The Atlantic High Pressure System should pump fresh breeze across our islands overnight into Thursday.The dust concentrations of varying intensity are being transported by the High Pressure wind flow and a thick patch is expected to cross our area overnight, with PM2.5 levels reaching near 86µg/m3 and PM10 levels reaching near 120µg/m3. Meanwhile, a pocket of mid level moisture
and weak upper level support could result in few scattered morning showers. At the lower levels, with shearlines/trough expected across our area and a thinning out of dust concentrations on Friday, scattered showers are anticipated. The upper level support should decrease on Saturday and more dry air should limit any possible showers on Saturday.
A tropical wave is expected to pass south of our area over this weekend, with some moisture/showers spreading across the southern Windward Islands (including SVG) by Sunday. Another initialized today, near 21W and south of 14N, should be near 42W by Sunday…will be monitored.
Moderate to mostly fresh (25 - 40km/h) easterly breeze can be expected overnight, becoming east south-easterly during Friday. An increase in wind speeds (strong) is possible by late Sunday.
Mean sea-level pressure should range 1014 - 1016 mb rising slightly to range 1016 - 1018 mb by Friday. Slight to moderate easterly sea swells can be expected to peak near 1.2m on west coasts and near 2.0m on east coasts over the next couple days. A gradual increase in wave heights are expected to by Saturday, in response to increased winds just east of the island chain.
The Dust concentrations associated with Sahara Air Layer extends across the Atlantic Ocean into the Caribbean Sea; reducing shower chances, visibility and air quality. A thinning out is expected across our islands on Friday, possibly thickening again during Sunday. Persons with respiratory issues should be alert and Small craft operators/Mariners should exercise caution for reduced visibility in dust haze and brisk winds.
Note: AT 3pm today, tropical storm Aletta centered near 14.2N 107.9W in North Pacific Ocean...with maximum sustained winds of 40kt and minimal central pressure of 1000hpa. The storm is moving westward expected to briefly strengthen to a hurricane on Thursday.