CSU is predicting nine more named storms through November, three hurricanes, and one major hurricane of Category 3 or higher. Today’s forecast does not include sub-tropical storm Alberto, or hurricanes Beryl and Chris.
A normal season has 12 named storms, six hurricanes and three major hurricanes.
“If this were June, they would probably start tracking it, but the climatology is really against something forming this early,” said Weather Underground co-founder Jeff Masters about the NHC. “This does have a chance of becoming a sub tropical depression or depression by Saturday. I give it a 10 percent chance.”
For the past three years, tropical systems have formed before the June 1 start date.
Tropical Storm Arlene formed in April 2017. In 2016, Hurricane Alex formed in January, followed by Tropical Storm Bonnie spinning up in May. Tropical Storm Ana formed in May 2015.
Storms that form early in the year outside of the deep tropics are not a foreshadowing to a busier hurricane season.
In 2012, two tropical storms occurred in May — Alberto and Beryl. That turned out to be a busy year with 19 named storms and 10 hurricanes. But in 2015 Tropical Storm Ana formed in May, and there were just 11 named storms and four hurricanes.
In roughly the past decade, back to 2007, there have been six Atlantic tropical storms to form in May. All but one have formed somewhere between the Carolinas and the Bahamas. Interesting feature in the models near the Bahamas late this week – wet for Puerto Rico.
It’s hard to believe but the official start of the 2018 hurricane season is just around the corner.
To get ready for the June 1 kickoff, emergency managers, meteorologists and law enforcement officials are meeting this week in Orlando to cover topics from Hurricane Irma’s traffic nightmare to an early look at what the season may have in store.
The 2017 season had three of the top five most expensive hurricanes on record with hurricanes Harvey, Irma and Maria.
Phil Klotzbach, a Colorado State University hurricane expert, will speak today about what’s happening in the atmosphere that may influence the 2018 season.
Also today, state leaders will discuss evacuation planning and what lessons were learned about fuel supplies during Hurricane Irma.
Follow me on Twitter @kmillerweather for updates. I’ll be participating in a session this morning on making sure the media get correct and timely information from emergency managers to relay to the public.
If you have any questions, please email me at firstname.lastname@example.org.
As far as total named storms, this season is tied now with 2016, which had Hurricane Otto form in late November. Otto, which was upgraded this year to a Category 3 after a reanalysis, made landfall in Nicaragua on Oct. 24.
The 2012 storm season made it all the way to Tropical Storm Tony, which formed in late October.
Update 5 p.m.: Tropical Storm Franklin weakened a little as it made its trek across the Yucatan Peninsula with maximum sustained winds of 40 mph at the 5 p.m. advisory from the National Hurricane Center.
Forecasters expect Franklin to strengthen over the very warm waters of the Bay of Campeche, which it will move across tonight and Wednesday.
The storm should be near the coast of mainland Mexico Wednesday night or early Thursday with 70 mph winds.
That’s not quite hurricane strength, but the hurricane center isn’t ruling it out.
“Given that it is quite possible that Franklin could become a hurricane by the time of landfall, it is prudent to maintain the hurricane watch for the southwest Gulf coast of Mexico,” forecasters wrote.
If it gains hurricane-strength, it would be the first of the 2017 season.
Previous story: Tropical Storm Franklin was still packing 45 mph winds this morning eight hours after making landfall on the Yucatan Peninsula.
As of the 8 a.m. advisory from the National Hurricane Center, Franklin was 95 miles east-southeast of Campeche, Mexico, heading west-northwest at 14 mph.
The chances of Franklin becoming the first hurricane of the 2017 season were lowered this morning with forecasters expecting it to only restrengthen in the Bay of Campeche to a strong tropical storm with 70 mph winds.
Southeast Florida, and the Florida Keys in particular, is a Tornado Alley for waterspouts, according to the National Weather Service in Miami and the International Centre for Waterspout Research’s website.
The waters surrounding Florida provide warmth and moisture for growing clouds that can spawn waterspouts. Often, the clouds that form them are not thunderstorms. In fact, it doesn’t have to be raining for a waterspout to develop, and they can occur while skies are partly sunny.
Waterspouts are caused by a convergence of very light winds — a land breeze and an ocean breeze, 5 knots or less from each direction, he said.
But the premature birth of disturbances in the main development region of the Atlantic, and now Tropical Storm Don, has also been a past indicator of a busy storm season.
“It is unusual to have frequent disturbances in the main development reason in June and July, since ocean temperatures in that region still do not support development in most years,” said Todd Crawford, chief meteorologist for The Weather Company.
The sea-surface temperatures, however, are unusually warm in the area of the tropics where storms typically don’t start appearing until August through October.
“All other things being equal, this is foreboding as we head into the heart of the season, and we do expect a relatively active season this year given the warm ocean waters,” Crawford said.
Klotzbach’s updated hurricane forecast now calls for a total of 15 named storms, eight hurricanes and three major hurricanes. These numbers include the three tropical storms that formed prior to Don on Monday.
The average storm season has 12 named storms, 6 hurricanes, and 3 major hurricanes.
“Often, our July update doesn’t change, but this year we did up it because it is just looking more conducive for activity,” Klotzbach said. “Having a lot of these kinds of systems coming off and looking decent, that tends to be a sign for a nasty season.”
But there are always caveats, Klotzbach said. The 2013 season was forecast to be above average and it ended with only two hurricanes.
“The Atlantic is always on the edge of getting a lot, or getting a little,” Klotzbach said.
This is a breaking news story. Please check back for updates.
Update 5:20 p.m.: A flood warning has been issued for areas of central and south Palm Beach County, including West Palm Beach.
Up to 3 inches of rain is possible with tonight’s storms, with localized higher amounts. Areas with poor drainage and those that are prone to flooding are vulnerable.
The warning is in effect until 11:15 p.m.
“Key to the flood threat is how long any of the heavier cells remain over the area,” said Robert Molleda, the warning coordination meteorologist with the National Weather Service in Miami. “The main band is moving fairly quickly, but showers and thunderstorms developing ahead of the rain band could prolong the period of heaviest rainfall over southeast Florida.”
Update 4:20 p.m.: Commuters will face another stormy rush hour today as showers begin in Palm Beach County.
The National Weather Service has extended the flood watch for Palm Beach County through 2 a.m. Thursday and have warned of wind gusts of up to 55 mph with the most robust thunderstorms.
A storm moving through southwest Palm Beach County triggered a special weather statement for frequent lightning and high winds. The storm, located 28 miles west of Davie, was moving northeast at 40 mph.
Update 2:52 p.m.: The National Weather Service extended the flood watch for Palm Beach County through 2 a.m. Thursday as showers move in from the west.
Additional periods of heavy rain are expected across South Florida through this evening and into the early morning hours. That’s on top of heavy rains over the past 24 hours, including more than 10 inches in west Boca Raton.
“Any additional rainfall on top of already saturated conditions could cause roadways to become impassible,” forecasters wrote.
Up to 4 more inches of rain is in South Florida’s future through Friday with water managers working pumps overtime to avoid flooding.
The deluge of rains is expected to continue throughout today and into tomorrow so the alerts may be extended as slow moving thunderstorms lumber through the area.
The National Weather Service in Miami is reporting no major flooding in Palm Beach County, although some neighborhood streets are underwater and caution is urged during the morning commute.
Heavy rainfall on top of already saturated conditions may lead to more flooding in some urban and poor drainage areas. Some roadways could become impassible, forecasters note.
“It’s incredible what’s going on, really,” said Dan Kottlowski, a senior meteorologist with AccuWeather. “When you look at the upper air maps, it doesn’t look like early June.”
The unusual combination of a deep dip in the subtropical jet stream over Florida and leftover moisture from the now fizzled Tropical Storm Beatriz, which formed in the Pacific this past week, has left South Florida in a soggy situation.
Kottlowski said the polar jet stream is near the Canadian border, but a cold pool of air over the Great Lakes caused a split that pushed the subtropical jet deep into the Gulf of Mexico and across Florida. There is also a slow-moving low pressure system in the northern Gulf helping pull warm, tropical air into Florida.
The updated forecast more closely aligns with the Climate Prediction Center’s forecast, which was released last week. The center is predicting 11 to 17 named storms, five to nine hurricanes, and two to four major hurricanes of Category 3 strength or higher.
Colorado State University hurricane expert Phil Klotzbach hinted Friday that his early April forecast may have undercut the number of storms possible this hurricane season.
While his next official forecast will be released June 1, he told an audience of more than 100 at the Governor’s Hurricane Conference in West Palm Beach that changes in the atmosphere since March may bolster storm activity.
His April 6 forecast called for a slightly below average hurricane season with 11 named storms, four hurricanes and two major hurricanes of Category 3 strength or higher.
An average hurricane season based on 30 years of climatology consists of 12 named storms, six hurricanes and two major hurricanes.
“I think indications are the season will be more active than what we talked about in our April forecast,” Klotzbach said. “The Pacific is on the warm side of normal, but not up to an El Niño threshold.”
Klotzbach, and others who put out seasonal forecasts, rely heavily on what El Niño is doing to make their predictions.
The global climate pattern, marked by a warming of the equatorial Pacific Ocean, works against hurricanes. Its west-to-east wind pattern can shred storms as they develop in the Atlantic basin.
Computer models have hinted at an El Niño since at least December, but its appearance would be unusual because it would be on the heels of the strong El Niño that occurred in 2015-2016.
The Climate Prediction Center had put the chances of El Niño starting in late summer or fall at 50 percent. That has since been reduced to 45 percent because of a “lack of a clear shift toward El Niño in the observational data.”
Instead there is a lot of warm water along the west coast of Africa and east coast of the U.S. While the warm water along the U.S. coast isn’t a clear predictor for a more active season, Africa is a different story.
“If that pattern were to persist, it tends to be relatively conducive for active hurricane seasons,” Klotzbach said. “Next month is going to be critical.”
If Klotzbach adjusts his forecast, he doesn’t think it will be by much, likely just bringing it up to an average season and to account for Tropical Storm Arlene.
Arlene formed April 20 hundreds of miles west of the Azores. While it was not a threat to the U.S., it was notable for such an early formation – a full month before the official June 1 of the hurricane season.
Klotzbach said early storms are not an indication of a busier season.
CSU’s forecast also considers the probabilities of at least one major hurricane making landfall in the U.S. The chances for a hurricane to hit the East Coast, including the Florida peninsula, are 24 percent this season, below the average for the last century of 31 percent.
For the Gulf Coast, including the Florida Panhandle, the chances are 24 percent, below the average of 30 percent.
The National Oceanic and Atmospheric Administration’s Climate Prediction Center is scheduled to release its 2017 hurricane forecast on May 25.