Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 324 AM EDT Wed Mar 17 2021 Valid 00Z Thu Mar 18 2021 - 00Z Thu Mar 25 2021 Upper troughing will be slow to abate during the next few days as surface high pressure slips eastward just north of 30N. Breezy northeast trades will increase with the high's closest approach this weekend. Drier air will remain in place over the area, supporting lighter rainfall amounts and coverage than in recent days. Windward and mauka showers are expected for the period as precipitable water values hover around one inch through the weekend. By next Mon-Wed, a stronger trough will dig near 160W north of 30N and likely form a closed low by early Tuesday. This may bring an increase in moisture from the south as trades veer. Precipitable water values may rise to over 1.25-1.50 inches per the guidance. The 00Z ECMWF was rather aggressive with its moisture plume into the region (and thus QPF) while the 00Z GFS was more in line with the ensembles at this point. The 00Z Canadian was farther west with its closed low placement (as were its ensembles) along with its QPF. Prefer to side with the GFS for now but unpredictability of closed lows suggests leaving many options on the table at this lead time. Fracasso