NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

PHZ122 Big Island Windward Waters- 341 Pm Hst Thu Nov 30 2023
.small craft advisory in effect through early Friday morning...
Tonight..East winds to 25 knots. Wind waves to 7 feet. Northwest swell 4 feet. Numerous heavy showers with isolated Thunderstorms.
Friday..Southeast winds to 25 knots. Wind waves to 7 feet. Northwest swell 3 feet. Numerous heavy showers in the morning. Isolated Thunderstorms. Scattered heavy showers in the afternoon.
Friday night..Southeast winds 20 knots. Wind waves to 5 feet. Northwest swell 3 feet. Scattered showers with a slight chance of Thunderstorms.
Saturday..East winds to 25 knots. Wind waves to 5 feet. Northwest swell 3 feet. A slight chance of Thunderstorms in the morning. Scattered showers.
Saturday night..East winds 20 knots. Wind waves to 4 feet. Northwest swell 5 feet. A slight chance of Thunderstorms in the evening. Scattered showers.
Sunday..East winds 20 knots. Wind waves to 5 feet. Northwest swell 6 feet. Scattered showers, mainly in the morning.
Sunday night..East winds 20 knots. Wind waves to 5 feet. Northwest swell 6 feet. Scattered showers.
Monday..East winds 20 knots. Wind waves around 5 feet. Northwest swell 5 to 6 feet. Scattered showers.
Tuesday..East winds to 25 knots. Wind waves around 6 feet. North swell 5 feet. Numerous showers.
winds and seas higher in and near tstms.

PHZ100 341 Pm Hst Thu Nov 30 2023
Synopsis for hawaiian coastal waters.. A kona low west of kauai has maintained moderate southeast winds. Periods of heavy showers and isolated Thunderstorms will occur through Friday in association with this low. The low will weaken into a trough over the weekend with ridging building in north of the island chain.

FXHW60 PHFO 010136 AFDHFO

Area Forecast Discussion National Weather Service Honolulu HI 336 PM HST Thu Nov 30 2023

SYNOPSIS
A kona low west of the islands will bring a continued threat for heavy rain and flooding through Friday. Isolated thunderstorms are also possible. Conditions will improve during the weekend into early next week as drier air moves in and trade winds return.

DISCUSSION

Excellent mid-level divergence and right entrance dynamics that defined the first half of today and supported very heavy rain over Windward Big Island and Maui is beginning to weaken. IR imagery indicates warming cloud tops areawide with substantially reduced rain rates now reaching 1-2"/hr on an isolated basis instead of frequent pulses up to 3-4"/hr that was observed several hours ago.

As the kona low drifts westward, local winds have backed from southerly to southeasterly. Going forward, this will tend to advect deep tropical moisture characterized by PWATs in excess of 2" westward across the area and would typically focus the most organized rainfall over southeast-facing slopes of Maui and the Big Island. However, building downstream ridging and subtle height rises will be working against deep convection over the eastern end of the state suggesting with high confidence that this event has peaked there. Thus, attention for tonight turns to the smaller islands as activity over the Big Island gradually diminishes in coverage and intensity. Enhanced low-level convergence at the interface of retreating southerlies and emerging southeasterlies is supporting a band of heavy showers south and west of Kauai this afternon. Any organized heavy rain potential over Oahu and Kauai rests heavily on the evolution of this band which is shown by the latest GFS to lift into Kauai late tonight. This is supported by the latest radar trends which show gradual northward progress toward the island. For the remainder of the state, confidence in heavy rain potential tonight is much lower.

By Friday, the mid-level trough finally begins to feel the pull of the mid-latitude westerlies and begins to gradually open and shift eastward toward the islands. The associated trough axis will work eastward through the state Friday afternoon through Saturday night bringing one final, progressive wave of enhanced forcing. During this time, the deepest moisture is modeled to be over the western islands, leading to an increased threat for heavy rainfall over Kauai and Oahu late Friday through Friday night then, to a lesser extent, Maui and the Big Island on Saturday.

Light to moderate trades return on Sunday then gradually strengthen through early next week.

AVIATION

Weakening kona low about 300 nm W of PHBK is moving WNW 5 kt. A broad belt of deep tropical moisture wraps around this large feature, bringing clouds, rain, and a few embedded TS from time to time near the main Hawaiian Islands.

As the low continues to weaken, overall conditions will gradually improve tonight and Friday. However, there's still plenty of moisture for additional +SHRA and isolated +TSRA development along mesoscale convergence bands, and the high resolution guidance bears this idea out, mainly near and S-SW of Kauai and Oahu overnight into Friday. The high resolution guidance also shows a fairly rapid improvement over the eastern part of the state overnight, although some MVFR SHRA is still certainly possible especially on E and SE facing slopes.

Aside from turbulence and icing associated with any TS that develops, AIRMET for mid-level turb will also likely continue to be needed tonight into Friday, as plenty of PIREPS indicating up to MDT TURB due to wind shear in the 100-FL200 layer. Light icing in layered clouds has also been reported. Will continue this mention in the evening AIRMETs, but will probably be able to drop it as the layered cloud deck gradually diminishes overnight.

MARINE

The positioning of a broad, decaying kona low located approximately 250 nautical miles west northwest of Kauai, along with surface high pressure to the far northeast, will maintain moderate to locally strong southeast winds particularly around more eastern island through early Friday. A Small Craft Advisory has been extended through early Friday for the waters east of the Kaiwi Channel with the exception of the Pailolo Channel, Maalaea Bay and southeast Big Island waters. The kona low will continue to fill in and become a trough by Saturday. A series of North Pacific systems traveling east within the westerlies, with weak high pressure developing just north of the islands, this weekend will guarantee easing winds transitioning back to trade flow by Sunday. Trades will gradually strengthen next week as high pressure builds in from the northwest.

Per afternoon nearshore buoy observations, a recent small to moderate, medium period northwest (320 degree) swell has peaked and will be gradually declining through Saturday. The next moderate size, longer period northwest (320 degree) swell will arrive and begin to fill in Saturday afternoon and evening. This swell will peak surf to near High Surf Advisory (HSA) heights Sunday, then slowly subside Monday. A reinforcing north northwest (330-350 degree) swell arriving early Tuesday may lift surf well above HSA thresholds Tuesday and Wednesday. Expect the short period wind wave chop to persist along south-facing shores the next day or so in response to these recent moderate to fresh southerlies in tandem with a very small, medium period southwest background swell. Less choppy eastern shore conditions can be expected over the weekend as surf along eastern exposures is forecast to hold near seasonal levels before falling below December averages early next week. Strengthening trades during the middle of next week could boost east shore chop back up to above seasonal heights.

HFO WATCHES/WARNINGS/ADVISORIES
Flood Watch through Friday afternoon for all Hawaii islands-

Winter Weather Advisory until 6 AM HST Friday for Big Island Summits.

Small Craft Advisory until 6 PM HST this evening for Maui County Windward Waters-Maui County Leeward Waters-Alenuihaha Channel- Big Island Windward Waters-Big Island Leeward Waters.

toggle option: (graph/table)

Hilo
Click for Map
Thu -- 05:08 AM HST     2.83 feet High Tide
Thu -- 06:37 AM HST     Sunrise
Thu -- 09:52 AM HST     Moonset
Thu -- 01:20 PM HST     0.41 feet Low Tide
Thu -- 05:08 PM HST     1.01 feet High Tide
Thu -- 05:39 PM HST     Sunset
Thu -- 08:53 PM HST     Moonrise
Thu -- 09:46 PM HST     0.30 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Hilo, Hawaii Island, Hawaii, Tide feet

Hilo
Click for Map
Thu -- 05:21 AM HST     2.87 feet High Tide
Thu -- 06:37 AM HST     Sunrise
Thu -- 09:52 AM HST     Moonset
Thu -- 12:28 PM HST     0.90 feet Low Tide
Thu -- 04:13 PM HST     1.19 feet High Tide
Thu -- 05:39 PM HST     Sunset
Thu -- 08:53 PM HST     Moonrise
Thu -- 10:20 PM HST     0.05 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Hilo, Hilo Bay, Hawaii, Tide feet

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Kamuela/Honolulu,HI