Forecast: Tracking windward and mauka showers before periods of heavier rain
(Image: Hawaii News Now)
Good Wednesday Morning! It will be a windy Wednesday with the gusty trade winds. We are forecasting big changes in your 7 day outlook as we head towards the weekend.
We are tracking an area of high pressure northeast of the state that will keep a breezy to locally windy trade wind flow in place through Thursday, with showers favoring windward and mauka areas. The trades will weaken and shift around to the southeast and south late in the week and over the upcoming weekend.
With the shift in winds, we will see it carry deep tropical moisture and locally heavy rainfall northward into the island chain. We will be tapped into this moisture source for several days allowing for the threat of thunderstorms popping up across the state. There is also a chance for snow to fall over our Big Island summits the next several nights. You can track the rain and possible thunderstorms using our interactive radar on our Hawaii News Now Weather Now app.
You can expect a string of days that we will see periods of heavy rain. During Thursday night through the weekend our weather conditions will likely become increasingly unsettled across many neighborhoods, with the potential for heavy rainfall and flooding a possibility. Not everywhere will be a washout, but where it does come down, we may potentially see flooding issues.
A trough, an area of low pressure aloft, will begin to develop to the west of the state Thursday night as a deep upper level trough begins to approach from the west. It will take along with it unstable air and cold air aloft to hang over the state. These ingredients along with the tropical moisture will lead to heavy downpours.
Our weather team has posted a first alert and the National Weather Service will likely issued a Flash Flood Watch as models continue to show these elements coming together. Stay tuned.
It will likely remain somewhat unsettled as we head into next week, due to a muggy southerly flow. That is expected to continue into early next week, but overall the brunt of the most severe weather will occur this week into the weekend before we will begin to see conditions improve early next week as the deepest moisture and more unstable weather lifts north of the Aloha state.
Let's talk surf.
Front runners from a long period northwest swell are forecast to reach the islands Thursday night, peaking Friday, then gradually subsiding through the weekend. This swell is expected to bring advisory-level surf to exposed north and west facing shores from Thursday night through Friday.
Stay safe on the slick roadways as rain and even snow for Big Island summits hits the pavement here in Hawaii.