Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 301 AM EST Sat Jan 23 2021 Valid 00Z Sun Jan 24 2021 - 00Z Sun Jan 31 2021 Latest models and ensembles continue to depict a similar pattern evolution through the period. Strong high pressure to the north/northeast of the state, periodically reinforced by upstream high centers, will maintain brisk to strong easterly/southeasterly winds for most of the period. Rainfall will focus over windward and mountain locales but some activity could stray to other areas as well. From the weekend into the first half of next week guidance continues to show the northwestward transport of enhanced moisture toward/across the islands in response to flow between a developing upper/surface system just west of 170W longitude and the deep-layer ridge to the north/northeast of the state. Repositioning of the upper ridge should help to push drier air into the region from midweek onward. Although guidance agrees on the general scenario, there are still significant differences in the magnitude of rainfall totals associated with next week's moisture surge. These differences are most pronounced over the northwestern islands while there is better agreement in principle for some locally heavy rainfall over the Big Island. GFS runs (with support in principle from the GEFS mean though of course with lighter values) continue to be heaviest over the northwestern islands with latest ECMWF/UKMET/CMC runs all suggesting that the axis of heaviest rainfall should lie farther west. This difference corresponds to the GFS/GEFS being weakest with the upper ridge to the north of the state and allowing for lower surface pressures over/southwest of the islands. The guidance comparison for mass fields would support hedging somewhat away from the GFS/GEFS scenario. On the other hand guidance as a whole has trended higher with precipitable water values over the past 24 hours. The 00Z ECMWF is once again between the highest 00Z GFS and somewhat lower 00Z GEFS/12Z ECMWF means. The higher trend for moisture offers potential for at least locally heavier amounts than what the non-GFS cluster is advertising. Rausch