Storm Discussion

035
WTNT41 KNHC 220836
TCDAT1

Tropical Depression Eleven Discussion Number 2
NWS National Hurricane Center Miami FL AL112018
500 AM AST Sat Sep 22 2018

Deep convection remains displaced to the east of the depression''s
center due to 30-40 kt of westerly shear. Although Dvorak final-T
numbers from TAFB and SAB have decreased since yesterday--now a
consensus T1.0--the initial intensity is held, perhaps generously,
at 30 kt. Strong westerly shear is expected to persist for several
days, which at the very least will prevent the depression from
getting any better organized. Since the global models show the
depression opening up into a trough in about 24 hours, the new NHC
intensity forecast brings down the winds a little faster, shows the
system becoming a remnant low by 36 hours, and dissipates the low
entirely by 48 hours well east of the Windward Islands. This
evolution could certainly occur more quickly than indicated by the
official forecast.

The center of the depression has not been moving much, and it''s
possible the sheared convection is trying to pull it back toward
the east. However, the average motion over the past 12 hours is
westward, or 270/4 kt. The track guidance insists that the
depression should move slowly west-northwestward over the next
couple of days, but given that the system has not made any
northward progress, I elected to skirt the southern edge of the
guidance envelope. This new forecast is a little south of the
previous NHC track prediction.


FORECAST POSITIONS AND MAX WINDS

INIT 22/0900Z 13.0N 53.5W 30 KT 35 MPH
12H 22/1800Z 13.3N 54.3W 30 KT 35 MPH
24H 23/0600Z 13.6N 55.4W 25 KT 30 MPH
36H 23/1800Z 13.8N 56.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 24/0600Z...DISSIPATED

Isaac Likely to Make Closest Pass to V.I. Early Friday

Hurricane and tropical storm watches have been posted for several Caribbean islands as a weakening Tropical Storm Isaac continues its trek toward the Leeward and Windward Islands.

Tropical storm warnings have been issued for Martinique, Dominica, and Guadeloupe. Tropical storm watches are in effect for Montserrat, St. Kitts and Nevis, Antigua, and Saba and St. Eustatius.

According to the National Hurricane Center’s 11 p.m. Tuesday update, Isaac has weakened somewhat in the previous 24 hours and is now expected to enter the Caribbean Thursday evening as a tropical storm, rather than a hurricane.

At 5 p.m. Tuesday, the center of the tropical storm was located approximately 916 miles east-southeast of St. Croix near 14.6 degrees North, 51.3 west. The storm is packing top winds of 70 miles per hour while tracking to the west at 17 miles per hour. Tropical-storm force winds extend outward to 105 miles from the center.

The NHC expects Isaac to move near or over the central Lesser Antilles on Thursday, move into the Eastern Caribbean Sea Thursday night, and move into the central Caribbean Sea by the weekend. Current estimates have Isaac passing almost 150 miles south of St. Croix early Friday morning. At that time, Isaac will be a strong tropical storm with top winds of 60 miles per hour. The winds of Isaac are not expected to affect the Virgin Islands.

But that hasn’t stopped the territory from preparing for the worst. Effective at 8 p.m. Tuesday, the Coast Guard Sector San Juan captain of the port set port condition X-ray for the USVI and Puerto Rico due to the expectation of sustained gale force winds of 25 mph and gusts up to 40 mph generated by tropical storm Isaac that may arrive within 48 hours.

Under Port Condition X-Ray, ports and facilities are open to all commercial traffic and all transfer operations may continue.

Varlack Ventures announced Tuesday evening that it anticipates the ports will be closed at 8 a.m. Thursday, and said it will announce the last runs between Cruz Bay and Red Hook after Wednesday’s 1 p.m. advisories.

According to the NHC 11 p.m. Tuesday update, Tropical Storm Isaac’s center is “outrunning” the deep convection by about a degree due to strengthening westerly shear. Vertical shear is expected to increase and turn more northwesterly during the next 36 hours, and Isaac’s structure could degrade further over the next day or two.

Shared content for Virgin Islands Source and St. John Tradewinds.

Coast Guard Sets Port Condition Whiskey as Issac Approaches

The U.S. Coast Guard Captain of the Port San Juan set port condition Whiskey effective at 8 p.m. Monday for the the U.S. Virgins Islands and Puerto Rico, which weakened slightly Monday evening but is still expected to be at or near hurricane force as it passes through the region later this week.

Port conditions are used to alert the maritime community to changes in port operations needed to prepare for the arrival of a tropical storm or hurricane.

The port conditions established by the U.S. Coast Guard, are:

Whiskey: Gale force winds (34 knots or 39 mph) are predicted to arrive within 72 hours.
X-Ray: Gale force winds are predicted to arrive within 48 hours.
Yankee: Gale force winds are predicted to arrive within 24 hours. Ports status: Closed to inbound traffic and vessel traffic control measures in effect on vessel movements within the port.
Zulu: Gale force winds are predicted to arrive within 12 hours. Port closed to all inbound and outbound traffic.
Recovery: The storm is no longer a threat to the area, however some damage may have occurred and response and recovery operations are in progress.

During port condition Whiskey, port facilities are open to all commercial traffic and all transfer operations may continue while Whiskey remains in effect. Pleasure craft are advised to seek safe harbor. Maritime and port facilities are reminded to review and update their heavy weather response plans and make any additional preparations needed to adequately prepare in case of a potential impact to the area.

Mariners are advised there are no safe havens in these facilities, and ports are safest when the inventory of vessels is at a minimum. All ocean-going commercial vessels 500 gross tons and above should make plans for departing the port.

Coast Guard Captain of the Port San Juan anticipates setting port condition X-Ray at 8 p.m. Tuesday.

While most of the nation’s attention is on Hurricane Florence, which on Monday blew up into a Category 4 hurricane that is threatening the U.S. east coast, in the Caribbean all eyes are on Tropical Storm Issac.

In its 11 p.m. update, the National Hurricane Center reported that Issac had weakened slightly during the evening, but cautioned that it is still likely to be at or near hurricane strength when it passes through the regions. Several microwave images that arrived at the NHC after the 5 p.m. update revealed that the low-level center of Isaac had raced ahead of the main convective mass.

“The system is poorly vertically aligned,” the NHC reported at 11 p.m. “The system also recently passed very near NOAA buoy 41041, which confirmed that the center is on the western side of the central dense overcast. The maximum winds observed by the buoy were only about 30 knots.”

The NHC’s forecasters retained high confidence in the track forecast, which predicts Isaac will move westward into the Caribbean within the next 72 hour (or Thursday evening.) The NHC track forecast continues to favor “the typically more reliable global models” and shows a steady westward motion.

The hurricane experts cautioned: “Interests in the Lesser Antilles should continue to monitor Isaac during the next few days. Watches will likely be required for portions of the Lesser Antilles” on Tuesday.

The Coast Guard is warning the public of these safety messages:

– Stay off the water. The Coast Guard’s search and rescue capabilities degrade as storm conditions strengthen. This means help could be delayed. Boaters should heed weather watches, warnings, and small craft advisories.

– Evacuate as necessary. If mandatory evacuations are set for an area, the public should evacuate without delay. Coast Guard personnel and other emergency responders may not be able to evacuate or rescue those in danger during the storm.

– Secure belongings. Owners of large boats are urged to move their vessels to inland marinas where they will be less vulnerable to breaking free of their moorings or to sustaining damage. Trailer-able boats should be pulled from the water and stored in a place that is not prone to flooding. Those who are leaving their boats in the water are reminded to remove EPIRBs and to secure life rings, lifejackets and small boats. These items, if not properly secured, can break free and require valuable search and rescue resources be diverted to ensure people are not in distress.

– Stay clear of beaches. Wave heights and currents typically increase before a storm makes landfall. Even the best swimmers can fall victim to the strong waves and rip currents caused by hurricanes. Swimmers should stay clear of beaches until local lifeguards and law enforcement officials say the water is safe.

– Be prepared. Area residents should be prepared by developing a family plan, creating a disaster supply kit, having a place to go, securing their home and having a plan for pets. Information can be found at the National Hurricane Center’s webpage.

– Stay informed. The public should monitor the progress and strength of the storm through local television, radio and internet. Boaters can monitor its progress on VHF radio channel 16. Information can also be obtained on small craft advisories and warnings on VHF radio channel 16.

– Don’t rely on social media. People in distress should use 911 to request assistance whenever possible. Social media should not be used to report life-threatening distress due to limited resources to monitor the dozens of social media platforms during a hurricane or large-scale rescue event.

Shared content for Virgin Islands Source and St. John Tradewinds.

Hurricane Maria Death Toll Estimate Climbs To Nearly 3,000: Study

Researchers found that, among other issues, physicians weren’t properly trained to certify deaths in disasters.

Why the Atlantic Hurricane Season Is So Different Right Now Compared to a Year Ago

Conditions in the atmosphere and ocean waters of the tropical Atlantic basin are different now compared to a year ago, providing a potential signal for what forecasters expect to be a less active hurricane season.

Here are three ways the Atlantic looks different than it did a year ago.

(MORE: Hurricane Central)

Satellite Image Comparison

We can assess the difference in the Atlantic between mid-August 2017 and 2018 by looking at one of the most basic tools meteorologists use: satellite imagery.

A year ago Thursday, Aug. 16, Hurricane Gert was well off the U.S. East Coast and several other tropical disturbances were lined up across the Atlantic. One of those disturbances would become Hurricane Harvey several days later.

In its tropical weather outlook issued on the afternoon of Aug. 16, 2017, the National Hurricane Center was tracking Gert and was monitoring three other systems for development.

This year, the tropical Atlantic couldn't look much quieter on satellite imagery.

There are some seeds for tropical storm development called tropical waves in the Atlantic now, but they are poorly organized and not producing much shower and thunderstorm activity.

A moist atmosphere is needed for tropical waves to have concentrated shower and thunderstorm activity, which helps them perk up and become organized tropical storms or hurricanes.

Instead, dry air has been abundant recently from portions of the Caribbean into the tropical Atlantic, putting a lid on the ability of the tropical waves to produce persistent stormy weather.

Cooler Sea-Surface Temperatures 

Sea-surface temperatures (SSTs) in the tropical Atlantic are colder now compared to a year ago.

In early August 2017, the SSTs in the Atlantic were solidly above average, providing a boost for tropical disturbances to grow into tropical storms and hurricanes.

This year, water temperatures in the tropical Atlantic are cooler overall, with some areas running a bit below average for the first part of August. Cooler waters can deter the development of tropical storms and hurricanes.

The animation below compares widespread above-average water temperatures in the Atlantic Aug. 10, 2017, to near or even below-average water temperatures Aug. 9, 2018.

As of Monday, SSTs as a whole are running just below average in the main development region (MDR) of the Atlantic, according to analysis from tropicaltidbits.com. The MDR is a swath of the tropical Atlantic Ocean that stretches from Africa's western coast into the Caribbean.

Stronger Wind Shear

When wind shear is strong, it can keep tropical storms from forming and can rip apart existing storms. Strong wind shear means winds strongly change with height, either in speed and/or direction.

In the first 10 days of August 2017, wind shear was below average in a swath from the western Gulf of Mexico through the Caribbean and into parts of the tropical Atlantic. The lower wind shear helped aid in the active 2017 hurricane season.

In the first 10 days of August this year, there's been a greater than average amount of wind shear from the Gulf of Mexico to the Caribbean and the tropical Atlantic. Stronger wind shear in combination with dry air can be detrimental to the formation of tropical storms.

Of course, all of this does not mean we are off the hook for an impactful tropical storm or hurricane in the Caribbean or the United States in the peak of the season. It takes only one storm to produce major impacts and a memorable hurricane season.

Residents of coastal locations should have a hurricane preparedness plan in place every year no matter how active a season is projected to be.

Marine Weather for AM 712

Aguas Costeras Del Norte De Puerto Rico Hasta 10 Millas Nauticas Mar

Afuera-

Hoy

Vientos del este de 15 a 20 nudos. Oleaje de 4 a 6 pies con oleaje ocasional hasta 8 pies. Periodo dominante de 7 segundos. Aguaceros dispersos.

Esta Noche

Vientos del este de 15 a 20 nudos. Oleaje de 4 a 6 pies con oleaje ocasional hasta 8 pies. Periodo dominante de 7 segundos. Aguaceros dispersos al anochecer. Tronadas aisladas durante la noche.

Lunes

Vientos del este de 20 a 25 nudos. Oleaje de 6 a 8 pies con oleaje ocasional hasta 10 pies. Periodo dominante de 7 segundos. Marejadas del noreste a alrededor de 4 pies en la tarde. Aguaceros y tronadas dispersas.

Lunes En La Noche

Vientos del este de 15 a 20 nudos. Oleaje de 6 a 8 pies con oleaje ocasional hasta 10 pies. Periodo dominante de 8 segundos. Marejadas del noreste a alrededor de 4 pies. Aguaceros numerosos y tronadas dispersas.

Martes

Vientos del este de 15 a 20 nudos. Oleaje de 4 a 6 pies con oleaje ocasional hasta 8 pies. Periodo dominante de 8 segundos. Tronadas aisladas, luego aguaceros aislados.

Miercoles

Vientos del este de 15 a 20 nudos. Oleaje de 3 a 5 pies con oleaje ocasional hasta 6 pies. Periodo dominante de 8 segundos. Aguaceros aislados.

Jueves

Vientos del este de 10 a 15 nudos. Oleaje de 2 a 4 pies con oleaje ocasional hasta 5 pies. Periodo dominante de 10 segundos. Aguaceros aislados.

If A Hurricane Were To Threaten The USVI, Evacuation Of Residents Would Be Among Considerations, FEMA Administrator, Mona Barnes, Say

ST. CROIX — During a press conference held at the Federal Emergency Management Agency’s offices in Sunny Isle here on Wednesday, F.E.M.A. Administrator William Long said the federal agency has been making preparations to ensure an immediate response for the U.S. Virgin Islands in case of a hurricane. Mr. Long, joined at the press event by F.E.M.A. Coordinating Officer for Region II William Vogel, and Mona Barnes, the Virgin Islands Territorial Emergency Management Agency (V.I.T.E.M.A.) director, had met with the governor a day before where the teams discussed contingency plans for the 2018 Hurricane Season — among them what would happen if another major storm were to affect the U.S.V.I.

What would happen if a hurricane were to threaten the U S.V.I. in the coming days? The Consortium posed the question to Mr. Long in light of the over 10,600 residents who have sought help from F.E.M.A.’s Emergency VI Home Repair Program and most of whom have yet to see their homes repaired. The slow progress on the program can be attributed to a snag in the VI government’s ability to access the funds; F.E.M.A. requires the local government to pay upfront for the projects’ costs, while F.E.M.A. reimburses the full cost thereafter. The U.S. Treasury has allocated $186 million so far for the work with more to come, but only $13.6 million had been received by the local government as of Tuesday to pay contractors, according to Mr. Vogel.

Further more, according to Ms. Barnes, V.I.T.E.M.A. had inspected 20 facilities in the territory, and “maybe two or three” were ready to serve as shelters. “We know that’s not going to work,” Ms. Barnes said. “One of the things we’re going to have to start thinking about is evacuation prior to [a storm]. When we usually plan for a storm, it’s 72 hours before a storm; we now have to look at a 120 days because, as Mr. Long said, if we got to move not only patients, we might have to move residents and so we now have to start thinking about the 10,600 people who are part of the emergency program. If they don’t get a roof on and they’re under a blue roof, and we have to move them, we now have to start to think of making decisions.”

Ms. Barnes said the vulnerability of residents whose homes have on blue roofs meant part of the consideration must include evacuation. Pressed by The Consortium to give a concise answer on the evacuation option, Ms. Barnes said, “I’m saying it’s something that we would have to look at.” Mr. Long added, “Evacuation off an island is never optimal. The goal is shelter in place first, and then to be able to maximize the shelter and capacity, and that’s what we’re here doing everyday.”

Still, if a storm were to threaten the territory in the next few days, there would not be enough shelters to house residents, and Virgin Islanders would most likely have to be evacuated.

From left: William Vogel, FEMA Coordinating Officer for Region II, and William “Brock” Long, FEMA administrator (Credit: Ernice Gilbert, VIC)

To that end and with no major storms currently forecast, Mr. Vogel said F.E.M.A. has been assisting the territory in finding ways to expedite release of the $186 million for the home repairs program so that residents’ homes could be repaired before potential hurricanes. Asked directly whether the local government, even in light of its inability to cover the upfront costs, would receive the hundreds of millions allocated to the territory for the repairs, Mr. Vogel said “we have no concerns” that the monies will be released.

“We can write certain projects where we do what they call expedited project worksheets. And in that project worksheet for that project, we can take some of the money and we can obligate it to the territory as soon as we understand exactly what the entire project is going to look like,” Mr. Vogel explained. “We can take 50 percent of the total amount of money for that project, write this expedited project worksheet, the territory agrees with what it is that we have come up with on this project worksheet, and then obligate the money to the territory — and that money is available in the territory’s smartlink account for them to be able to use towards recovery or restoration.”

In a letter to Mr. Long on Tuesday, Mr. Mapp said, “I am imploring you to act now and help us to pre-position immediate sheltering options for the people of the Virgin Islands as we brace for what is expected to be another busy hurricane season. We are asking you to consider all possibilities, including preparing to provide aircraft and cruise ships in advance of a storm to evacuate as many people as feasible to safety until the storm passes.”

During the press briefing, Mr. Long lauded the Mapp administration and its efforts following the two Category 5 hurricanes in 2017, and the government’s continued work in preparing the U.S.V.I. for the current season. He said F.E.M.A. had provided over $20 billion in federal funding around the U.S. and its territories following last year’s hurricanes and other natural disasters — including the California fires — with $1.6 billion already provided to the U.S. Virgin Islands.

The administrator also committed F.E.M.A.’s presence in the territory for additional years to facilitate the recovery.

Sargassum: The Good, the Bad and the Smelly

You don’t have to see it to know it’s here. The brown sea grass called Sargassum has made a grand entrance into the territory. And it smells.

It started as a nuisance in 2011 when the volume grew considerably. Seven years later, the combination of global warming, pollution and hurricanes formed the perfect conditions for it to grow and prosper. When it gets to land and decomposes, the sulfur-like stench can be overwhelming.

Like many other scientists, Tyler Smith, a marine biologist at the University of the Virgin Islands, is eager to find out the secrets of these floating islands.

“The tremendous amount of grass that has entered our waters seems to have come up from the coast of Brazil and from the Sargasso Sea, a two-million square mile area at the Bermuda Triangle,” Smith said.

This sea without borders is confined by the North Atlantic Gyre, a set of currents that move water around the ocean.

“An estimated 10 million tons of grass, sometimes three to five feet thick, is gathered in this location,” Smith said, adding that scientists believes “the trifecta of warmer waters, pollution and storms conspired to increase the volume and send much of it our way. It is the most we’ve ever seen.”

Sargassum is nothing new. Christopher Columbus is said to have sailed through the thick of it in 1492. Until recently, it was simply a minor feature among the flotsam of the sea.
The situation today gives marine biologists the opportunity to study the grasses in depth and its effect on coral.

“Our post-hurricane monitoring is ongoing at 32 sites from 19 to 220 feet (in depth) and it is our best look at coral ever. The good news is that it is unlikely to harm our corals, perhaps excepting some small, shallow coves,” Smith said. “Our colonies at 100 plus feet are surprisingly healthy. The large reef we study in Brewers Bay is thriving. The storms have lowered the deep water temperatures and that will hopefully be a boost to the coral and a bust to hurricane formation.”

Marine scientist Blair Worthington compared the sargassum and ocean to their seeming opposite.

“The open sea is like a desert and Sargassum is an oasis in that desert,” Worthington said.

The grass provides food, refuge and breeding grounds for turtles, sea birds and crabs and is a nursery for Mahi-Mahi. This habitat available because it floats at the surface thanks to the small, gas-filled “berries” that adorn the branches.

Another benefit is its use in pharmaceutical research (it has been used in Chinese medicine since the 8th Century) and as an important ingredient in biofuel. The grass also helps in the formation of dunes by catching and holding blowing sand.

On the negative side, Sargassum often carries bacteria that can cause irritation in allergic humans, and might be a support system for the invasive species of lionfish. The prolific intruders decimate the local reef fish. Their population is being held in check by the human harvesters who target the species and offer them for sale to restaurants. The lionfish is gaining repute as a delicacy for its tasty white flesh, similar to the butterfish.

The grass should have no effect on ciguatera, the toxin found in small reef fish. Incidents of fish poisoning in the territory have remained at approximately 12 cases per thousand for several years.

Finally, the last but not least negative is its dizzying smell of rotting fish.

Coral Bay Survey Finds Two Thirds of Respondents Feel Unprepared for 2018 Storm Season

A full two thirds of respondents to an online survey conducted by the Coral Bay Community Council say they don’t feel prepared for the 2018 hurricane season that began at the start of June.

Coral Bay, St. John, was one of the areas of the areas in the Virgin Islands hardest hit by Hurricane Irma in September 2017. With predictions calling for an average to active 2018 storm season, the CBCC created its 24-question survey in May with the goal of finding out where things stand with Coral Bay residents, many of whom said they felt neglected in the aftermath of Irma and Maria.

The survey included questions about homes and infrastructure, priorities, ratings of assistance and insurance, and personal situations and long-term goals.

“We wanted to get the complete results out as fast as possible,” said CBCC’s president Sharon Coldren. “We hope the information will be useful and inspiring to government agencies, relief organizations and individuals in prioritizing actions we can take.”

More than 60 percent of the survey’s 178 respondents were full time residents of St. John, with the rest a mixture of winter residents, repeat visitors, and vacation rental owners.

According to the most recent U.S. census of the Virgin Islands, 634 people resided in the Coral Bay subdistrict in 2010, with another 51 people residing on the island’s east end, where residents were also invited to participate in the CBCC survey.

More than 70 percent of respondents to the CBCC survey were over the age of 55.

A news release from the CBCC said the survey results were divided into full time residents, vacation rental owners and business owners to see if there was a difference in perspectives on the recovery among those groups.

“There are some differences in perspectives, but overall people have the same priorities,” the release states.

Unsurprisingly, the survey found that almost all respondents suffered some damage to their homes and business in 2017’s back-to-back category 5 storms. But, while only 33 percent said they feel prepared to face down another storm, nearly 70 percent reported they are making steady recovery progress, and only 12 percent say they have no safe place to stay during any storms that might arrive in 2018.

However, 36 percent of respondents said they have no reliable way to reach 911 today due to lack of any reliable communications at their home – cell, internet or landline. According to the CBCC this is also making rental owners nervous for their visitors, who cannot use their cell phones due to currently limited service areas.

The survey found that debris removal remains a pressing concern in the Coral Bay area – both to avoid the debris causing damage in future storms, and to put on a good face for tourism. About 88 percent of respondents said removal of debris piles from roadsides is still an immediate need nine months after the hurricanes, while 76 percent said removal of debris from private property is an immediate need.

Respondents did not rank their experiences with the Federal Emergency Management Agency (FEMA) highly. Over half ranked their FEMA experiences as poor, partially OK, or OK, while only 23 percent ranked their experiences as pretty good or excellent.

CBCC itself received high marks from respondents for its efforts to help in Coral Bay’s recovery. More than 85 percent rated the assistance given by CBCC after the hurricanes as pretty good or excellent.

“More analysis and the open-ended comments may be added to the website and in future reports later, and we are happy to discuss detailed responses with anyone trying to assist in our overall recovery,” Coldren said.

The results of CBCC’s survey can be viewed at: https://coralbaycommunitycouncil.org/hurricane-recovery-2/survey-hurricane-recovery-status-update-for-coral-bay-st-john-may-2018/

More information is available by contacting Sharon Coldren, CBCC at 340-513-4298.

El Niño Watch Issued: Chance of El Niño Conditions Developing Increases During Upcoming Fall, Winter

An El Niño watch was issued in the latest outlook from NOAA, indicating an increasing chance for El Niño conditions to develop later this year.

(MORE: Warm Water Creeps Eastward in the Pacific)

ENSO-neutral conditions have been in place this spring, meaning sea-surface temperatures across the central and eastern equatorial Pacific have been close to average, and as mentioned, are expected to remain in place into this summer.

As a reminder, the criteria for El Niño conditions are that the average sea-surface temperatures in a region of the central and eastern equatorial Pacific known as Niño 3.4 need to be at least 0.5 degrees Celsius warmer than average in the preceding month and the anomaly has persisted or is expected to persist for three consecutive months. In addition, the atmosphere over the tropical Pacific also needs to exhibit certain characteristics.

Over the past four weeks equatorial water temperatures were near average across most of the Pacific Ocean, with the exception of the western Pacific, which has continued to have above-average water temperatures.

Water temperatures in the far eastern equatorial Pacific remain slightly cooler-than-average, but as shown in the map below, the change from early May to early June has been an increase in temperature.

Recently there has been a build-up of heat within the tropical Pacific Ocean, NOAA noted in its outlook. This would support a gradual development of El Niño conditions.

In addition, positive subsurface temperature anomalies have strengthened and expanded across the equatorial Pacific over the past two months, the NOAA report notes.

The majority of computer models indicate that El Niño conditions become most likely during the upcoming fall and winter.

What Does This Mean For U.S. Weather?

If El Niño conditions were to develop, there are implications to the weather in the U.S.

First, if an El Niño pattern were to emerge this fall during the Atlantic hurricane season the number of tropical cyclones that develop could be suppressed.

(MORE: 2018 Atlantic Hurricane Season Outlook)

When El Niño is in place during hurricane season, stronger-than-average upper-level winds develop over portions of the Atlantic Ocean. As a result, possible tropical cyclones are torn apart.

However, there are other factors that contribute to the number of named storms that develop, so a developing El Niño does not mean there will be fewer storms.

If El Niño conditions are present during the winter, the jet stream pattern over the U.S. shifts and can result in a wetter-than-average winter across the southern tier of the U.S., including portions of California. 

During an El Niño winter temperatures are also typically cooler-than-average from the southern Plains into the Southeast and warmer-than-average from eastern Alaska into western and central Canada and into the Pacific Northwest, northern Plains and Midwest.

The strength of the El Niño plays an important role in impacts across the U.S., including in the tropical Atlantic. At this point, it is too early to know when an El Niño pattern may develop and how strong it might be.