• Home
• MK Forecast
• Trends
• Statistics

• Current Conditions
• Seeing
• Web Cams
• Interactive Map
• Road Conditions
• NWS Bulletins

• Satellite
• Geostationary
• Polar Orbiter

• Radar
• Models
• GFS
• WRF

• Archive
• Links
• Symposium on Seeing
• Glossary
• Feedback
• Disclaimer

Affiliations

Menu of Text Products for the Hawaiian Islands and the Tropical Pacific/Atlantic Oceans: Select a text product: Hawaiian Islands Synoptic Discussion and Guidance Hawaiian Islands 7-day Zone Forecast Radar Message Special Messages Terminal Aerodome Foreasts (TAFS) Area Forecast for Hawaii and Adjacent Coastal Waters AIRMETs for IFR Conditions, Turbulence, and Icing Central/North Pacific Tropical Weather Outlook Oahu Surf Observation and Forecast/Coastal Forecast for Hawaiian Waters Offshore Forecast for Hawaiian Waters North Pacific High Seas Forecast South Pacific High Seas Forecast Hawaiian Islands Automated Surface Observation System Hourly Weather Roundup Hawaiian Islands Wind Data Hawaiian Islands Rainfall Summary Daily Hawaii Cooperative Observations

Narrow the Menu List Select Time Limit: 12 hours | 24 hours | 48 hours | 72 hours | No time limit Select Product Type: All | Routine Bulletins/FCSTS | Warnings/Watches/Advisories | HAWN Weather | Tropical | Marine | Aviation | Daily Obs | Special

Hawaiian Islands Synoptic Discussion and Guidance 658 FXHW60 PHFO 151356 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 356 AM HST Fri Nov 15 2019 .SYNOPSIS... A light wind regime will continue as a cold front approaches Kauai from the northwest and a low level trough moves into the Big Island from the southeast. Expect land and sea breezes for all islands today and tonight with increasing shower activity over Kauai and the Big Island through the afternoon hours. Returning trade winds will help to spread clouds and showers to Oahu and Maui County on Saturday. Expect wet unsettled weather to linger into the middle of next week with moderate trade winds in the forecast. && .DISCUSSION... This mornings satellite imagery shows a low level trough moving into the windward Big Island and a cold front slowly approaching Kauai from the northwest. Convergent shower bands are developing ahead of this frontal boundary near Kauai this morning. Expect increasing clouds and showers over Kauai and Hawaii Counties through the day. A trend towards wet and unsettled weather arrives today as two low pressure systems begin to converge over the Hawaiian Islands today and tomorrow, spreading scattered to numerous showers across the island chain through the weekend. Deeper moisture and instability will move in with two bands of Precipitable Water (PW) ranging from 1.5 to 2.0 inches. Weak southerly winds will develop near Kauai today with prefrontal shower bands favoring the southern and western slopes of the island. Big Island showers will start along the windward slopes this morning then spread into interior and leeward sections later this afternoon and tonight. Unstable wet weather will spread into Oahu and Maui County from Saturday afternoon into Sunday with scattered to numerous rain showers forecast statewide by Sunday morning. Moderate trade winds also return to the region and higher rainfall amounts will favor windward and mountain slopes on Sunday. Enough instability aloft will produce periods of heavy rainfall and a few thunderstorms. Persistent and slow moving heavy rain bands may develop, increasing the threat for localized flooding. By Sunday night cold air aloft will produce an upper level low over the state. Colder temperatures will keep an unstable environment anchored over the region with wet trades in the forecast through Tuesday night. Low chances for a few thunderstorms remain in the forecast mix through Monday, much will depend upon the strength and location of this upper level low. && .AVIATION... A light wind regime will continue across the island chain during the next 24 hours, with overnight land breezes and daytime sea breezes expected statewide. The airmass will remain generally dry and stable across Oahu and Maui County, with only a few isolated showers expected. Deeper moisture associated with an approaching front west of the state and an approaching trough of low pressure east of the islands, could bring some more shower activity to Kauai and the Big Island this afternoon through tonight. No AIRMETs are currently in effect. && .MARINE... The current north-northwest swell has been 1 to 3 feet higher than the Wave Watch III Model guidance according to overnight observations from buoys 51001, 51101, and 51000, as well as the Waimea Bay and Pauwela buoys. Therefore, a High Surf Advisory (HSA) remains in effect through this afternoon for north facing shores of most islands, as well as west facing shores of Kauai and Niihau. In addition, a Small Craft Advisory (SCA) remains in effect for all waters exposed to the large north-northwest swell, including the Kauai and Kaiwi Channels. As the current north-northwest swell gradually fades during the next 24 hours, an even larger west-northwest swell is expected to arrive late tonight. This will cause surf to again reach the HSA criteria along most north and west facing shores of the smaller islands starting Saturday. This swell may be large enough to approach the High Surf Warning thresholds along some shorelines from Saturday night into Sunday. In addition, surf may reach the HSA criteria along west facing shores of the Big Island starting Saturday night. Combined seas are also forecast to reach the SCA criteria over waters exposed to this swell this weekend. Looking ahead to next week, another large northwest swell arriving early Wednesday may cause surf to reach the HSA criteria along most north and west facing shores of the smaller islands from late Wednesday through Thursday. A front approaching Kauai from the northwest will cause the winds to shift to a more southerly direction today. The winds will eventually become northeast late tonight and Saturday. A combination of increasing moisture and unstable atmospheric conditions is expected to cause increasing clouds and showers, along with the possibility of thunderstorms developing over portions of the coastal waters this weekend. Mariners should be aware that any thunderstorms they encounter may be capable of producing locally gusty winds, reduced visibilities in heavy downpours and dangerous cloud to surface lightning. Looking ahead to early next week, easterly trade winds will gradually strengthen, and may approach SCA levels over the typically windy waters adjacent to the islands of Maui County and the Big Island. Small southerly swells will persist through this weekend. Surf will also remain small along east facing shores into early next week due to the light winds over and upstream of the state. The surf will increase slightly along east facing shores by late Monday or Tuesday as the trades strengthen. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 PM HST this evening for Niihau-Kauai Windward-Kauai Leeward-Oahu North Shore-Oahu Koolau-Olomana- Molokai-Maui Windward West-Maui Central Valley-Windward Haleakala-Big Island North and East. Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters-Kauai Windward Waters-Kauai Channel-Oahu Windward Waters-Kaiwi Channel-Maui County Windward Waters-Big Island Windward Waters. && $$ DISCUSSION...Bohlin AVIATION...Jelsema MARINE...Houston Bulletins, Forecasts and Observations are courtesy of Honolulu National Weather Service Forecast Office

Home | Forecast | Current OBS | Satellite | Radar | Models | Archive | Links | Disclaimer

This page was last modified on: Wed, Dec 17 2014 - 1841 UTC
Send comments to: Ryan Lyman