← Previous May 31, 2023 2:53 AM
FXHW01 KWNH 310753 PMDHI Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 353 AM EDT Wed May 31 2023 Valid 00Z Thu Jun 01 2023 - 00Z Thu Jun 08 2023 Continue to expect trades of varying strength through the period. Winds should reach moderate to brisk levels into Thursday and then weaken during the weekend as a front temporarily disrupts surface ridging to the north. The GFS/GEFS mean are somewhat deeper than most other guidance with the supporting upper trough, so at least a compromise may be reasonable in terms of resolving differences in winds during that time. Either way, there may be a period when background flow could be light enough to allow for some land/sea breeze influence on showers versus the prevailing windward focus. The elongated upper weakness currently over or just north of the state, helping to elevate precipitable water values above climatological values, should dissipate after Wednesday or Thursday. While there will be a weak lingering trough to the west/southwest of the state thereafter, recent trends have been clustering toward there being enough influence from flow to the north to favor the drying trend during the weekend (with below normal PWATs). This scenario turns out to be on the ECMWF/ECMWF mean side of the prior spread, with the GEFS mean adjusting toward it by yesterday. After varying ways of holding onto more moisture over the Big Island if not more of the state in recent days, the 00Z GFS has finally shifted more fully to the other guidance. Moisture may fluctuate by Monday-Wednesday depending on low-predictability pockets of wetter or drier air carried along within the trade flow. Moisture trends should favor rainfall mostly in the light to moderate part of the spectrum from the weekend onward. Rausch $$