• Storm churns off U.S. East Coast as models fail to find track
  • Warm water forecast to build storm to Category 1 hurricane

Tropical Storm Joaquin jumped in strength and is forecast to become a Category 1 hurricane by Wednesday, even as computer models disagree on where it will end up.

Joaquin’s top winds reached 65 miles (105 kilometers) per hour, up from 45 mph earlier Tuesday, the Miami-based National Hurricane Center said in a 5 p.m. advisory. The system was moving west-southwest at 5 mph and was about 405 miles east of the northwestern Bahamas.

“Additional strengthening is forecast during the next 48 hours,” according to the advisory written by senior hurricane specialist Richard Pasch. “Joaquin could become a hurricane on Wednesday.”

Storm shown in photo taken by NOAA satellite Sept. 29, 2015, east of Bahamas.
Storm shown in photo taken by NOAA satellite Sept. 29, 2015, east of Bahamas.

Joaquin, the 10th storm of the six-month Atlantic hurricane season that ends on Nov. 30, is forecast to reach sustained winds of 90 mph by Friday, making it a strong Category 1 system on the five-step Saffir-Simpson scale.

Warm Waters

Wind shear, which had been tearing at its structure, is expected to drop off, and the storm will pass across water that is about 86 degrees Fahrenheit (30 Celsius), the warmest ever in that part of the Atlantic in records going back to 1880, Jeff Masters, Weather Underground co-founder, wrote on his blog Tuesday.

“It looks like the bottom may fall out of this one,” said Phil Klotzbach, lead author of the Colorado State University seasonal hurricane forecast. The warm water runs deep and that can allow the storm to intensify rapidly.

While the storm’s strength is coming into clearer focus, its path has remained hard to determine.

The forecast is complicated by the number of moving parts on the weather map right now, said Tom Downs, a meteorologist with WeatherBell LLC in New York.

“Meteorologically, the interesting thing is the number of players on the field,” Downs said, citing a cold front, a system that was in the western Gulf of Mexico, another that moved over Florida from the eastern Gulf of Mexico and the remnants of Tropical Storm Ida, farther east in the Atlantic. “This is one of the reasons the forecast is so challenging and the wide range of potential solutions.”

Models Disagree

Two computer models disagreed on the storm’s five-day track by 1,000 miles, Klotzbach said.

Two runs of the European Centre for Medium Range Weather Forecasting model came back with different locations as to where the storm would be on Sunday, Masters said in an e-mail interview.

“So the forecast situation is unusual and complex,” he said.

The situation should clear up as reconnaissance aircraft flying into Joaquin get better data to feed into the computer models, Masters said. The National Oceanic and Atmospheric Administration will leave a dropsonde instrument package in the storm.

Track Uncertain

“Anyone who says they have any confidence in where it is going to go is lying to you,” said Rob Carolan, a meteorologist at Hometown Forecast Services Inc. in Nashua, New Hampshire.

On top of the threat from the storm itself, the U.S. Northeast, including New York, will get drenched from “fire-hose precipitation,” Carolan said. This will be in addition to heavy rain falling on the area from other weather systems through Wednesday.

Through the next week, nearly 9 inches (23 centimeters) of rain is forecast to fall across New England, and about 8 inches in southern New York and northern New Jersey, the U.S. Weather Prediction Center said.

All that water will be flowing into urban rivers and heavily populated areas, which could make the flooding worse, Carolan said.

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