Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service San Juan PR
940 PM AST Monday Jan 26 2015
Synopsis...upper level ridge will weaken Tuesday night through Friday as
deepening polar trough over eastern noam translates east. Trough
weakens and begins to lift out during the weekend with ridging
building in early next week.
Discussion...deep moisture will continue to advect north-northwest overnight
on south-southeast flow with isolated-scattered showers mainly over SW PR and Mona
Passage. Activity re-develops during Tuesday afternoon with scattered
activity concentrating over northwest PR. Drying takes place Tuesday night
through Wednesday. Height falls Wednesday night through Friday will promote
moisture transport and weakening of the subsidence inversion with
deep convection likely Thursday and Friday over western PR. Gradual drying
takes place early next week as trough lifts out and surface to upper
level ridging begins to build in from the west.
Aviation...MVFR ceilings at jbq and jmz Tuesday afternoon in rain showers.
Otherwise...VFR at all other taf sites.
Marine...seas 3-5 feet and winds mainly below 17 knots
Preliminary point temps/pops...
sju 74 87 74 86 / 10 20 20 20
stt 75 83 75 84 / 10 20 20 30