Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
314 AM EST Thu Nov 14 2019

Valid 00Z Fri Nov 15 2019 - 00Z Fri Nov 22 2019

...Weekend Heavy Rain Threat...

Upper ridging to the northeast of Hawai'i will move toward
California late Friday into Saturday. This will allow troughing to
develop/deepen over the area this weekend as a surface cold front
pushes through the northwestern islands. A closed low is forecast
to dip over the region early next week as heights build to its
north. The 00Z GFS was a bit to the east of the consensus that
includes the 00Z ECMWF/Canadian and ensemble means. The 00Z UKMET
was farther west. Deeper tropical moisture is forecast to increase
over the Aloha state this weekend with precipitable water values
rising up to 2 inches in conjunction with moisture from an
easterly wave. Threat of locally heavy rainfall will extend from
this weekend into early next week. By Mon/Tue, the upper low will
jog westward then begin to turn back to the northeast per the 00Z
ECMWF/GEFS and 12Z/13 ECMWF ensemble mean consensus. Around
Wednesday, heights should start to build from the west, coaxing
the upper low to the east away from the area. More typical trades
should resume by the end of the period as the rainfall coverage
decreases.

Fracasso