A wet Christmas, as well as a green one, appears likely, according to the National Weather Service.
Forecaster John Bravender said today “will be a typical day with regular tradewind showers.”
“Friday, there will be an upper-level low (pressure system) that will come in and destabilize things a little bit, kind of like the past few days,” he added. “So, we could get a few heavier showers off and on. Nothing particularly organized, like with a (storm) system coming in but more rainfall.”
The extended forecast for Hilo predicts a 70 percent chance of showers today, with an 80 percent chance of rainfall tonight through Saturday night.
Tuesday night brought thundershowers to the Hilo area. Rainfall totals for the 24-hour period ending at 8 a.m. Wednesday were 2.72 inches at Hilo International Airport, 2.25 inches in Mountain View, 2.02 inches in Glenwood and 3.02 inches in Piihonua, above Hilo town.
And while December usually is a wet month in Hilo — with last year a notable exception — there has been above-average rainfall this month, with 10.87 inches as of Wednesday, almost 2 inches above the norm of 8.96 inches.
It’s also been a wetter-than-normal 2015, with the Hilo airport totaling 141.9 inches as of Wednesday, almost 18 inches more than the average of 124.11 inches.
The snowfall dusting on the summit of Mauna Kea earlier this week had mostly melted away by Wednesday, but there is a possibility of more, Bravender said.
“We could get some more this weekend with that upper (low pressure system) trough coming in, keeping us unstable and affecting the Hilo side. It looks like it will be deep enough or tall enough to reach up to the summit level and bring some winter weather to the summit areas,” he noted.
Forecasters have been predicting a drier-than-usual winter because of El Niño, the Pacific weather phenomenon marked by warmer-than-normal ocean waters. Bravender is standing by that forecast.
“It looks like, starting early next week, we’ll see more of an El Niño-like pattern, where there’s a strong (high-pressure) system going across the North Pacific,” he said. “There’ll be a ridge right over us, so winds will get lighter and it’ll also be drier than we have been. Any weather disturbances will be well north of us, and we’ll have the ridge keeping us stable and relatively dry.
“Overall, we’re expecting the winter to be drier than normal. We haven’t really seen that so much the last month or two, but as we get later into the season, we’re expecting to get more of this drier-than-normal pattern.”
Email John Burnett at jburnett@hawaiitribune-herald.com.
