Current Conditions
Temp-1.1 C
RH97 %
WindWSW 39 mph
RoadOpen (4x4)
Mauna Kea Observatories Forecast
10 AM HST (2000 UTC) Tuesday 20 March 2018
Fog, ice, sustained to strong winds.
Cloud Cover and Fog/Precipitation Forecast
While high clouds will be breaking down through the day and part of this evening, more high clouds are expected to approach the area from the west later tonight. Summit level clouds will linger in the afternoon, evening. Frozen precipitation is possible this afternoon.
Summary of Key Meteorological Variables
Summit temperatures will be near -1.5C this afternoon, -4 C this evening and -3 tonight. Winds will be from the NW at 25-40 mph with possible higher gusts. Precipitable water is expected to still exceed 4 mm, and observing conditions will continue to be poor.
The airmasses continue to be saturated well above summit level. Precipitation might develop over the eastern slopes this afternoon and some precipitation in the form of ice/flurries might reach the summit then. The air masses are expected to dry out some in the mid/summit levels through tomorrow and part of Wednesday, nevertheless blobs of moisture will be passing by through Thursday and the airmasses are expected to be saturated by early Friday and into the weekend. Daytime clouds will be extensive throughout.

High clouds from the West will be breaking down some through today but more high clouds are expected to approach the area still from the West tonight. Although they might also break and thin some through Wednesday and Thursday, they will ticken in time and get more organized from Friday and onward when close up the summit sky.

Precipitable water will continue to exceed 4 mm throughout the forecast period.

Observing conditions will remain poor to inoperable as winds at the summit remain sustained/strong, moisture continue to plague the area and shear aloft also increase.

While the high pressure far north of the Hawaiian Islands shifts southeastward through this week, the surface gradients increases and as a result the wind at the summit will remain sustained, at times strong, through at least Wednesday. The airmasses being quite moist will dry out a little today through tomorrow, but deep moisture is expected to be advected over the area by a short wave trough approaching the State from the West on Friday. The resulting front will cross the islands through the weekend bringing unsettled weather and unoperable conditions at the summit. The model project the front to move eastward and away at the beginning of the coming week dragging the bulk of the moisture out of the islands' chain.
WRF Astronomical Observing Quality Guidance
Cloud Cover and Precipitable Water Analyses
MK CN² Profiles
5 Day Forecast Summary (Graphical Trend)
HST Cloud Fog/Precip Temp Wind Seeing PW
Cover (%) Height (km) Probability (%) (Celcius) (Dir/MPH) (Arcseconds) (mm)
Tue Mar 20 - 2 PM60-804-7100 / 80-1.5WNW/35-50NaN4-8
8 PM30-504.5-7100 / 60-4NW/35-501.3-1.74-8
Wed Mar 21 - 2 AM50-704-760 / 10-3NW/25-401.3-1.74-8
2 PM60-804-750 / 51NW/20-35NaN4-8
8 PM60-805-740 / 0-1NW/20-301.3-1.76-10
Thu Mar 22 - 2 AM40-605-730 / 0-2WNW/10-201-1.46-10
2 PM60-804-780 / 201WSW/15-25NaN6-10
8 PM60-804-740 / 0-1.5W/15-251-1.48-12
Fri Mar 23 - 2 AM80-1004-840 / 0-1.5W/15-250.7-1.18-12
2 PM80-1004-8100 / 90-1WSW/15-25NaN10-12
Sat Mar 24 - 2 AM80-1004-9100 / 90-3WSW/25-401.3-1.712-16
2 PM80-1004-9100 / 90-1SW/30-50NaN12-16
Sun Mar 25 - 2 AM80-1004-9100 / 90-4W/25-401.3-1.712-16
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
Tue Mar 20 - Wed Mar 21 18:42 19:46 5:12 6:16 N/A 21:59 16 3 07.9 12 03
Wed Mar 21 - Thu Mar 22 18:42 19:47 5:11 6:15 N/A 22:58 25 4 02.7 15 30
Thu Mar 22 - Fri Mar 23 18:42 19:47 5:10 6:14 N/A 23:58 35 4 59.7 18 06
Fri Mar 23 - Sat Mar 24 18:43 19:47 5:09 6:13 N/A 0:59 47 5 58.9 19 38
Sat Mar 24 - Sun Mar 25 18:43 19:47 5:08 6:13 N/A 1:57 58 6 59.3 19 56
Forecast Issued by: Tiziana Cherubini
Next update at 5 PM HST Tuesday 20 March (0300 UTC Wednesday 21 March) 2018.
Additional Information
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This message is also available at the MKWC road conditions page.
NWS Hawaiian Islands Synoptic Discussion and Guidance
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