FXHW01 KWNH 110739
PMDHI

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
339 AM EDT Fri Sep 11 2026

Valid 00Z Sat 12 Sep 2026 - 00Z Sat 19 Sep 2026

Relatively benign weather pattern through the weekend as any
impacts from Lowell will finally be put to rest by the end Friday
with a return to a more general trade wind pattern as high
pressure over the northern Pacific dominates the overall pattern.
By Monday next week, there are hints of another tropical wave
might try to develop into something more appreciable to the
southwest of the islands with a bit of an elevated moisture flux
correlating with the potential disturbance. Most guidance
maintains a low probability of formation, but consensus in the
ensembles are for at least an uptick in areal PWATs, closer to a
+2 standard deviation anomaly which would place PWAT values
between 1.7-2.0" throughout the island chain. 

The National Hurricane Center has maintained a low chance (20%) 
of development over the next 7-days. Despite the low probability
of any tropical formation, the time frame of Tuesday through 
Wednesday, expect a greater coverage of rain across the windward 
sides as compared to the typical day. Consensus is for the
windward sides of the Big Island and Maui to see the greatest
uptick in heavy rain prospects and totals a bit elevated compared
to the normal trade wind pattern. Generally, the weather should 
improve by Thursday, as weak ridging returns the convective 
coverage back to normal, albeit PWATs remaining a bit elevated
according to anomaly forecasts. 

Kleebauer