Hilo

Tonight: Partly cloudy with isolated showers. Lows 57 to 65 near the shore to 45 to 52 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 20 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs 72 to 79 near the shore to 58 to 65 at 4000 feet. North winds up to 15 mph. Chance of rain 20 percent.

Monday Night: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 56 to 65 near the shore to 45 to 52 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 30 percent.

Kona

Tonight: Mostly clear. Isolated showers in the evening. Lows around 69 near the shore to 41 to 48 near 5000 feet. Light winds. Chance of rain 20 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs 78 to 84 near the shore to around 63 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Monday Night: Mostly clear. Isolated showers in the evening. Lows around 68 near the shore to 40 to 46 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Tonight: Partly cloudy with isolated showers. Lows 57 to 66 near the shore to 49 to 56 near 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs around 73 near the shore to 62 to 72 near 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Monday Night: Partly cloudy with isolated showers. Lows 56 to 66 near the shore to 48 to 55 near 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Kohala

Tonight: Partly cloudy with isolated showers. Lows 57 to 66 near the shore to 49 to 56 near 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs around 73 near the shore to 62 to 72 near 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Monday Night: Partly cloudy with isolated showers. Lows 56 to 66 near the shore to 48 to 55 near 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

South Big Island

Tonight: Mostly clear. Lows around 70 near the shore to around 48 near 5000 feet. Light winds.

Monday: Sunny. Isolated showers in the afternoon. Highs around 80 near the shore to around 63 near 5000 feet. Southwest winds up to 10 mph. Chance of rain 20 percent.

Monday Night: Mostly clear. Isolated showers in the evening. Lows around 69 near the shore to around 47 near 5000 feet. Light winds. Chance of rain 20 percent.

Puna

Tonight: Partly cloudy with isolated showers. Lows 57 to 65 near the shore to 45 to 52 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 20 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs 72 to 79 near the shore to 58 to 65 at 4000 feet. North winds up to 15 mph. Chance of rain 20 percent.

Monday Night: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 56 to 65 near the shore to 45 to 52 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 30 percent.

Waikoloa

Tonight: Mostly clear. Lows 65 to 70 near the shore to 44 to 50 above 4000 feet. East winds up to 15 mph.

Monday: Sunny and breezy. Highs 78 to 85 near the shore to 62 to 67 above 4000 feet. Northeast winds up to 20 mph.

Monday Night: Mostly clear. Lows 64 to 70 near the shore to 43 to 49 above 4000 feet. East winds up to 15 mph.

Detailed Forecast

Synopsis

Overall, a dry north northeasterly wind pattern will persist through the first half of the week. The second half of the week may briefly get disrupted by a weak front but then a more typical easterly trade wind pattern shall take over end of the week into the weekend.

Discussion

Latest satellite imagery shows a weak high northwest of the state that is driving breezy north northeast trade winds and thinning, shallow scattered cumulus cloud field over the state. CIMSS precipitable water imagery shows a dry airmass has filled in across the state. Due to limited available moisture and upper level ridging aloft expect clouds to be limited along exposed windward and mauka areas with very little rainfall, if any. Chances of rainfall may increase slightly tonight for windward and mauka areas in response to typical diurnal patterns.
A weak and shallow band of moisture assoicated with a remnant front will move over the state Monday afternoon into Tuesday. Expect just a slight increase in windward clouds and showers as winds remain in a north northeast flow. North northeast winds will persist through Tuesday as the high west of the state slowly tracks northeast. Wednesday winds may weaken enough to allow for land seabreeze pattern to take over as the high tracks north of the state and weakens and a front approaches from the northwest. Thursday into Friday, deterministic guidance continues to shows a shortwave trough deepening the upper level trough associated with the front moving through or just north of the state during the second half of the week. The ECMWF is a little more progressive at bringing the front through the state where as the GFS shows a weaker front passing north of the state. Thus confidence in this in the day 4 through 5 forecast is low. However, due to the weak nature of this feature no significant weather is expected. A strong high pressure will build northeast of the state late in the week and over the weekend returning typical easterly trades in the wake of the front.

Aviation

North to northeast flow will continue to support a stable and very dry airmass through the day on Monday. Cloud cover will develop along windward and north facing slopes, especially on the Big Island, but VFR conditions will prevail as little rain falls. Some increase in shower activity is possible around Kauai near sundown tomorrow. No AIRMETs are in effect.

Marine

Gentle to moderate NE winds strengthen slightly tonight as a weak high pressure northwest of the state slowly tracks eastward. Trade winds remain just under Small Craft Advisory through the forecast period for the windier waters and channels around Maui County and the Big Island.
A combo of a moderate to large medium period NNE swell and a small, medium period NW swell will produce moderate to large surf along north facing shores. N swell gradually fills in this evening, peaking tonight and Monday before gradually declining through the middle of the week. Surf may approach or briefly touch the High Surf Advisory (HSA) threshold during its peak for N facing shores. Another small to moderate NW swell is also expected to fill Monday, and peak Tuesday before declining through the end of next week.
Surf along east facing shores will remain small except for shorelines exposed to the north- northeast swell through the first half of the week. Surf along south facing shores will remain tiny through the forecast period with mainly background energy.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov