2-4 foot
3-5 foot
0-2 foot
Flat

A ridge north of the area will shift south ahead of a front approaching from the northwest. Winds will weaken and shift out of the southeast today as the ridge moves over the area. Winds may shift out of the south Monday and could become locally fresh again as the front approaches. The front is expected to reach the Kauai waters Monday evening and push down to the Big Island waters by Tuesday evening. Heavy showers and thunderstorms are possible ahead of and along the front. Fresh to locally strong north winds will spread over the islands behind the front. The winds will slowly veer to northeast by the end of next week.

A northwest swell expected later today and Monday will likely produce surf near the advisory threshold along north facing shores overnight. This swell will diminish Monday night, but a bigger northwest swell Tuesday and Wednesday will likely produce surf well above the advisory threshold for north and west facing shores. The swell will also boost combined seas above the 10 foot level, so a Small Craft Advisory will likely be needed. An even larger northwest swell is forecast to arrive Friday. That swell could produce warning level surf along north and west facing shores.

A low east of New Zealand generated a swell which will produce surf near the advisory level along south facing shores later today and Monday. See the Collaborative Surf Discussion for details.

Hawaii Wave Height Model

Tide Predictions

High tide at Kahului was 2.4 foot at 2:00 PM early this afternoon, dropping to a low of 0.9 foot at 2:00 PM early this afternoon, then rising to a high of 1.6 foot at 2:00 PM early this afternoon, before once again dropping to a low of 0.1 foot at 2:00 PM early this afternoon

The sunrise was at 06:23 am this morning and will set at 05:56 pm this evening. The Moon is currently 3 days old, and is in a Waxing Crescent phase. The next First Quarter will occur at 10:23 PM on Friday, October 27th.

Hawaii Wind Report

Maui Weather

75°/76°
Wind: N at 22 mph
Sunrise: 6:40 AM
Sunset: 5:43 PM
current observations as of 3pm November 20th, 2017

Weather Outlook for Sunday, 22nd October 2017

Summary

Afternoon clouds and showers are expected to become focused over interior and leeward areas today as sea breezes develop and push inland. Some heavier showers over the eastern half of the Big Island will be possible later today and tonight as moisture begins to increase and fill in from the east. Monday through Wednesday, heavy showers and thunderstorms associated with a strong cold front that is forecast to move down the island chain could lead to flash flooding from Oahu to the Big Island. Winds are forecast to become gusty across the Big Island Summits late Monday through Tuesday as a strong upper trough digs south over the region. Cool and dry air will fill in behind the front through the second half of the week.

Detailed Discussion

After a long stretch of breezy to windy conditions across the islands, trade winds have dropped off considerably through the overnight hours. Observations are depicting light offshore winds (land breezes) this morning at many stations across the islands. The low-level wind flow will gradually shift toward the south through the day as a cold front begins to approach from the northwest. The latest surface analysis showed this frontal boundary north of Midway extending westward from a developing storm-force low around 1000 miles north-northwest of Kauai. A weak surface trough was analyzed north-northeast of Maui County, marking the leading edge of a broad area of higher moisture. The latest satellite-derived precipitable water (PW) imagery reflected this and showed a large area of 1.75 to 2″ PWs approaching the Big Island from the east.

The latest short-term (today-Tuesday) guidance remains in good agreement and indicates increasing deep layer moisture filling in across the islands as a cold front and upper trough approach from the northwest. Model PWs are forecast to rise into 1.75 to 2″ range, with the highest moisture expected to become focused over the eastern half of the state in response to a pre-frontal convergence boundary setting up Monday. The low-level flow is forecast to shift toward the south today, then toward the south-southwest and strengthen Monday and Monday night (850 mb SW winds 25-35 mph) ahead of the front. The front is forecast to reach Kauai Monday night, then progress eastward over the rest of the island chain Tuesday through Tuesday night. A combination of falling upper heights associated with the upper trough, increasing instability and isentropic lift, shear (effective 0-6 km bulk shear up to 40 kt), and plenty of deep tropical moisture will support heavy rain and thunderstorms developing.

Impacts associated with this front and upper trough will include: the potential for flash flooding, strong thunderstorms (an isolated severe storm can’t be ruled out), gusty downslope winds mixing down over windward areas (Oahu and Kauai), and the potential for a wintry mix over the summits Monday night into Tuesday. A flash flood watch has been issued this morning that includes Oahu, Maui County and the Big Island for the Monday through Tuesday period. A high wind watch has been issued for the summits on the Big Island for late Monday through Tuesday as southwest winds ahead of the upper trough strengthen and become hazardous (gusts to 65 to 70 mph).

Drier and cooler air with north-northeast flow across the islands is anticipated to fill in from west to east Tuesday through midweek in the wake of the front. Dewpoints are forecast to reach the 50s over Oahu and Kauai Tuesday through Wednesday. Guidance supports this drier air spreading across the eastern half of the state through the second half of the week as the slowly nudges eastward.

Central Valley (Kahului, Spreckelsville):

FLASH FLOOD WATCH IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON. Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs around 87. Light winds. Chance of rain 20 percent.

Leeward West (Lahaina, Ka`anapali):

FLASH FLOOD WATCH IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON. Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs around 85. Light winds. Chance of rain 20 percent.

Windward West (Wailuku, Waiehu):

FLASH FLOOD WATCH IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON. Partly sunny with scattered showers. Highs 71 to 85. Light winds. Chance of rain 50 percent.

Windard Haleakala (Hana, Haiku, Makawao):

FLASH FLOOD WATCH IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON. Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs around 81 at the shore to around 69 at 5000 feet. East winds around 10 mph. Chance of rain 50 percent.

Leeward Haleakala (Kihei, Wailea, Makena):

FLASH FLOOD WATCH IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON. Sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 87 at the shore to 69 to 77 upcountry. Light winds becoming southwest around 10 mph in the afternoon. Chance of rain 50 percent.

Haleakala Summit

FLASH FLOOD WATCH IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON. Sunny in the morning then becoming partly sunny. Scattered showers. Highs 55 to 70. South winds around 10 mph. Chance of rain 50 percent.

Photo of the Day