Weather forecast for Hawaii County on Thursday, October 8, 2026, show say low pressure wey dey strengthen about 750 miles north of Kauai go bring stronger south winds through Thursday and pull deep tropical moisture over at least western half of di island chain.
Di threat of heavy flooding rainfall and thunderstorms go greatest tonight and Thursday over Kauai and Oahu, where a Flood Watch dey in effect.
Chances for heavy rain go reduce on Friday as di low weaken several hundred miles northwest of Kauai.
Di low go slowly fill on Saturday and Sunday, even though a few heavy showers fit still linger through di weekend under southeast to east winds.
For Hawaii County, forecast for rest of tonight na mostly cloudy early in di evening, then partly cloudy with scattered showers after midnight. Lows go be 68 to 75 near di shore to around 61 at 4000 feet. Southwest winds up to 15 mph. Chance of rain 50 percent.
Thursday forecast for Hawaii County na partly sunny. E go breezy. Scattered showers early in di morning. Showers late in di morning, then scattered showers in di afternoon. Highs go around 84 near di shore to around 71 at 4000 feet. South winds up to 20 mph shifting to di southeast 10 to 20 mph in di afternoon. Chance of rain 80 percent.
Thursday Night forecast for Hawaii County na mostly cloudy. Scattered showers early in di evening, then isolated showers in di late evening and overnight. Lows go be 69 to 76 near di shore to around 63 at 4000 feet. South winds up to 10 mph. Chance of rain 50 percent.
Di flood threat go diminish significantly on Big Island. Southeast slopes of di Puna and Kau Districts fit experience a brief period of heavy rainfall, and spotty showers go possible elsewhere on di island, mainly in di afternoon.
While gusty downsloping winds to di north of terrain dey usually a concern in dis setup, di flow no appear strong enough for gusts to reach di advisory level of 50 mph.
Flood Watch dey through Thursday afternoon for Niihau, Kauai, and Oahu. Wind Advisory dey until 4 PM HST Thursday for Big Island Summits.
Maui County go dey on di outer edge of di zone of concern for heavy showers, and even though dem no include am in di Flood Watch, there still be some chance of impacts, especially on Molokai and Lanai.
Di low go stall and begin to gradually weaken roughly 800 miles northwest of Kauai on Friday. Di jet stream on its eastern flank go retreat northwest of di islands. Dis go reduce upper level support for widespread heavy rainfall.
But light southeast winds go persist and rich but shallow moisture go remain pooled over di islands. Under dis humid conditions with dew points hovering in di low to mid 70s, isolated pockets of heavy showers fit still flare up, especially along terrain.
At dis time, extension of di Flood Watch no dey planned, even though e possible. Guidance suggest light east to east-southeast winds go gradually push di high precipitable water air mass westward during di weekend as di low fill northwest of Kauai.
Chances of heavy rainfall go diminish, though some isolated nuisance flooding go still possible near terrain. Dis one go also bring some relief from di humidity as dew points slowly lower.
Guidance diverge somewhat early next week. Di GFS clears out di low and ushers in a moderate trade wind flow, but di ECMWF maintains some lingering remnants of di low north of di state and keeps di trade wind flow very light.
Gentle to moderate south to southeast winds go continue over di next couple of days as a low pressure system develops north of Hawaii. Enhanced showers with di potential for a few thunderstorms dey forecast for di western half of di state through Thursday.
A surface trough go linger near di area through di weekend and early next week keeping potential for variable winds and unsettled weather.
South swell go maintain into next week with pulses of long period reinforcement arriving Thursday and Saturday. Surf go stay below advisory levels along south facing shores. Small to moderate surf along north and west facing shores go continue through di rest of di week as swell energy dey reinforced by di slowly moving surface low northwest of di Hawaiian Islands. A larger swell go arrive around Tuesday, bringing north and west shore surf to just below advisory thresholds. Surf along east facing shores go remain small as local winds remain fairly weak.
Moist and humid conditions under moderate south winds go develop overnight and persist through Thursday. Chances for widespread rainfall go diminish on Friday while humid and light southeast winds prevail. Light to moderate easterly trade winds dey expected dis weekend. Di inversion go wiped out by evening and go likely not redevelop until di weekend.
