1637%2C889&ssl=18891637adminadmin2025-01-17 16:36:282025-01-17 16:36:312024 Climate Records, Near Records
Atypical Season Took Dip Where Peak Should Have Been
But 2024 was an atypical season. It started with a bang, fell into a lull, and then ended with a record.
Hurricane Beryl was the earliest Atlantic basin Category-5 hurricane on record. It caused significant storm surge flooding across parts of Texas and Louisiana after making landfall near Matagorda, Texas, as a Category-1 storm. People on my street are still cleaning up from Beryl!
However, later in the year, Mother Nature hit the pause button on tropical formation. Matthew Rosencrans, lead hurricane forecaster at NOAA’s Climate Prediction Center, a division of NOAA’s National Weather Service said, “Several possible factors contributed to the peak season lull in the Atlantic region. The particularly intense winds and rains over Western Africa created an environment that was less hospitable for storm development.”
But, strangely, at the time tropical activity should have been tapering off, we saw record-setting activity.
“Twelve named storms formed after the climatological peak of the season in early September. Seven hurricanes formed in the Atlantic since September 25 — the most on record for this period,” said the NHC.
Record Setters
Hurricane Beryl was the earliest Cat 5 storm on record for the Atlantic Basin.
Cat 4 Helene became the deadliest since Katrina in 2005. It caused more than 150 direct fatalities, mostly in North and South Carolina. Helene was also the strongest hurricane ever to make landfall in Florida’s Big Bend region.
In late September, Hurricane Helene also marked the first time ever that NOAA’s National Hurricane Center (NHC) forecasted a system to become a major hurricane before it became a tropical depression or tropical storm.
Hurricane Milton’s rate of rapid intensification was among the highest ever observed, with a 90-mile-per-hour increase in wind speed during the 24-hour period from early October 6 to early October 7.
Milton’s central pressure dropped to 897 millibars – the lowest pressure for an Atlantic Hurricane since Wilma in 2005.
Storm-By-Storm Summary
The table below shows the dates and maximum winds of each named storm in the Atlantic basin during 2024.
Name
Dates
Max Wind (mph)
TS Alberto
19-20 June
50
MH Beryl
28 June – 9 July
165
TS Chris
30 June – 1 July
45
H Debbie
3-9 August
80
H Ernesto
12-20 August
100
H Francine
9-12 September
100
TS Gordon
11-17 September
45
MH Helene
24-27 September
140
H Isaac
26-30 September
105
TS Joyce
27 September – 1 October
50
MH Kirk
29 September – 7 October
145
H Leslie
2-12 October
105
MH Milton
5-10 October
180
TS Nadine
19-20 October
60
H Oscar
19-22 October
85
TS Patty
2-4 November
65
MH Rafael
4-10 November
120
TS Sara
14-18 November
50
Source: NOAA. TS = Tropical Storm, H = Hurricane, MH = major hurricane.
While the Atlantic hurricane season officially ended on November 30, NOAA satellites continue to keep watch for any developing storms.
NHC reminds us that hurricanes can and do form during any month of the year.
Posted by Bob Rehak on 12/1/2024
2651 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/12/Hurricane-Outlook-List-End-English-Nov-2024-PLACEHOLDER-scaled.jpg?fit=2560%2C1592&ssl=115922560adminadmin2024-12-01 11:14:492024-12-01 11:14:50Looking Back at the 2024 Hurricane Season
8/12/24 – An August 8 update to NOAA’s 2024 Atlantic Hurricane Season Outlook still calls for an extremely active hurricane season with 17-24 named storms, including four so far with a fifth brewing in the Atlantic. The main difference between this and NOAA’s May predictions? A higher confidence level.
As of 2PM EDT, NHC indicated that sustained winds from Potential Tropical Cyclone (PTC) 5 averaged 35 MPH. That puts it just 4 MPH from becoming the fifth named storm of the year, Ernesto. Here’s what it looks like this afternoon.
PTC 5 as of 8/12/24 Noon CDT.
NHC gives PTC 5 a 100% chance of formation. It should intensify into a tropical storm later today and a hurricane by Thursday. However, it will curve northward into the open Atlantic and does not pose a threat to the Gulf Coast.
We normally don’t get a fifth named storm in the Atlantic until August 22. After that, we normally get a named storm every 7-10 days through October 11. This year, they will likely be more frequent.
Teach Your Family about Hurricanes
The National Hurricane Center website provides an almost bottomless well of free, educational resources. Today, I clicked on Outreach Resources and found presentations and publications geared to all age and professional levels.
Learning Opportunities for K-12 Students (Resources for Teachers) includes:
Again, #5 contains additional explanation when slide graphics in presentations 1-4 may not be totally intuitive.
Information that Saves Lives
FEMA geared the presentations in the second two groups to adults, both in an out of government. The coastal presentations contain more emphasis on storm surge. The inland presentations emphasize riverine flooding from the heavy rains that often accompany hurricanes.
The information in both groups can benefit teachers, parents, first responders, emergency managers, and government leaders.
They explain various tools, terms and graphics used by NOAA, NHC, NWS, and NHP to help everyone make informed decisions when planning for and responding to hurricane threats.
For instance, I found the discussion on inundation mapping that involved forecasts and “nowcasts” very illuminating. Ditto for the discussion about how NHC determines the timing and probabilities in its graphics. How much water it takes to make cars float and lose traction. How emergency planners work together. And more. Much more.
Posted by Bob Rehak on 8/12/24
2540 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/08/IMAGE-Update-Hurricane-Outlook-August-2024-ENGLISH-Pie-080824-NOAA.png?fit=3840%2C2373&ssl=123733840adminadmin2024-08-12 13:33:302024-08-12 13:34:192024 Hurricane Season Update, PTC 5 Status and Learning Resources
May 23, 2024 – This morning, NOAA issued its highest hurricane season forecast ever. The extreme predictions are consistent with earlier forecasts by other organizations. They also exceed NOAA’s own forecasts from 2005 and 2010, two previous record-setting years.
NOAA’s forecast underscores the importance of starting your preparations early. Hurricane season begins next week.
Reasons Behind Predictions
In issuing the forecast, NOAA pointed to a combination of several factors: extremely high sea surface temperatures, the onset of La Niña, an above-normal West African monsoon and extremely high levels of Accumulated Cyclone Energy (ACE).
To sum up, more storms will come off the African coast. High sea surface temperatures will intensify them. And a reduction in shear normally associated with La Niña will let them blossom into tropical events. The high ACE levels confirm that the elements above are likely to combine in dangerous ways.
NOAA says it is currently seeing sea surface temperatures in May normally associated with August.
2024 By the Numbers
The chart below shows the number of named storms, hurricanes and major hurricanes (Cat 3, 4 or 5) that NOAA predicts.
NOAA Predictions one week before start of 2024 hurricane season.
NOAA forecasts 17 to 25 total named storms (winds of 39 mph or higher). Of those, they predict 8 to 13 will become hurricanes (winds of 74 mph or higher). And of those, they predict 4 to 7 will become major hurricanes (category 3, 4 or 5; with winds of 111 mph or higher).
The chart also shows the degree of confidence in the “above normal” prediction: 85%. The probability of an average or below normal season totals only 15%.
ACE Explained
At the press conference, a NOAA scientist explained how accumulated cyclone energy is measured. Forecasters add up the wind velocity measured at reporting stations every six hours, square the result, and divide by 10,000 to make the result more manageable.
The accumulated cyclone energy measured this year is the second highest ever.
NOAA Press Conference
New Cone Graphic Will Include Watches and Warnings
To protect lives, NOAA is enhancing communication, providing new tools for hurricane forecasting, and upgrading its systems.
For instance, the familiar “cone forecast” graphics will take on a new look this year. The maps will include watches and warnings associated with a storm. These can extend outside the cone of uncertainty
The old cones indicated only the probable centerlines of storm paths. But the width of a storm can create impacts far outside the cone. See below.
New NOAA Cone Graphic this year will feature watches and warnings
NOAA also warned this morning that threats can linger even after a storm has passed. For instance, rising water from heavy rains can create inland flooding that traps people in vehicles. It’s not only about storm surge. Remember: Turn around, don’t drown.
Ninety percent of storm-related fatalities occur from water.
NOAA
Many people are also killed during cleanup when they leave their homes too soon. Listen to local authorities.
They also reminded people to make sure they operate generators outdoors. Many die from carbon monoxide poisoning when operating generators indoors or in garages.
Seasonal Forecast Not a Landfall Prediction
NOAA’s outlook is for overall seasonal activity and is not a landfall forecast. However, other forecasters have predicted that less wind sheer associated with La Niña will let more storms enter the Gulf or form in the Gulf.
This new updated hurricane strike chart shows landfalls since 1950. Hurricanes can and have struck almost every point on the U.S. Gulf and East coasts. It only takes one storm to alter your life forever. So…
The Message: Start Preparing Now
The time to prepare for hurricane season is NOW. NOAA noted during the press conference that every Category 5 storm they have monitored was a tropical storm or less just three days earlier. That means you have only about 60 hours to prepare for and/or evacuate from the deadliest storms.
People with health or mobility issues need to take special precautions. NOAA offers extensive advice for hurricane preparation which you can find on this page in English and Spanish.
I’ve also provided a large number of links to specialized websites that focus on different aspects of preparedness. They include such things as checklists for generators, vehicles, kids, valuables, pets, etc. Look under the Preparedness heading on this Links Page.
In addition to the Atlantic seasonal outlook, NOAA also issues seasonal hurricane outlooks for the eastern Pacific, central Pacific and western north Pacific hurricane basins.
NOAA’s Climate Prediction Center will update the 2024 Atlantic seasonal outlook in early August, prior to the historical peak of the season.
Posted by Bob Rehak on 5/23/24
2459 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/05/IMAGE-Hurricane-Outlook-May-2024-ENGLISH-Pie-052324-NOAA.png?fit=3840%2C2373&ssl=123733840adminadmin2024-05-23 12:34:332024-05-23 12:46:02NOAA Issues Highest Hurricane Season Forecast Ever
For demonstration purposes, let’s focus on the Harris County Flood Warning System.
By default, the home page shows a map with the locations of gages with rainfall in the last 24 hours. But you can also select other time periods in the sidebar. The storm dropped water during most of the week. So I selected “7 Days.” I also selected “All Gages” to see the varying amounts of rainfall across the region.
Then I clicked “Watersheds,” and “Channels.” Automagically, 7-day rainfall totals appear over a map that lets you see which watersheds the rain fell in. That determines how it will work its way downstream to the Gulf.
From Harris County Flood Warning System on 1/27/24 at 6:18 am.
On the low side, values ranged from 4″ to 6″ south of Lake Houston. On the high side, they ranged from 9″ to almost 11″ north and west of Lake Conroe. Such variation is common.
Step Two: Find the Duration and Distribution of the Rainfall
When you click on any gage location, a “For more information” box pops up. Click the link to see the distribution and duration of rainfall.
The gage at the San Jacinto West Fork and US59 received 5″ during five days. If a giant peak on one day outweighed all others, you might want to investigate that particular day further. But in this case, most days were within a half inch of each other.
Now, you’re ready to find how that compares to other storms.
Step Three: Compare Recorded Totals to Precipitation Frequency Estimates
Next, compare recorded rainfall to expected rainfalls of different intensities and durations.
Most hydrologists currently use precipitation frequency estimates called “Atlas 14.” NOAA determines them.
To find the estimates for your area, enter your address here. You should see a table like the one below although your numbers may vary slightly depending on where you live.
This is where some judgment comes in.
Determine the “best fit” between your observations and NOAA’s estimates.
So, I started by looking across the seven-day row and highlighted the first box. It showed 5.76 inches. The smaller numbers in parentheses indicate possible variation due to uncertainty. Almost all the lower numbers fell within this range.
At the high end of the observed rainfall totals, I highlighted the 10.4 inch box as the most representative. Again, all of the observed totals north and west of Lake Conroe fell into the range in parentheses.
Atlas-14 rainfall probability statistics for the Humble/Kingwood area.
Looking up to the top of the table, you can see that the highlighted boxes correspond to the volume of rain you could expect once every year to five-years. Meteorologists also refer to these as “100% and 20% annual-chance” storms.
If you live elsewhere on the map, you might find your area received a 50% annual-chance storm.
Rainfall Chances Do Not Automatically Translate into Flood Chances
For the record, the flood at the West Fork and US59 this morning peaked at 53.71 feet. That’s three feet LESS than a 10-year flood at this location.
From NWS at 6 am Saturday Jan. 27, 2024
So, in this case, the flood level was generally consistent with a 5-year rainfall upstream. But that’s not always the case.
Many people assume that a rainfall recurrence interval of 1- to 5 years automatically translates into the same probabilities for flooding. It doesn’t.
First, for large watersheds, such as the San Jacinto, rain can vary drastically. Variation upstream will determine how high the resulting water surface elevations are at various points downstream when peaks arrive.
Also understand that annual exceedance probabilities for floods incorporate many more variables than rainfall probabilities. For instance:
Landscape/Slope – Is it flat or hilly? Will water be bottlenecked or does it have room to spread out?
Degree of development – Are you surrounded by farms or do you live in an urban area which produces more runoff faster?
Soil type – More water infiltrates into sandy soils than clay.
Regardless, engineers still consider rainfall probabilities.
How Engineers Use Rainfall Estimates
Why are rainfall estimates important? Engineers must design drainage and infrastructure to handle extreme rainfalls.
For instance, most storm sewers are designed to handle the type of rain you can expect every year or two. When you see water ponding in streets or underpasses, it’s because the storm sewers can’t carry the water away fast enough.
Engineers use these estimates when determining the elevation of homes, setbacks from a river, the size of stormwater detention basins and more.
When you see flooding of streets or neighborhoods, it’s generally a sign that:
Rainfall exceeded the design standard
Something changed, for instance, a sewer was blocked, sediment has clogged a drainage ditch, etc.
Someone miscalculated or cut corners during design and construction
Infrastructure was designed to old (lower) rainfall probability standards.
Last night, before the West Fork (upper left) peaked, water started flowing across Hamblen Road, cutting off some residents in North Shore.
Experts base the probability of extreme future events on the frequency of extremely rare past events using a branch of mathematics called extreme value analysis.
It’s important to understand that rainfall probability estimates change periodically – especially after major storms, such as Tropical Storm Allison or Hurricane Harvey. Meteorologists acquire additional data on extreme storms from these events.
All rainfall probability estimates represent best guesses given knowledge at a point in time.
NOAA is already working on Atlas-15 estimates. Atlas 15 will take climate change estimates into account for the first time.
Going forward, NOAA will compile new precipitation-frequency estimates every 10-years.
Posted by Bob Rehak on 1/27/24
2342 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/01/20240126-DJI_0425.jpg?fit=1100%2C733&ssl=17331100adminadmin2024-01-27 10:34:102024-01-27 10:40:51How Bad Was That Storm?
Adapted from NOAA Post: The above-normal 2023 Atlantic hurricane season officially ended on Nov. 30. It was characterized by record-warm Atlantic sea-surface temperatures, a strong El Niño, and the fourth highest number of named storms in a season.
NOAA’s GOES-16 satellite captured Hurricane Idalia approaching the western coast of Florida while Hurricane Franklin churned in the Atlantic Ocean at 5:01 p.m. EDT on August 29, 2023. (Image credit: NOAA Satellites )
20 Named Storms, One of Which was Unnamed
The Atlantic basin saw 20 named storms in 2023. That ranks fourth for the most-named storms in a year since 1950. The unnamed-named storm was a tropical storm in January that was retroactively classified as a tropical storm.
Seven storms were hurricanes and three intensified to major hurricanes. An average season has 14 named storms, seven hurricanes and three major hurricanes.
The Atlantic basin saw 20 named storms in 2023, ranking 4th for most-named storms in a year. Tropical cyclone names are selected by the World Meteorological Organization. (Image credit: NOAA)
Only One U.S. Landfalling Hurricane
Hurricane Idalia was the only U.S. landfalling hurricane in 2023. It made landfall as a category-3 hurricane on Aug. 30 near Keaton Beach, Florida, causing storm surge inundation of 7 to 12 feet and widespread rainfall flooding in Florida and throughout the southeast.
Tropical Storm Ophelia made landfall as a strong tropical storm with 70 mph winds on Emerald Isle, North Carolina, on Sept. 23 causing widespread heavy rainfall, gusty winds and significant river and storm surge flooding in portions of eastern North Carolina.
Hurricane Lee made landfall as a post-tropical cyclone in Nova Scotia, Canada, on Sept. 16. Swells generated by Lee caused dangerous surf and rip currents along the entire U.S. Atlantic coast. Strong winds with hurricane‑force gusts from Lee caused extensive power outages in Maine and in parts of Canada.
“The Atlantic basin produced the most named storms of any El Nino influenced year in the modern record,” said Matthew Rosencrans, lead hurricane forecaster at NOAA’s Climate Prediction Center — a division of NOAA’s National Weather Service. “The record-warm ocean temperatures in the Atlantic provided a strong counterbalance to the traditional El Nino impacts.”
Eastern Pacific Also Above Normal, but Within Predicted Range
The eastern Pacific basin hurricane season was also above normal with 17 named storms, of which 10 were hurricanes and eight of those major hurricanes. From Aug. 16 to 21, Tropical Storm Hilary brought widespread heavy rainfall and flooding to Southern California, with some areas receiving up to 600% of their normal August rainfall. Hilary resulted in the first ever issuance of Tropical Storm Watches and Warnings for the Southern California coastline by NOAA’s National Hurricane Center. In addition, the Center distributed key hazard focused messages for Hilary in Spanish through the agency’s new language translation project.
Hurricane Otis made landfall near Acapulco, Mexico, on Oct. 25 as a category-5 hurricane with sustained winds of 165 mph. Otis holds the record as the strongest landfalling hurricane in the eastern Pacific after undergoing rapid intensification in which wind speeds increased by 115 mph in 24 hours.
The central Pacific basin had a near-normal season with four tropical systems traversing the basin. Hurricane Dora, a category-4 storm, passed south of Hawaii in early August, marking the first major hurricane in the central Pacific basin since 2020. The strong gradient between a high pressure system to the north and Dora to the south was a contributing factor to the wind-driven, fast-moving wildfires in Hawaii.
Hazards Felt Well Inland Underscores Need for Planning
“Another active hurricane season comes to a close where hazards from the storms extended well inland from the landfall location,” said NOAA National Hurricane Center Director Michael Brennan, Ph.D. “This underscores the importance of having a plan to stay safe whether you’re at the coast or inland.”
New System Improved Intensity Predictions, Response Times
NOAA’s new Hurricane Analysis and Forecast System helped National Hurricane Center forecasters improve intensity predictions this season. NOAA’s intensity forecasts showed Hurricane Idalia as a major hurricane impacting the coast of Florida as early as Aug. 28.
This lead time gave those in threatened areas more time to prepare and respond, and there were no storm surge fatalities from Idalia despite storm surge inundation of as much as 12 feet above ground level in some areas. Further, extending the National Hurricane Center’s tropical weather outlook product from five to seven days, this season provided emergency managers more time to prepare and stage resources before a storm.
NOAA’s Hurricane Research and Response
This season, NOAA Hurricane Hunter aircraft flew 468 mission hours to collect atmospheric data that is critical to hurricane forecasting and research, passing through the eye of a hurricane 120 times and deploying over 1,400 scientific instruments. Since 2020 through this 2023 season, NOAA’s two Lockheed WP-3D Orion have flown 40% more hurricane mission flights than the preceding four years (2016-2019).
NOAA celebrated the first operational launch of a Black Swift drone from a NOAA WP-3D Orion to gather atmospheric data in and around Hurricane Tammy. Further, the first successful coordination of a low-flying drone (Anduril’s Altius 600), atmospheric profilers (dropsondes), and ocean profilers (bathythermographs) also launched from a NOAA WP-3D Orion.
Observations and information from these deployments are being evaluated to determine the feasibility of using the data to help with hurricane forecasting in the future.
NOAA’s Beechcraft King Air flew 28 mission hours to collect aerial imagery used for emergency response after Hurricanes Idalia and Lee. Following Hurricane Idalia, NOAA’s National Ocean Service provided support to enable safe maritime navigation, gathering survey data for 36.8 linear nautical miles and identifying 29 potential obstructions along Florida’s coastal waterways.
NOAA also worked to identify hazards caused by capsized vessels, damaged docks and piers, parts of homes and other types of marine debris, and shared findings with Florida’s debris task force following Hurricane Idalia.
New Use of Weather Satellites
NOAA’s geostationary and polar-orbiting weather satellites provided vital information for monitoring and forecasting the hurricanes and tropical weather that threatened our lives and property this season. Forecasters used one-minute geostationary satellite imagery to assess structure changes during the rapid intensity of storms such as Idalia, Lee and Otis.
NOAA’s polar-orbiting satellites orbit the Earth from pole to pole 14 times a day, providing full global coverage twice daily. Throughout the hurricane season, these satellites made sophisticated and precise observations of the atmosphere, ocean and land, which were critical to developing daily and 3-5 day forecasts.
Timing for Next Year’s Forecast and Official 2023 Report
The National Hurricane Center and Central Pacific Hurricane Center Tropical Cyclone Reports for 2023, including synoptic history, meteorological statistics, casualties and damages, and the post-analysis best track, will be published on the 2023 Tropical Cyclone Report site in March 2024.
NOAA’s Climate Prediction Center, a division of the National Weather Service, will issue its 2024 hurricane seasonal outlook in May 2024. The hurricane season officially begins on June 1.
Adapted from NOAA Story by Bob Rehak
2290 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/12/IMAGE-Hurricane-Outlook-End-English-Nov-2023-e1701905255102.png?fit=1200%2C746&ssl=17461200adminadmin2023-12-06 17:38:102023-12-06 17:38:122023 Hurricane Season Ranked 4th in Named Storms
NOAA’s new Atlas 15 precipitation-frequency estimates will soon replace recently introduced Atlas 14 estimates – even before the Atlas 14 estimates have been fully adopted and integrated into local regulations.
About Precipitation-Frequency Estimates
Engineers use precipitation-frequency estimates to design, plan and manage infrastructure under Federal, State and local regulations. For instance, to ensure homes are built X feet above the 100-year floodplain, engineers must “know” how much rain will fall in a 100-year storm. Predicting that is one of NOAA’s jobs.
However, haphazard adoption of the new estimates has created a patchwork quilt of regulations across Texas and the U.S. One of the dirty, little secrets in the flood mitigation business is that many jurisdictions fail to adopt the new estimates and update their regulations accordingly. It’s costly, time-consuming, and raises the bar for developers.
So, many jurisdictions continue to use lower estimates to help attract development.
But designing infrastructure around artificially low rainfall estimates can lead to insufficient mitigation that increases flood risk for everyone.
Some Estimates Now in Effect Go Back 60 Years
In 2018, NOAA introduced Atlas 14 precipitation-frequency estimates for Texas. They replaced earlier estimates published by NOAA as early as the 1960s. Some parts of the Houston region still use those earlier estimates today.
Atlas 14 estimates superseded those published in:
Weather Bureau Technical Paper No. 40, Rainfall Frequency Atlas of the United States for Durations from 30 Minutes to 24 Hours and Return Periods from 1 to 100 Years (Hershfield, 1961)
Weather Bureau Technical Paper No. 49, Two- to Ten-Day Precipitation for Return Periods of 2 to 100 Years in the Contiguous United States (Miller, 1964).
Newest Estimates Will Incorporate Climate Change
Compared to those, Atlas 14 estimates are more accurate. They incorporate data from newer technologies and more data collected over longer periods. Atlas 14 totals increased 30-40% for the Lake Houston Area.
The Atlas 15 estimates are just getting underway and have not yet been developed. NOAA expects to release them in 2027.
NOAA claims its Atlas-15 update will improve precipitation-frequency estimates by leveraging non-stationary climate estimates. Previous estimates, such as Atlas 14, have assumed a stationary climate.
In statistics, “non-stationary” means the underlying environment changes, say due to some strong trend or seasonality. Many people believe climate is changing and hence the desire to build that into the new precipitation-frequency estimates.
National Funding, New Updates Every 10 Years
Historically, NOAA precipitation-frequency estimates have been funded by states and other users, on a cost-reimbursable basis. However, that is changing.
Moving forward, the Federal government will fund precipitation-frequency updates. Under the Floods Act, signed into law in December 2022, NOAA will update precipitation-frequency estimates every 10 years.
Goals include:
Updating standards
Incorporating climate change
For the entire country.
Voluntary, Local Participation
But there’s a dirty little secret that not many people know about. Nothing forces individual cities, counties or states to adopt the estimates and work them into their regulations.
That’s a big job. And an expensive one. So, not all jurisdictions do it. Many areas surrounding Houston still plan infrastructure using data developed 60 years ago.
If you plan on less rain, channels can be narrower and stormwater-detention basins smaller. But residents are not protected as much as they should be.
Posted by Bob Rehak on 9/5/2023 based on information from NOAA.
2198 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/09/Screenshot-2023-09-05-at-3.14.21-PM.png?fit=1686%2C846&ssl=18461686adminadmin2023-09-05 16:12:162023-09-05 16:12:17Here Come New Precipitation-Frequency Estimates…Again
Scientists at NOAA’s Climate Prediction Center — a division of the National Weather Service — have increased their prediction for the ongoing 2023 Atlantic hurricane season from a near-normal level of activity to an above-normal level of activity.
Forecasters believe that current ocean and atmospheric conditions, such as record-warm Atlantic sea surface temperatures, are likely to counterbalance the usually limiting atmospheric conditions associated with the ongoing El Nino event.
Chances of Above Normal Season Increase from 30% to 60%
NOAA forecasters have increased the likelihood of an above-normal Atlantic hurricane season to 60% (increased from the outlook issued in May, which predicted a 30% chance). The likelihood of near-normal activity has decreased to 25%, down from the 40% chances outlined in May’s outlook. This new update gives the Atlantic a 15% chance of seeing a below-normal season.
Prediction for Named Storms Increase from 12-17 to 14-21
In May 2023, NOAA predicted 12-17 named storms. NOAA’s update calls for 14-21 named storms (winds of 39 mph or greater). Of those, 6-11 could become hurricanes (winds of 74 mph or greater). And of those, 2-5 could become major hurricanes (winds of 111 mph or greater).
NOAA provides these ranges with a 70% confidence. These updated ranges include storms that have already formed this season.
The updated 2023 Atlantic hurricane season probability and number of named storms. (Image credit: NOAA)
The Atlantic basin experienced an active start to the hurricane season with five storms that have reached at least tropical storm strength, including one hurricane already. An average hurricane season produces 14 named storms, of which seven become hurricanes, including three major hurricanes.
Climate Factors Influencing Predictions
“The main climate factors expected to influence the 2023 Atlantic hurricane activity are the ongoing El Nino and the warm phase of the Atlantic Multi-Decadal Oscillation, including record-warm Atlantic sea surface temperatures,” said Matthew Rosencrans, lead hurricane season forecaster with NOAA’s Climate Prediction Center.
Sea surface temperature departures from normal for August 10, 2023.Source: NOAA
Considering those factors, the updated outlook calls for more activity, so NOAA urges everyone to prepare now for the continuing season.
Activity should ramp up quickly in August and September, if this season follows the pattern for the last 100 years.
El Nino conditions are currently being observed and there is a greater than 95% chance that El Nino will continue through the Northern Hemisphere winter, according to the latest ENSO discussion from the Climate Prediction Center.
El Nino usually results in atmospheric conditions that help to lessen tropical activity during the Atlantic hurricane season. So far, those limiting conditions have been slow to develop.
Climate scientists forecast that the El-Nino associated impacts that limit tropical cyclone activity may not be in place for much of the remaining hurricane season.
NOAA’s Climate Prediction Center
A below-normal wind shear forecast, slightly below-normal Atlantic trade winds and a near- or above-normal West African Monsoon were also key factors in shaping this updated seasonal forecast.
Five Storms Already
The Atlantic basin experienced a tropical storm in January which was unnamed. Since the start of the season, we have already experienced four other storms.
The 2023 Atlantic tropical cyclone names selected by the World Meteorological Organization. (Image credit: NOAA)
More About Hurricane Season Outlooks
NOAA’s hurricane outlooks are forecasts of overall season activity, not landfalls. A storm’s landfall is usually the result of mesoscale weather patterns and are typically predictable within roughly one week of a storm approaching a landmass.
In June, NOAA deployed a new model to help produce hurricane forecasts. The Hurricane Analysis and Forecast System was put into operations on June 27 and will run alongside existing models for the 2023 season before replacing them as NOAA’s premier hurricane forecasting model.
NOAA urges everyone in vulnerable areas to have a well-thought-out hurricane plan and stay informed through official channels as this season progresses.
I bookmark the National Hurricane Center landing page and check it first thing every morning during the season. NHC expects no tropical activity in the Atlantic during the next seven days.
Reposted by Bob Rehak on 8/11/2023 from the National Hurricane Center
2073 Days since Hurricane Harvey
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