Sunday 28th May 2023
Today and Monday look beautiful with comfortable humidity, light winds, and only isolated showers most locations. Afternoon clouds and widely scattered showers are likely over the interior of our island.
Showers slowly increase from widely scattered early Tuesday to possibly frequent by Wednesday. Some of the showers could be heavy at times. Isolated thunder over our mountains is possible in the afternoon/early evening hours on Tuesday and Wednesday. Winds remain mostly light.
Late Wednesday and Thursday moderate easterly Trade winds return, along with scattered windward showers. Some of these showers could be briefly heavy at times.
An mid/upper level trough to our north is responsible of light Trade winds the next couple of days (1st chart).
Through Monday we are on the west (more stable) side of the trough aloft. Another impulse drops into the long wave trough near the Dateline Tuesday/Wednesday. This places us on the less stable, eastern side, of this mid/upper level feature (2nd chart). With the trough axis to our west we see deeper moisture to riding in on southwesterly flow. The increase in moisture and instability (coldest air aloft overhead late Tuesday/early Wednesday) should translate to an increase in shower intensity and coverage.
Tuesday/Wednesday the trough weakens, allowing the surface high in the far north Pacific to push south, bringing a return of easterly Trade winds to our shores. Residual moisture and cooler air aloft means the returning Trades are likely to be wet with possible periods of frequent showers.