Current Conditions
Temp-1.1 C
RH96 %
WindESE 17 mph
RoadClosed
Mauna Kea Observatories Forecast
5 PM HST Friday 02 December (0300 UTC Saturday 3 December) 2016
Warning(s)
Fog, ice and flurries/rain
Chance for convection and moderate/heavy snow
Cloud Cover and Fog/Precipitation Forecast
Fog, high humidity, clouds, ice and/or light flurries will continue to plague the summit through the night. There is also a possibility for periods of moderate/heavy snow and convection in the area, mainly for this afternoon and early tomorrow morning.
Summary of Key Meteorological Variables
Summit temperatures will be near -2.5 C, with winds from the SSE at 20-35 mph for the night. Precipitable water and seeing are exected to exceed 4 mm and 1 arcsecond, respectively.
Discussion
The atmosphere near the Big Island will remain, for the most part, saturated and a bit unstable probably throughout most of the forecast period. This will allow extensive fog, high humidity, ice and/or light flurries/rain to plague the summit over the next 5 nights. Periods of moderate/heavy snow as well as convection in the area are also possible at virtually anytime, though it should favor the afternoon hours and near sunrise. Extensive daytime clouds are expected throughout the forecast period.

With the possible exception of parts of tomorrow night, broken to overcast thick clouds will continuously stream in from the south and blanket most, if not all of the sky throughout the forecast period.

Precipitable water is expected to exceed 4 mm throughout most of the forecast period (there is a possibility it will briefly slip toward 2-3 mm mainly around sunrise/sunset on Saturday and again early Monday evening).

A mixture of boundary layer turbulence, upper-level instability/turbulence, poor/wet conditions and/or cloudy skies will contribute to poor/bad seeing throughout the forecast period.

No change since the morning forecast...The mid/upper-level low currently lingering in the area will continue to weaken and lift off toward the north, but will also draw an abundant supply of moisture over the area, allowing the atmosphere to remain quite saturated during its departure over the next 24 hours. In addition, a new trough/low will quickly develop to the west through the weekend and will rejuvenate this stream, eventually setting up a persistent frontal feature over the state as the trough becomes quasi-stationary and is continously reinforced by passing short-wave troughs perhaps through next week. It should be noted, that the last several model runs consistently suggests a partial clearing/break in the moisture/clouds just prior to the deepening of this new trough around Sunday morning. However, more deep moisture is set to rapidly pour in by noon allowing for the development of aformentioned frontal band thereafter. Nevertheless, this nearly continous supply of moisture flowing into the area will allow extensive fog, high humidity, clouds and light flurries/rain to plague the summit throughout most of the forecast period. There is also a possibility for convection in the area, as well as periods of blizzard-like conditions at the summit at virtually anytime, but particularly through sunrise tomorrow, for Sunday night and perhaps again around Tuesday. Long term outlook suggests that these bad wet/icy conditions could persist into next weekend...
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)
Fri Dec 02 - 8 PM80-1004-9100 / 95-2.5SE/20-351-28-12
Sat Dec 03 - 2 AM80-1004-9100 / 90-2.5S/20-351-28-12
2 PM80-1004-895 / 750S/15-30NaN8-12
8 PM60-804-890 / 60-1SSW/20-350.7-1.58-12
Sun Dec 04 - 2 AM60-805-980 / 50-1SW/25-300.8-1.66-10
2 PM80-1004-10100 / 95-2S/35-50NaN10-15
8 PM80-1004-10100 / 95-4S/40-351-310-15
Mon Dec 05 - 2 AM80-1004-10100 / 95-4SW/25-401-310-15
2 PM80-1004-1095 / 901SW/20-35NaN10-15
Tue Dec 06 - 2 AM80-1004-995 / 85-1SW/15-301-210-15
2 PM80-1004-1095 / 901SSW/15-30NaN10-15
Wed Dec 07 - 2 AM80-1004-1095 / 90-1SW/15-301-210-15
2 PM80-1004-1095 / 900.5S/20-35NaN10-15
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
Sun Dec 04 - Mon Dec 05 17:52 19:00 5:25 6:34 N/A 22:37 29 21 24.5 -13 38
Mon Dec 05 - Tue Dec 06 17:52 19:01 5:26 6:34 N/A 23:31 39 22 15.6 -10 22
Tue Dec 06 - Wed Dec 07 17:52 19:01 5:26 6:35 N/A 0:26 50 23 06.9 -6 30
Wed Dec 07 - Thu Dec 08 17:53 19:01 5:27 6:35 N/A 1:23 61 23 59.1 -2 11
Thu Dec 08 - Fri Dec 09 17:53 19:01 5:27 6:36 N/A 2:21 71 0 52.6 2 23
Forecast Issued by: Ryan Lyman
Next update at 10 AM HST (2000 UTC) Monday 5 December 2016.
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.
NWS Hawaiian Islands Synoptic Discussion and Guidance
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