Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
963 FXHW60 PHFO 131947 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 947 AM HST Sat Jul 13 2024 .SYNOPSIS... A large area of high pressure generally north of the Hawaiian Islands will maintain breezy to locally strong trades over the next several days. Shallow and stable stratocumulus clouds will continue to produce light showers over windward and mauka areas mainly during the early morning and overnight hours. Trades should weaken during the second half of the week with moderate trade wind weather expected. && .DISCUSSION... A broad area of high pressure north of the state will maintain locally strong trade winds across the state today. This morning`s satellite imagery shows a dense layer of stratocumulus clouds moving in from the east, which will bring partly to mostly cloudy weather over windward areas today. Over on the leeward side, mountain waves can be seen on select islands especially downwind of the Ko`olau mountain range. This indicates stable and gusty weather conditions, which are supported by the strong inversion at 5000 feet as seen on the Lihue 12Z sounding and strong trade winds. Although weather conditions are on the cloudier side for summer standards, with the strong and low inversion, rainfall amounts will be limited with only light showers expected over windward areas and possibly a light drizzle over leeward areas today. For Sunday, a fairly similar day is expected with a few light showers focused over windward and mountain areas. Trade winds are expected to weaken slightly but will continue to remain breezy. Overall, stable and mostly dry conditions will continue through at least the first half of next week with breezy trades. Passing showers are expected at times, especially over windward and mountain areas during the early mornings and overnight periods. Any rainfall amounts should remain light. Trades could weaken into the moderate speed range Wednesday into Thursday as a front passes far northeast of the state. && .AVIATION... Breezy to locally windy trades will continue over the next few days. Showers and low clouds will favor windward and mauka locations, bringing periods of MVFR conditions to these areas. Otherwise, VFR conditions should generally prevail. AIRMET Sierra for mountain obscuration remains in effect for N through SE sections of Kauai, Oahu, Molokai, Maui and the Big Island. AIRMET Tango for moderate low-level turbulence lee of island terrain is in effect and will likely be needed for the next several days due to the strong trades under a strong inversion. && .MARINE... A strong high pressure ridge remains north of the islands and will continue to drive fresh to strong trade winds to the region through the remainder of the weekend. The typical windier waters near Maui County and the Big Island will see the strongest winds (near gale force at times), and seas approaching 10 feet. However all coastal waters are under a Small Craft Advisory (SCA) through tonight. SCA conditions will continue for the typical windier waters through much of the week, and may linger for additional waters. Will be monitoring the latest ASCAT and model data to determine in/when changes to the forecast are needed. A long period south swell is filling in today, and will more than likely reach High Surf Advisory (HSA) levels for south facing shores on Sunday and Monday. Will be monitoring the swell`s arrival today and likely will be posting the HSA later today. West facing shores will see a decent south swell wrap, boosting surf heights as well, with the Big Island west facing shores likely reaching HSA levels on Sunday. A gradual downward trend is expected Tuesday through midweek. Due to the strong trade winds upstream of the state, surf along east facing shores will remain rough and choppy through early in the new week. A downward trend is possible around midweek as the upstream fetch weakens and the local trades begin to ease. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 AM HST Sunday for all Hawaiian waters- && $$ DISCUSSION...Kino AVIATION...Farris MARINE...M Ballard