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NHC Issues Advisory on Potential Tropical Cyclone 4

8/2/24 5PM – The National Hurricane Center (NHC) has issued an advisory about Potential Tropical Cyclone 4. It affects people on the west coast of Florida for now. Since yesterday, models have come into closer alignment. There is now a higher degree of certainty that the PTC4 will track up the west coast of Florida, then cut east around Tampa and emerge into the Atlantic.

Current Status and Forecast

Land interaction with Cuba has limited strengthening of the storm today. But by 2PM Saturday, it should emerge into the eastern Gulf and intensify into a tropical storm before making landfall.

Maximum sustained winds are currently at 30 MPH, but will accelerate Saturday and Sunday.

NHC forecasts a 40-50% probability that the Florida’s western coast will see tropical storm force winds (one minute average >= 39MPH). The earliest arrival time on the southern tip of Florida is 8 AM Saturday 8/3/24.

So far, the tropical wave has not yet reached tropical storm force anywhere in the Atlantic or Caribbean. However, tropical storm watches and warnings are up for the entire western coast of Florida.

NOAA’s latest satellite imagery shows the storm centered over Cuba at 21:40 Z on 8/2/24.

*PTC4’s position over Cuba as of 4:40 CDT.*

Up to a Foot of Rain and 4 Feet of Storm Surge

NHC expects tropical storm conditions to follow the storm up the eastern seaboard through next Wednesday. They also warn of life-threatening storm surge (2-4 feet) and coastal flooding from Georgia to North Carolina next week. Finally, they warn of isolated river flooding.

Expect rainfall totals of 4 to 8 inches, with maximum rainfall totals up to 12 inches, across portions of Florida and along the Southeast U.S. coast this weekend through Wednesday morning.

Next Storm Name Is Debby

This storm should become “Debby.” Chris had a short life and veered into northern Mexico as Beryl was moving toward Houston.

For the time being, people in the Houston area can breathe easier. But the Atlantic hurricane season is just starting to heat up. It will peak on September 10.

peak of hurricane season — *From: https://www.nhc.noaa.gov/climo/*

Where to Find the Latest Information

Those with friends, relatives or vacation plans in the southeast can track the progress of the storm in satellite images at:

https://www.nhc.noaa.gov/satellite.php.

For the latest NHC forecasts, visit: https://www.nhc.noaa.gov/graphics_at4.shtml?start#contents.

NHC issues updates every 4 hours when a storm threatens.

Posted by Bob Rehak on 8/2/24 at 5:30 PM

2530 Days since Hurricane Harvey

New Forecasts Show Latest Disturbance Now Moving Toward Gulf

8/1/24 – 7PM Update – Since posting this story earlier today, NHC has shifted its predictions even farther west and increased development chances to 40% in two cays and 70% in 7 days.

8/1/24, 9 AM – According to the National Hurricane Center (NHC), a well-defined tropical wave is now moving toward the Gulf. This represents a significant change from earlier predictions that took the storm east of Florida.

The system is currently producing a large area of disorganized showers and thunderstorms over the southwestern Atlantic and northeastern Caribbean Sea.

Development Chances

Development of this system should occur slowly during the next two days. Environmental conditions will soon become more conducive for development. And a tropical depression could form this weekend or early next week over the eastern Gulf of Mexico.

The system has a 20% chance of formation in the next 2 days and a 60% chance in the next 7.
National Hurricane Center

NHC and others have discussed this tropical wave for about a week now. In the last 2 days, shower and thunderstorm development has become better organized, but there is still no defined circulation at the surface at this time.

The wave axis should reach Cuba by early this weekend. According to Jeff Lindner, Harris County meteorologist, land interaction will likely prevent any sort of significant development in the near term – unless a center forms either south or north of the inlands.

Likely Track

Toward this weekend it is now likely that the wave will enter the eastern Gulf of Mexico. After that, the steering patterns become highly complex.

Forecasts have a high degree of uncertainty. Different models show numerous outcomes in the eastern Gulf during the next 5-7 days.

Weak Storm Likely at This Point

Intensity forecasts are also very uncertain at this point. Most models predict a weak system. But once a defined surface center forms, intensification looks likely.

Factors Supporting Development

Lindner points to three factors supporting eventual development.

Conditions supporting intensification over the eastern Gulf of Mexico include:

Very warm sea surface temperatures
Light wind shear
Potential for dual outflow channels aloft.

Role of Dual Outflow Channels in Formation

Meteorologists frequently talk about shear and sea surface temperatures in relation to hurricane formation. But they talk less often about the importance of outflow channels. How do outflow channels support hurricane formation?

Dual outflow channels are important in hurricane formation because they can enhance the efficiency and intensity of a storm.

According to ChatGPT, they provide:

Enhanced Ventilation: This allows the hurricane to expel air more efficiently, promoting a stronger inflow at the surface.
Symmetrical Structure: With outflow in multiple directions, the hurricane maintains a more symmetrical structure.
Lower Pressure: Efficient outflow channels contribute to lowering the central pressure of the hurricane. Lower pressure at the core leads to higher wind speeds and a more powerful storm.
Sustained Intensification: Dual outflow channels can support sustained intensification by continually removing air from the upper levels, allowing the storm to draw in warm, moist air from the ocean surface.
Balanced Energy Distribution: The channels help distribute energy more evenly around the storm, preventing one side from becoming too dominant and potentially disrupting the hurricane’s structure.

Dual outflow channels thus help enhance the structural integrity, efficiency, and intensity of hurricanes.

Preparations

At this time, no one predicts that the storm will reach as far west as Houston. But last week, no one predicted that it would reach the Gulf either.

As always, your best bet is to be prepared for anything. Restock food, water and batteries used after Beryl. Recharge your backups. And monitor the NHC daily.

Posted by Bob Rehak on 8/1/24

2529 Days since Hurricane Harvey

Beryl Becomes Earliest Cat 5 Hurricane Ever

7/2/24 – Beryl has become an incredibly intense hurricane with maximum sustained winds of 165 MPH and a central pressure of 935mb. See this Infrared Satellite Loop at Tropical Tidbits. This is an unprecedented hurricane event for July.

According to Harris County Meteorologist Jeff Lindner, Beryl is the earliest Category 5 hurricane on record since 1851. It beats out hurricane Emily (2005), which became a Category 5 on July 17.

Beryl is now moving through the central Caribbean Sea toward Jamaica and the Cayman Islands.

Status Overview as of 8 AM 7/2/24

Based on NOAA aircraft data, hurricane force winds (75mph) extend outward 40 miles from the center. Tropical storm force winds (40mph) extend outward 125 miles from the center.

Beryl is moving toward the west-northwest near 22 mph.

On the forecast track, the center of Beryl will move quickly across the southeastern and central Caribbean Sea today. It should pass near Jamaica on Wednesday and the Cayman Islands on Thursday.

Weakening should begin later today, but Beryl is still expected to be near major hurricane intensity as it passes Jamaica and the Caymans.

Intensity Forecast Uncertain

The National Hurricane Center (NHC) cautions that Beryl’s intensity forecast is rather uncertain. Model guidance indicates that the hurricane will begin to weaken later today as Beryl encounters moderate-to-strong vertical wind shear. Later on, factors such as:

Possible interaction with the Jamaican elevated terrain
Dry air intrusions
Structure of the vertical wind shear

…will all play a role in the rate of weakening.

As Beryl approaches the Yucatan, models show quite a wide range of solutions – from a strong tropical storm to a major hurricane. However, the NHC forecast shows Beryl reaching the Yucatan as a hurricane in about 72 hours and emerging as a tropical storm into the Gulf of Mexico on Saturday.

Track Shifted North

Beryl has tracked slightly north of predictions during the last 12 hours. This is likely due to the much stronger intensity of the hurricane.

Overall the direction has been trending north over the last 24 hours. Beryl is being steered by a strong high pressure ridge to the north. A W to WNW motion through the next 72 hours is likely. That will likely bring core of the hurricane to the eastern Yucatan early Friday morning.

Beryl will cross into the southern Gulf of Mexico by early this weekend. At that time, the current ridge of high pressure over the southern plains will be breaking down and moving east. Low pressure should replace it, pulling Beryl a little more to north, compared to the current track.

However, there is also uncertainty with the track in the Gulf of Mexico. It is difficult to tell how organized Beryl will be when it emerges from the Yucatan. It is also difficult to predict how quickly the southern plains high will break down.

Such factors also will affect the forward speed of the hurricane.

Due to Beryl’s high forward speed, it could drop a foot of rain on Jamaica. But as it slows in the Gulf…

Lindner urges people along the Texas and Louisiana coast to monitor Beryl’s progress closely. NHC is now updating information on Beryl every few hours on this page.

For those who need a refresher course in hurricane preparation, ReduceFlooding’s Links page contains advice from 19 authoritative sources.

Posted by Bob Rehak on 7/2/24

2499 Days since Hurricane Harvey

Beryl Goes from Tropical Storm to Cat 4 in One Day

6/30/24, 4 PM – Beryl intensified from a tropical storm yesterday morning to a category 4 hurricane with 130 mph winds this afternoon.

Elsewhere, Tropical Depression #3 has formed in the Bay of Campeche. NHC predicts it will become a tropical storm by tonight and make landfall near where Alberto did in Mexico less than two weeks ago.

4PM Update on Beryl

The National Hurricane Center (NHC) says that the hurricane continues to move swiftly westward at 18 kt, steered by a strong subtropical ridge to its north. Beryl has made only a minor shift to the north since this morning, following the trend in the latest models.

Potentially catastrophic hurricane-force winds, a life-threatening storm surge, and damaging waves are expected when the hurricane passes over portions of the Windward Islands. At highest risk: St. Vincent and the Grenadines, and Grenada beginning early Monday morning.

*Latest cone of uncertainty for Beryl as of 3PM CDT*, *6/30/24*

As the hurricane tracks across the Caribbean Sea, there likely will be a gradual increase in wind shear, which should weaken it slightly. However, NHC predicts that Beryl will remain a significant hurricane during its entire trek across the Caribbean region.

So far, the storm’s path has been eerily reminiscent of Harvey’s.

Here are the latest track forecasts of various models for today’s storm.

*Some models take the path toward Houston, but the consensus seems a bit west.*

Sea Surface Temps in Gulf

If Beryl makes it to the Gulf, it will encounter favorable sea surface temps.

*Sea Surface Temperature departures from normal. 2 degrees Celsius = 3.6 degrees Fahrenheit.*

It is too early to predict atmospheric conditions in the Gulf next weekend.

Record-Breaking Beryl

As it spins across the Atlantic, Beryl has already set two records:

Farthest east a hurricane has ever formed in the Atlantic in June
Earliest Cat 4 Hurricane on record.

Before this storm, the record earliest Category 4 hurricane was Dennis on July 8, 2005.

Posted by Bob Rehak at 4PM CDT on 6/30/24

2497 Days since Hurricane Harvey

Beryl Expected to Become Category 4 Hurricane

6/30/24, 7 AM CDT – The National Hurricane Center (NHC) now predicts that Hurricane Beryl could rapidly intensify into a Category 4 hurricane before reaching the Windward Islands early Monday morning. At 7 AM CDT, NHC estimated Beryl’s maximum sustained winds at 115 mph. That would currently make it a Category 3 hurricane on the Saffir-Simpson Wind Scale, which estimates damage to structures at various wind speeds. (See below.)

High SSTs, Low Wind Shear

Sea surface temperatures in Beryl’s path reach 84.2 degrees Fahrenheit, more typical of August than June. And as Beryl moves westward, wind sheer is decreasing. Both factors favor rapid intensification.

Thus, the latest NHC intensity forecast continues to show rapid intensification over the next day, making Beryl an extremely dangerous Category 4 hurricane before it reaches the Windward islands.

Once Beryl enters the Caribbean, increasing shear will likely cause the hurricane’s intensity to level off, then start weakening around midweek, according to NHC.

Eye Wall Development

Recent satellite imagery shows the development of an eye, with cooling cloud tops in the eyewall and a warming eye.

*From National Hurricane Center at 6:20 CDT on 6/30/24*

Two Hurricane Hunter aircraft measured the maximum wind speed this morning.

Beryl Continues to Track Mostly Westward

The hurricane is moving slightly north of due west at about 20 mph. There aren’t any significant track changes from the previous advisory. An extensive mid-level, high-pressure ridge north of Beryl will steer the system westward or west-northwestward for several days.

Model guidance remains in tight agreement on the forecast track. NHC’s 4 AM Atlantic Standard Time update notes that track prediction is basically an update of the previous one.

The farther out you get, the more models diverge. The average of all models eventually shows the storm moving into the western Gulf.

Category 4 Risks

This is a very serious situation developing for the Windward Islands. Beryl will bring destructive winds, life-threatening storm surge, heavy rainfall and flooding for much of the Windward Islands tonight and Monday.

Saffir-Simpson Wind Scale Categories

For those new to the Gulf Coast, the Saffir-Simpson Hurricane Wind Scale is a 1 to 5 rating based only on a hurricane’s maximum sustained wind speed.

This scale does not take into account other potentially deadly hazards such as storm surge, rainfall flooding, and tornadoes.

The Saffir-Simpson Hurricane Wind Scale estimates potential property damage. While all hurricanes produce life-threatening winds, hurricanes rated Category 3 and higher are known as major hurricanes.

Major hurricanes can cause devastating to catastrophic wind damage and significant loss of life simply due to the strength of their winds.

Hurricanes of all categories can produce deadly storm surge, rain-induced floods, and tornadoes.

Category	Sustained Winds	Types of Damage Due to Hurricane Winds
1	74-95 mph	Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.
2	96-110 mph	Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.
3 (major)	111-129 mph	Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
4 (major)	130-156 mph	Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
5 (major)	157 mph or higher	Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

From National Hurricane Center

Posted by Bob Rehak on 6/30/24 at 7 AM CDT

2497 Days since Hurricane Harvey

Alberto, First Named Storm of Season, Lashes Mexico, South TX

6/19/24 – Potential Tropical Cyclone #1 just became Tropical Storm Alberto, according to the National Hurricane Center’s (NHC) 10 AM update. Alberto will reach the coast of northeast Mexico early tomorrow morning.

Texas Impacts from Alberto

Until then, the entire Texas Coast up to San Luis Pass is under a tropical storm warning. Residents can expect heavy rains, coastal flooding and gusty winds through Thursday.

NHC expects Alberto to weaken quickly once it comes ashore early Thursday. The storm is moving at 9 miles per hour with maximum sustained winds of 40 MPH. Tropical-storm-force winds extend outward up to 415 miles north of the center.

Peak storm surge will reach 2-4 feet along the upper Texas Coast and Galveston Bay.

Rainfall Still Ratcheting Down

Rainfall predictions continue to ratchet down, however, especially for the Houston area as Alberto is pushed south by higher pressure from the northeast U.S.

Alberto should produce 5 to 10 inches of rainfall across northeast Mexico into South Texas. Maximum totals around 20 inches are possible. This rainfall will likely produce considerable flash and urban flooding along with new and renewed river flooding.

NHC will produce more advisories on Alberto at 1 and 4 PM today.

Make Alberto a Learning Experience

If you have kids home from school looking for something to do, this is an excellent chance to teach them about tropical cyclones.

NHC offers dozens of educational resources geared toward students from K-12 all the way up to continuing education for weather professionals. Harness your child’s natural curiosity while storms are in the news.

I found NHC’s course on Hurricane Basics very informative. Before Alberto became Alberto, it had winds strong enough to qualify as a tropical storm, but NHC kept calling it a potential tropical cyclone instead. Do you know the other attributes that define tropical cyclones? Hurricane Basics tells you.

Want to know what it takes to get a tropical cyclone started?

What affects their intensity?

Or how various factors come together to produce more or less rainfall?

NHC describes each of the factors above and provides clear, simple illustrations that make them easy to understand.

This particular presentation also covers:

Storm tracks
Where hurricanes will most likely form depending on month of the season
Tropical distrubances
Track forecasting
Associated hazards, such as hurricanes
Relative risks from wind, rainfall, surge, flash flooding, etc.
Categories of storms and types of damage associated with each
More, much more.

Trivia: By the way, NHC provides climate data, too. Did you know, for instance, that the first named storm of the season usually occurs on June 20th in the Atlantic Basin. This year, the first named storm occurred on June 19.

Posted by Bob Rehak on 6/19/24

2486 Days since Hurricane Harvey

Hurricane Center Posts First Tropical Threats of Season for Gulf

6/13/24 – NOAA’s National Hurricane Center’s 7-day outlook shows the first tropical threats of the season for the Gulf of Mexico and Atlantic.

*From National Hurricane Center as of 1:16AM EDT on 6/14/24*

That orange area in the Bay of Campeche carries a 40% risk of formation within 7 days.

According to NHC forecasters, “A broad area of low pressure is forecast to form over the southwestern Gulf of Mexico this weekend. Environmental conditions appear conducive for gradual development of this system, and a tropical depression could form during the early or middle part of next week while it moves slowly westward or west-northwestward.”

The Weather Channel says, “That would bring locally heavy rain to parts of the Gulf Coast from Louisiana to as far west as Texas and eastern Mexico, beginning Sunday and lasting well into the week. Exactly where the heaviest rain could fall remains uncertain this far out in time.”

As the system moves farther north, it will encounter record-warm sea-surface temperatures and wind shear should decrease.

The torrential rains in Florida this week serve as a warning that widespread damage doesn’t require a full-blown hurricane. Parts of Florida received 18-24 inches of life-threatening rain. News media are filled with images of flooded streets and stalled cars. The system could still turn into a tropical storm as it moves up the east coast.

If either of these storms turns into a tropical storm, its name will be Alberto. The next will be Beryl.

As Houston faces new tropical threats, the area is still recovering from non-tropical May storms.

Jeff Lindner, Harris County’s meteorologist, predicts we could see another 2-4 inches of rain from this next threat. He expects the heaviest rains to fall near the coast with decreasing amounts inland. Lindner also warns of strong wind and wave action near the coast.

Posted by Bob Rehak on 6/13/24

2480 Days since Hurricane Harvey

Tropics Show More Activity, Higher Probabilities since Yesterday

What a difference a day makes! Yesterday, the Atlantic Basin had four areas of concern. Today, it has five. And, according to the National Hurricane Center (NHC), the chances of tropical development have increased for all of them since yesterday. See the seven-day outlook for the Atlantic Basin below and note the time: Saturday, August 19, 2023 at 3:35 Eastern time.

The NHC diagram below shows a veritable parade of potential storms marching from Africa toward the Americas.

Lowdown on the Lows

Starting with the yellow area moving off the coast of Western Africa:

Yellow Area on Right

A tropical wave located near the western coast of Africa is producing a large area of disorganized showers and thunderstorms. Some slow development is possible while it moves generally west-northwestward across the tropical eastern Atlantic during the next several days. Formation chance through 7 days…still low…20 percent.

Red Area with X

The red cross-hatched area to the left of the yellow is a broad area of low pressure located several hundred miles west of the Cabo Verde Islands. Shower and thunderstorm activity continues. Environmental conditions appear generally favorable for further development. A short-lived tropical depression will likely form this weekend and move west-northwestward at about 10 mph across the eastern tropical Atlantic. By early next week, upper-level winds over the system are forecast to increase, and further development is not expected. Formation chance through 7 days…high…70 percent.

TD #6

Tropical Depression #6 formed in the central, tropical Atlantic this afternoon. The system will move west-northwestward at 10 to 15 mph. However, upper-level winds will become increasingly unfavorable by late this weekend, so NHC does not anticipate any further development.

Orange Area Entering Caribbean

A broad area of low pressure has formed near the Windward Islands. Shower and thunderstorm activity has become better organized since yesterday. Some additional development of this system is likely and a tropical depression could form by early next week when the system moves into the eastern and central Caribbean Sea. Formation chance through 7 days…medium…60 percent.

Orange Area Entering Gulf

An area of disturbed weather located near the Bahamas will move into the Gulf of Mexico by early next week where a broad area of low pressure will form. Some slow development is possible thereafter. A tropical depression could form as it moves westward and approaches the western Gulf of Mexico coastline by the middle of next week. The storm will likely make landfall in South Texas and bring little rainfall to the Houston area north of I-10. Formation chance through 7 days…medium…50 percent.

Satellite Image Shows Current Conditions in Gulf and Eastern Pacific

The last area represents the most imminent threat to Texas. Here’s what it looks like in a satellite image. Not very impressive at the moment, especially compared to Hurricane Hilary in the Pacific (on the left).

Conditions can change rapidly so prepare and stay aware.

Posted by Bob Rehak on 8/19/23 based on information from the NHC

2181 Days since Hurricane Harvey

Tropical Forecast Suddenly More Active

Still three weeks from the peak of hurricane season (September 10), the tropical forecast has suddenly become more active. The latest seven-day outlook from the National Hurricane Center (NHC) shows four areas of concern. Two will not affect the Texas Gulf Coast. Eventually, the other two could get close.

Chances of Tropical Formation

According to the NHC 8 a.m. update:

The red area at the right currently has a 70% chance of tropical formation in the next seven days.
The orange area has a 40% chance. Environmental conditions are only marginally conducive for further development of this system, but a tropical depression could still form during the next couple of days while it moves west-northwestward at 10 to 15 mph across the central tropical Atlantic.
Neither of those systems poses a threat to Texas.
The yellow area in the middle approaching the Lesser Antilles has a 30% chance of formation.
The yellow area on the left will move toward the Gulf of Mexico by early next week. It also has a 30% chance of tropical formation.

The NHC updates its website several times a day during hurricane season. So bookmark it and check back often for the latest forecasts.

Local Impact Felt by Next Tuesday

Jeff Lindner, Harris County’s meteorologist, has been sending out updates all week long on the last system. Here’s what he had to say on Friday morning, 8/18/23. “A low chance of tropical cyclone formation remains possible over the western Gulf early to mid next week.”

“A tropical wave will reach the eastern Gulf of Mexico late this weekend. As high pressure over Texas lifts northward and centers over the Midwest early next week, this wave will continue westward and approach the Texas coast by Tuesday or Wednesday,” said Lindner.

Possibilities include a tropical wave, tropical depression, or weak tropical storm moving inland along the lower or middle Texas coast. Conditions appear to be generally favorable for some slow development, but dry air is lurking along the U.S. Gulf coast that could wrap into any developing system. Also any developing system could encounter wind shear over the western Gulf from the outflow of powerful Hurricane Hilary in the eastern Pacific Ocean.

Any Development Most Likely Near Coast

“With that said, the system will be moving over warm sea surface temperatures and systems, especially in the NW Gulf under the right conditions can tighten up just prior to landfall. This may be a situation where whatever is going to happen with any development occurs very near the coast,” said Lindner.

Most Moisture Near Coast and West of Houston

Lindner concludes, “Regardless of development, tropical moisture will surge into the Texas coast as early as late Monday, but more likely Tuesday or Wednesday. For now, the greatest moisture looks to remain along and south of the I-10 corridor with areas north of I-10 still under the influence of the high pressure ridge over the Midwest. There will likely be a strong gradient in rain chances from south to north over the area next week with the potential for some desperately needed rainfall across the coastal locations.”

Subsiding air from the high to the north will determine how far inland the moisture and rain/bands reach. This map from the National Weather Service (NWS) helps visualize what the situation will look like by Monday, August 21.

Flood Risk Less than 5%

The risk of excessive rainfall that could cause flash flooding is less than 5% according to the NWS.

It’s pretty sad when you start wishing for a tropical storm. But we sure could use something to break the drought and cool us off. Yesterday’s high of 105 was the highest temp recorded in Houston since 1909, according to ABC13. And it could get close to that again today.

Posted by Bob Rehak on 8/18/23

2180 Days since Hurricane Harvey

NOAA Increases 2023 Atlantic Hurricane Season Forecast

Reprinted from the National Hurricane Center website with some additions.

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.

2023 Atlantic Hurricane Season Forecast — *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.

2023 Atlantic Hurricane Season Names — *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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