Mauna Kea Stargazing

The tradewind inversion will remain rather indistinct and elevated near 11-12 thousand feet, which could allow for periods of fog and high humidity at the summit mainly through early tomorrow evening. The risk for fog/high humidity will subside as the inversion slowly takes shape near 6-7 thousand feet through the weekend and into early next week. Precipitation is unlikely through the next 5 nights. Extensive daytime clouds is likely for tomorrow, then may taper a tad for the weekend and Monday, only to pick up again on Tuesday. Skies overhead will remain predominately clear of high/mid-level clouds through the next 5 nights. PW is expected to linger nea 4 mm into Saturday evening, but could slip toward 3 mm by sunrise Sunday and linger near that value likely through Monday night. An increase in boundary layer turbulence, combined with an elevated inversion will likely contribute to poor seeing over the next 2 nights. There is a good chance that seeing will begin to improve as the inversion restrengthens and winds subside through Saturday night and may settle in near 0.45-0.5 arcseconds as relatively calm skies prevail in the free atmosphere for the following 2 nights. The fog/high humidity risk has diminished a bit since the morning forecast...Although a surface ridge will continue to sit in the NE Pacific, a band of lingering moisture will slowly dissipate near the Big Island area over the next several days. Forthermore, a rather deep mid/upper-level low will persist to the NE of the state, before dissipating in response to an upper-level ridge building in from the SE late in the weekend. This combination will likely keep the inversion rather weak/elevated just below the summit, which could allow for more periods of fog/high humidity mainly into tomorrow evening. There is good chance that increased subsidence on the SE flank of the upper-level low will fill into the area, enhancing the dispersment of the residual moisture in the area beginnng late Friday night. This should help to gradually rebuild the inversion and decrease the risk for fog/high humidity at the summit as the weekend progresses and into early part of next week. The addition of the upper-level ridge filling in from the SE will help reinforce subsidence in the area, further strengthening the inversion by late Sunday. However, models point to residual tropical waves continously filling in with the low-level easterly trades over much of next week. This may contribute to periodic lifting of the inversion and perhaps increase the risk for fog/high humidity at the summit during that time.