MKWC archive forecast page For the time being, this page will (obviously) using the old MKWC web page design...Sorry for the inconvenience Please select a year and month and links of all available forecasts for that period will be given in the 'Select Forecast' menu. Select Year: 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Select Month: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Select Forecast: Sep 02 2003 (morning) Sep 02 2003 (afternoon) Sep 03 2003 (morning) Sep 03 2003 (afternoon) Sep 04 2003 (morning) Sep 04 2003 (afternoon) Sep 05 2003 (morning) Sep 05 2003 (afternoon) Sep 08 2003 (morning) Sep 08 2003 (afternoon) Sep 09 2003 (morning) Sep 09 2003 (afternoon) Sep 10 2003 (morning) Sep 10 2003 (afternoon) Sep 11 2003 (morning) Sep 11 2003 (afternoon) Sep 12 2003 (morning) Sep 12 2003 (afternoon) Sep 15 2003 (morning) Sep 15 2003 (afternoon) Sep 16 2003 (morning) Sep 16 2003 (afternoon) Sep 17 2003 (morning) Sep 17 2003 (afternoon) Sep 18 2003 (afternoon) Sep 19 2003 (morning) Sep 19 2003 (afternoon) Sep 22 2003 (morning) Sep 22 2003 (afternoon) Sep 23 2003 (morning) Sep 23 2003 (afternoon) Sep 24 2003 (morning) Sep 24 2003 (afternoon) Sep 25 2003 (morning) Sep 25 2003 (afternoon) Sep 26 2003 (morning) Sep 26 2003 (afternoon) Sep 29 2003 (morning) Sep 29 2003 (afternoon) Sep 30 2003 (morning) Sep 30 2003 (afternoon) Selection: 2003 09 Sep 03 2003 (morning)

Warnings None Cloud Cover and Precipitation Forecast The summit will remain clear and dry through the night. Summary of Key Meteorological Variables Summit temperatures will be near 10 C today, 5 C tonight, and 4.5 C tomorrow morning. Precipitable water is expected to be in the 2 to 2.5 mm range tonight and 1.75 to 2.25 mm range tomorrow morning. Winds will be from the northeast at 20 to 30 mph this afternoon, 15 to 25 mph tonight, and 10 to 20 mph tomorrow morning. Shear will be between 25 to 35 mph. Discussion The tradewind inversion will remain strong and well-defined below 6 to 8 thousand feet through the next three nights. This will limit low-level moisture ascent and keep the summit free of fog and precipitation during this time. Daytime clouds will be very minimal and short-lived, if at all. No high clouds are expected to be within 700 km of the summit through Friday night. Summit winds are projected to drop from the 20 to 30 mph range to 15 to 25 mph by tonight, eventually settling in the 10 to 20 mph range tomorrow morning through Friday night. Wind direction will start out from the northeast but will be slowly veering to easterlies over the next three nights. Minimum overnight summit temperatures will be near 4.5 C tonight and 3.5 C on Thursday and Friday night. Precipitable water is expected to drop from around 2 mm for tonight to about 1.5 mm (possibly slightly lower) for Thursday and Friday night. The mid-level ridge still remains to the northwest of the Islands. However, it continues to slide eastward, stretching its dominance across the Pacific Ocean. This ridge will remain in control of summit weather as it prompts large-scale subsidence over our region during the next three nights, at the very least. This will help maintain a strong and low tradewind inversion, which in turn will keep summit air dry. Precipitable water is also expected to decline as the subsidence dries out the 300 to 400 mb layer. Finally, summit temperatures will remain relatively high due to adiabatic warming induced by the subsidence. Meanwhile, the tropical upper tropospheric trough will continue to be meekly established over the Islands during the next 3 days. In fact, a weak upper-level low is slated to develop to the west of the Islands on Friday. However, neither the TUTT nor the low will bring or develop any high clouds near the summit through Saturday. Overall, excellent conditions are expected over the next three nights. Astronomical Observing Quality Guidance Vertical Profiles from MM5 (vertical coordinate is pressure in mb): 2 pm HST Wed 03 Sep (0000 UTC Thu 04 Sep) Seeing Cn2 5 pm HST Wed 03 Sep (0300 UTC Thu 04 Sep) Seeing Cn2 8 pm HST Wed 03 Sep (0600 UTC Thu 04 Sep) Seeing Cn2 11 pm HST Wed 03 Sep (0900 UTC Thu 04 Sep) Seeing Cn2 2 am HST Thu 04 Sep (1200 UTC Thu 04 Sep) Seeing Cn2 5 am HST Thu 04 Sep (1500 UTC Thu 04 Sep) Seeing Cn2 8 am HST Thu 04 Sep (1800 UTC Thu 04 Sep) Seeing Cn2 Tonight's (Wednesday Night) Collage Seeing Cn2 Thursday Night's Collage (available after 0800 HST on Thursday) Seeing Cn2 Friday Night's Collage (available after 0800 HST on Friday) Seeing Cn2

3-day Forecast Summary (Latest GFS Trend)	2 pm HST Wed 03 Sep	8 pm HST Wed 03 Sep	2 am HST Thu 04 Sep	2 pm HST Thu 04 Sep	8 pm HST Thu 04 Sep	2 am HST Fri 05 Sep	2 pm HST Fri 05 Sep	8 pm HST Fri 05 Sep	2 am HST Sat 06 Sep
	0000 UTC Thu 04 Sep	0600 UTC Thu 04 Sep	1200 UTC Thu 04 Sep	0000 UTC Fri 05 Sep	0600 UTC Fri 05 Sep	1200 UTC Fri 05 Sep	0000 UTC Sat 06 Sep	0600 UTC Sat 06 Sep	1200 UTC Sat 06 Sep
PW (mm, summit upward)	2.5 to 3.5	2 to 2.5	1.75 to 2.25	1.5 to 2	1.25 to 1.75	1.25 to 1.75	1.25 to 1.75	1.25 to 1.75	1.25 to 1.75
Summit Temp (oC)	10	5	4.5	9.5	4	3.5	10	4	3.5
Wind Dir/Speed (mph)     Summit     19,000 ft (500 hPa)     24,500 ft (400 hPa)     31,000 ft (300 hPa)     35,000 ft (250 hPa)     40,000 ft (200 hPa)     46,000 ft (150 hPa)     54,000 ft (100 hPa)	NE/20 to 30 NNE/12 NW/8 NW/11 NW/13 NNW/11 N/10 ENE/8	NE/15 to 25 NNE/11 NW/8 WNW/13 WNW/17 NW/17 NW/3 ENE/9	NE/10 to 20 NNE/7 NW/8 W/19 WNW/24 WNW/21 W/9 ENE/12	ENE/10 to 20 NE/3 WSW/4 WSW/18 W/26 WSW/24 WSW/16 ESE/13	ENE/10 to 20 ENE/3 SW/5 WSW/19 WSW/23 WSW/24 WSW/13 E/13	ENE/10 to 20 ESE/3 SSW/10 SW/23 WSW/23 WSW/21 SW/10 ESE/12	E/10 to 20 SSE/8 SSW/19 SW/25 SW/24 SSW/26 SSW/21 ESE/13	ESE/10 to 20 SE/10 S/21 SSW/22 SSW/22 SSW/24 SSW/17 ESE/16	E/10 to 20 ESE/15 SSE/18 SSW/18 SSW/20 SSW/22 SSW/15 ESE/13

Night (HST)	Sun Set	Twilight End	Twilight Beg	Sun Rise	Moon Rise	Moon Set	Illum (%)	RA	Dec
Wed.Sep.03/Thu.Sep.04	18:44	19:50	4:53	5:58	N/A	0:29	59	17 25.5	-26 10
Thu.Sep.04/Fri.Sep.05	18:43	19:49	4:53	5:58	N/A	1:28	70	18 27.8	-27 14
Fri.Sep.05/Sat.Sep.06	18:43	19:48	4:53	5:59	N/A	2:29	80	19 29.8	-26 37

Forecast issued by: Ryan Lyman
rlyman@hawaii.edu
(808) 932-2323

Next update at 5 pm HST Wednesday 03 September (0300 UTC Thursday 04 September) 2003.
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This page was last modified on: Wed, Apr 22 2009 - 2058 UTC
Send comments to: Ryan Lyman