Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 804 AM EDT Mon Aug 21 2017 Valid 00Z Tue Aug 22 2017 - 00Z Tue Aug 29 2017 Through Tuesday expect an inverted upper trough (likely containing a low center to the north-northwest of the state) plus fairly high precipitable water values to promote some enhanced shower activity. Then a drier trend will commence as the upper feature and deep moisture continue westward. By next Monday model differences emerge regarding a potential increase of moisture coming into the Big Island and vicinity, with 00z/06z GFS runs being somewhat quicker than the past couple ECMWF runs. The 00z GEFS mean is slightly slower than the GFS runs with the moisture's arrival, so a compromise appears to be a reasonable forecast at this time. Over the course of the period trades will fluctuate in response to evolution/progression of mid-latitude high pressure, tending to be in the moderate range overall. The majority of shower activity should be windward-focused. A little sea-breeze influence may be possible during periods of relatively lighter trade flow from now into Tuesday and during Friday-Saturday. Rausch