Light to occasionally breezy trades with an increase in showers. Higher moisture lingering over Hawaii will create thicker overcast and more frequent periods of rain through Wednesday. Recent trade behavior will remain steady through mid week with a slight strengthening of winds expected later in the week. Hurricane Fausto will remain far east of the state the next several days but may influence trade flow early next week.
Early morning satellite imagery is depicting better organized areas of thick clouds surrounding the island chain. This is in association with a moist air mass lingering over the islands. Veering winds within a deeper, moistened boundary layer will yield the potential for areawide rain through tomorrow. Precipitation has filled in across the state since midnight with the majority of the smaller islands picking up a couple of tenths to about a half an inch of rain, with localized greater than one inch amounts, the past six hours. The quick pace and widely scattered nature of these cells should keep any localized flooding concerns at bay. Heavier, more intense pockets of rain may cause nuisance low lying area flooding and street ponding today and tomorrow.
This noticeable boost in statewide shower activity will likely hang with us into Wednesday afternoon as this batch of higher low to mid layer moisture lingers over the region. Typically drier leeward communities may experience more frequent showers such as enhanced shower coverage over lee Oahu in response to east southeast wind convergence downstream of Maui County. After a couple of days of weaker winds, trades will become more fresh as northeastern Pacific surface high pressure building south tightens the gradient across the area. Drier air filling in behind this west-exiting moist air mass late Wednesday will ensure a drier end of the week. Breezy trades, higher stability and limited showers focused windward and upslope mauka will be the day-to-day theme at week's close.
Although decent northerly shear continues to impact Hurricane Fausto, currently located about 650 nm off Cabo San Lucas, BCS, he is slowly intensifying. NHC is forecasting Fausto to continue on a slow and steady west to slight northwest track through Thursday. A pick up in speed is expected with the majority of the numerical model guidance keeping the storm just south of 20N into Saturday as it nears 140W. If Hurricane Fausto stays on this west northwesterly track, localized trade flow will be interrupted as the cyclone passes northeast of the state early to mid next week.
Latest radar and satellite imagery overnight depicts showers impacting most windward sites across the state. Weather models suggest that this will continue into the daytime hours today, with chances for periodic spillover showers into leeward sites. Otherwise, expect another day of moderate trades.
AIRMET Sierra is in effect for the windward side of most islands due to ongoing shower activity. This is expected to continue until at least the early evening hours Tuesday, when showers are roughly estimated to decrease in coverage.
The trade winds will hold at mostly moderate speeds through today as a subtle trough moves through the state. Trade winds strengthen to fresh and locally strong speeds Wednesday and could strengthen another notch late Thursday into Friday with widespread strong trade winds possible towards the end of the work week.
The High Surf Advisory for south facing shores has been cancelled due to the downward trend shown on the nearshore and offshore buoys. The current south-southeast swell should slowly fade over the next few days.
A powerful low pressure system tracked eastward well south of Tasmania and New Zealand last week. OSCAT pass showed a wide fetch of storm force winds with altimeter passes showing seas above 50 feet. This should translate into very long period forerunners arriving as early as early Wednesday morning and steadily filling in throughout the day Wednesday and peaking on Thursday out of the south-southwest. Surf should reach advisory thresholds by Thursday. The very long-period energy will make for inconsistent, but powerful waves when they arrive. Several days of advisory level surf is expected starting from Thursday and possibly continuing through Sunday as reinforcing energy arrives over the weekend.
Surf along east-facing shores will remain slightly below seasonal levels today as the trades ease upstream of the islands. The Hilo buoy this morning is showing a slight increase across the 12 to 14 second energy bands, which was likely generated by former TC Elida. Easterly swell from TC Elida should peak on Wednesday near seasonal levels. Stronger trade winds will also support an increase of short-period energy by Wednesday, This weekend, larger surf for east shores generated by Hurricane Fausto is possible and could bring advisory level surf along east facing shores as well.
Surf along north-facing shores will remain at flat to tiny levels through the weekend.
None.