FXHW01 KWNH 030713

PMDHI 



Hawaii Extended Forecast Discussion

NWS Weather Prediction Center College Park MD

213 AM EST Tue Feb 3 2026



Valid 00Z Wed 04 Feb 2026 - 00Z Wed 11 Feb 2026



...Potential for Heavy Rainfall and Flash Flooding over the

Western and Central Islands This Weekend into Early Next Week..



As has been advertised, the upper-level pattern across the Central

Pacific will undergo significant amplification heading into this 

weekend. By Sunday, the global guidance is fairly well clustered 

with the positively tilted upper trough along or just west of the 

western islands. Into early next week, the upper trough shifts 

very little, though by Sunday night and Monday, despite some 

timing differences, all the 00Z global models (operational runs) 

show a low closing off at 500 mb low southwest of the islands. 



The pattern shift begins on Friday, as the new frontal system

approaches from the northwest. Increasing pre-frontal 

southwesterly (Kona) winds will bring an increase in humidity and

cloud cover to the western and central islands Friday and Friday 

night, as the axis of higher PWATs (1.7-1.8 inches) and pre- 

frontal shower bands are likely to reach Kauai and Niihau by 

Friday evening.



From Saturday through Tuesday, the setup favors a prolonged 

period of more humid conditions as deep tropical moisture is

transported northward into the stalled surface boundary 

downstream of the cutoff low, with persistent difluence at upper 

levels and PWATs exceeding 1.7 inches. Highest confidence of more

widespread, heavier showers (highest PoPs) will be across the 

western and central islands (Kauai, Niihau, and Oahu), where 

repeated rounds of heavy showers and thunderstorms may result in 

areas of flash flooding. Meanwhile, the rainfall coverage across 

the eastern islands will mostly confined across the favored 

upslope regions.



$$



Hurley