Image Department Meteorology
Meteorology_Home Weather_Server News/Seminars
Academics Application Contact_Us

Links Disclaimer

Menu of Text Products for the Hawaiian Islands and the Tropical Pacific/Atlantic Oceans:
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

FXHW60 PHFO 081323

Area Forecast Discussion
National Weather Service Honolulu HI
323 AM HST Sat Aug 8 2020

Breezy trade winds will prevail through the weekend, then trend
down Tuesday through midweek as high pressure to the northeast
weakens. Clouds and showers will favor windward and mountain areas
each day, especially through the overnight and early morning
periods as pockets of moisture move through. Windward shower
coverage may decrease later in the weekend and into early next
week some drier air moves into the area.


Latest surface analysis and satellite imagery showed the
subtropical ridge anchored north of the islands and patchy low-
level clouds approaching and moving through from east to west.
Some of these clouds are generating brief/mostly light showers as
they move through - especially over the western end of the island
chain where a band of higher than average moisture (PWs up to 2
inches) lingers. Rain gages around the islands reflected this and
showed peak accumulations ranging from 1 to 2 inches on Kauai in
the past 24-Hrs (through 2 AM HST). Elsewhere, peak accumulations
ranged from a quarter to three quarters of an inch through this
period. Expect the showery and breezy pattern to hold into tonight
as this area of higher moisture remains in the area.

Guidance has initialized well with the current pattern and shows
upper heights gradually rising through the weekend as the upper
trough that moved over the past couple of days continues westward
and away from the area. This combined with PWs trending back down
toward normal will translate to a slightly drier and more stable
trade wind pattern returning Sunday into Monday. Trades will
remain gusty through the weekend as high pressure strengthens to
the north, but should trend down through the first half of next
week. Another area of lower heights moving in aloft early next
week could enhance shower coverage once again through midweek,
mostly for windward and mountain locations.


High pressure far northeast of the state will bring persistent
moderate trades through the remainder of this morning. Thus,
tempo moderate turbulence will likely form in the lee of the
mountains. Expect scattered showers caught up in the flow to move
over the windward coasts and slopes. This may bring periods of
MVFR ceilings and visibility. Isolated showers expected elsewhere.

AIRMET TANGO remains in effect below 9000 feet over and
immediately south thru west of mountains for tempo moderate

AIRMET SIERRA remains in effect above 2500 feet for north thru
east sections of Kauai, Oahu, Maui, Lanai and the Big Island for
tempo mountain obscuration from clouds and showers.


High pressure to the north-northeast is expected to strengthen
this weekend, which will boost trade winds across the coastal
waters. An overnight ASCAT pass shows an increase in winds having
spread into the Maui County Windward Waters and the Kaiwi Channel.
The Small Craft Advisory (SCA), previously in effect for only the
typical windier areas near Maui County and the Big Island, has now
been expanded to include the Maui Windward Waters, the Kaiwi
Channel and Oahu Leeward Waters through Sunday afternoon. Winds
are expected to trend down early next week, which should once
again bring the SCA level winds to the typical areas near Maui
County and the Big Island.

Surf along south facing shores is expected to return to
background levels today and remain below summer average into next
week. Small short period southeast swell will continue, with the
Big Island blocking some of that energy from reaching the smaller
islands. Surf along east facing shores will build through the
weekend as trade winds strengthen, but is expected to remain below
the advisory levels. A small north-northwest swell will provide a
bit of energy to the north facing shores, keeping surf just above
flat through Saturday.


Small Craft Advisory until 6 PM HST Sunday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters.



MARINE...M Ballard

Bulletins, Forecasts and Observations are courtesy of Honolulu National Weather Service Forecast Office

This page is maintained voluntarily by the MKWC and the UHMET faculty, staff, and students.
It was last modified on: Wed, Dec 17 2014 - 1841 UTC
Send comments to: Ryan Lyman