Rain, Surf to Target Hawaii as Niala Approaches

By Brett Rathbun, AccuWeather.com Meteorologist

September 26,2015; 11:20PM,EDT

 

 

Although Tropical Storm Niala is not expected to make a direct landfall to Hawaii, it will bypass close enough to bring heavy rain and high surf to the Islands.
As of 5 p.m. HST Saturday (11 p.m. EDT Saturday), Niala was located about 245 miles southeast of Hilo, Hawaii.
Niala formed on Thursday afternoon local time before strengthening into a tropical storm on Friday morning local time.
Latest Satellite Loop of Niala, and thumbnail photos (Image/NOAA).
According to AccuWeather Senior Meteorologist Michael LeSeney, "Niala will track west to west-northwesterly this weekend before tracking west-southwesterly early next week, passing south of the Islands."
Niala will be steered around a large dome of high pressure currently located over the central Pacific, north of Hawaii.
Niala will be entering into an area of strong wind shear as it approaches the Islands. This will cause Niala to maintain its strength this weekend before weakening early next week.
With Niala currently in an area of weaker wind shear, this storm may strengthen slightly early this weekend, but is not expected to intensify into a hurricane.

Heavy rain, capable of flash flooding, and mudslides are expected, mainly across the Big Island as Niala holds an abundant amount of tropical moisture.
"Rainfall will be heaviest across the mountainous terrain and across the Southeast portion of the Big Island," LeSeney said.
High surf will continue along the northern, eastern and southern-facing shores of the Big Island and the northern shores of the smaller islands through Monday. This could lead to dangerous seas for boaters and swimmers. This can even catch seasoned surfers off guard.
Some areas across Hawaii have seen a large amount of rainfall so far during the month of September.
September Rainfall (ending Sept. 25)

City	Rainfall (inches)	Normal (inches) for month
Hilo	21.05	9.94
Lihue	4.77	2.12
Honolulu	4.47	0.55
Wheeler AFB	4.11	3.89
Kalaeloa	2.56	0.79
Kailua	1.45	0.65
Lanai	0.46	0.75
Kahului	0.28	0.38

Due to the amount of rain recently across the state, nearly 96 percent of Hawaii is currently drought free, according to the U.S. Drought Monitor.
The southeast portions of the small islands of Maui and Kauai remain in either an abnormally dry or moderate drought. The heaviest rain from Niala may reach the southern half of Maui but miss Kauai.
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Conditions will improve early next week as Niala weakens and moves away from the islands.
According to AccuWeather Senior Meteorologist Alex Sosnowski, "On average, four to five tropical systems affect the Central Pacific basin each year and most originate from the Eastern Pacific."
"So far, there have been 11 named systems in the Central Pacific during 2015," he added.
The reason for a busier tropical season in the central Pacific is related to a strong El Niño.
"With El Niño forecast to remain strong into the fall, the risk of a tropical system impacting the nearby waters of Hawaii will continue through September and into October. However, steering winds tend to shift during the fall," Sosnowski said.
According to AccuWeather Meteorologist Anthony Sagliani, "By late October, winds aloft usually become too hostile for tropical systems to form or maintain themselves over the Central Pacific."