Hilo, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

901
FXHW60 PHFO 061319
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
319 AM HST Fri Jun 6 2025

.SYNOPSIS...
A weak upper low just north of the Hawaiian Islands will slowly
weaken as it drifts northeastward away from the region. Enough
instability aloft will linger for brief periods of showers lasting
through the weekend favoring the overnight to early morning hours.
More stable conditions with drier trends will return from next
week Monday through Friday as high pressure builds in over the
region. Moderate easterly trade winds will develop each day through
much of next week.

&&

.DISCUSSION...
This mornings satellite imagery in the water vapor channel shows a
weak upper level low just north of the island chain, providing
enough divergence aloft for brief periods of showers mainly along
windward and mountain areas. This low will continue to weaken as
it slowly drifts towards the northeast direction over the next few
days. The infra-red satellite picture shows fairly stable clouds
riding in on the easterly trade winds, and a few showers will
develop as these clouds are driven up windward mountain slopes.

A general troughing pattern remains in place in the upper levels,
which will keep brief passing showers in the overnight to early
morning windward and mountain, and brief showers over island
interior sections during the day are in the forecast through the
weekend. On Monday this upper level pattern changes to a more
stable environment lasting through much of next week, as an upper
level ridge moves over the state, and the temperature inversion
heights drop to around 5,000 to 6,000 feet.

In our wind forecast guidance, we see light to moderate easterly
trades will continue into next week as the high pressure ridge
north of the state weakens in response to a migrating low pressure
system slowly drifting across the North Pacific. Some expansion
of daytime sea breezes along terrain sheltered western island
slopes should be expected during this time period. This means a
hybrid trade wind sea breeze weather regime will take hold over
each island with brief afternoon showers possible over island
interior sections this weekend due to the lingering troughing
environment and low level wind convergence bands forming along
trade wind and sea breeze boundaries.

&&

.AVIATION...
Expect light to moderate trade winds to develop across the region
each day with an expansion of sea breezes along terrain sheltered
western slopes of each island. A hybrid wind pattern between the
trade winds and sea breezes will converge during the afternoon
producing some cloud bands and a few showers over island mountain
and interior sections. Mostly VFR conditions will prevail.

No AIRMETs in effect.

&&

.MARINE...
Trades will gradually ease today, becoming gentle to fresh by
mid-morning as high pressure northeast of the state weakens.
Thus, the Small Craft Advisory for typical wind prone areas around
Maui and the Big Island has been allowed to expire. East-
northeast trades will remain gentle to fresh through this weekend,
then restrengthen early next week as high pressure rebuilds to
the north. In addition, a surface trough may develop west of the
islands which would act to veer winds slightly east- southeast.

Long period forerunners from a moderate south southwest (200-220)
swell are already beginning to show up on some of the near shore
buoys. This swell is expected to gradually fill through the
remainder of today, peak late tonight through early Sunday near
High Surf Advisory criteria, then slowly fade by early next week.

Choppy surf along east facing shores will persist today as a
moderate, medium period northeast swell peaks then slowly fades
through this weekend. Surf along north facing shores will remain
small through early next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Bohlin
AVIATION...Bohlin
MARINE...JT