


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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999 FXHW01 KWNH 190717 PMDHI Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 317 AM EDT Sat Apr 19 2025 Valid 00Z Sun 20 Apr 2025 - 00Z Sun 27 Apr 2025 Models and ensembles again seem reasonably well clustered, bolstering forecast confidence in a favored composite solution that again should tend to mitigate lingering smaller scale variances consistent with individual predictability. An upper trough lingering atop Hawaii will slowly lose influence today along with trade disrupting inverted troughing. Winter weather advisories for the Big Island summits linger in the short term. For the weekend, the upper trough is forecast to further weaken and slowly shift away to the east, while Pacific surface high pressure develops/bridges well to the north of the state and allow trades to gradually increase. Expect a generally wet trade pattern through early next week as fueled by lingering moisture. Then from around the middle to later next week, another upper trough and possible closed low is forecast to dig just to the west of the state. This will once again cause the mean flow to veer for southeasterly/southerly winds that may be stronger this round so there is potential for moisture and showers to again increase. Schichtel