Forecasters hit the brakes on 2018 hurricane outlooks

Tropical Atlantic SST

Colorado State University issued its updated 2018 hurricane forecast Thursday calling for 13 more named storms, six hurricanes and two major hurricanes — a downgrade from its April 5 forecast. One reason for the pull-back is persistently cooler than average water in the tropical Atlantic. (Image credit: CSU/ Philip Klotzbach via Twitter)

There’s been considerable attention in the media this spring to forecasts for an above-normal 2018 hurricane season, which officially kicks off Friday. But some of the most reliable forecasting organizations are making downward adjustments after considering new data suggesting that activity may be slower than originally thought.

NOAA’s forecast, issued last week, projected up to 16 named storms, although forecasters give themselves plenty of wiggle room by offering a range — this year from 10-16. The average is 12 named storms, so if we hit 16 it would certainly qualify as another busy season.

On April 5, Colorado State University predicted 14 named storms with seven hurricanes and three majors, Category 3 or higher.

In the UK, Tropical Storm Risk, a consortium of insurance experts and meteorologists that has a pretty decent track record over the years, predicted 12, six and two.

North Carolina State University issued the most dire forecast on April 16, for up to 18 named storms with 11 hurricanes and up to five majors.

But on Thursday, the CSU forecast was adjusted to 13/six/ and two. The total does not include Subtropical Storm Alberto.

“While we still do not anticipate a significant El Niño during the 2018 Atlantic hurricane season, most of the North Atlantic has continued to anomalously cool over the past two months,” said Phil Klotzbach, the CSU tropical weather researcher who writes the forecasts along with Michael Bell. “The eastern and central tropical Atlantic is cooler than normal at present. We anticipate a near-average probability for major hurricanes making landfall along the United States coastline and in the Caribbean.”

On Wednesday, TSR issued a revised forecast for nine named storms and noted: “Uncertainties remain sizeable but the odds favour hurricane activity in 2018 being well below average.”

Forecasters referred to “considerable cooling of sea surface temperatures in the tropical North Atlantic and Caribbean Sea.” They also predict stronger trade winds and higher pressures in the Atlantic and Caribbean, all of which are not conducive to tropical storm development.

The Penn State University forecast was for 10 named storms this year, with a bottom-range low of seven storms and a top-range high of 13.

Should these reduced forecasts pan out, 2018 could be the slowest Atlantic hurricane season in four years. The last time we had nine named storms was in 2014, although those nine storms included six hurricanes and two majors. Hurricane Gonzalo, a Category 4, did a number on the Lesser Antilles in October, and Hurricane Fay damaged Bermuda a week earlier.

Could we have a quiet hurricane season even though it started early with Subtropical Storm Alberto? The answer is yes, according to experts. Early season activity does not portend a busy season overall.

Unfortunately, a slow hurricane season doesn’t let anyone off the hook. Forecasters often point to 1992 as proof. That year, the first named storm didn’t materialize until late August, and then it was a doozy — Hurricane Andrew.

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FL May rainfall
The graphic shows total May rainfall around the Florida peninsula. Areas of the Treasure Coast will end the month with more than 20 inches of rain, according to the national Weather Service in Melbourne. (Image credit: NWS-Melbourne)

RECORD WATCH: Daytona Beach was walloped Wednesday with 2.27 inches of rain, a record for May 30. The old record was 1.56 inches set way back in 1930.

Sanford reported 1.02 inches, which also set a record. The previous mark was 0.86 of an inch set in 1996.

The National Weather Service in Tampa announced that Lakeland has set a record for the most rainfall ever recorded in May — 17.86 inches. The old record was 16.03 inches set in 1979. Lakeland joins four other locations in West-Central Florida in posting record-breaking rainfall this month. (See Wednesday Florida Weather Watch post for details.)

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DROUGHT WATCH: Florida’s wet May, topped off with the recent soaking from Subtropical Storm Alberto has wiped out any remaining drought conditions around the state, the U.S. Drought Monitor reported.

In fact, drought has been eliminated in most of the eastern U.S., with just a few Abnormally Dry areas remaining.

 

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Week-long rain train derails Florida drought

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HOW DOES JUNE LOOK IN FLORIDA? Wet, according to the new forecast released by the Climate Prediction Center Thursday. It’s calling for above-average rainfall for the entire state, which is nothing to sniff at considering June is normally one of the wettest months of the year. (Image credit: NOAA/ CPC)

Florida’s heavy rain event over the past week washed away drought conditions and Abnormally Dry conditions over much of South Florida and Central Florida, although pockets remained on Thursday, according to the latest U.S. Drought Monitor report.

Severe Drought in northern Miami-Dade County was reduced to Moderate Drought, as it was in Collier County. The Abnormally Dry conditions in most of Palm Beach County were removed, and counties north of Fort Myers went from Moderate Drought into the Abnormally Dry category.

Pockets of Moderate Drought remained in the Orlando area.

RAINFALL REPORT: Showers and thunderstorms didn’t make it to South Florida’s East Coast on Wednesday as brisk easterly winds kept most of the convection in the western burbs and the peninsula’s interior.

Miami International Airport posted precipitation goose eggs for the first time since May 11, and only a trace of rain fell in Fort Lauderdale and West Palm Beach. Naples managed to pick up 0.08 of an inch, but Marco Island checked in with a hefty 2.46 inches.

Other areas of the peninsula continued to get hammered on Wednesday. The Community Collaborative Rain, Hail & Snow Network reported more than 4 inches falling in northeastern Martin County; 3 inches in St. Lucie County; more than 4 inches in Columbia County in North Florida; and more than 2 inches in the Jacksonville area.

Rain remains in the forecast for the next week.

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TROPICS WATCH: The GFS is back to showing tropical development in the Caribbean prior to Memorial Day Weekend. These model runs are entering broken record territory — repeat, repeat, repeat — and the eventual storm has been pushed back several times.

The experts say this is typical GFS bias for this time of the year, which is still off-season (the hurricane season starts June 1, although nature isn’t very good at calendar watching).

In addressing this issue in his blog, Weather Underground Director of Meteorology Jeff Masters said: “The GFS model suffers from a known bias in over-predicting tropical cyclone formation in the Western Caribbean this time of year.”

Michael Ventrice, a Ph.D. meteorologist who specializes in tropical weather for The Weather Company, parent company of the Weather Channel and Weather Underground, tweeted on May 12: “This is how you know the GFS tropical cyclogenesis Caribbean bias is showing its ugly head. This past week of runs alone are likely going to result in a huge false alarm to genesis ratio for 2018.”

But now, rather interestingly, the European (ECMWF), which doesn’t usually mess around with phantom tropical storms, has hopped on board the Caribbean development train for the holiday weekend. The Thursday run shows a storm — not strong enough to be a hurricane — running up Florida’s West Coast.

Thursday’s run of the GFS brings this system up the West Coast as well, perhaps making landfall just north of Tampa, possibly as a vigorous tropical storm, putting a big damper on the holiday weekend.

Ditto for the Canadian (CMC), which brings it on-shore from the Gulf a bit farther south and has it crossing the peninsula around Lake Okeechobee.

The Navy’s forecast model (NAVGEM) only goes out to the Wednesday prior to the weekend, but also shows a low developing in the western Caribbean off the coast of the Yucatan Peninsula.

Luckily, even though more forecast models are getting into sync on this (still unlikely) event, it’s at least a week away, so there’s plenty of time for forecasts to change. With the wet pattern we’ve been in during this second-half of May, perhaps what we’ll see is just a continuation of that trend, with another round of very heavy rainfall over the Memorial Day Weekend.

Drought conditions expand on Florida’s West Coast

DROUGHT WATCH: Moderate Drought conditions edged north along the Gulf Coast this week, the U.S. Drought Monitor reported Thursday. Moderate Drought now encompasses all of Lee County (Fort Myers area) north into Sarasota County.

Severe Drought continued on the southeastern coast from northern Miami-Dade County west into Collier County. Most of the remainder of the Central and South Florida peninsula remained Abnormally Dry, except Brevard County and Osceola County in Central Florida are dealing with Moderate Drought.

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Keys weather balloon

SPACE ALIENS SIGHTED HOVERING OVER FLORIDA GULF COAST: Well, OK no … it’s a weather balloon, according to the National Weather Service in Tampa (that’s what they always say).  The balloon was launched Wednesday from the NWS office in Ruskin, south of Tampa. It was headed southwest over the Gulf of Mexico. As it cleared 10,000 feet, forecasters reported on Facebook: “The seat belt sign has been turned off…”

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THURSDAY PM UPDATE: The first tropical depression of the 2018 hurricane season in the eastern Pacific formed Thursday afternoon, the National Hurricane Center in Miami said. Tropical Depression One-E was moving west-northwest at 5 mph with winds of 35 mph. It was not forecast to become the Pacific season’s first tropical storm, and was expected to decay into a remnant low on Friday. However, NHC forecasters had reduced chances of development for the system on Wednesday and early Thursday morning, so the low has continued to surprise.

ORIGINAL POST: The National Hurricane Center in Miami was losing interest in the first Pacific invest of the season, 90E, which became less organized on Wednesday as the day wore on. It was given a low chance of development, and could puff out completely on Thursday or Friday as upper level winds become increasingly hostile to tropical development.

Meanwhile, the GFS continued to stubbornly cling to its forecast for tropical development in the Caribbean and Gulf of Mexico toward the end of next week. The Navy tropical forecast model is on board with a low developing off the coast of Central America, but neither the European (ECMWF) nor the Canadian (CMC) had echoed the GFS as of Thursday morning’s runs. Stay tuned ….

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RAIN DELAY: The heavy rains expected to sweep into the Florida peninsula from the Caribbean may be postponed a day or two — but the National Weather Service in Miami is still forecasting a very wet Sunday through mid-week.

From the NWS forecast discussion in Miami Thursday: “The ingredients appear to be coming into place for a very prolonged period of high rain chances and the potential for localized flooding may increase as next week progresses. Rainfall amounts will range between 1 to 2 inches with possible isolated higher amounts.” Forecasters said 2-3 inches are possible for South Florida’s East Coast.

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RECORD WATCH: Wednesday’s high in Naples was 93, which tied a record high set in 2014. It was the third high temperature record tied or set in Naples so far this month.

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CHANGES IN THE PACIFIC: NOAA’s Climate Prediction Center issued its final La Niña Advisory Thursday and said neutral conditions returned to the tropical Pacific in April. The big question now is whether an El Niño will follow summer’s neutral ENSO in fall and winter. If it does, that could have the effect of ramping down the hurricane season.

“The forecaster consensus hedges in the direction of El Niño as the winter approaches,” forecasters said. “But given the considerable uncertainty in ENSO forecasts made at this time of year, the probabilities for El Niño are below 50 percent.”

 

Forecasters keeping eye on Bahamas disturbance

SFL weekend rainfall

New analysis released by the National Weather Service Thursday afternoon calls for some significant rainfall, this weekend, particularly in coastal areas. (Image credit: NWS-Miami)

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Thursday’s Caribbean satellite image showed showers and storms brewing southeast of the Bahamas near Hispaniola, at the tail end of an old cold front. The system is expected to move toward Florida over the weekend. (Image credit: NOAA)

Will we see another early start to the hurricane season?

The disturbance near the Bahamas that has been tracked and analyzed by National Weather Service offices in Florida over the past couple of days has a slight chance of developing into a tropical depression or storm, Weather Underground’s Jeff Masters said Wednesday.

The National Hurricane Center wasn’t talking development on Thursday, but Masters gave the system a 10 percent chance of becoming a tropical depression or Tropical Storm Alberto if wind shear falls on Friday and Saturday as it approaches Florida.

The NHC said in its early Thursday morning Tropical Weather Discussion: “Active weather spawned by the instability of the cold-core low along with abundant moisture drawn northward in a fresh to strong SE wind flow will accompany the surface trough as it moves west through the Bahamas by late Friday and into the Florida peninsula Saturday.

“Showers and thunderstorms will be possible  across South Florida this weekend as well as over western Cuba.”

The National Weather Service in Miami jacked up rain chances for South Florida to 40 percent Friday before rising to 50 percent Sunday through Monday night. NWS forecasters point to a second ingredient that should trigger rainfall over the peninsula — a cold front that’s expected to meander down from the north over the weekend.

“The combination of an approaching front and the moisture associated with the disturbance will result in increasing showers and slight chances of thunderstorms across South Florida starting Saturday,” forecasters in Miami said Thursday morning.

Masters notes that although tropical storms in the Atlantic aren’t common before May 15, we’ve seen such development in each of the past three years, going back to 2015.

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DROUGHT UPDATE: Drought conditions continued to dwindle across parts of South Florida this week thanks to rain that fell late last week. Most of Palm Beach County is now out of Moderate Drought, although it remains Abnormally Dry, the U.S. Drought Monitor reported Thursday. Moderate Drought was also removed from Martin County and southeastern St. Lucie County.

Most of Broward County remains under Moderate or Severe Drought, as does Miami-Dade County, Mainland Monroe and Collier County.

Osceola County and Brevard County also remain under Moderate Drought.

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Small Craft Advisory

A Small Craft Advisory remains in effect through Thursday off Florida’s southeast coast. A gust of 33 mph was reported Wednesday at Fowey Rocks Lighthouse in Biscayne Bay. (Image credit: NWS-Miami)

R-E-L-I-E-F: Rainfall tops 1 inch in parts of the Florida Keys

Keys rainfall

(Image credit: NWS-Key West)

The Florida Keys finally received some substantial rain on Friday and Saturday — just what the doctor ordered for fire-ravaged areas of Big Pine Key.

Marathon picked up 1.43 inches of rain on Saturday after 0.03 on Friday, the National Weather Service reported. Key West measured just a trace of rain on Saturday and 0.04 on Friday.

But heftier amounts were reported by citizen observers in the Keys, including 1.70 inches at Big Pine Key. As the National Weather Service noted, the highest amounts were in the Upper Keys. Key Largo picked up 2.34 inches.

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(Image credit: NOAA/ CPC)

The full May outlook will be issued by NOAA on Monday, but the four-week rainfall forecast posted Friday doesn’t look particularly good, at least for the northern parts of the Florida peninsula and the panhandle.

April rains in the north and the south have helped make a decent dent in drought conditions that have been building over the winter and early spring, but will that continue?

The Climate Prediction Center is calling for normal to above-normal precipitation to start the month, followed by the above shift to drier conditions.

The rainy season in South Florida generally starts around May 20, but that’s hardly locked in.

For example, South Florida has had a decent start to the rainy season the last two years — 2016 and 2017. But in 2015 Miami had more than a 9-inch precipitation shortfall in May and June.

 

Drought conditions improve in coastal South Florida

Red tide

PM UPDATE: A Beach Hazard Statement for potential breathing problems in Collier County due to red tide was posted by the National Weather Service Thursday afternoon. It’s caused by the rapid growth of a microscopic algae. Red tide breakouts are detected by satellite and can cause “high respiratory irritation.” (Image credit: NWS-Miami)

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ANOTHER ROUND OF RAIN FOR FLORIDA’S EAST COAST? A weak cold front slides down the peninsula on Friday, which could set off the next round of showers and thunderstorms. But forecasters at the National Weather Service are not particularly impressed with this system’s potential. Rain chances are around 40 percent Friday in Orlando, Melbourne and Tampa; and 20 percent Friday and Friday night in South Florida. (Image credit: NOAA/ SPC)

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WET WEATHER DAMPENS DROUGHT: Drought conditions improved a bit in southeast Florida thanks to some substantial rainfall early in the week, the U.S. Drought Monitor reported Thursday.

Southeast Martin County, eastern Palm Beach County, and northeast Broward County were upgraded from Moderate Drought to Abnormally Dry in this week’s analysis.

At the same time, though, Severe Drought spread across the Everglades from northwest Miami-Dade into most of Collier County, including Naples, and southern Lee County in the Fort Myers area.

All of Mainland Monroe County is now dealing with Moderate Drought.

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Hurricane Sandy in 2012 was the largest Atlantic hurricane on record. At its peak, tropical storm force winds were massive and stretched from the Upper Peninsula in Michigan to Lake Okeechobee. (Credit: NOAA via Wikimedia Commons)

TROPICS TALK: Global warming will likely increase the intensity of hurricanes by up to 11 percent, experts say — and it may lead to an increase in the size of storms.

That’s the subject of Jeff Masters’ blog post Wednesday on Weather Underground. He says a warming planet will probably boost the number of major storms, Category 4 and 5, and they could pack 20 percent more rain by the end of the century.

The size of storms could also be affected — but that remains an open question.

Masters, who attended the American Meteorological Society Conference on Hurricanes and Tropical Meteorology last week, said two of three computer modeling presented suggest an 8-9 percent increase in hurricanes and tropical storms by 2100. The increased size could occur late in the storm’s life, researchers said.

However, a detailed look at the size of tropical storms over the last 35 years indicates no significant change in their size.

“Until we have a better theoretical understanding of what controls tropical cyclone size, predictions of how this quantity might change in the future climate should be viewed as uncertain,” he said.

Wetter weather pattern may extend into May

May precip

(Image credit: NOAA/ CPC)

Will South Florida’s dry season end early this year?

The Climate Prediction Center is calling for above normal rainfall over the Florida peninsula from April 27 all the way through May 18, which is getting close to the normal start of the rainy season.

And the new monthly outlook released Thursday calls for above normal rainfall in Florida through the month of May.

To kick things this weekend, most of the Florida peninsula will be dealing with rain and possible thunderstorms through Tuesday, while NOAA’s Storm Prediction Center has put the panhandle under a Marginal Risk for severe weather on Sunday.

“Most areas north of an Immokalee to Hollywood line will likely end up with a general 1-2 inches of rain,” the National Weather Service in Miami said in its Sunday morning forecast discussion of conditions through Monday night. “But some isolated amounts over 3-4 inches will be possible just about anywhere, which may bring brief periods of flooding to streets and the usual vulnerable locations.”

More rain is expected on Tuesday until the front is swept away by another  weather system.

Miami hasn’t had a month with above normal rainfall since November, when 4.41 inches fell.

Orlando is running slightly on the precipitation plus side in April, but before this month the city has had below normal rainfall since October. It’s a similar story in Tampa, although Tampa had an unusually wet January.

In Key West, four out of the last six months were on the dry side.

Rainfall totals normally edge up in May, to over 5 inches in Miami; 3 inches in Key West; a little over 2 inches in Tampa and Orlando.

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THE PLASTIC PLANET: Today is the 48th annual Earth Day, and to mark the event Vox.com has a story about seven things we’ve learned about the planet since the last Earth Day.

Topping the list: “The plastic problem is even worse than we thought.” A six-ton sperm whale washed up on the coast of Spain with 64 pounds of plastic in its stomach.

A study published in March by Scientific Reports offers evidence that the “Great Pacific Garbage Patch is rapidly accumulating plastic.”

The Vox report is not all gloom and doom. Another study out in March says the Chesapeake Bay is cleaning up, as evidenced by the proliferation of seagrass, which is now at its highest level in 50 years.

Fertilizer runoff has been limited and states have cracked down on sewage treatment plants that were dumping waste into the Chesapeake.