Maunakea Observatories Forecast
645 AM HST (1645 UTC) Friday 06 March 2026
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Warning(s)
None
Cloud Cover and Fog/Precipitation Forecast
The summit will remain dry and stable, while scattered to broken high clouds build in from the west, perhaps contributing to periods of extensive cloud cover during the second half of the night.
Summary of Key Meteorological Variables
Summit temperatures will be near 5.5 C this afternoon and -0.5 C for the night. Winds will be from the NE at 10-20 mph, with seeing near 0.7-0.8 arcseconds through the night. PW is expected to be in the 1.5-2 mm range through throughout the night.
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Discussion
A distinct tradewind inversion will continue to cap low-level moisture primarily near 7 thousand feet and ensure a dry/stable summit-level air mass through at least Sunday night. There is a possibility that deep moisture will begin to build into the area and increase the risk for fog, high humidity and ice through Monday night. The atmosphere will likely turn quite saturated on Tuesday, further increasing this risk as well as the possibility for snow for that night. Daytime clouds will be minimal and short-lived through Monday, but could turn extensive for Tuesday and Wednesday.
A band of scattered to broken high clouds is expected to build in from the west, contributing to periods of extensive cloud cover mainly during the second half of the night. This band will sweep to the south of the Big Island as more high clouds fill in from the NW later tomorrow, but cloud cover is expected to decrease as the weekend progresses. There is a possibility that patches of mid-level clouds will build in from the west and this band may start to creep northward late Monday night. This could contribute to overcast skies as these clouds converge for Tuesday night.
Precipitable water is expected to slip into the 1.5-2 mm range for tonight, then settle in around 0.8-0.9 mm for Saturday and Sunday night. There is a good chance that PW will trend toward 4 mm through Monday night, and probably jump to 10+ mm for Tuesday night.
Increasing turbulence just below the summit and/or within the boundary layer will likely contribute to poor/bad seeing over the next 2 nights (particularly Saturday evening). There is a possibility that seeing will settle back in around 0.5-0.55 arcseconds as calmer skies and a stable air mass prevails for Sunday night. However, a potential increase in boundary layer turbulence and an influx of moisture will likely degrade seeing through Monday night and contribute to bad seeing for Tuesday night.
A deep mid/surface ridge will continue to sit to the NE of the state and promote strong/steady large-scale subsidence in the area into the early part of next week. This subsidence will easily maintain a well-defined inversion near 7-8 thousand feet and ensure a dry/stable summit-level air mass through at least the weekend. Residual widespread mid-level moisture is also set to rapidly detrain into the surrounding air mass, allowing PW to slip below 2 mm for tonight and settle in near 0.8-0.9 mm for the following 2 nights. Unfortunately, a mid/upper-level low is expected to develop to the SE, and may tighten the wind gradient in the area over the next 2 nights (particularly Saturday evening). This will likely produce turbulence near summit-level and contribute poor/bad seeing during that period. This low is projected to progress northward (to the east of the state) late in the weekend which should help help mid-level winds to taper and allow seeing to improve for Sunday night. However, there is a possibility that this low will draw deeper moisture in from the west from a develop large-scale trough near the Dateline. This moisture could begin to fill in overhead early Tuesday morning and eventually saturate the entire air mass by later that day. As a result, this will significantly increase the risk for fog, ice and snow at the summit by that night.
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5 Day Forecast Summary (Graphical Trend)
| HST |
Cloud |
Fog/Precip |
Temp |
Wind |
Seeing |
PW |
| Cover (%) |
Height (km) |
Probability (%) |
(Celsius) |
(Dir/MPH) |
(Arcseconds) |
(mm) |
| Fri Mar 06 - 2 PM | 10-30 | 8-9 | 0 / 0 | 5.5 | NE/10-20 | NaN | 1.5-2.5 |
| 8 PM | 20-40 | 8-9 | 0 / 0 | -0.5 | NE/10-20 | 0.6-0.9 | 1.5-2 |
| Sat Mar 07 - 2 AM | 40-60 | 7.5-9 | 0 / 0 | -0.5 | NE/10-20 | 0.6-0.9 | 1.5-2 |
| 2 PM | 30-50 | 7.5-9 | 0 / 0 | 4.5 | NE/10-20 | NaN | 1-2 |
| 8 PM | 20-40 | 7-8.5 | 0 / 0 | -2 | ENE/10-20 | 0.55-0.95 | 0.8-1 |
| Sun Mar 08 - 2 AM | 10-30 | 7.5-8.5 | 0 / 0 | -3 | E/15-30 | 0.7-1.3 | 0.8-1 |
| 2 PM | 0-20 | 7.5-8 | 0 / 0 | 2 | E/10-20 | NaN | 1-1.5 |
| 8 PM | 0-20 | 7.5-8 | 0 / 0 | -3.5 | ENE/5-15 | 0.45-0.65 | 0.7-1 |
| Mon Mar 09 - 2 AM | 0-20 | 7.5-8 | 0 / 0 | -3.5 | NE/0-10 | 0.4-0.6 | 0.7-1 |
| 2 PM | 0-20 | 7.5-8 | 0 / 0 | 2 | NW/5-15 | NaN | 1-2 |
| Tue Mar 10 - 2 AM | 20-40 | 6-8 | 20 / 5 | -2.5 | W/10-20 | 0.5-0.9 | 2-4 |
| 2 PM | 60-80 | 4-9 | 60 / 30 | 1 | SW/15-30 | NaN | 4-8 |
| Wed Mar 11 - 2 AM | 80-100 | 4-10 | 90 / 60 | -3 | SSW/15-30 | 0.8-1.6 | 6-10 |
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Rise and Set times for the Sun and Moon
| Night (HST) |
Sun Set |
Twilight End |
Twilight Beg |
Sun Rise |
Moon Rise |
Moon Set |
Illumination (%) |
RA |
DEC |
| Fri Mar 06 - Sat Mar 07 |
18:38 |
19:42 |
5:24 |
6:28 |
21:29 |
N/A |
84 |
14 00.1 |
-17 00 |
| Sat Mar 07 - Sun Mar 08 |
18:38 |
19:42 |
5:23 |
6:27 |
22:22 |
N/A |
76 |
14 48.2 |
-21 27 |
| Sun Mar 08 - Mon Mar 09 |
18:38 |
19:43 |
5:22 |
6:26 |
23:15 |
N/A |
68 |
15 38.1 |
-24 56 |
| Mon Mar 09 - Tue Mar 10 |
18:39 |
19:43 |
5:21 |
6:25 |
0:09 |
N/A |
59 |
16 29.9 |
-27 20 |
| Tue Mar 10 - Wed Mar 11 |
18:39 |
19:43 |
5:20 |
6:25 |
1:02 |
N/A |
49 |
17 23.1 |
-28 30 |
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Forecast Issued by: Ryan Lyman
Next update at 5 PM HST Friday 06 March (0300 UTC Saturday 7 March) 2026.
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Additional Information
For public road conditions and snow report message please call (808) 935-6268.
This message is also available at the MKWC road conditions page.
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