####018001564####
FXHW01 KWNH 120744

PMDHI 



Hawaii Extended Forecast Discussion

NWS Weather Prediction Center College Park MD

344 AM EDT Fri Apr 12 2024



Valid 00Z Sat Apr 13 2024 - 00Z Sat Apr 20 2024



...Heavy rainfall threat over the western islands late this week...



A deep upper low and surface system currently posititioned

northwest of Hawaii will eventually open up as it lifts

northeastward this weekend. Ongoing heavy rainfall across mainly

Kauai and Oahu will continue today/Friday with abundant deep

moisture and precipitable water values surging beyond three

standard deviations above normal. The guidance continues to

suggest a break around Saturday as the front drifts back to the

west a bit, and then a return of enhanced rainfall to the western

and possibly central parts of the main islands as progression of

the remaining upper trough pushes the front eastward later this

weekend/early next week. The front may stall upon reaching either

side of the Big Island after early next week but rainfall should

not be as heavy given less extreme precipitable water values.



By next week, there is increasing uncertainty in the details of a

weaker closed low northeast of the state and any additional

shortwave energy tracking through the state around mid-week.

Regardless, there is consensus that surface high pressure should

again build north of the state, allowing for a return to breezy

easterly trades and showers favoring the typical windward

locations later next week.



Santorelli



$$