Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
805 AM EDT Wed Mar 27 2019

Valid 00Z Thu Mar 28 2019 - 00Z Thu Apr 04 2019

Persistent mean upper-level troughing across the north central
Pacific through the next week will keep Hawaii on the southern
periphery of a broad area of negative 500 hPa height anomalies. A
cold front is expected to cross the state starting Wed night
before stalling across the eastern islands by late Thu. Models
show the deepest moisture associated with this system remaining
mostly north of Hawaii, so any associated precipitation should be
relatively sparse. Light to moderate north-northeast winds should
spread across the state in the wake of the front, becoming
variable by Sun as the front washes out. Moisture may begin to
increase a bit across the state by early next week. Model
solutions differ on the details, but they all agree that another
relatively deep upper trough should amplify across the north
central Pacific by Mon, perhaps drawing higher PWs (1.3-1.5 in.)
north across the state. Next cold front should cross the state Mon
night or Tue, with surface high pressure building just north of
the state in its wake. Lingering moisture from the weakening front
and a return of light to moderate trades south of the surface high
should bring a return of more typical windward shower activity by
next Tue or Wed.


Ryan