Tropical System May Threaten Hawaii Next Weekend, Development Near Mexico May Follow

By Alex Sosnowski, AccuWeather.com Senior Meteorologist

July 5,2015; 9:20PM,EDT

 

As a pulse of showers and thunderstorms rolls slowly eastward across the Pacific, an uptick in tropical activity is likely around Hawaii and then near the shores of Mexico as July progresses.
This pulse of shower and thunderstorms is known as the Madden-Julian Oscillation (MJO) and tends to migrate slowly eastward around the equatorial regions of the globe. The MJO can cause quite tropical areas to turn active and can cause modest tropical activity to strengthen.
One area of concern for the first full week of July is southeast of Hawaii.
According to AccuWeather Hurricane Expert Dan Kottlowski, one of several disturbances lurking south of Hawaii, over the Central Pacific could develop this week.

"The disturbance that has the best chance of development is currently located about 2,000 miles southeast of Hawaii, but may approach the islands during the second weekend of July."
People traveling to or living in the Hawaiian Islands will want to monitor the progress of the disturbance, which could develop into a tropical storm or hurricane. The next name on the list, depending on where the system develops is Dolores in the East Pacific or Ela in the Central Pacific.
"Because of shifting upper-level winds in the atmosphere, it is too early to say for sure whether this system would track very close to Hawaii or veer to the west or east of the island," Kottlowski said.
RELATED:
El Nino to Weaken Monsoon, Exacerbate Drought in Pakistan, Northwestern India
East Pacific Hurricane & Tropical Storm Center
Atlantic Hurricane & Tropical Storm Center
The MJO pulse is believed to have caused the latest uptick in tropical activity in the western Pacific in the past week and during June in the Indian basin.
The pulse will expand toward the central Pacific during the first full week of July.
Along with the pulse, El Niño will continue to be the main driver for development in the Pacific and limited development in the Atlantic this season.

"During El Niño years, there is often close impact with tropical systems on Hawaii and a higher number of tropical systems in the Central Pacific basin in general," Kottlowski said.
As the MJO pulse continues eastward, it could lead to development near the west coast Mexico and perhaps in the western Gulf of Mexico during the middle part of July.
"Whether this is development or not in these areas at mid-month will not be entirely depending on the MJO, but more so with favorable winds aloft and a moist environment verses strong winds aloft and extensive dry air," Kottlowski said.

The effects of El Niño tend to be neutral along the Pacific Coast of Mexico, but a significant deterrent against a great number of tropical storms and hurricanes in the Atlantic basin, which includes the Caribbean and the Gulf of Mexico.